1
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Li Y, Ding J, Qin W. Enhanced Selectivity in Microdroplet-Mediated Enzyme Catalysis. J Am Chem Soc 2024. [PMID: 39073863 DOI: 10.1021/jacs.4c06171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Natural enzymes with enhanced catalytic activity and selectivity have long been studied by tuning the microenvironment around the active site, but how to modulate the active-site electric field in a simple fashion remains challenging. Here, we demonstrate that microdroplets as a simple yet versatile reactor can enhance the electric field at the active site of an enzyme. By using horseradish peroxidase as a model, improved selectivity in microdroplet-mediated enzyme catalysis can be obtained. Quantum mechanical/molecular dynamics calculations and vibrational Stark spectroscopy reveal that the electric field at the microdroplet interface can influence the electrostatic preorganization and orientation of the enzyme to enhance its internal electric field. As a result, the free energies of the substrate and heme can be tuned by the internal electric field, thereby changing its catalytic reaction pathway for a classical substrate, 3,3',5,5'-tetramethylbenzidine, and enabling selective C-N additions for specific substrates. This finding provides a green, simple, and effective way to modulate enzyme-catalyzed reactions and holds promise for a broad spectrum of biosensing and biosynthesis applications.
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Affiliation(s)
- Yinhao Li
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jiawang Ding
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Wei Qin
- CAS Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research (YIC), Chinese Academy of Sciences (CAS), Shandong Key Laboratory of Coastal Environmental Processes, YICCAS, Yantai, Shandong 264003, P. R. China
- Laboratory for Marine Biology and Biotechnology, Qingdao Marine Science and Technology Center, Qingdao, Shandong 266237, P. R. China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong 266071, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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2
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Wu A, Fan Y, Tao C, Chen X, Dappe YJ, Du J, Zhang Q. Molecular Diodes Induced by a Schottky Barrier with a Gold-Silicon Doped Electrode. J Phys Chem Lett 2024; 15:7011-7019. [PMID: 38949616 DOI: 10.1021/acs.jpclett.4c01351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
To create complementary metal oxide semiconductor compatible molecular devices, more insights into the electrode property regarding its metal/semiconductor doping level and creating a functional molecular device are required. In this work, we constructed an EGaIn/alkanethiol/Au-Si molecular diode (with a rectification ratio R of 50.70) induced by Schottky barriers within a gold-silicon doped electrode instead of the functional property of molecules. The relationship between the rectification ratio and the number of methylene units in alkanethiol was analyzed, revealing a gradual increase in the ratio from 3.33 for C6H14S to 50.70 for C16H34S. The rectification ratio of the junction is well modulated by the temperature due to the change in the Schottky barrier. Such a mechanism is explained by the energy band diagrams of the surface space charge region and a combination of density functional theory and Keldysh-Green formalism calculations.
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Affiliation(s)
- An Wu
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Yidan Fan
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Changyuan Tao
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Xiaoping Chen
- College of Chemistry and Environment, Minnan Normal University, Zhangzhou 363000, China
| | - Yannick J Dappe
- SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, Gif-sur-Yvette Cedex 91191, France
| | - Jun Du
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
| | - Qian Zhang
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
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3
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Lu Z, Hou S, Lin R, Shi J, Wu Q, Lin L, Shi J, Yang Y, Lambert C, Hong W. Conductance Quantization in 2D Semi-Metallic Transition Metal Dichalcogenides. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024:e2311491. [PMID: 38682729 DOI: 10.1002/smll.202311491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/09/2024] [Indexed: 05/01/2024]
Abstract
Conductance quantization of 2D materials is significant for understanding the charge transport at the atomic scale, which provides a platform to manipulate the quantum states, showing promising applications for nanoelectronics and memristors. However, the conventional methods for investigating conductance quantization are only applicable to materials consisting of one element, such as metal and graphene. The experimental observation of conductance quantization in transition metal dichalcogenides (TMDCs) with complex compositions and structures remains a challenge. To address this issue, an approach is proposed to characterize the charge transport across a single atom in TMDCs by integrating in situ synthesized 1T'-WTe2 electrodes with scanning tunneling microscope break junction (STM-BJ) technique. The quantized conductance of 1T'-WTe2 is measured for the first time, and the quantum states can be modulated by stretching speed and solvent. Combined with theoretical calculations, the evolution of quantized and corresponding configurations during the break junction process is demonstrated. This work provides a facile and reliable avenue to characterize and modulate conductance quantization of 2D materials, intensively expanding the research scope of quantum effects in diverse materials.
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Affiliation(s)
- Zhixing Lu
- Engineering Research Center of Polymer Green Recycling of Ministry of Education, College of Environmental and Resource Sciences, Fujian Normal University, Fuzhou, 350117, China
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Songjun Hou
- Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK
| | - Rongjian Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Jie Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Qingqing Wu
- Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK
| | - Luchun Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Yang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
| | - Colin Lambert
- Department of Physics, Lancaster University, Lancaster, LA1 4YB, UK
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen, 361005, China
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4
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Chen L, Yang Z, Lin Q, Li X, Bai J, Hong W. Evolution of Single-Molecule Electronic Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:1988-2004. [PMID: 38227964 DOI: 10.1021/acs.langmuir.3c03104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Single-molecule electronics can fabricate single-molecule devices via the construction of molecule-electrode interfaces and also provide a unique tool to investigate single-molecule scale physicochemical processes at these interfaces. To investigate single-molecule electronic devices with desired functionalities, an understanding of the interface evolution processes in single-molecule devices is essential. In this review, we focus on the evolution of molecule-electrode interface properties, including the background of interface evolution in single-molecule electronics, the construction of different types of single-molecule interfaces, and the regulation methods. Finally, we discuss the perspective of future characterization techniques and applications for single-molecule electronic interfaces.
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Affiliation(s)
- Lichuan Chen
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Zixian Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Qichao Lin
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Xiaohui Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Jie Bai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & College of Materials & IKKEM, Xiamen University, Xiamen 361000, China
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5
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Hurtado C, Andreoli T, Le Brun AP, MacGregor M, Darwish N, Ciampi S. Galinstan Liquid Metal Electrical Contacts for Monolayer-Modified Silicon Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:201-210. [PMID: 38101331 DOI: 10.1021/acs.langmuir.3c02340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Galinstan is the brand name for a low-melting gallium-based alloy, which is a promising nontoxic alternative to mercury, the only elemental metal found in the liquid state at room temperature. Liquid alloys such as Galinstan have found applications as electromechanical actuators, sensors, and soft contacts for molecular electronics. In this work, we validate the scope of Galinstan top contacts to probe the electrical characteristics of Schottky junctions made on Si(111) and Si(211) crystals modified with Si-C-bound organic monolayers. We show that the surface-to-volume ratio of the Galinstan drop used as a macroscopic contact defines the junction stability. Further, we explore chemical strategies to increase Galinstan surface tension to obtain control over the junction area, hence improving the repeatability and reproducibility of current-voltage (I-V) measurements. We explore Galinstan top contacts as a means to monitor changes in rectification ratios caused by surface reactions and use these data, most notably the static junction leakage, toward making qualitative predictions on the DC outputs recorded when these semiconductor systems are incorporated in Schottky-based triboelectric nanogenerators. We found that the introduction of iron particles leads to poor data repeatability for capacitance-voltage (C-V) measurements but has only a small negative impact in a dynamic current measurement (I-V).
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Affiliation(s)
- Carlos Hurtado
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Tony Andreoli
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Anton P Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, Lucas Heights, New South Wales 2234, Australia
| | - Melanie MacGregor
- Flinders Institute for Nanoscale Science and Technology, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
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6
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Bennett TLR, Long NJ. A convenient synthesis of ferrocene-(ethynylphenyl)thioacetates. Dalton Trans 2023; 52:16465-16471. [PMID: 37873649 DOI: 10.1039/d3dt02954a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Ferrocene is popular within the field of molecular electronics due to its well-defined electronic properties. However, where the conductance of highly-conjugated oligophenylethylenes has been widely studied, work on analogous ferrocenyl systems has been relatively rare, possibly due to difficulties associated with the synthesis of molecules containing terminal thioacetates, which are often used to bind molecules to metallic electrodes. Herein, a widely applicable synthetic methodology is demonstrated which can be used to synthesize a variety of conjugated ferrocene-alkyne systems terminated with thioacetates, including symmetric, asymmetric and multi-ferrocene systems. Conjugation of the ferrocene units to their terminal atoms is then shown through the use of both UV/Vis spectroscopy and cyclic voltammetry. This work paves the way for future studies and applications of conjugated ferrocene systems in the field of nanoelectronics.
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Affiliation(s)
- Troy L R Bennett
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK.
| | - Nicholas J Long
- Department of Chemistry, Imperial College London, London, W12 0BZ, UK.
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7
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Kim M, Joo SH, Wang M, Menabde SG, Luo D, Jin S, Kim H, Seong WK, Jang MS, Kwak SK, Lee SH, Ruoff RS. Direct Electrochemical Functionalization of Graphene Grown on Cu Including the Reaction Rate Dependence on the Cu Facet Type. ACS NANO 2023; 17:18914-18923. [PMID: 37781814 DOI: 10.1021/acsnano.3c04138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
We present an electrochemical method to functionalize single-crystal graphene grown on copper foils with a (111) surface orientation by chemical vapor deposition (CVD). Graphene on Cu(111) is functionalized with 4-iodoaniline by applying a constant negative potential, and the degree of functionalization depends on the applied potential and reaction time. Our approach stands out from previous methods due to its transfer-free method, which enables more precise and efficient functionalization of single-crystal graphene. We report the suggested effects of the Cu substrate facet by comparing the reactivity of graphene on Cu(111) and Cu(115). The electrochemical reaction rate changes dramatically at the potential threshold for each facet. Kelvin probe force microscopy was used to measure the work function, and the difference in onset potentials of the electrochemical reaction on these two different facets are explained in terms of the difference in work function values. Density functional theory and Monte Carlo calculations were used to calculate the work function of graphene and the thermodynamic stability of the aniline functionalized graphene on these two facets. This study provides a deeper understanding of the electrochemical behavior of graphene (including single-crystal graphene) on Cu(111) and Cu(115). It also serves as a basis for further study of a broad range of reagents and thus functional groups and of the role of metal substrate beneath graphene.
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Affiliation(s)
- Minhyeok Kim
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Se Hun Joo
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Meihui Wang
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Sergey G Menabde
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Da Luo
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Sunghwan Jin
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Hyeongjun Kim
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
| | - Won Kyung Seong
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Min Seok Jang
- School of Electrical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Republic of Korea
| | - Sang Kyu Kwak
- Department of Chemical and Biological Engineering, Korea University, Seoul 02841, Republic of Korea
| | - Sun Hwa Lee
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
| | - Rodney S Ruoff
- Center for Multidimensional Carbon Materials (CMCM), Institute for Basic Science (IBS), Ulsan 44919, Republic of Korea
- Department of Chemistry, School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
- Department of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, Republic of Korea
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8
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Tong L, Yu Z, Gao YJ, Li XC, Zheng JF, Shao Y, Wang YH, Zhou XS. Local cation-tuned reversible single-molecule switch in electric double layer. Nat Commun 2023; 14:3397. [PMID: 37296181 DOI: 10.1038/s41467-023-39206-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 06/02/2023] [Indexed: 06/12/2023] Open
Abstract
The nature of molecule-electrode interface is critical for the integration of atomically precise molecules as functional components into circuits. Herein, we demonstrate that the electric field localized metal cations in outer Helmholtz plane can modulate interfacial Au-carboxyl contacts, realizing a reversible single-molecule switch. STM break junction and I-V measurements show the electrochemical gating of aliphatic and aromatic carboxylic acids have a conductance ON/OFF behavior in electrolyte solution containing metal cations (i.e., Na+, K+, Mg2+ and Ca2+), compared to almost no change in conductance without metal cations. In situ Raman spectra reveal strong molecular carboxyl-metal cation coordination at the negatively charged electrode surface, hindering the formation of molecular junctions for electron tunnelling. This work validates the critical role of localized cations in the electric double layer to regulate electron transport at the single-molecule level.
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Affiliation(s)
- Ling Tong
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
| | - Zhou Yu
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
| | - Yi-Jing Gao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
- Zhejiang Engineering Laboratory for Green Syntheses and Applications of Fluorine-Containing Specialty Chemicals, Institute of Advanced Fluorine-Containing Materials, Zhejiang Normal University, 321004, Jinhua, China
| | - Xiao-Chong Li
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
| | - Ju-Fang Zheng
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
| | - Yong Shao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China
| | - Ya-Hao Wang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China.
| | - Xiao-Shun Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, 321004, Jinhua, China.
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9
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Song K, Lin J, Song X, Yang B, Zhu J, Zang Y, Zhu D. Formation of covalent metal-carbon contacts assisted by Ag + for single molecule junctions. Chem Commun (Camb) 2023; 59:6207-6210. [PMID: 37129042 DOI: 10.1039/d3cc01113e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Covalent metal-carbon (M-C) contacts have long been pursued for constructing robust and high-performance molecular devices. Existing methods for creating such contacts usually rely on direct chemical reactions between metal electrodes and designed molecular ligands. An inherent limitation of this approach is that the commonly used metal electrodes (e.g., Au) are chemically inert, making it generally difficult to form covalent M-C bonds with molecules. Intriguingly, employing the scanning tunneling microscope-break junction technique, we find that simply adding Ag+ ions to molecular solution enables direct covalent bonding of terminal alkynes to Au electrodes. The bonding process is driven by Ag+ ion coupled in situ reactions and efficiently creates covalent Au/Ag-C interfaces in single molecule junctions. This metal ion assisted method avoids the need for complex synthesis of molecular ligands and works robustly for a wide range of alkyne-terminated molecules, offering a facile and versatile approach for precisely tuning the metal-molecule interface.
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Affiliation(s)
- Kai Song
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Junfeng Lin
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuwei Song
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Bowen Yang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Jia Zhu
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, Beijing 100190, China.
- College of Chemistry, Key Laboratory of Theoretical & Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100875, China
| | - Yaping Zang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Daoben Zhu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
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10
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Dief EM, Low PJ, Díez-Pérez I, Darwish N. Advances in single-molecule junctions as tools for chemical and biochemical analysis. Nat Chem 2023; 15:600-614. [PMID: 37106094 DOI: 10.1038/s41557-023-01178-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 03/02/2023] [Indexed: 04/29/2023]
Abstract
The development of miniaturized electronics has led to the design and construction of powerful experimental platforms capable of measuring electronic properties to the level of single molecules, along with new theoretical concepts to aid in the interpretation of the data. A new area of activity is now emerging concerned with repurposing the tools of molecular electronics for applications in chemical and biological analysis. Single-molecule junction techniques, such as the scanning tunnelling microscope break junction and related single-molecule circuit approaches have a remarkable capacity to transduce chemical information from individual molecules, sampled in real time, to electrical signals. In this Review, we discuss single-molecule junction approaches as emerging analytical tools for the chemical and biological sciences. We demonstrate how these analytical techniques are being extended to systems capable of probing chemical reaction mechanisms. We also examine how molecular junctions enable the detection of RNA, DNA, and traces of proteins in solution with limits of detection at the zeptomole level.
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Affiliation(s)
- Essam M Dief
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Paul J Low
- School of Molecular Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Ismael Díez-Pérez
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, London, UK
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia.
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11
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Gardner Z, Rahpeima S, Sun Q, Zou J, Darwish N, Vimalanathan K, Raston CL. High Shear Thin Film Synthesis of Partially Oxidized Gallium and Indium Composite 2D Sheets. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023:e2300577. [PMID: 37010011 DOI: 10.1002/smll.202300577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/16/2023] [Indexed: 06/19/2023]
Abstract
Reducing resistance in silicon-based devices is important as they get miniaturized further. 2D materials offer an opportunity to increase conductivity whilst reducing size. A scalable, environmentally benign method is developed for preparing partially oxidized gallium/indium sheets down to 10 nm thick from a eutectic melt of the two metals. Exfoliation of the planar/corrugated oxide skin of the melt is achieved using the vortex fluidic device with a variation in composition across the sheets determined using Auger spectroscopy. From an application perspective, the oxidized gallium indium sheets reduce the contact resistance between metals such as platinum and silicon (Si) as a semiconductor. Current-voltage measurements between a platinum atomic force microscopy tip and a Si-H substrate show that the current switches from being a rectifier to a highly conducting ohmic contact. These characteristics offer new opportunities for controlling Si surface properties at the nanoscale and enable the integration of new materials with Si platforms.
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Affiliation(s)
- Zoe Gardner
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
| | - Soraya Rahpeima
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
- School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Qiang Sun
- School of Mechanical and Mining Engineering and Centre for Microscopy and Microanalysis, University of Queensland, St Lucia, QLD, 4072, Australia
| | - Jin Zou
- School of Mechanical and Mining Engineering and Centre for Microscopy and Microanalysis, University of Queensland, St Lucia, QLD, 4072, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Kasturi Vimalanathan
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
| | - Colin L Raston
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
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12
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Cleavage of non-polar C(sp 2)‒C(sp 2) bonds in cycloparaphenylenes via electric field-catalyzed electrophilic aromatic substitution. Nat Commun 2023; 14:293. [PMID: 36653339 PMCID: PMC9849230 DOI: 10.1038/s41467-022-35686-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 12/20/2022] [Indexed: 01/19/2023] Open
Abstract
Electrophilic aromatic substitution (EAS) is one of the most fundamental reactions in organic chemistry. Using an oriented external electric field (OEEF) instead of traditional reagents to tune the EAS reactivity can offer an environmentally friendly method to synthesize aromatic compounds and hold the promise of broadening its scope. Despite these advantages, OEEF catalysis of EAS is difficult to realize, due to the challenge of microscopically orienting OEEF along the direction of electron reorganizations. In this work, we demonstrate OEEF-catalyzed EAS reactions in a series of cycloparaphenylenes (CPPs) using the scanning tunneling microscope break junction (STM-BJ) technique. Crucially, the unique radial π-conjugation of CPPs enables a desired alignment for the OEEF to catalyze the EAS with Au STM tip (or substrate) acting as an electrophile. Under mild conditions, the OEEF-catalyzed EAS reactions can cleave the inherently inert C(sp2)-C(sp2) bond, leading to high-yield (~97%) formation of linear oligophenylenes terminated with covalent Au-C bonds. These results not only demonstrate the feasibility of OEEF catalysis of EAS, but also offer a way of exploring new mechanistic principles of classic organic reactions aided by OEEF.
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13
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Datson Z, Dief E, Li T, Le Brun A, Darwish N. Electrochemical grafting of organic films on silica. Chem Commun (Camb) 2022; 58:11378-11381. [PMID: 36124693 DOI: 10.1039/d2cc03169h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Traditionally, self-assembled monolayers formed on silicon require the removal of the insulating and chemically inert silica layer that naturally forms on the surface of crystalline silicon. The removal of silica is thought to be necessary in order to expose the conducting Si-H surface, which is reactive towards molecules. Here we report the unexpected result of electrochemical formation of thin organic films on silica-terminated silicon with silica thickness up to 20 nm. The process is facilitated by the electrochemical generation of aryl radicals that react with silanol groups at the distal end of silica.
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Affiliation(s)
- Zane Datson
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, WA 6102, Australia.
| | - Essam Dief
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, WA 6102, Australia.
| | - Tiexin Li
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, WA 6102, Australia.
| | - Anton Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization (ANSTO), Lucas Heights, NSW 2234, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, WA 6102, Australia.
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14
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Feng A, Hou S, Yan J, Wu Q, Tang Y, Yang Y, Shi J, Xiao ZY, Lambert CJ, Zheng N, Hong W. Conductance Growth of Single-Cluster Junctions with Increasing Sizes. J Am Chem Soc 2022; 144:15680-15688. [PMID: 35984293 DOI: 10.1021/jacs.2c05856] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Quantum-tunneling-based nanoelectronics has the potential for the miniaturization of electronics toward the sub-5 nm scale. However, the nature of phase-coherent quantum tunneling leads to the rapid decays of the electrical conductance with tunneling transport distance, especially in organic molecule-based nanodevices. In this work, we investigated the conductance of the single-cluster junctions of a series of atomically well-defined silver nanoclusters, with varying sizes from 0.9 to 3.0 nm, using the mechanically controllable break junction (MCBJ) technique combined with quantum transport theory. Our charge transport investigations of these single-cluster junctions revealed that the conductance grows with increasing cluster size. The conductance decay constant was determined to be ∼-0.4 nm-1, which is of opposite sign to that of organic molecules. Comparison between experiment and theory reveals that although charge transport through the silver single-cluster junctions occurs via phase-coherent tunneling, this is compensated by a rapid decrease in the energy gap between the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO gap) with size and the increase in the electrode-cluster coupling, which results in their conductance increase up to lengths of ∼3.0 nm. These results demonstrate that such families of nanoclusters provide unique bottom-up building blocks for the fabrication of nanodevices in the sub-5 nm size range.
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Affiliation(s)
- Anni Feng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Songjun Hou
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Juanzhu Yan
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Qingqing Wu
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Yongxiang Tang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Yang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Zong-Yuan Xiao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Colin J Lambert
- Department of Physics, Lancaster University, Lancaster LA1 4YB, United Kingdom
| | - Nanfeng Zheng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering & Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province (IKKEM), Xiamen University, 361005 Xiamen, China
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15
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Li T, Ciampi S, Darwish N. The Surface Potential of Zero Charge Controls the Kinetics of Diazonium Salts Electropolymerization. ChemElectroChem 2022. [DOI: 10.1002/celc.202200255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Tiexin Li
- School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences Curtin University Bentley WA 6102 Australia
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16
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Li P, Zhou L, Zhao C, Ju H, Gao Q, Si W, Cheng L, Hao J, Li M, Chen Y, Jia C, Guo X. Single-molecule nano-optoelectronics: insights from physics. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2022; 85:086401. [PMID: 35623319 DOI: 10.1088/1361-6633/ac7401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/27/2022] [Indexed: 06/15/2023]
Abstract
Single-molecule optoelectronic devices promise a potential solution for miniaturization and functionalization of silicon-based microelectronic circuits in the future. For decades of its fast development, this field has made significant progress in the synthesis of optoelectronic materials, the fabrication of single-molecule devices and the realization of optoelectronic functions. On the other hand, single-molecule optoelectronic devices offer a reliable platform to investigate the intrinsic physical phenomena and regulation rules of matters at the single-molecule level. To further realize and regulate the optoelectronic functions toward practical applications, it is necessary to clarify the intrinsic physical mechanisms of single-molecule optoelectronic nanodevices. Here, we provide a timely review to survey the physical phenomena and laws involved in single-molecule optoelectronic materials and devices, including charge effects, spin effects, exciton effects, vibronic effects, structural and orbital effects. In particular, we will systematically summarize the basics of molecular optoelectronic materials, and the physical effects and manipulations of single-molecule optoelectronic nanodevices. In addition, fundamentals of single-molecule electronics, which are basic of single-molecule optoelectronics, can also be found in this review. At last, we tend to focus the discussion on the opportunities and challenges arising in the field of single-molecule optoelectronics, and propose further potential breakthroughs.
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Affiliation(s)
- Peihui Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Zhou
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Cong Zhao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Hongyu Ju
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- School of Pharmaceutical Science and Technology, Tianjin University, 92 Weijin Road, Nankai District, Tianjin 300072, People's Republic of China
| | - Qinghua Gao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Wei Si
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Li Cheng
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Jie Hao
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Mengmeng Li
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Yijian Chen
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
| | - Chuancheng Jia
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
| | - Xuefeng Guo
- Center of Single-Molecule Sciences, Institute of Modern Optics, Frontiers Science Center for New Organic Matter, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, College of Electronic Information and Optical Engineering, Nankai University, 38 Tongyan Road, Jinnan District, Tianjin 300350, People's Republic of China
- Beijing National Laboratory for Molecular Sciences, National Biomedical Imaging Center, College of Chemistry and Molecular Engineering, Peking University, 292 Chengfu Road, Haidian District, Beijing 100871, People's Republic of China
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17
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Electro-polymerization rates of diazonium salts are dependent on the crystal orientation of the surface. J Colloid Interface Sci 2022; 626:985-994. [PMID: 35839679 DOI: 10.1016/j.jcis.2022.07.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/30/2022] [Accepted: 07/03/2022] [Indexed: 02/05/2023]
Abstract
Electro-polymerization of diazonium salts is widely used for modifying surfaces with thin organic films. Initially this method was primarily applied to carbon, then to metals, and more recently to semiconducting Si. Unlike on other surfaces, electrochemical reduction of diazonium salts on Si, which is one of the most industrially dominant material, is not well understood. Here, we report the electrochemical reduction of diazonium salts on a range of silicon electrodes of different crystal orientations (111, 211, 311, 411, and 100). We show that the kinetics of surface reaction and the reduction potential is Si crystal-facet dependent and is more favorable in the hierarchical order (111) > (211) > (311) > (411) > (100), a finding that offers control over the surface chemistry of diazonium salts on Si. The dependence of the surface reaction kinetics on the crystal orientation was found to be directly related to differences in the potential of zero charge (PZC) of each crystal orientation, which in turn controls the adsorption of the diazonium cations prior to reduction. Another consequence of the effect of PZC on the adsorption of diazonium cations, is that molecules terminated by distal diazonium moieties form a compact film in less time and requires less reduction potentials compared to that formed from diazonium molecules terminated by only one diazo moiety. In addition, at higher concentrations of diazonium cations, the mechanism of electrochemical polymerization on the surface becomes PZC-controlled adsorption-dominated inner-sphere electron transfer while at lower concentrations, diffusion-based outer-sphere electron transfer dominates. These findings help understanding the electro-polymerization reaction of diazonium salts on Si en route towards an integrated molecular and Si electronics technology.
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18
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Zhang H, Xu W, Song K, Lu T, Zhang G, Zang Y, Hong W, Zhang D. Dual Modulation of Single Molecule Conductance via Tuning Side Chains and Electric Field with Conjugated Molecules Entailing Intramolecular O•••S Interactions. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105667. [PMID: 35434941 PMCID: PMC9189668 DOI: 10.1002/advs.202105667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Herein, single-molecule conductance studies of TBT1-TBT6 which entails 1,4-dithienylbenzene as the backbone and SMe groups as the anchoring units, with the scanning tunneling microscope break junction (STM-BJ) technique, are reported. The molecular conductance of TBT1 with intramolecular O•••S noncovalent interactions is enhanced by about one order of magnitude in comparison to their analogue TBT2 (which contains alkyl instead of alkoxy chains). By replacing the methoxy groups in TBT1 with extending alkoxy chains in TBT3, TBT4, and TBT5, the molecular backbones become twisted and as a consequence the single-molecule conductance decreases gradually, showing that the intramolecular O•••S noncovalent interaction is influenced by the structural features of alkoxy chains. More importantly, the single-molecule conductance of TBT3, TBT4, and TBT5 can be boosted by increasing the electric field applied to the molecular junctions. Remarkably, the conductance of TBT3, TBT4, and TBT5 can be reversibly modulated due to the conformational changes between twisted and planar ones by varying the electric field. These results demonstrate that molecules with intramolecular O•••S noncovalent interactions have the potential for in situ control of the electrical properties of molecular-scale devices.
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Affiliation(s)
- Hua Zhang
- Beijing National Laboratory for Molecular SciencesOrganic Solids LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- School of Chemical SciencesUniversity of Chinese Academy of SciencesBeijing100049China
| | - Wei Xu
- State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China
| | - Kai Song
- Beijing National Laboratory for Molecular SciencesOrganic Solids LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing100190China
| | - Taige Lu
- State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China
| | - Guanxin Zhang
- Beijing National Laboratory for Molecular SciencesOrganic Solids LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- School of Chemical SciencesUniversity of Chinese Academy of SciencesBeijing100049China
| | - Yaping Zang
- Beijing National Laboratory for Molecular SciencesOrganic Solids LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- School of Chemical SciencesUniversity of Chinese Academy of SciencesBeijing100049China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid SurfacesCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China
| | - Deqing Zhang
- Beijing National Laboratory for Molecular SciencesOrganic Solids LaboratoryInstitute of ChemistryChinese Academy of SciencesBeijing100190China
- School of Chemical SciencesUniversity of Chinese Academy of SciencesBeijing100049China
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19
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Li T, Dief EM, Kalužná Z, MacGregor M, Foroutan-Nejad C, Darwish N. On-Surface Azide-Alkyne Cycloaddition Reaction: Does It Click with Ruthenium Catalysts? LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:5532-5541. [PMID: 35470670 PMCID: PMC9097529 DOI: 10.1021/acs.langmuir.2c00100] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 04/11/2022] [Indexed: 05/12/2023]
Abstract
Owing to its simplicity, selectivity, high yield, and the absence of byproducts, the "click" azide-alkyne reaction is widely used in many areas. The reaction is usually catalyzed by copper(I), which selectively produces the 1,4-disubstituted 1,2,3-triazole regioisomer. Ruthenium-based catalysts were later developed to selectively produce the opposite regioselectivity─the 1,5-disubstituted 1,2,3-triazole isomer. Ruthenium-based catalysis, however, remains only tested for click reactions in solution, and the suitability of ruthenium catalysts for surface-based click reactions remains unknown. Also unknown are the electrical properties of the 1,4- and 1,5-regioisomers, and to measure them, both isomers need to be assembled on the electrode surface. Here, we test whether ruthenium catalysts can be used to catalyze surface azide-alkyne reactions to produce 1,5-disubstituted 1,2,3-triazole, and compare their electrochemical properties, in terms of surface coverages and electron transfer kinetics, to those of the compound formed by copper catalysis, 1,4-disubstituted 1,2,3-triazole isomer. Results show that ruthenium(II) complexes catalyze the click reaction on surfaces yielding the 1,5-disubstituted isomer, but the rate of the reaction is remarkably slower than that of the copper-catalyzed reaction, and this is related to the size of the catalyst involved as an intermediate in the reaction. The electron transfer rate constant (ket) for the ruthenium-catalyzed reaction is 30% of that measured for the copper-catalyzed 1,4-isomer. The lower conductivity of the 1,5-isomer is confirmed by performing nonequilibrium Green's function computations on relevant model systems. These findings demonstrate the feasibility of ruthenium-based catalysis of surface click reactions and point toward an electrical method for detecting the isomers of click reactions.
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Affiliation(s)
- Tiexin Li
- School
of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Essam M. Dief
- School
of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Zlatica Kalužná
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224Warsaw, Poland
- University
of Warsaw, Faculty of Physics, Pasteura 5, 00-092Warsaw, Poland
| | - Melanie MacGregor
- Flinders
Institute for Nanoscale Science & Technology, Flinders University, Bedford
Park, South Australia5042, Australia
| | - Cina Foroutan-Nejad
- Institute
of Organic Chemistry, Polish Academy of
Sciences, Kasprzaka 44/52, 01-224Warsaw, Poland
- Institute
of Organic Chemistry and Biochemistry, Czech
Academy of Sciences, Flemingovo nám. 2, CZ-16610Prague, Czech Republic
| | - Nadim Darwish
- School
of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
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20
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Electrografting a Hybrid Bilayer Membrane via Diazonium Chemistry for Electrochemical Impedance Spectroscopy of Amyloid-β Aggregation. MICROMACHINES 2022; 13:mi13040574. [PMID: 35457879 PMCID: PMC9029378 DOI: 10.3390/mi13040574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/20/2022] [Accepted: 03/24/2022] [Indexed: 11/23/2022]
Abstract
Herein, a novel hybrid bilayer membrane is introduced as a platform to study the aggregation of amyloid-β1–42 (Aβ1–42) peptide on surfaces. The first layer was covalently attached to a glassy carbon electrode (GCE) via diazonium electrodeposition, which provided a highly stable template for the hybrid bilayer formation. To prepare the long-chain hybrid bilayer membrane (lcHBLM)-modified electrodes, GCE surfaces were modified with 4-dodecylbenzenediazonium (DDAN) followed by the modification with dihexadecyl phosphate (DHP) as the second layer. For the preparation of short-chain hybrid bilayer membrane (scHBLM)-modified electrodes, GCE surfaces were modified with 4-ethyldiazonium (EDAN) as the first layer and bis(2-ethylhexyl) phosphate (BEHP) was utilized as the second layer. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) were used to characterize the bilayer formation. Both positively charged [Ru(NH3)6]3+ and negatively charged ([Fe(CN)6]3-/4-) redox probes were used for electrochemical characterization of the modified surfaces using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). EIS results showed a decrease in charge transfer resistance (Rct) upon incubation of Aβ1–42 on the hybrid bilayer-modified surfaces. This framework provides a promising electrochemical platform for designing hybrid bilayers with various physicochemical properties to study the interaction of membrane-bound receptors and biomolecules on surfaces.
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21
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Li T, Peiris C, Dief EM, MacGregor M, Ciampi S, Darwish N. Effect of Electric Fields on Silicon-Based Monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:2986-2992. [PMID: 35220713 DOI: 10.1021/acs.langmuir.2c00015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Electric fields can induce bond breaking and bond forming, catalyze chemical reactions on surfaces, and change the structure of self-assembled monolayers on electrode surfaces. Here, we study the effect of electric fields supplied either by an electrochemical potential or by conducting atomic force microscopy (C-AFM) on Si-based monolayers. We report that typical monolayers on silicon undergo partial desorption followed by the oxidation of the underneath silicon at +1.5 V vs Ag/AgCl. The monolayer loses 28% of its surface coverage and 55% of its electron transfer rate constant (ket) when +1.5 V electrochemical potential is applied on the Si surface for 10 min. Similarly, a bias voltage of +5 V applied by C-AFM induces complete desorption of the monolayer at specific sites accompanied by an average oxide growth of 2.6 nm when the duration of the bias applied is 8 min. Current-voltage plots progressively change from rectifying, typical of metal-semiconductor junctions, to insulating as the oxide grows. These results define the stability of Si-based organic monolayers toward electric fields and have implication in the design of silicon-based monolayers, molecular electronics devices, and on the interpretation of charge-transfer kinetics across them.
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Affiliation(s)
- Tiexin Li
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, Western Australia, Australia
| | - Chandramalika Peiris
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, Western Australia, Australia
| | - Essam M Dief
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, Western Australia, Australia
| | - Melanie MacGregor
- Flinders Institute for Nanoscale Science & Technology, Flinders University, Bedford Park 5042, South Australia, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, Western Australia, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley 6102, Western Australia, Australia
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22
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Electrochemical Detection of Dinitrobenzene on Silicon Electrodes: Toward Explosives Sensors. SURFACES 2022. [DOI: 10.3390/surfaces5010015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Detection of explosives is vital for protection and criminal investigations, and developing novel explosives’ sensors stands at the forefront of the analytical and forensic chemistry endeavors. Due to the presence of terminal nitro groups that can be electrochemically reduced, nitroaromatic compounds (NACs) have been an analytical target for explosives’ electrochemical sensors. Various electrode materials have been used to detect NACs in solution, including glassy carbon electrodes (GCE), platinum (Pt), and gold (Au) electrodes, by tracking the reversible oxidation/reduction properties of the NACs on these electrodes. Here, we show that the reduction of dinitrobenzene (DNB) on oxide-free silicon (Si–H) electrodes is irreversible with two reduction peaks that disappear within the successive voltammetric scanning. AFM imaging showed the formation of a polymeric film whose thickness scales up with the DNB concentration. This suggest that Si–H surfaces can serve as DNB sensors and possibly other explosive substances. Cyclic voltammetry (CV) measurements showed that the limit of detection (LoD) on Si–H is one order of magnitude lower than that obtained on GCE. In addition, EIS measurements showed that the LoD of DNB on Si–H is two orders of magnitude lower than the CV method. The fact that a Si–H surface can be used to track the presence of DNB makes it a suitable surface to be implemented as a sensing platform. To translate this concept into a sensor, however, it would require engineering and fabrication prospect to be compatible with the current semiconductor technologies.
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23
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Zeng BF, Wei JY, Zhang XG, Liang QM, Hu S, Wang G, Lei ZC, Zhao SQ, Zhang HW, Shi J, Hong W, Tian ZQ, Yang Y. In situ lattice tuning of quasi-single-crystal surfaces for continuous electrochemical modulation. Chem Sci 2022; 13:7765-7772. [PMID: 35865890 PMCID: PMC9258404 DOI: 10.1039/d2sc01868c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/18/2022] [Indexed: 12/02/2022] Open
Abstract
The ability to control the atomic-level structure of a solid represents a straightforward strategy for fabricating high-performance catalysts and semiconductor materials. Herein we explore the capability of the mechanically controllable surface strain method in adjusting the surface structure of a gold film. Underpotential deposition measurements provide a quantitative and ultrasensitive approach for monitoring the evolution of surface structures. The electrochemical activities of the quasi-single-crystalline gold films are enhanced productively by controlling the surface tension, resulting in a more positive potential for copper deposition. Our method provides an effective way to tune the atom arrangement of solid surfaces with sub-angstrom precision and to achieve a reduction in power consumption, which has vast applications in electrocatalysis, molecular electronics, and materials science. We reported a new method capable of adjusting the lattice structure of solid surfaces with sub-angstrom precision and achieved in situ and continuous control over electrochemical activity.![]()
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Affiliation(s)
- Biao-Feng Zeng
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Jun-Ying Wei
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Xia-Guang Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Qing-Man Liang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Shu Hu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Gan Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Zhi-Chao Lei
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Shi-Qiang Zhao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - He-Wei Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Jia Shi
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Zhong-Qun Tian
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
| | - Yang Yang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, Pen-Tung Sah Institute of Micro-Nano Science and Technology, College of Chemistry and Chemical Engineering, IKKEM, Xiamen University, Xiamen 361005, China
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Aragonès AC, Martín‐Rodríguez A, Aravena D, Palma G, Qian W, Puigmartí‐Luis J, Aliaga‐Alcalde N, González‐Campo A, Díez‐Pérez I, Ruiz E. Room‐Temperature Spin‐Dependent Transport in Metalloporphyrin‐Based Supramolecular Wires. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202110515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Albert C. Aragonès
- Department of Chemistry Faculty of Natural & Mathematical Sciences King's College London Britannia House, 7 Trinity Street London SE1 1DB United Kingdom
- Current address: Molecular Spectroscopy Department Max Planck Institute for Polymer Research Ackermannweg 10 55128 Mainz Germany
| | - Alejandro Martín‐Rodríguez
- Departament de Química Inorgànica i Orgànica Diagonal 645 08028 Barcelona Spain
- Institut de Química Teòrica i Computacional Universitat de Barcelona Diagonal 645 08028 Barcelona Spain
| | - Daniel Aravena
- Departamento de Química de los Materiales Facultad de Química y Biología Universidad de Santiago de Chile (USACH) Casilla 40, Correo 33 Chile
| | - Giuseppe Palma
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC Campus UAB 08193 Bellaterra Spain
| | - Wenjie Qian
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC Campus UAB 08193 Bellaterra Spain
| | - Josep Puigmartí‐Luis
- Institut de Química Teòrica i Computacional Universitat de Barcelona Diagonal 645 08028 Barcelona Spain
- ICREA (Institució Catalana de Recerca i Estudis Avançats) Passeig Lluis Companys 23 08010 Barcelona Spain
- Departament de Ciència dels Materials i Química Física Diagonal 645 08028 Barcelona Spain
| | - Núria Aliaga‐Alcalde
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC Campus UAB 08193 Bellaterra Spain
- ICREA (Institució Catalana de Recerca i Estudis Avançats) Passeig Lluis Companys 23 08010 Barcelona Spain
| | | | - Ismael Díez‐Pérez
- Department of Chemistry Faculty of Natural & Mathematical Sciences King's College London Britannia House, 7 Trinity Street London SE1 1DB United Kingdom
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica Diagonal 645 08028 Barcelona Spain
- Institut de Química Teòrica i Computacional Universitat de Barcelona Diagonal 645 08028 Barcelona Spain
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Aragonès AC, Martín-Rodríguez A, Aravena D, di Palma G, Qian W, Puigmartí-Luis J, Aliaga-Alcalde N, González-Campo A, Díez-Pérez I, Ruiz E. Room-Temperature Spin-Dependent Transport in Metalloporphyrin-Based Supramolecular Wires. Angew Chem Int Ed Engl 2021; 60:25958-25965. [PMID: 34726815 PMCID: PMC9298358 DOI: 10.1002/anie.202110515] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/23/2021] [Indexed: 11/17/2022]
Abstract
Here we present room‐temperature spin‐dependent charge transport measurements in single‐molecule junctions made of metalloporphyrin‐based supramolecular assemblies. They display large conductance switching for magnetoresistance in a single‐molecule junction. The magnetoresistance depends acutely on the probed electron pathway through the supramolecular wire: those involving the metal center showed marked magnetoresistance effects as opposed to those exclusively involving the porphyrin ring which present nearly complete absence of spin‐dependent charge transport. The molecular junction magnetoresistance is highly anisotropic, being observable when the magnetization of the ferromagnetic junction electrode is oriented along the main molecular junction axis, and almost suppressed when it is perpendicular. The key ingredients for the above effect to manifest are the electronic structure of the paramagnetic metalloporphyrin, and the spinterface created at the molecule–electrode contact.
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Affiliation(s)
- Albert C Aragonès
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, United Kingdom.,Current address: Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128, Mainz, Germany
| | - Alejandro Martín-Rodríguez
- Departament de Química Inorgànica i Orgànica, Diagonal 645, 08028, Barcelona, Spain.,Institut de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028, Barcelona, Spain
| | - Daniel Aravena
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile (USACH), Casilla 40, Correo 33, Chile
| | - Giuseppe di Palma
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193, Bellaterra, Spain
| | - Wenjie Qian
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193, Bellaterra, Spain
| | - Josep Puigmartí-Luis
- Institut de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028, Barcelona, Spain.,ICREA (Institució Catalana de Recerca i Estudis Avançats), Passeig Lluis Companys 23, 08010, Barcelona, Spain.,Departament de Ciència dels Materials i Química Física, Diagonal 645, 08028, Barcelona, Spain
| | - Núria Aliaga-Alcalde
- Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193, Bellaterra, Spain.,ICREA (Institució Catalana de Recerca i Estudis Avançats), Passeig Lluis Companys 23, 08010, Barcelona, Spain
| | | | - Ismael Díez-Pérez
- Department of Chemistry, Faculty of Natural & Mathematical Sciences, King's College London, Britannia House, 7 Trinity Street, London, SE1 1DB, United Kingdom
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica, Diagonal 645, 08028, Barcelona, Spain.,Institut de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028, Barcelona, Spain
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Peng W, Wang H, Lu H, Yin L, Wang Y, Grandidier B, Yang D, Pi X. Recent Progress on the Scanning Tunneling Microscopy and Spectroscopy Study of Semiconductor Heterojunctions. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2100655. [PMID: 34337855 DOI: 10.1002/smll.202100655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/18/2021] [Indexed: 06/13/2023]
Abstract
The band alignment, interface states, interface coupling, and carrier transport of semiconductor heterojunctions (SHs) need to be well understood for the design and fabrication of various important semiconductor structures and devices. Scanning tunneling microscopy (STM) with high spatial resolution and scanning tunneling spectroscopy (STS) with high energy resolution are significantly contributing to the understanding on the important properties of SHs. In this work, the recent progress on the use of STM and STS to study lateral, vertical and bulk SHs is reviewed. The spatial structures of SHs with atomically flat surface have been examined with STM. The electronic band structures (e. g., the band offset, interface state, and space charge region) of SHs are measured with STS. Combined with the spatial structures and the tunneling spectra features, the mechanism for the carrier transport in the SH may be proposed.
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Affiliation(s)
- Wenbing Peng
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Haolin Wang
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Hui Lu
- Institute of Advanced Semiconductors, Hangzhou Innovation Center, Zhejiang University, Hangzhou, Zhejiang, 311215, China
| | - Lei Yin
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Yue Wang
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
| | - Bruno Grandidier
- Univ. Lille, CNRS, Centrale Lille, Univ. Polytechnique Hauts-de-France, Junia-ISEN, UMR 8520 - IEMN, Lille, 59000, France
| | - Deren Yang
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
- Institute of Advanced Semiconductors, Hangzhou Innovation Center, Zhejiang University, Hangzhou, Zhejiang, 311215, China
| | - Xiaodong Pi
- State Key Laboratory of Silicon Materials and School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang, 310027, China
- Institute of Advanced Semiconductors, Hangzhou Innovation Center, Zhejiang University, Hangzhou, Zhejiang, 311215, China
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27
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Zhu Y, Tan Z, Hong W. Simultaneous Electrical and Mechanical Characterization of Single-Molecule Junctions Using AFM-BJ Technique. ACS OMEGA 2021; 6:30873-30888. [PMID: 34841131 PMCID: PMC8613807 DOI: 10.1021/acsomega.1c04785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/29/2021] [Indexed: 06/13/2023]
Abstract
The fabrication and characterization of single-molecule junctions provide a unique platform to study the physical phenomena of a single molecule, and the electrical characterization enables us to understand the electrical transport properties of a single molecule and guide the fabrication of molecular electronic devices. However, the electrical characterization of single-molecule junctions is sometimes insufficient to extract the structural information on single-molecule junctions, and an alternate method to address this problem is to characterize the mechanical properties of single-molecule junctions. Simultaneous measurement of mechanical and electrical properties can provide complementary information on single molecules to analyze the correlations of their electrical and mechanical properties in the evolution of single-molecule junctions. In this mini-review, we summarize the progress on the simultaneous characterizations of mechanical and electrical properties for single-molecule junctions, and discuss the challenges and perspectives of this research area.
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Affiliation(s)
- Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia, Australia.
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29
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Huang M, Yu L, Zhang M, Wang Z, Xiao B, Liu Y, He J, Chang S. Developing Longer-Lived Single Molecule Junctions with a Functional Flexible Electrode. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2101911. [PMID: 34292668 DOI: 10.1002/smll.202101911] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/30/2021] [Indexed: 06/13/2023]
Abstract
Creating single-molecule junctions with a long-lived lifetime at room temperature is an open challenge. Finding simple and efficient approaches to increase the durability of single-molecule junction is also of practical value in molecular electronics. Here it is shown that a flexible gold-coated nanopipette electrode can be utilized in scanning tunneling microscope (STM) break-junction measurements to efficiently enhance the stability of molecular junctions by comparing with the measurements using conventional solid gold probes. The stabilizing effect of the flexible electrode displays anchor group dependence, which increases with the binding energy between the anchor group and gold. An empirical model is proposed and shows that the flexible electrode could promote stable binding geometries at the gold-molecule interface and slow down the junction breakage caused by the external perturbations, thereby extending the junction lifetime. Finally, it is demonstrated for the first time that the internal conduit of the flexible STM tip can be utilized for the controlled molecule delivery and molecular junction formation.
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Affiliation(s)
- Mingzhu Huang
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
- Department of Physics, Biomolecular Science Institute, Florida International University, Miami, FL, 33199, USA
| | - Lei Yu
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
| | - Mingyang Zhang
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
| | - Zhe Wang
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
| | - Bohuai Xiao
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
| | - Yichong Liu
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
| | - Jin He
- Department of Physics, Biomolecular Science Institute, Florida International University, Miami, FL, 33199, USA
| | - Shuai Chang
- The State Key Laboratory of Refractories and Metallurgy, the Institute of Advanced Materials and Nanotechnology, College of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan, Hubei, 430081, China
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Abstract
Chemical reactions that occur at nanostructured electrodes have garnered widespread interest because of their potential applications in fields including nanotechnology, green chemistry and fundamental physical organic chemistry. Much of our present understanding of these reactions comes from probes that interrogate ensembles of molecules undergoing various stages of the transformation concurrently. Exquisite control over single-molecule reactivity lets us construct new molecules and further our understanding of nanoscale chemical phenomena. We can study single molecules using instruments such as the scanning tunnelling microscope, which can additionally be part of a mechanically controlled break junction. These are unique tools that can offer a high level of detail. They probe the electronic conductance of individual molecules and catalyse chemical reactions by establishing environments with reactive metal sites on nanoscale electrodes. This Review describes how chemical reactions involving bond cleavage and formation can be triggered at nanoscale electrodes and studied one molecule at a time.
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Rahpeima S, Dief EM, Ciampi S, Raston CL, Darwish N. Impermeable Graphene Oxide Protects Silicon from Oxidation. ACS APPLIED MATERIALS & INTERFACES 2021; 13:38799-38807. [PMID: 34342425 DOI: 10.1021/acsami.1c06495] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The presence of a natural silicon oxide (SiOx) layer over the surface of silicon (Si) has been a roadblock for hybrid semiconductor and organic electronics technology. The presence of an insulating oxide layer is a limiting operational factor, which blocks charge transfer and therefore electrical signals for a range of applications. Etching the SiOx layer by fluoride solutions leaves a reactive Si-H surface that is only stable for few hours before it starts reoxidizing under ambient conditions. Controlled passivation of silicon is also of key importance for improving Si photovoltaic efficiency. Here, we show that a thin layer of graphene oxide (GOx) prevents Si surfaces from oxidation under ambient conditions for more than 30 days. In addition, we show that the protective GOx layer can be modified with molecules enabling a functional surface that allows for further chemical conjugation or connections with upper electrodes, while preserving the underneath Si in a nonoxidized form. The GOx layer can be switched electrochemically to reduced graphene oxide, allowing the development of a dynamic material for molecular electronics technologies. These findings demonstrate that 2D materials are alternatives to organic self-assembled monolayers that are typically used to protect and tune the properties of Si and open a realm of possibilities that combine Si and 2D materials technologies.
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Affiliation(s)
- Soraya Rahpeima
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Essam M Dief
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
| | - Colin L Raston
- Flinders Institute for Nanoscale Science and Technology, College of Science and Engineering, Flinders University, Bedford Park, South Australia 5042, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Perth, Western Australia 6102, Australia
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Yao X, Vonesch M, Combes M, Weiss J, Sun X, Lacroix JC. Single-Molecule Junctions with Highly Improved Stability. NANO LETTERS 2021; 21:6540-6548. [PMID: 34286999 DOI: 10.1021/acs.nanolett.1c01747] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Single-molecule junctions (SMJs) have been fabricated using layers generated by diazonium electroreduction. This process creates a C-Au covalent bond between the molecule and the electrode. Rigid oligomers of variable length, based on porphyrin derivatives in their free base or cobalt complex forms, have been grafted on the surface. The conductance of the oligomers has been studied by a scanning tunneling microscopy break junction (STM-bj) technique and G(t) measurements, and the lifetime of the SMJs has been investigated. The conductance histograms indicate that charge transport in the porphyrins is relatively efficient and influenced by the presence of the cobalt center. With both systems, random telegraph G(t) signals are easily recorded, showing SMJ on/off states. The SMJs then stabilize and exhibit a surprisingly long lifetime around 10 s, and attenuation plots, obtained by both G(t) and STM-bj measurements, give identical values. This work shows that highly stable SMJs can be prepared using a diazonium grafting approach.
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Affiliation(s)
- Xinlei Yao
- ITODYS, CNRS-UMR 7086, Université de Paris, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Maxime Vonesch
- Institut de Chimie de Strasbourg, CNRS-UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - Maïwenn Combes
- Institut de Chimie de Strasbourg, CNRS-UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - Jean Weiss
- Institut de Chimie de Strasbourg, CNRS-UMR 7177, Université de Strasbourg, 4 rue Blaise Pascal, 67000 Strasbourg, France
| | - Xiaonan Sun
- ITODYS, CNRS-UMR 7086, Université de Paris, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Jean-Christophe Lacroix
- ITODYS, CNRS-UMR 7086, Université de Paris, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
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Huang L, Zhou Y, Chen Y, Ye J, Liu J, Xiao Z, Tang C, Xia H, Hong W. Sub-nanometer supramolecular rectifier based on the symmetric building block with destructive σ-interference. Sci China Chem 2021. [DOI: 10.1007/s11426-021-1086-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Zhang L, Yang X, Li S, Zhang J. Functionalized Silicon Electrodes Toward Electrostatic Catalysis. Front Chem 2021; 9:715647. [PMID: 34386481 PMCID: PMC8353247 DOI: 10.3389/fchem.2021.715647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 06/22/2021] [Indexed: 11/13/2022] Open
Abstract
Oriented external electric fields are now emerging as "smart effectors" of chemical changes. The key challenges in experimentally studying electrostatic catalysis are (i) controlling the orientation of fields along the reaction axis and (ii) finely adjusting the magnitudes of electrostatic stimuli. Surface models provide a versatile platform for addressing the direction of electric fields with respect to reactants and balancing the trade-off between the solubility of charged species and the intensity of electric fields. In this mini-review, we present the recent advances that have been investigated of the electrostatic effect on the chemical reaction on the monolayer-functionalized silicon surfaces. We mainly focus on elucidating the mediator/catalysis role of static electric fields induced from either solid/liquid electric double layers at electrode/electrolyte interfaces or space charges in the semiconductors, indicating the electrostatic aspects is of great significance in the semiconductor electrochemistry, redox electroactivity, and chemical bonding. Herein, the functionalization of silicon surfaces allows scientists to explore electrostatic catalysis from nanoscale to mesoscale; most importantly, it provides glimpses of the wide-ranging potentials of oriented electric fields for switching on/off the macroscale synthetic organic electrochemistry and living radical polymerization.
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Affiliation(s)
- Long Zhang
- Institute of Quantum and Sustainable Technology (IQST), School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, China
- Foshan (Southern China) Institute for New Materials, Foshan, China
| | - Xiaohua Yang
- Institute of Quantum and Sustainable Technology (IQST), School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, China
| | - Shun Li
- Institute of Quantum and Sustainable Technology (IQST), School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, China
| | - JianMing Zhang
- Institute of Quantum and Sustainable Technology (IQST), School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang, China
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Wu T, Fitchett CM, Brooksby PA, Downard AJ. Building Tailored Interfaces through Covalent Coupling Reactions at Layers Grafted from Aryldiazonium Salts. ACS APPLIED MATERIALS & INTERFACES 2021; 13:11545-11570. [PMID: 33683855 DOI: 10.1021/acsami.0c22387] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Aryldiazonium ions are widely used reagents for surface modification. Attractive aspects of their use include wide substrate compatibility (ranging from plastics to carbons to metals and metal oxides), formation of stable covalent bonding to the substrate, simplicity of modification methods that are compatible with organic and aqueous solvents, and the commercial availability of many aniline precursors with a straightforward conversion to the active reagent. Importantly, the strong bonding of the modifying layer to the surface makes the method ideally suited to further on-surface (postfunctionalization) chemistry. After an initial grafting from a suitable aryldiazonium ion to give an anchor layer, a target species can be coupled to the layer, hugely expanding the range of species that can be immobilized. This strategy has been widely employed to prepare materials for numerous applications including chemical sensors, biosensors, catalysis, optoelectronics, composite materials, and energy conversion and storage. In this Review our goal is first to summarize how a target species with a particular functional group may be covalently coupled to an appropriate anchor layer. We then review applications of the resulting materials.
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Affiliation(s)
- Ting Wu
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
| | - Christopher M Fitchett
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
| | - Paula A Brooksby
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
| | - Alison J Downard
- School of Physical and Chemical Sciences, University of Canterbury, Christchurch, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Canterbury, Christchurch, New Zealand
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Spontaneous Grafting of OH-Terminated Molecules on Si−H Surfaces via Si–O–C Covalent Bonding. SURFACES 2021. [DOI: 10.3390/surfaces4010010] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The surface functionalization of oxide-free hydrogen-terminated silicon (Si−H) enables predictably tuning its electronic properties, by incorporating tailored functionality for applications such as photovoltaics, biosensing and molecular electronics devices. Most of the available chemical functionalization approaches require an external radical initiator, such as UV light, heat or chemical reagents. Here, we report forming organic monolayers on Si–H surfaces using molecules comprising terminal alcohol (–OH) groups. Self-assembled monolayer (SAM) formation is spontaneous, requires no external stimuli–and yields Si–O–C covalently bound monolayers. The SAMs were characterized by X-ray photoelectron spectroscopy (XPS) to determine the chemical bonding, by X-ray reflectometry (XRR) to determine the monolayers thicknesses on the surface and by atomic force microscopy (AFM) to probe surface topography and surface roughness. The redox activity and the electrochemical properties of the SAMs were studied using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The availability and the ease of incorporating OH groups in organic molecules, makes this spontaneous grafting as a reliable method to attach molecules to Si surfaces in applications ranging from sensing to molecular electronics where incorporating radical initiator setups is not accessible.
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37
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Dief EM, Darwish N. Ultrasonic Generation of Thiyl Radicals: A General Method of Rapidly Connecting Molecules to a Range of Electrodes for Electrochemical and Molecular Electronics Applications. ACS Sens 2021; 6:573-580. [PMID: 33355460 DOI: 10.1021/acssensors.0c02413] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Herein, we report ultrasonic generation of thiyl radicals as a general method for functionalizing a range of surfaces with organic molecules. The method is simple, rapid, can be utilized at ambient conditions and involves sonicating a solution of disulfide molecules, homolytically cleaving S-S bonds and generating thiyl radicals that react with the surfaces by forming covalently bound monolayers. Full molecular coverages on conducting oxides (ITO), semiconductors (Si-H), and carbon (GC) electrode surfaces can be achieved within a time scale of 15-90 min. The suitability of this method to connect the same molecule to different electrodes enabled comparing the conductivity of single molecules and the electrochemical electron transfer kinetics of redox active monolayers as a function of the molecule-electrode contact. We demonstrate, using STM break-junction technique, single-molecule heterojunction comprising Au-molecule-ITO and Au-molecule-carbon circuits. We found that despite using the same molecule, the single-molecule conductivity of Au-molecule-carbon circuits is about an order of magnitude higher than that of Au-molecule-ITO circuits. The same trend was observed for electron transfer kinetics, measured using electrochemical impedance spectroscopy for ferrocene-terminated monolayers on carbon and ITO. This suggests that the interfacial bond between different electrodes and the same molecule can be used to tune the conductivity of single-molecule devices and to control the rate of charge transport in redox active monolayers, opening prospects for relating various types of interfacial charge-transfer rate processes.
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Affiliation(s)
- Essam M. Dief
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia
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38
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Li XM, Wang YH, Seng JW, Zheng JF, Cao R, Shao Y, Chen JZ, Li JF, Zhou XS, Mao BW. z-Piezo Pulse-Modulated STM Break Junction: Toward Single-Molecule Rectifiers with Dissimilar Metal Electrodes. ACS APPLIED MATERIALS & INTERFACES 2021; 13:8656-8663. [PMID: 33587592 DOI: 10.1021/acsami.0c21435] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Fabricating single-molecule junctions with asymmetric metal electrodes is significant for realizing single-molecule diodes, but it remains a big challenge. Herein, we develop a z-piezo pulse-modulated scanning tunneling microscopy break junction (STM-BJ) technique to construct a robust asymmetric junction with different metal electrodes. The asymmetric Ag/BPY-EE/Au single-molecule junctions exhibit a middle conductance value in between those of the two individual symmetric metal electrode junctions, which is consistent with the order of calculated energy-dependent transmission coefficient T(E) of the asymmetric junctions at EF. Furthermore, the single-molecule conductance of Ag/BPY-EE/Au decreases by about 70% when reversing the bias voltage from 100 to -100 mV, and a clear asymmetric I-V feature at the single-molecule level is observed for these junctions. This rectifying behavior could be ascribed to a different interfacial coupling of molecules at the two end electrodes, which is confirmed by the different displacement of T(E) at the two bias voltages. Other asymmetric junctions exhibit similar rectifying behavior. The current work provides a feasible way to fabricate hybrid junctions based on asymmetric metal electrodes and investigate their electron transport toward the design of molecular rectifiers.
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Affiliation(s)
- Xiao-Mei Li
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Ya-Hao Wang
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Jing-Wen Seng
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Ju-Fang Zheng
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Rui Cao
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Yong Shao
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Jing-Zhe Chen
- Department of Physics, Shanghai University, Shanghai 200444, China
| | - Jian-Feng Li
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| | - Xiao-Shun Zhou
- Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, Institute of Physical Chemistry, Zhejiang Normal University, Jinhua 321004, China
| | - Bing-Wei Mao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, iChEM, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
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39
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Gao T, Liu Y, Zhang X, Bai J, Hong W. Preparation and Application of Microelectrodes at the Single-Molecule Scale. Chem Asian J 2021; 16:253-260. [PMID: 33378120 DOI: 10.1002/asia.202001372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/28/2020] [Indexed: 11/10/2022]
Abstract
Molecular electronics offers a potential solution for the miniaturization of electronics beyond conventional silicon electronics. A key goal of molecular electronics is to fabricate the single-molecule junction with the functions of electronic units. The term "molecular junction" means a molecular cluster or a single molecule incorporated between two microelectrodes, and electrons are transported across it. The methods of constructing molecular junctions dynamically were developed, such as STM-BJ, AFM-BJ, and MCBJ, providing precise control of the gap and easy measurement of thousands of junctions. Electrodes based on these techniques are commonly called microelectrodes because at least one dimension is on the micron scale. In this manuscript, we summarize the preparation methods of microelectrodes and their application in single-molecule measurements. In addition, we discuss the electrode factor that influences the molecular electrical properties, such as material, curvature radius and cone angle, and further provide a brief prospect of molecular electronics.
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Affiliation(s)
- Tengyang Gao
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Yuyan Liu
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Xueqing Zhang
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Jie Bai
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China
| | - Wenjing Hong
- State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, P. R. China.,Beijing National Laboratory for Molecular Sciences, Beijing, 100190, P. R. China
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40
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Zhang S, Ferrie S, Peiris CR, Lyu X, Vogel YB, Darwish N, Ciampi S. Common Background Signals in Voltammograms of Crystalline Silicon Electrodes are Reversible Silica-Silicon Redox Chemistry at Highly Conductive Surface Sites. J Am Chem Soc 2021; 143:1267-1272. [PMID: 33373229 DOI: 10.1021/jacs.0c10713] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The electrochemical reduction of bulk silica, due to its high electrical resistance, is of limited viability, namely, requiring temperatures in excess of 850 °C. By means of electrochemical and electrical measurements in atomic force microscopy, we demonstrate that at a buried interface, where silica has grown on highly conductive Si(110) crystal facets, the silica-silicon conversion becomes reversible at room temperature and accessible within a narrow potential window. We conclude that parasitic signals commonly observed in voltammograms of silicon electrodes originate from silica-silicon redox chemistry. While these findings do not remove the requirement of high temperature toward bulk silica electrochemical reduction, they redefine for silicon the potential window free from parasitic signals and, as such, significantly restrict the conditions where electroanalytical methods can be applied to the study of silicon surface reactivity.
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Affiliation(s)
- Song Zhang
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Stuart Ferrie
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Chandramalika R Peiris
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Xin Lyu
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Yan B Vogel
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University, Bentley, Western Australia 6102, Australia
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41
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Yao X, Sun X, Lafolet F, Lacroix JC. Long-Range Charge Transport in Diazonium-Based Single-Molecule Junctions. NANO LETTERS 2020; 20:6899-6907. [PMID: 32786941 DOI: 10.1021/acs.nanolett.0c03000] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Thin layers of cobalt and ruthenium polypyridyl-oligomers with thicknesses between 2 and 8 nm were deposited on gold by electrochemical reduction of diazonium salts. A scanning tunneling microscope was used to create single-molecule junctions (SMJs). The charge transport properties of the Au-[Co(tpy)2]n-Au (n = 1-4) SMJs do not depend markedly on the oligomer length, have an extremely low attenuation factor (β ∼ 0.19 nm-1), and do not show a thickness-dependent transition between two mechanisms. Resonant charge transport is proposed as the main transport mechanism. The SMJ conductance decreases by 1 order of magnitude upon changing the metal from Co to Ru. In Au-[Ru(tpy)2]n-Au and Au-[Ru(bpy)3]n-Au SMJs, a charge transport transition from direct tunneling to hopping is evidenced by a break in the length-dependent β-plot. The three different mechanisms observed are a clear molecular signature on transport in SMJs. Most importantly, these results are in good agreement with those obtained on large-area molecular junctions.
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Affiliation(s)
- Xinlei Yao
- Université de Paris, ITODYS, CNRS-UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Xiaonan Sun
- Université de Paris, ITODYS, CNRS-UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Frédéric Lafolet
- Université de Paris, ITODYS, CNRS-UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
| | - Jean-Christophe Lacroix
- Université de Paris, ITODYS, CNRS-UMR 7086, 15 rue Jean-Antoine de Baïf, 75205 Paris Cedex 13, France
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42
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Meng M, Tang Z, Mallick S, Luo MH, Tan Z, Liu JY, Shi J, Yang Y, Liu CY, Hong W. Enhanced charge transport via d(δ)-p(π) conjugation in Mo 2-integrated single-molecule junctions. NANOSCALE 2020; 12:10320-10327. [PMID: 32367099 DOI: 10.1039/d0nr00195c] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
A trans-dimolybdenum nicotinate (m-Mo2) complex and its isonicotinate isomer (p-Mo2) were synthesized and characterized crystallographically, and their single-molecule charge transport properties were investigated using the STM break junction (STM-BJ) technique. With a quadruply bonded Mo2 complex unit integrated into molecular backbones, the single-molecule conductance for complex molecules was increased by more than one order of magnitude compared with that of the organic π-conjugated analogues 1,4-bis(4-pyridyl)benzene (p-Ph) and 1,4-bis(3-pyridyl)benzene (m-Ph). More interestingly, unlike m-Ph, m-Mo2 with meta connected pyridyl anchors presents larger conductance than that of p-Mo2 with two para connected pyridyl groups. DFT-based transmission calculations revealed that the significant conductance enhancement of Mo2 molecules originates from the largely reduced HOMO-LUMO gap, and the unique d(δ)-p(π) conjugation between the Mo2 unit and the pyridine rings gives rise to a delocalized electronic structure that endows the Mo2 molecules with an unexpected high conductance.
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Affiliation(s)
- Miao Meng
- Department of Chemistry, Jinan University, 601 Huang-Pu Avenue West, Guangzhou 510632, China.
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43
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Peiris CR, Ciampi S, Dief EM, Zhang J, Canfield PJ, Le Brun AP, Kosov DS, Reimers JR, Darwish N. Spontaneous S-Si bonding of alkanethiols to Si(111)-H: towards Si-molecule-Si circuits. Chem Sci 2020; 11:5246-5256. [PMID: 34122981 PMCID: PMC8159313 DOI: 10.1039/d0sc01073a] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We report the synthesis of covalently linked self-assembled monolayers (SAMs) on silicon surfaces, using mild conditions, in a way that is compatible with silicon-electronics fabrication technologies. In molecular electronics, SAMs of functional molecules tethered to gold via sulfur linkages dominate, but these devices are not robust in design and not amenable to scalable manufacture. Whereas covalent bonding to silicon has long been recognized as an attractive alternative, only formation processes involving high temperature and/or pressure, strong chemicals, or irradiation are known. To make molecular devices on silicon under mild conditions with properties reminiscent of Au–S ones, we exploit the susceptibility of thiols to oxidation by dissolved O2, initiating free-radical polymerization mechanisms without causing oxidative damage to the surface. Without thiols present, dissolved O2 would normally oxidize the silicon and hence reaction conditions such as these have been strenuously avoided in the past. The surface coverage on Si(111)–H is measured to be very high, 75% of a full monolayer, with density-functional theory calculations used to profile spontaneous reaction mechanisms. The impact of the Si–S chemistry in single-molecule electronics is demonstrated using STM-junction approaches by forming Si–hexanedithiol–Si junctions. Si–S contacts result in single-molecule wires that are mechanically stable, with an average lifetime at room temperature of 2.7 s, which is five folds higher than that reported for conventional molecular junctions formed between gold electrodes. The enhanced “ON” lifetime of this single-molecule circuit enables previously inaccessible electrical measurements on single molecules. Spontaneously formed Si–S bonds enable monolayer and single-molecule Si–molecule–Si circuits.![]()
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Affiliation(s)
- Chandramalika R Peiris
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Essam M Dief
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Jinyang Zhang
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
| | - Peter J Canfield
- International Centre for Quantum and Molecular Structures, School of Physics, Shanghai University Shanghai 200444 China.,School of Chemistry, The University of Sydney NSW 2006 Australia
| | - Anton P Le Brun
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization (ANSTO) Lucas Heights NSW 2234 Australia
| | - Daniel S Kosov
- College of Science and Engineering, James Cook University Townsville QLD 4811 Australia
| | - Jeffrey R Reimers
- International Centre for Quantum and Molecular Structures, School of Physics, Shanghai University Shanghai 200444 China.,School of Mathematical and Physical Sciences, University of Technology Sydney NSW 2007 Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences, Curtin Institute of Functional Molecules and Interfaces, Curtin University Bentley WA 6102 Australia
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44
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Sachan P, Mondal PC. Versatile electrochemical approaches towards the fabrication of molecular electronic devices. Analyst 2020; 145:1563-1582. [DOI: 10.1039/c9an01948k] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We highlight state-of-the-art electrochemical approaches for diazonium electroreduction on various electrodes that may be suitable for flexible molecular electronic junctions.
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Affiliation(s)
- Pradeep Sachan
- Department of Chemistry
- Indian Institute of Technology
- Kanpur
- India
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45
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Hasegawa Y, Harashima T, Jono Y, Seki T, Kiguchi M, Nishino T. Kinetic investigation of a chemical process in single-molecule junction. Chem Commun (Camb) 2020; 56:309-312. [DOI: 10.1039/c9cc08383a] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein, we report on the kinetic investigation for the breakdown of single-molecule junctions.
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Affiliation(s)
- Yusuke Hasegawa
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Takanori Harashima
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Yuki Jono
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Takumi Seki
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Manabu Kiguchi
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
| | - Tomoaki Nishino
- Department of Chemistry
- School of Science
- Tokyo Institute of Technology
- Tokyo 152-8551
- Japan
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46
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Rahpeima S, Dief EM, Peiris CR, Ferrie S, Duan A, Ciampi S, Raston CL, Darwish N. Reduced graphene oxide–silicon interface involving direct Si–O bonding as a conductive and mechanical stable ohmic contact. Chem Commun (Camb) 2020; 56:6209-6212. [DOI: 10.1039/d0cc02310h] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrochemically reduced graphene oxide, chemically bonded to silicon, lowers the contact resistance to metals and enables a tunable ohmic contact.
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Affiliation(s)
- Soraya Rahpeima
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
| | - Essam M. Dief
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
| | - Chandramalika R. Peiris
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
| | - Stuart Ferrie
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
| | - Alex Duan
- Trace Analysis for Chemical, Earth and Environmental Sciences (TrACEES)
- The University of Melbourne, Melbourne
- Australia
| | - Simone Ciampi
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
| | - Colin L. Raston
- Flinders Institute for Nanoscale Science and Technology
- College of Science and Engineering
- Flinders University
- Adelaide
- Australia
| | - Nadim Darwish
- School of Molecular and Life Sciences
- Curtin Institute of Functional Molecules and Interfaces
- Curtin University
- Bentley
- Australia
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