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Lei P, Li Q, Meng T, Deng K, Wan J, Xiao X, Zeng Q. Diverse Self-assembly Structures of a Macrocycle Revealed with STM by Adjusting the Solution Concentration. Chem Asian J 2021; 17:e202101246. [PMID: 34843178 DOI: 10.1002/asia.202101246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 11/27/2021] [Indexed: 11/11/2022]
Abstract
The macrocyclic molecule [3]C12 TT-TPA was synthesized by a Stille coupling reaction through alternately connecting 4,7-bisthienyl-2,1,3-thienothiazole and triphenylamine units. The concentration-dependent self-assembly structures of [3]C12 TT-TPA were explored in liquid/solid interface by scanning tunneling microscopy and density functional theory. After increasing the solution concentration, five different nanostructures were constructed and the molecular packing densities were gradually enhanced. Those structural transformations from loose structures to compact structures are thermodynamically favourable because those transformations are accompanied by the adsorption of more [3]C12 TT-TPA molecules from liquid phase, which increases the interactions between molecules and the interactions between molecules and substrate considerably. This study of fundamental exploration is important to understand the basic formation mechanisms and the stability of two-dimensional functional materials.
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Affiliation(s)
- Peng Lei
- National Center for Nanoscience and Technology, No. 11, North First Street, Zhongguancun, Haidian District, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.,College of Chemical Engineering, Ningbo University of Technology, Ningbo, 315211, P. R. China
| | - Qianhui Li
- Key Laboratory of organosilicon chemistry and material technology of ministry of education, Hangzhou Normal University, No. 2318 yuhangtang Road, Yuhang District, Hangzhou, Zhejiang, P. R. China
| | - Ting Meng
- National Center for Nanoscience and Technology, No. 11, North First Street, Zhongguancun, Haidian District, Beijing, 100190, P. R. China.,University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Ke Deng
- National Center for Nanoscience and Technology, No. 11, North First Street, Zhongguancun, Haidian District, Beijing, 100190, P. R. China
| | - Junhua Wan
- Key Laboratory of organosilicon chemistry and material technology of ministry of education, Hangzhou Normal University, No. 2318 yuhangtang Road, Yuhang District, Hangzhou, Zhejiang, P. R. China
| | - Xunwen Xiao
- College of Chemical Engineering, Ningbo University of Technology, Ningbo, 315211, P. R. China
| | - Qingdao Zeng
- National Center for Nanoscience and Technology, No. 11, North First Street, Zhongguancun, Haidian District, Beijing, 100190, P. R. China
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2
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Direct Electrochemical Enzyme Electron Transfer on Electrodes Modified by Self-Assembled Molecular Monolayers. Catalysts 2020. [DOI: 10.3390/catal10121458] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Self-assembled molecular monolayers (SAMs) have long been recognized as crucial “bridges” between redox enzymes and solid electrode surfaces, on which the enzymes undergo direct electron transfer (DET)—for example, in enzymatic biofuel cells (EBFCs) and biosensors. SAMs possess a wide range of terminal groups that enable productive enzyme adsorption and fine-tuning in favorable orientations on the electrode. The tunneling distance and SAM chain length, and the contacting terminal SAM groups, are the most significant controlling factors in DET-type bioelectrocatalysis. In particular, SAM-modified nanostructured electrode materials have recently been extensively explored to improve the catalytic activity and stability of redox proteins immobilized on electrochemical surfaces. In this report, we present an overview of recent investigations of electrochemical enzyme DET processes on SAMs with a focus on single-crystal and nanoporous gold electrodes. Specifically, we consider the preparation and characterization methods of SAMs, as well as SAM applications in promoting interfacial electrochemical electron transfer of redox proteins and enzymes. The strategic selection of SAMs to accord with the properties of the core redox protein/enzymes is also highlighted.
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3
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Cisternas E, dos Santos GJ, Flores M, Vogel EE, Ramirez-Pastor AJ. Self-assembled monolayer formation of pentamers-like molecules onto FCC(111) surfaces: the case of curcuminoids onto Au(111) surface. NANO EXPRESS 2020. [DOI: 10.1088/2632-959x/ab8961] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
The adsorption of rigid straight electrically polarized pentamers over a FCC(111) surface is studied. The model was inspired by the deposition of 2-thiophene molecules over the Au(111) surface, which was previously characterized by experimental techniques and simulated under the frame of the density functional theory. We now obtain and report the charge distribution of the molecule which allows to propose a deposition model followed by Monte Carlo simulations over an ad-hoc lattice gas model. We show that for a certain value of the chemical potential there exists an isotropic-nematic phase transition which can explain the formation of a self-assembled monolayer like the one observed in the transmission electron microscopy images. An order parameter is defined to characterize the transition which presents a step-like behavior at a critical chemical potential value. The possible nature of the nematic transition in conjunction with an ergodicity breakdown is discussed as future work by means of statistical physics techniques.
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Gutiérrez-Ceron C, Oñate R, Zagal JH, Pizarro A, Silva JF, Castro-Castillo C, Rezende MC, Flores M, Cortés-Arriagada D, Toro-Labbé A, Campos LM, Venkataraman L, Ponce I. Molecular conductance versus inductive effects of axial ligands on the electrocatalytic activity of self-assembled iron phthalocyanines: The oxygen reduction reaction. Electrochim Acta 2019. [DOI: 10.1016/j.electacta.2019.134996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Engelbrekt C, Nazmutdinov RR, Zinkicheva TT, Glukhov DV, Yan J, Mao B, Ulstrup J, Zhang J. Chemistry of cysteine assembly on Au(100): electrochemistry, in situ STM and molecular modeling. NANOSCALE 2019; 11:17235-17251. [PMID: 31418761 DOI: 10.1039/c9nr02477h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cysteine (Cys) is an essential amino acid with a carboxylic acid, an amine and a thiol group. We have studied the surface structure and adsorption dynamics of l-cysteine adlayers on Au(100) from aqueous solution using electrochemistry, high-resolution electrochemical scanning tunnelling microscopy (in situ STM), and molecular modelling. Cys adsorption on this low-index Au-surface has been much less studied than Cys adsorption on Au(111)- and Au(110)-electrode surfaces. Chronopotentiometry was employed to monitor the adsorption dynamics at sub-second resolution and showed that adsorption is completed in 30 minutes at Cys concentrations above 100 μM. Two consecutive steps could be fitted to these data. Two separate reductive desorption peaks of Cys adlayers on Au(100) with a total coverage of 2.52 (±0.15) × 10-10 mol cm-2 were observed. In situ STM showed that the adsorbed Cys is organized in stripes with "fork-like" features which co-exist in (11 × 2)-2Cys and (7 × 2)-2Cys lattices, quite differently from Cys adsorption on Au(111)-electrode surfaces. Stripe structures with bright STM contrast in the center suggest that a second Cys adlayer on top of a first adlayer is formed, supporting the dual-peak reductive desorption of Cys adlayers. In addition, monolayers of both pure l-Cys and pure d-Cys and a 1 : 1 racemic mixture of l- and d-Cys on Au(100) were studied. Virtually identical macroscopic electrochemical features were found, but in situ STM discloses many more defects for the racemic mixture than for the pure enantiomers due to structural mismatch of l- and d-Cys. Density functional theory (DFT) calculations combined with a cluster model for the Au(100) surface were carried out to investigate the adsorption energy and geometry of the adsorbed monomer and dimer Cys species in different orientations, with detailed attention to the chirality effects. Optimized DFT geometries were used to construct model STM images, and kinetic Monte Carlo simulations undertaken to illuminate the growth of adsorbate rows and the mechanism of the adlayer formation as well as the Cys adsorption patterns specific to the Au(100)-electrode surface.
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Affiliation(s)
- Christian Engelbrekt
- Department of Chemistry, Building 207, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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6
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Zhang L, Ulstrup J, Zhang J. Voltammetry and molecular assembly of G-quadruplex DNAzyme on single-crystal Au(111)-electrode surfaces - hemin as an electrochemical intercalator. Faraday Discuss 2018; 193:99-112. [PMID: 27722546 DOI: 10.1039/c6fd00091f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
DNA quadruplexes (qs) are a class of "non-canonical" oligonucleotides (OGNs) composed of stacked guanine (G) quartets stabilized by specific cations. Metal porphyrins selectively bind to G-qs complexes to form what is known as DNAzyme, which can exhibit peroxidase and other catalytic activity similar to heme group metalloenzymes. In the present study we investigate the electrochemical properties and the structure of DNAzyme monolayers on single-crystal Au(111)-electrode surfaces using cyclic voltammetry and scanning tunnelling microscopy under electrochemical potential control (in situ STM). The target DNAzyme is formed from a single-strand OGN with 12 guanines and iron(iii) porphyrin IX (hemin), and assembles on Au(111) through a mercapto alkyl linker. The DNAzyme monolayers exhibit a strong pair of redox peaks at 0.0 V (NHE) at pH 7 in acetate buffer, shifted positively by about 50 mV compared to free hemin weakly physisorbed on the Au(111)-electrode surface. The voltammetric hemin signal of DNAzyme is enhanced 15 times compared with that of hemin adsorbed directly on the Au(111)-electrode surface. This is indicative of both the formation of a close to dense DNAzyme monolayer and that hemin is strongly bound to the immobilized 12G-qs in well-defined orientation favorable for interfacial ET with a rate constant of 6.0 ± 0.4 s-1. This is supported by in situ STM which discloses single-molecule G-quartet structures with a size of 1.6 ± 0.2 nm.
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Affiliation(s)
- Ling Zhang
- Department of Chemistry, Technical University of Denmark, Building 207, Kemitorvet, DK-2800 Kgs. Lyngby, Denmark.
| | - Jens Ulstrup
- Department of Chemistry, Technical University of Denmark, Building 207, Kemitorvet, DK-2800 Kgs. Lyngby, Denmark.
| | - Jingdong Zhang
- Department of Chemistry, Technical University of Denmark, Building 207, Kemitorvet, DK-2800 Kgs. Lyngby, Denmark.
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Zhang L, Kepp KP, Ulstrup J, Zhang J. Redox Potentials and Electronic States of Iron Porphyrin IX Adsorbed on Single Crystal Gold Electrode Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:3610-3618. [PMID: 29510058 DOI: 10.1021/acs.langmuir.8b00163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Metalloporphyrins are active sites in metalloproteins and synthetic catalysts. They have also been studied extensively by electrochemistry as well as being prominent targets in electrochemical scanning tunneling microscopy (STM). Previous studies of FePPIX adsorbed on graphite and alkylthiol modified Au electrodes showed a pair of reversible Fe(III/II)PPIX peaks at about -0.41 V (vs NHE) at high solution pH. We recently used iron protoporphyrin IX (FePPIX) as an intercalating probe for long-range electrochemical electron transfer through a G-quadruplex oligonucleotide (DNAzyme); this study disclosed two, rather than a single pair of voltammetric peaks with a new and dominating peak, shifted 200 mV positive relative to the ≈-0.4 V peak. Prompted by this unexpected observation, we report here a study of the voltammetry of FePPIX itself on single-crystal Au(111), (100), and (110) and polycrystalline Au electrode surfaces. In all cases the dominating pair of new Fe(III/II)PPIX redox peaks, shifted positively by more than 200 mV compared to those of previous studies appeared. This observation is supported by density functional theory (DFT) which shows that strong dispersion forces in the FePPIX/Au electronic interaction drive the midpoint potential toward positive values. The FePPIX spin states depend on interaction with the Au(111) interface, converting all the Fe(II)/(III)PPIX species into low-spin states. These results support electrochemical evidence for the nature of the electronic coupling between FePPIX and Au-surfaces, and the electronic states of adsorbate molecules, with a bearing also on recent reports of magnetic FePPIX/Au(111) interactions in ultrahigh vacuum (UHV).
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Affiliation(s)
- Ling Zhang
- Department of Chemistry , Technical University of Denmark , Building 207, Kemitorvet, DK-2800 Kgs. Lyngby , Denmark
| | - Kasper P Kepp
- Department of Chemistry , Technical University of Denmark , Building 207, Kemitorvet, DK-2800 Kgs. Lyngby , Denmark
| | - Jens Ulstrup
- Department of Chemistry , Technical University of Denmark , Building 207, Kemitorvet, DK-2800 Kgs. Lyngby , Denmark
| | - Jingdong Zhang
- Department of Chemistry , Technical University of Denmark , Building 207, Kemitorvet, DK-2800 Kgs. Lyngby , Denmark
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8
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Dourado AHB, Pastrián FC, Torresi SICDE. The long and successful journey of electrochemically active amino acids. From fundamental adsorption studies to potential surface engineering tools. AN ACAD BRAS CIENC 2018; 90:607-630. [PMID: 29340478 DOI: 10.1590/0001-3765201720170434] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/26/2017] [Indexed: 12/11/2022] Open
Abstract
Proteins have been the subject of electrochemical studies. It is possible to apply electrochemical techniques to obtain information about their structure due to the presence of five electroactive amino acids that can be oriented to the outside of the peptidic chain. These amino acids are L-Tryptophan (L-Trp), L-Tyrosine (L-Tyr), L-Histidine (L-His), L-Methionine (L-Met) and L-Cysteine (L-Cys); their electrochemical behavior being subject of extensive research, but it is still controversial. No spectroscopic investigations have been reported on L-Trp, and due to the short life time of the intermediates, ex situ techniques cannot be employed, leading to a never-ending discussion about possible intermediates. In the L-Tyr and L-His cases, spectroelectrochemical studies were performed and different intermediates were observed, suggesting that some intermediates may be observed under specific conditions, as proposed for L-Cys. This amino acid is the most interesting among the electroactive ones because of the presence of a thiol moiety at its side chain, leading to a wide range of oxidation states. It can adsorb onto surfaces of different crystallographic orientation in stereoselective conformation, modifying the surface for different applications.as a surface engineering tool since it plays the role of as an anchor for the growing of nanocrystals inside proteic templates.
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Affiliation(s)
- André H B Dourado
- Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, SP, Brazil
| | - Fabián C Pastrián
- Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, SP, Brazil
| | - Susana I Córdoba DE Torresi
- Instituto de Química, Universidade de São Paulo, Av. Prof. Lineu Prestes, 748, 05508-000 São Paulo, SP, Brazil
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9
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Lettieri R, Di Giorgio F, Colella A, Magnusson R, Bjorefors F, Placidi E, Palleschi A, Venanzi M, Gatto E. DPPTE Thiolipid Self-Assembled Monolayer: A Critical Assay. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11560-11572. [PMID: 27689538 DOI: 10.1021/acs.langmuir.6b01912] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Supported lipid membranes represent an elegant way to design a fluid interface able to mimic the physicochemical properties of biological membranes, with potential biotechnological applications. In this work, a diacyl phospholipid, the 1,2-dipalmitoyl-sn-glycero-3-phosphothioethanol (DPPTE), functionalized with a thiol group, was immobilized on a gold surface. In this molecule, the thiol group, responsible for the Au-S bond (45 kJ/mol) is located on the phospholipid polar head, letting the hydrophobic chain protrude from the film. This system is widely used in the literature but is no less challenging, since its characterization is not complete, as several discordant data have been obtained. In this work, the film was characterized by cyclic voltammetry blocking experiments, to verify the SAM formation, and by reductive desorption measurements, to estimate the molecular density of DPPTE on the gold surface. This value has been compared to that obtained by quartz crystal microbalance measurements. Ellipsometry and impedance spectroscopy measurements have been performed to obtain information about the monolayer thickness and capacitance. The film morphology was investigated by atomic force microscopy. Finally, Monte Carlo simulations were carried out, in order to gain molecular information about the morphologies of the DPPTE SAM and compare them to the experimental results. We demonstrate that DPPTE molecules, incubated 18 h below the phase transition temperature (T = 41.1 ± 0.4 °C) in ethanol solution, are able to form a self-assembled monolayer on the gold surface, with domain structures of different order, which have never been reported before. Our results make possible rationalization of the scattered results so far obtained on this system, giving a new insight into the formation of phospholipids SAMs on a gold surface.
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Affiliation(s)
- Raffaella Lettieri
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Floriana Di Giorgio
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Alessandra Colella
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Roger Magnusson
- Department of Physics, Chemistry and Biology (IFM), University of Linköping , 581 83 Linköping, Sweden
| | - Fredrik Bjorefors
- Ångström Laboratory, Department of Chemistry, Uppsala University , Box 538, SE-75121 Uppsala, Sweden
| | - Ernesto Placidi
- Institute of Structure of Matter, CNR, Department of Physics, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Antonio Palleschi
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Mariano Venanzi
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
| | - Emanuela Gatto
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata , 00133 Rome, Italy
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10
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Holze R. The adsorption of thiophenol on gold--a spectroelectrochemical study. Phys Chem Chem Phys 2015; 17:21364-72. [PMID: 25790963 DOI: 10.1039/c5cp00884k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The adsorbate formed by adsorption of thiophenol on a polycrystalline gold electrode and brought into contact with aqueous solutions of 1 M HClO4 and 0.1 M KClO4 has been studied using cyclic voltammetry and surface-enhanced Raman spectroscopy. A strong adsorption is deduced from observations made using cyclic voltammetry. From the SER spectra, interactions of thiophenol with the gold surface via a gold-sulfur bond with the aromatic ring pointing away from the surface is concluded for both electrolyte solutions.
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Affiliation(s)
- Rudolf Holze
- Technische Universität Chemnitz, Institut für Chemie, AG Elektrochemie, 09107 Chemnitz, Germany.
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11
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Renner FU, Ankah GN, Bashir A, Ma D, Biedermann PU, Shrestha BR, Nellessen M, Khorashadizadeh A, Losada-Pérez P, Duarte MJ, Raabe D, Valtiner M. Star-Shaped Crystallographic Cracking of Localized Nanoporous Defects. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2015; 27:4877-4882. [PMID: 26192203 DOI: 10.1002/adma.201405565] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 06/15/2015] [Indexed: 06/04/2023]
Abstract
On self-assembled monolayer-covered Cu-Au substrates, localized volume shrinkage at initial dealloying sites leads to cracks within the attacked regions. It is started from well-controlled surface structures to gain fundamental insights in the driving mechanisms of localized corrosion and crack formation. Both the crack density and the crack morphology are critically dependent on surface orientation, crystallography, and inhibitor molecule species.
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Affiliation(s)
- Frank Uwe Renner
- Institute for Materials Research (IMO), Hasselt University and Associated Lab IMEC Division IMOMEC, Wetenschapspark 1, 3590, Diepenbeek, Belgium
| | - Genesis Ngwa Ankah
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Asif Bashir
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Duancheng Ma
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - P Ulrich Biedermann
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Buddha Ratna Shrestha
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Monika Nellessen
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Anahita Khorashadizadeh
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Patricia Losada-Pérez
- Institute for Materials Research (IMO), Hasselt University and Associated Lab IMEC Division IMOMEC, Wetenschapspark 1, 3590, Diepenbeek, Belgium
| | - Maria Jazmin Duarte
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Dierk Raabe
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
| | - Markus Valtiner
- Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, D-40237, Düsseldorf, Germany
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12
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Salvatore P, Nazmutdinov RR, Ulstrup J, Zhang J. DNA Bases Assembled on the Au(110)/Electrolyte Interface: A Combined Experimental and Theoretical Study. J Phys Chem B 2015; 119:3123-34. [DOI: 10.1021/jp511909f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Princia Salvatore
- Department
of Chemistry, Building 207, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Renat R. Nazmutdinov
- Kazan National
Research Technological University, K. Marx Str., 68, 420015 Kazan, Republic of Tatarstan, Russian Federation
| | - Jens Ulstrup
- Department
of Chemistry, Building 207, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - Jingdong Zhang
- Department
of Chemistry, Building 207, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
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13
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Rutkowska A, Freedman K, Skalkowska J, Kim MJ, Edel JB, Albrecht T. Electrodeposition and Bipolar Effects in Metallized Nanopores and Their Use in the Detection of Insulin. Anal Chem 2015; 87:2337-44. [DOI: 10.1021/ac504463r] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Agnieszka Rutkowska
- Department
of Chemistry, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom
| | - Kevin Freedman
- Department
of Chemistry, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom
- Department
of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Justyna Skalkowska
- Department
of Chemistry, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom
- Department
of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
| | - Min Jun Kim
- Department
of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Joshua B. Edel
- Department
of Chemistry, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom
| | - Tim Albrecht
- Department
of Chemistry, Imperial College London, South Kensington, SW7 2AZ, London, United Kingdom
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14
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Wei Z, Wang X, Borges A, Santella M, Li T, Sørensen JK, Vanin M, Hu W, Liu Y, Ulstrup J, Solomon GC, Chi Q, Bjørnholm T, Nørgaard K, Laursen BW. Triazatriangulene as binding group for molecular electronics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:14868-14876. [PMID: 25426950 DOI: 10.1021/la504056v] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The triazatriangulene (TATA) ring system was investigated as a binding group for tunnel junctions of molecular wires on gold surfaces. Self-assembled monolayers (SAMs) of TATA platforms with three different lengths of phenylene wires were fabricated, and their electrical conductance was recorded by both conducting probe-atomic force microscopy (CP-AFM) and scanning tunneling microscopy (STM). Similar measurements were performed for phenylene SAMs with thiol anchoring groups as references. It was found that, despite the presence of a sp(3) hybridized carbon atom in the conduction path, the TATA platform displays a contact resistance only slightly larger than the thiols. This surprising finding has not been reported before and was analyzed by theoretical computations of the transmission functions of the TATA anchored molecular wires. The relatively low contact resistance of the TATA platform along with its high stability and directionality make this binding group very attractive for molecular electronic measurements and devices.
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Affiliation(s)
- Zhongming Wei
- Nano-Science Center & Department of Chemistry, University of Copenhagen , Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark
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15
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Artés JM, López-Martínez M, Díez-Pérez I, Sanz F, Gorostiza P. Nanoscale charge transfer in redox proteins and DNA: Towards biomolecular electronics. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2014.05.089] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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16
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Claridge SA, Thomas JC, Silverman MA, Schwartz JJ, Yang Y, Wang C, Weiss PS. Differentiating amino acid residues and side chain orientations in peptides using scanning tunneling microscopy. J Am Chem Soc 2013; 135:18528-35. [PMID: 24219245 PMCID: PMC4117194 DOI: 10.1021/ja408550a] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Single-molecule measurements of complex biological structures such as proteins are an attractive route for determining structures of the large number of important biomolecules that have proved refractory to analysis through standard techniques such as X-ray crystallography and nuclear magnetic resonance. We use a custom-built low-current scanning tunneling microscope to image peptide structures at the single-molecule scale in a model peptide that forms β sheets, a structural motif common in protein misfolding diseases. We successfully differentiate between histidine and alanine amino acid residues, and further differentiate side chain orientations in individual histidine residues, by correlating features in scanning tunneling microscope images with those in energy-optimized models. Beta sheets containing histidine residues are used as a model system due to the role histidine plays in transition metal binding associated with amyloid oligomerization in Alzheimer's and other diseases. Such measurements are a first step toward analyzing peptide and protein structures at the single-molecule level.
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Affiliation(s)
- Shelley A. Claridge
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
| | - John C. Thomas
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
| | - Miles A. Silverman
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
| | - Jeffrey J. Schwartz
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
| | - Yanlian Yang
- National Center for Nanoscience and Technology, Beijing 100190, PR China
| | - Chen Wang
- National Center for Nanoscience and Technology, Beijing 100190, PR China
| | - Paul S. Weiss
- California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Physics and Astronomy, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095-7227, United States
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17
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Competition of anchoring groups in adsorption on gold electrodes—a comparative spectroelectrochemical study of 4-mercaptobenzonitrile and aromatic nitriles. J Solid State Electrochem 2013. [DOI: 10.1007/s10008-013-2076-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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18
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Forman CJ, Wang N, Yang ZY, Mowat CG, Jarvis S, Durkan C, Barker PD. Probing the location of displayed cytochrome b562 on amyloid by scanning tunnelling microscopy. NANOTECHNOLOGY 2013; 24:175102. [PMID: 23571459 DOI: 10.1088/0957-4484/24/17/175102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Amyloid fibres displaying cytochrome b562 were probed using scanning tunnelling microscopy (STM) in vacuo. The cytochromes are electron transfer proteins containing a haem cofactor and could, in principle, mediate electron transfer between the tip and the gold substrate. If the core fibres were insulating and electron transfer within the 3D haem network was detected, then the electron transport properties of the fibre could be controlled by genetic engineering. Three kinds of STM images were obtained. At a low bias (<1.5 V) the fibres appeared as regions of low conductivity with no evidence of cytochrome mediated electron transfer. At a high bias, stable peaks in tunnelling current were observed for all three fibre species containing haem and one species of fibre that did not contain haem. In images of this kind, some of the current peaks were collinear and spaced around 10 nm apart over ranges longer than 100 nm, but background monomers complicate interpretation. Images of the third kind were rare (1 in 150 fibres); in these, fully conducting structures with the approximate dimensions of fibres were observed, suggesting the possibility of an intermittent conduction mechanism, for which a precedent exists in DNA. To test the conductivity, some fibres were immobilized with sputtered gold, and no evidence of conduction between the grains of gold was seen. In control experiments, a variation of monomeric cytochrome b562 was not detected by STM, which was attributed to low adhesion, whereas a monomeric multi-haem protein, GSU1996, was readily imaged. We conclude that the fibre superstructure may be intermittently conducting, that the cytochromes have been seen within the fibres and that they are too far apart for detectable current flow between sites to occur. We predict that GSU1996, being 10 nm long, is more likely to mediate successful electron transfer along the fibre as well as being more readily detectable when displayed from amyloid.
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Affiliation(s)
- C J Forman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, UK.
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19
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Muglali MI, Erbe A, Chen Y, Barth C, Koelsch P, Rohwerder M. Modulation of electrochemical hydrogen evolution rate by araliphatic thiol monolayers on gold. Electrochim Acta 2013; 90. [PMID: 24235778 DOI: 10.1016/j.electacta.2012.11.116] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electroreductive desorption of a highly ordered self-assembled monolayer (SAM) formed by the araliphatic thiol (4-(4-(4-pyridyl)phenyl)phenyl)methanethiol leads to a concurrent rapid hydrogen evolution reaction (HER). The desorption process and resulting interfacial structure were investigated by voltammetric techniques, in situ spectroscopic ellipsometry, and in situ vibrational sum-frequency-generation (SFG) spectroscopy. Voltammetric experiments on SAM-modified electrodes exhibit extraordinarily high peak currents, which di er between Au(111) and polycrystalline Au substrates. Association of reductive desorption with HER is shown to be the origin of the observed excess cathodic charges. The studied SAM preserves its two-dimensional order near Au surface throughout a fast voltammetric scan even when the vertex potential is set several hundred millivolt beyond the desorption potential. A model is developed for the explanation of the observed rapid HER involving ordering and pre-orientation of water present in the nanometer-sized reaction volume between desorbed SAM and the Au electrode, by the structurally extremely stable monolayer, leading to the observed catalysis of the HER.
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Affiliation(s)
- Mutlu I Muglali
- Max-Planck-Institut für Eisenforschung GmbH, Department of Interface Chemistry and Surface Engineering, Max-Planck-Str. 1, 40237 Düsseldorf, Germany
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20
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Gatto E, Porchetta A, Scarselli M, De Crescenzi M, Formaggio F, Toniolo C, Venanzi M. Playing with peptides: how to build a supramolecular peptide nanostructure by exploiting helix···helix macrodipole interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:2817-2826. [PMID: 22214420 DOI: 10.1021/la204423d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A novel method to build bicomponent peptide self-assembled monolayers (SAMs) has been developed, by exploiting helix···helix macrodipole interactions. In this work, a peptide-based self-assembled monolayer composed of two helical peptides was immobilized on a gold surface. Specifically, a pyrene-containing octapeptide, devoid of any sulfur atom (A8Pyr), and a hexapeptide, functionalized at the N-terminus with (S,R) lipoic acid, for binding to gold substrates (SSA4WA) via a Au-S linkage, have been employed. Both peptides investigated attain a helical structure, because they are almost exclusively formed by strongly folding inducer C(α)-tetrasubstituted α-amino acids. We demonstrate that the two peptides generate a stable supramolecular nanostructure (a densely packed bicomponent peptide monolayer), where A8Pyr is incorporated into the SSA4WA palisade by exploiting helix···helix macrodipole interactions. The presence of both peptides on the gold surface was investigated by spectroscopic and electrochemical techniques, while the morphology of the monolayer was analyzed by ultra high-vacuum scanning tunnelling microscopy. The composition of the bicomponent SAM on the surface was studied by a combination of electrochemical and spectroscopic techniques. In particular, the amount of Au-S linkages from the sulfur-containing peptides was quantified from reductive desorption of the peptide-based SAM, while the amount of A8Pyr was estimated by fluorescence spectroscopy. The antiparallel orientation of the A8Pyr and SSA4WA peptide chains minimizes the interaction energy between the helix dipoles, suggesting that this kind of electrostatic phenomenon is the driving force that stabilizes the bicomponent SAM.
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Affiliation(s)
- E Gatto
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, 00133 Rome, Italy.
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21
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Smith SR, Han S, McDonald A, Zhe W, Shepherd JL. An electrochemical approach to fabricate a heterogeneous mixed monolayer on planar polycrystalline Au and its characterization with Lateral Force Microscopy. J Electroanal Chem (Lausanne) 2012. [DOI: 10.1016/j.jelechem.2011.12.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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22
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Interfacial electrochemical electron transfer in biology - towards the level of the single molecule. FEBS Lett 2011; 586:526-35. [PMID: 22024483 DOI: 10.1016/j.febslet.2011.10.023] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 10/04/2011] [Accepted: 10/11/2011] [Indexed: 11/21/2022]
Abstract
Physical electrochemistry has undergone a remarkable evolution over the last few decades, integrating advanced techniques and theory from solid state and surface physics. Single-crystal electrode surfaces have been a core notion, opening for scanning tunnelling microscopy directly in aqueous electrolyte (in situ STM). Interfacial electrochemistry of metalloproteins is presently going through a similar transition. Electrochemical surfaces with thiol-based promoter molecular monolayers (SAMs) as biomolecular electrochemical environments and the biomolecules themselves have been mapped with unprecedented resolution, opening a new area of single-molecule bioelectrochemistry. We consider first in situ STM of small redox molecules, followed by in situ STM of thiol-based SAMs as molecular views of bioelectrochemical environments. We then address electron transfer metalloproteins, and multi-centre metalloenzymes including applied single-biomolecular perspectives based on metalloprotein/metallic nanoparticle hybrids.
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