1
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Labra-Muñoz JA, van der Zant HSJ. Ferritin Single-Electron Transistor. J Phys Chem B 2024; 128:6387-6393. [PMID: 38916107 DOI: 10.1021/acs.jpcb.4c01937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
We report on the fabrication of a single-electron transistor based on ferritin using wide self-aligned nanogap devices. A local gate below the gap area enables three-terminal electrical measurements, showing the Coulomb blockade in good agreement with the single-electron tunneling theory. Comparison with this theory allows extraction of the tunnel resistances, capacitances, and gate coupling. Additionally, the data suggest the presence of two separate islands coupled in series or in parallel: information that was not possible to distinguish by using only two-terminal measurements. To interpret the charge transport features, we propose a scenario based on the established configuration structures of ferritin involving either iron sites in the organic shell or two dissimilar clusters within the core.
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Affiliation(s)
- Jacqueline A Labra-Muñoz
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
- Department of Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, 2300 RA Leiden, The Netherlands
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Delft, The Netherlands
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2
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van der Veen JR, Valianti S, van der Zant HSJ, Blanter YM, Meysman FJR. A model analysis of centimeter-long electron transport in cable bacteria. Phys Chem Chem Phys 2024; 26:3139-3151. [PMID: 38189548 DOI: 10.1039/d3cp04466a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
The recent discovery of cable bacteria has greatly expanded the known length scale of biological electron transport, as these multi-cellular bacteria are capable of mediating electrical currents across centimeter-scale distances. To enable such long-range conduction, cable bacteria embed a network of regularly spaced, parallel protein fibers in their cell envelope. These fibers exhibit extraordinary electrical properties for a biological material, including an electrical conductivity that can exceed 100 S cm-1. Traditionally, long-range electron transport through proteins is described as a multi-step hopping process, in which the individual hopping steps are described by Marcus electron transport theory. Here, we investigate to what extent such a classical hopping model can explain the conductance data recorded for individual cable bacterium filaments. To this end, the conductive fiber network in cable bacteria is modelled as a set of parallel one-dimensional hopping chains. Comparison of model simulated and experimental current(I)/voltage(V) curves, reveals that the charge transport is field-driven rather than concentration-driven, and there is no significant injection barrier between electrodes and filaments. However, the observed high conductivity levels (>100 S cm-1) can only be reproduced, if we include much longer hopping distances (a > 10 nm) and lower reorganisation energies (λ < 0.2 eV) than conventionally used in electron relay models of protein structures. Overall, our model analysis suggests that the conduction mechanism in cable bacteria is markedly distinct from other known forms of long-range biological electron transport, such as in multi-heme cytochromes.
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Affiliation(s)
- Jasper R van der Veen
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, 2628CJ, The Netherlands.
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft, 2629HZ, The Netherlands
| | - Stephanie Valianti
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, 2628CJ, The Netherlands.
| | - Herre S J van der Zant
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, 2628CJ, The Netherlands.
| | - Yaroslav M Blanter
- Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, Delft, 2628CJ, The Netherlands.
| | - Filip J R Meysman
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, Delft, 2629HZ, The Netherlands
- Excellence center for Microbial Systems Technology, University of Antwerp, Universiteitsplein 1, Wilrijk, 2610, Belgium.
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3
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López-Ortiz M, Zamora RA, Giannotti MI, Gorostiza P. The Protein Matrix of Plastocyanin Supports Long-Distance Charge Transport with Photosystem I and the Copper Ion Regulates Its Spatial Span and Conductance. ACS NANO 2023; 17:20334-20344. [PMID: 37797170 DOI: 10.1021/acsnano.3c06390] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/07/2023]
Abstract
Charge exchange is the fundamental process that sustains cellular respiration and photosynthesis by shuttling electrons in a cascade of electron transfer (ET) steps between redox cofactors. While intraprotein charge exchange is well characterized in protein complexes bearing multiple redox sites, interprotein processes are less understood due to the lack of suitable experimental approaches and the dynamic nature of the interactions. Proteins constrained between electrodes are known to support electron transport (ETp) through the protein matrix even without redox cofactors, as the charges housed by the redox sites in ET are furnished by the electrodes. However, it is unknown whether protein ETp mechanisms apply to the interprotein medium present under physiological conditions. We study interprotein charge exchange between plant photosystem I (PSI) and its soluble redox partner plastocyanin (Pc) and address the role of the Pc copper center. Using electrochemical scanning tunneling spectroscopy (ECSTS) current-distance and blinking measurements, we quantify the spatial span of charge exchange between individual Pc/PSI pairs and ETp through transient Pc/PSI complexes. Pc devoid of the redox center (Pcapo) can exchange charge with PSI at longer distances than with the copper ion (Pcholo). Conductance bursts associated with Pcapo/PSI complex formation are higher than in Pcholo/PSI. Thus, copper ions are not required for long-distance Pc/PSI ETp but regulate its spatial span and conductance. Our results suggest that the redox center that carries the charge in Pc is not necessary to exchange it in interprotein ET through the aqueous solution and question the canonical view of tight complex binding between redox protein partners.
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Affiliation(s)
- Manuel López-Ortiz
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
| | - Ricardo A Zamora
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
| | - Marina I Giannotti
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1-11, Barcelona 08028, Spain
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona 08028, Spain
- CIBER-BBN, ISCIII, Barcelona 08028, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona 08010, Spain
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4
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Afsari S, Mukherjee S, Halloran N, Ghirlanda G, Ryan E, Wang X, Lindsay S. Heavy Water Reduces the Electronic Conductance of Protein Wires via Deuteron Interactions with Aromatic Residues. NANO LETTERS 2023; 23:8907-8913. [PMID: 37772726 PMCID: PMC11177565 DOI: 10.1021/acs.nanolett.3c02263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/30/2023]
Abstract
Proteins are versatile, self-assembling nanoelectronic components, but their hopping conductivity is expected to be influenced by solvent fluctuations. The role of the solvent was investigated by measuring the single molecule conductance of several proteins in both H2O and D2O. The conductance of a homologous series of protein wires decreases more rapidly with length in D2O, indicating a 6-fold decrease in carrier diffusion constant relative to the same protein in H2O. The effect was found to depend on the specific aromatic amino acid composition. A tryptophan zipper protein showed a decrease in conductance similar to that of the protein wires, whereas a phenylalanine zipper protein was insensitive to solvent changes. Tryptophan contains an indole amine, whereas the phenylalanine aromatic ring has no exchangeable protons, so the effect of heavy water on conductance is a consequence of specific D- or H-interactions with the aromatic residues.
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Affiliation(s)
- Sepideh Afsari
- Biodesign Institute, Arizona State University, Tempe, AZ 85287
| | - Sohini Mukherjee
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
| | - Nicholas Halloran
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
| | | | - Eathen Ryan
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
| | - Xu Wang
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
| | - Stuart Lindsay
- Biodesign Institute, Arizona State University, Tempe, AZ 85287
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287
- Department of Physics, Arizona State University, Tempe, AZ 85287
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5
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Kong N, He J, Yang W. Formation of Molecular Junctions by Single-Entity Collision Electrochemistry. J Phys Chem Lett 2023; 14:8513-8524. [PMID: 37722010 DOI: 10.1021/acs.jpclett.3c01955] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Abstract
Controlling and understanding the chemistry of molecular junctions is one of the major themes in various fields ranging from chemistry and nanotechnology to biotechnology and biology. Stochastic single-entity collision electrochemistry (SECE) provides powerful tools to study a single entity, such as single cells, single particles, and even single molecules, in a nanoconfined space. Molecular junctions formed by SECE collision show various potential applications in monitoring molecular dynamics with high spatial resolution and high temporal resolution and in feasible combination with hybrid techniques. This Perspective highlights the new breakthroughs, seminal studies, and trends in the area that have been most recently reported. In addition, future challenges for the study of molecular junction dynamics with SECE are discussed.
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Affiliation(s)
- Na Kong
- School of Life and Environmental Science, Centre for Sustainable Bioproducts, Deakin University, Geelong, Victoria 3216, Australia
| | - Jin He
- Physics Department, Biomolecular Sciences Institute, Florida International University, Miami, Florida 33199, United States
| | - Wenrong Yang
- School of Life and Environmental Science, Centre for Sustainable Bioproducts, Deakin University, Geelong, Victoria 3216, Australia
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6
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Nazmutdinov RR, Shermokhamedov SA, Zinkicheva TT, Ulstrup J, Xiao X. Understanding molecular and electrochemical charge transfer: theory and computations. Chem Soc Rev 2023; 52:6230-6253. [PMID: 37551138 DOI: 10.1039/d2cs00006g] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Electron, proton, and proton-coupled electron transfer (PCET) are crucial elementary processes in chemistry, electrochemistry, and biology. We provide here a gentle overview of retrospective and currently developing theoretical formalisms of chemical, electrochemical and biological molecular charge transfer processes, with examples of how to bridge electron, proton, and PCET theory with experimental data. We offer first a theoretical minimum of molecular electron, proton, and PCET processes in homogeneous solution and at electrochemical interfaces. We illustrate next the use of the theory both for simple electron transfer processes, and for processes that involve molecular reorganization beyond the simplest harmonic approximation, with dissociative electron transfer and inclusion of all charge transfer parameters. A core example is the electrochemical reduction of the S2O82- anion. This is followed by discussion of core elements of proton and PCET processes and the electrochemical dihydrogen evolution reaction on different metal, semiconductor, and semimetal (say graphene) electrode surfaces. Other further focus is on stochastic chemical rate theory, and how this concept can rationalize highly non-traditional behaviour of charge transfer processes in mixed solvents. As a second major area we address ("long-range") chemical and electrochemical electron transfer through molecular frameworks using notions of superexchange and hopping. Single-molecule and single-entity electrochemistry are based on electrochemical scanning probe microscopies. (In operando) scanning tunnelling microscopy (STM) and atomic force microscopy (AFM) are particularly emphasized, with theoretical notions and new molecular electrochemical phenomena in the confined tunnelling gap. Single-molecule surface structure and electron transfer dynamics are illustrated by self-assembled thiol molecular monolayers and by more complex redox target molecules. This discussion also extends single-molecule electrochemistry to bioelectrochemistry of complex redox metalloproteins and metalloenzymes. Our third major area involves computational overviews of molecular and electronic structure of the electrochemical interface, with new computational challenges. These relate to solvent dynamics in bulk and confined space (say carbon nanostructures), electrocatalysis, metallic and semiconductor nanoparticles, d-band metals, carbon nanostructures, spin catalysis and "spintronics", and "hot" electrons. Further perspectives relate to metal-organic frameworks, chiral surfaces, and spintronics.
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Affiliation(s)
- Renat R Nazmutdinov
- Department of Inorganic Chemistry, Kazan National Research Technological University, K. Marx Str., 68, 420015 Kazan, Republic of Tatarstan, Russian Federation.
| | - Shokirbek A Shermokhamedov
- Department of Inorganic Chemistry, Kazan National Research Technological University, K. Marx Str., 68, 420015 Kazan, Republic of Tatarstan, Russian Federation.
| | - Tamara T Zinkicheva
- Department of Inorganic Chemistry, Kazan National Research Technological University, K. Marx Str., 68, 420015 Kazan, Republic of Tatarstan, Russian Federation.
| | - Jens Ulstrup
- Department of Inorganic Chemistry, Kazan National Research Technological University, K. Marx Str., 68, 420015 Kazan, Republic of Tatarstan, Russian Federation.
- Department of Chemistry, Technical University of Denmark, Building 207, Kemitorvet, 2800 Kongens Lyngby, Denmark.
| | - Xinxin Xiao
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
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7
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Jiang T, Zeng BF, Zhang B, Tang L. Single-molecular protein-based bioelectronics via electronic transport: fundamentals, devices and applications. Chem Soc Rev 2023; 52:5968-6002. [PMID: 37498342 DOI: 10.1039/d2cs00519k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Abstract
Biomolecular electronics is a rapidly growing multidisciplinary field that combines biology, nanoscience, and engineering to bridge the two important fields of life sciences and molecular electronics. Proteins are remarkable for their ability to recognize molecules and transport electrons, making the integration of proteins into electronic devices a long sought-after goal and leading to the emergence of the field of protein-based bioelectronics, also known as proteotronics. This field seeks to design and create new biomolecular electronic platforms that allow for the understanding and manipulation of protein-mediated electronic charge transport and related functional applications. In recent decades, there have been numerous reports on protein-based bioelectronics using a variety of nano-gapped electrical devices and techniques at the single molecular level, which are not achievable with conventional ensemble approaches. This review focuses on recent advances in physical electron transport mechanisms, device fabrication methodologies, and various applications in protein-based bioelectronics. We discuss the most recent progress of the single or few protein-bridged electrical junction fabrication strategies, summarise the work on fundamental and functional applications of protein bioelectronics that enable high and dynamic electron transport, and highlight future perspectives and challenges that still need to be addressed. We believe that this specific review will stimulate the interdisciplinary research of topics related to protein-related bioelectronics, and open up new possibilities for single-molecule biophysics and biomedicine.
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Affiliation(s)
- Tao Jiang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Biao-Feng Zeng
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Bintian Zhang
- Shenzhen Key Laboratory of Precision Measurement and Early Warning Technology for Urban Environmental Health Risks, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
| | - Longhua Tang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
- Institute of Quantum Sensing, Interdisciplinary Centre for Quantum Information, Zhejiang University, Hangzhou 310027, China
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8
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Jiang T, Yi L, Liu X, Ivanov AP, Edel JB, Tang L. Fabrication of electron tunneling probes for measuring single-protein conductance. Nat Protoc 2023; 18:2579-2599. [PMID: 37420088 DOI: 10.1038/s41596-023-00846-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 04/21/2023] [Indexed: 07/09/2023]
Abstract
Studying the electrical properties of individual proteins is a prominent research area in the field of bioelectronics. Electron tunnelling or quantum mechanical tunnelling (QMT) probes can act as powerful tools for investigating the electrical properties of proteins. However, current fabrication methods for these probes often have limited reproducibility, unreliable contact or inadequate binding of proteins onto the electrodes, so better solutions are required. Here, we detail a generalizable and straightforward set of instructions for fabricating simple, nanopipette-based, tunnelling probes, suitable for measuring conductance in single proteins. Our QMT probe is based on a high-aspect-ratio dual-channel nanopipette that integrates a pair of gold tunneling electrodes with a gap of less than 5 nm, fabricated via the pyrolytic deposition of carbon followed by the electrochemical deposition of gold. The gold tunneling electrodes can be functionalized using an extensive library of available surface modifications to achieve single-protein-electrode contact. We use a biotinylated thiol modification, in which a biotin-streptavidin-biotin bridge is used to form the single-protein junction. The resulting protein-coupled QMT probes enable the stable electrical measurement of the same single protein in solution for up to several hours. We also describe the analysis method used to interpret time-dependent single-protein conductance measurements, which can provide essential information for understanding electron transport and exploring protein dynamics. The total time required to complete the protocol is ~33 h and it can be carried out by users trained in less than 24 h.
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Affiliation(s)
- Tao Jiang
- State Key Laboratory of Modern Optical Instrumentation, Institute of Quantum Sensing, Interdisciplinary Centre for Quantum Information, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, China
| | - Long Yi
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Xu Liu
- State Key Laboratory of Modern Optical Instrumentation, Institute of Quantum Sensing, Interdisciplinary Centre for Quantum Information, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, China
| | - Aleksandar P Ivanov
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Joshua B Edel
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Longhua Tang
- State Key Laboratory of Modern Optical Instrumentation, Institute of Quantum Sensing, Interdisciplinary Centre for Quantum Information, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, China.
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9
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Abstract
The theory of electron transfer reactions establishes the conceptual foundation for redox solution chemistry, electrochemistry, and bioenergetics. Electron and proton transfer across the cellular membrane provide all energy of life gained through natural photosynthesis and mitochondrial respiration. Rates of biological charge transfer set kinetic bottlenecks for biological energy storage. The main system-specific parameter determining the activation barrier for a single electron-transfer hop is the reorganization energy of the medium. Both harvesting of light energy in natural and artificial photosynthesis and efficient electron transport in biological energy chains require reduction of the reorganization energy to allow fast transitions. This review article discusses mechanisms by which small values of the reorganization energy are achieved in protein electron transfer and how similar mechanisms can operate in other media, such as nonpolar and ionic liquids. One of the major mechanisms of reorganization energy reduction is through non-Gibbsian (nonergodic) sampling of the medium configurations on the reaction time. A number of alternative mechanisms, such as electrowetting of active sites of proteins, give rise to non-parabolic free energy surfaces of electron transfer. These mechanisms, and nonequilibrium population of donor-acceptor vibrations, lead to a universal phenomenology of separation between the Stokes shift and variance reorganization energies of electron transfer.
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Affiliation(s)
- Dmitry V Matyushov
- School of Molecular Sciences and Department of Physics, Arizona State University, PO Box 871504, Tempe, Arizona 85287-1504, USA.
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10
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Fyta M. Functionalized electrodes embedded in nanopores: read-out enhancement? Chem Asian J 2023; 18:e202200916. [PMID: 36372991 PMCID: PMC10107472 DOI: 10.1002/asia.202200916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 11/12/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022]
Abstract
In this review, functionalized nanogaps embedded in nanopores are discussed in view of their high biosensitivity in detecting biomolecules, their length, type, and sequence. Specific focus is given on nanoelectrodes functionalized with tiny nanometer-sized diamond-like particles offering vast functionalization possibilities for gold junction electrodes. This choice of the functionalization, in turn, offers nucleotide-specific binding possibilities improving the detection signals arising from such functionalized electrodes potentially embedded in a nanopore. The review sheds light onto the use and enhancement of the tunnelling recognition in functionalized nanogaps towards sensing DNA nucleotides and mutation detection, providing important input for a practical realization.
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Affiliation(s)
- Maria Fyta
- Computational Biotechnology, RWTH-Aachen University, Worringerweg 3, 52072, Aachen, Germany
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11
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Hall DA, Ananthapadmanabhan N, Choi C, Zheng L, Pan PP, Von Jutrzenka C, Nguyen T, Rizo J, Weinstein M, Lobaton R, Sinha P, Sauerbrey T, Sigala C, Bailey K, Mudondo PJ, Chaudhuri AR, Severi S, Fuller CW, Tour JM, Jin S, Mola PW, Merriman B. A Scalable CMOS Molecular Electronics Chip for Single-Molecule Biosensing. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2022; 16:1030-1043. [PMID: 36191107 DOI: 10.1109/tbcas.2022.3211420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
This work reports the first CMOS molecular electronics chip. It is configured as a biosensor, where the primary sensing element is a single molecule "molecular wire" consisting of a ∼100 GΩ, 25 nm long alpha-helical peptide integrated into a current monitoring circuit. The engineered peptide contains a central conjugation site for attachment of various probe molecules, such as DNA, proteins, enzymes, or antibodies, which program the biosensor to detect interactions with a specific target molecule. The current through the molecular wire under a dc applied voltage is monitored with millisecond temporal resolution. The detected signals are millisecond-scale, picoampere current pulses generated by each transient probe-target molecular interaction. Implemented in a 0.18 μm CMOS technology, 16k sensors are arrayed with a 20 μm pitch and read out at a 1 kHz frame rate. The resulting biosensor chip provides direct, real-time observation of the single-molecule interaction kinetics, unlike classical biosensors that measure ensemble averages of such events. This molecular electronics chip provides a platform for putting molecular biosensing "on-chip" to bring the power of semiconductor chips to diverse applications in biological research, diagnostics, sequencing, proteomics, drug discovery, and environmental monitoring.
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12
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Electrical/Spectroscopic Stability of Conducting and Biodegradable Graft‐Copolymer. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202200275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Tang L, Yi L, Jiang T, Ren R, Paulose Nadappuram B, Zhang B, Wu J, Liu X, Lindsay S, Edel JB, Ivanov AP. Measuring conductance switching in single proteins using quantum tunneling. SCIENCE ADVANCES 2022; 8:eabm8149. [PMID: 35584212 PMCID: PMC9116604 DOI: 10.1126/sciadv.abm8149] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Interpreting the electrical signatures of single proteins in electronic junctions has facilitated a better understanding of the intrinsic properties of proteins that are fundamental to chemical and biological processes. Often, this information is not accessible using ensemble and even single-molecule approaches. In addition, the fabrication of nanoscale single-protein junctions remains challenging as they often require sophisticated methods. We report on the fabrication of tunneling probes, direct measurement, and active control (switching) of single-protein conductance with an external field in solution. The probes allowed us to bridge a single streptavidin molecule to two independently addressable, biotin-terminated electrodes and measure single-protein tunneling response over long periods. We show that charge transport through the protein has multiple conductive pathways that depend on the magnitude of the applied bias. These findings open the door for the reliable fabrication of protein-based junctions and can enable their use in future protein-embedded bioelectronics applications.
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Affiliation(s)
- Longhua Tang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China
- Innovation Institute for Artificial Intelligence in Medicine, Zhejiang-California International NanoSystems Institute, Zhejiang University, Hangzhou 310000, China
- Corresponding author. (L.T.); (A.P.I.); (J.B.E.)
| | - Long Yi
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, UK
| | - Tao Jiang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China
| | - Ren Ren
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, UK
| | - Binoy Paulose Nadappuram
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, UK
- Department of Pure and Applied Chemistry, University of Strathclyde, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, UK
| | - Bintian Zhang
- Biodesign Institute; School of Life Sciences; Department of Physics; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Jian Wu
- Innovation Institute for Artificial Intelligence in Medicine, Zhejiang-California International NanoSystems Institute, Zhejiang University, Hangzhou 310000, China
| | - Xu Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, International Research Center for Advanced Photonics, Zhejiang University, Hangzhou 310027, China
| | - Stuart Lindsay
- Biodesign Institute; School of Life Sciences; Department of Physics; School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Joshua B. Edel
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, UK
- Corresponding author. (L.T.); (A.P.I.); (J.B.E.)
| | - Aleksandar P. Ivanov
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, White City Campus, 82 Wood Lane, London W12 0BZ, UK
- Corresponding author. (L.T.); (A.P.I.); (J.B.E.)
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14
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López-Ortiz M, Zamora RA, Giannotti MI, Hu C, Croce R, Gorostiza P. Distance and Potential Dependence of Charge Transport Through the Reaction Center of Individual Photosynthetic Complexes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2104366. [PMID: 34874621 DOI: 10.1002/smll.202104366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/11/2021] [Indexed: 06/13/2023]
Abstract
Charge separation and transport through the reaction center of photosystem I (PSI) is an essential part of the photosynthetic electron transport chain. A strategy is developed to immobilize and orient PSI complexes on gold electrodes allowing to probe the complex's electron acceptor side, the chlorophyll special pair P700. Electrochemical scanning tunneling microscopy (ECSTM) imaging and current-distance spectroscopy of single protein complex shows lateral size in agreement with its known dimensions, and a PSI apparent height that depends on the probe potential revealing a gating effect in protein conductance. In current-distance spectroscopy, it is observed that the distance-decay constant of the current between PSI and the ECSTM probe depends on the sample and probe electrode potentials. The longest charge exchange distance (lowest distance-decay constant β) is observed at sample potential 0 mV/SSC (SSC: reference electrode silver/silver chloride) and probe potential 400 mV/SSC. These potentials correspond to hole injection into an electronic state that is available in the absence of illumination. It is proposed that a pair of tryptophan residues located at the interface between P700 and the solution and known to support the hydrophobic recognition of the PSI redox partner plastocyanin, may have an additional role as hole exchange mediator in charge transport through PSI.
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Affiliation(s)
- Manuel López-Ortiz
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
| | - Ricardo A Zamora
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
| | - Marina Inés Giannotti
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
- Department of Materials Science and Physical Chemistry, University of Barcelona, Martí i Franquès 1-11, Barcelona, 08028, Spain
| | - Chen Hu
- Biophysics of PhotosynthesisDepartment of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Roberta Croce
- Biophysics of PhotosynthesisDepartment of Physics and Astronomy, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, 1081 HV, The Netherlands
| | - Pau Gorostiza
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Baldiri Reixac 10-12, Barcelona, 08028, Spain
- Network Biomedical Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Madrid, 28029, Spain
- Catalan Institution for Research and Advanced Studies (ICREA), Barcelona, 08010, Spain
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15
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Cahen D, Pecht I, Sheves M. What Can We Learn from Protein-Based Electron Transport Junctions? J Phys Chem Lett 2021; 12:11598-11603. [PMID: 34852460 PMCID: PMC8647078 DOI: 10.1021/acs.jpclett.1c02446] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Affiliation(s)
- David Cahen
- Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Israel Pecht
- Weizmann Institute of Science, Rehovot 7610001, Israel
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16
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Engelbrekt C, Nazmutdinov RR, Shermukhamedov S, Ulstrup J, Zinkicheva TT, Xiao X. Complex single‐molecule and molecular scale entities in electrochemical environments: Mechanisms and challenges. ELECTROCHEMICAL SCIENCE ADVANCES 2021. [DOI: 10.1002/elsa.202100157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Christian Engelbrekt
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
| | - Renat R. Nazmutdinov
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Shokirbek Shermukhamedov
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Jens Ulstrup
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
| | - Tamara T. Zinkicheva
- Department of Inorganic Chemistry Kazan National Research Technological University Karl Marx Str. 68 Kazan 420015 Russian Federation
| | - Xinxin Xiao
- Department of Chemistry Technical University of Denmark Building 207, DK0‐2800 Kgs. Lyngby Denmark
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17
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Zhang B, Ryan E, Wang X, Lindsay S. Probing Bioelectronic Connections Using Streptavidin Molecules with Modified Valency. J Am Chem Soc 2021; 143:15139-15144. [PMID: 34499834 PMCID: PMC8458255 DOI: 10.1021/jacs.1c05569] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
As molecular electronic components, proteins are distinguished by a remarkably long electronic decay length (∼10 nm) together with high contact resistance and extreme sensitivity to the chemical details of the contact. As a consequence, the conductance of even a large bioelectronic assembly is largely controlled by the conductance of the contacts. Streptavidin is a versatile linker protein that can tether together biotinylated electrodes and biotinylated proteins but with an ambiguity about the contact geometry that arises from its four possible binding sites for biotin. Here, we use engineered streptavidin tetramers, selected to contain a defined ratio of active monomers to "dead" monomers so as to define the biotin binding sites. We find a strong dependence of conductance on the separation of the biotin molecules, consistent with a short-range tunneling interaction within the streptavidin and in contrast to the long-range transport observed inside larger proteins. Hexaglutamate tails label the active monomers, and the additional negative charge enhances conductance significantly. This effect is quantitatively accounted for by an electronic resonance in the protein conductance.
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Affiliation(s)
- Bintian Zhang
- Biodesign Institute, Arizona State University, Tempe AZ 87287, USA
| | - Eathen Ryan
- School of Molecular Sciences, Arizona State University, Tempe AZ 87287, USA
| | - Xu Wang
- School of Molecular Sciences, Arizona State University, Tempe AZ 87287, USA
| | - Stuart Lindsay
- Biodesign Institute, Arizona State University, Tempe AZ 87287, USA
- School of Molecular Sciences, Arizona State University, Tempe AZ 87287, USA
- Department of Physics, Arizona State University, Tempe AZ 87287, USA
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18
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Pattiya Arachchillage KGG, Chandra S, Piso A, Qattan T, Artes Vivancos JM. RNA BioMolecular Electronics: towards new tools for biophysics and biomedicine. J Mater Chem B 2021; 9:6994-7006. [PMID: 34494636 DOI: 10.1039/d1tb01141c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The last half-century has witnessed the birth and development of a new multidisciplinary field at the edge between materials science, nanoscience, engineering, and chemistry known as Molecular Electronics. This field deals with the electronic properties of individual molecules and their integration as active components in electronic circuits and has also been applied to biomolecules, leading to BioMolecular Electronics and opening new perspectives for single-molecule biophysics and biomedicine. Herein, we provide a brief introduction and overview of the BioMolecular electronics field, focusing on nucleic acids and potential applications for these measurements. In particular, we review the recent demonstration of the first single-molecule electrical detection of a biologically-relevant nucleic acid. We also show how this could be used to study biomolecular interactions and applications in liquid biopsy for early cancer detection, among others. Finally, we discuss future perspectives and challenges in the applications of this fascinating research field.
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Affiliation(s)
| | - Subrata Chandra
- Department of Chemistry, University of Massachusetts Lowell, One University Ave, 01854 Lowell, MA, USA.
| | - Angela Piso
- Department of Chemistry, University of Massachusetts Lowell, One University Ave, 01854 Lowell, MA, USA.
| | - Tiba Qattan
- Department of Chemistry, University of Massachusetts Lowell, One University Ave, 01854 Lowell, MA, USA.
| | - Juan M Artes Vivancos
- Department of Chemistry, University of Massachusetts Lowell, One University Ave, 01854 Lowell, MA, USA.
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19
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Intrinsic electronic conductivity of individual atomically resolved amyloid crystals reveals micrometer-long hole hopping via tyrosines. Proc Natl Acad Sci U S A 2021; 118:2014139118. [PMID: 33372136 DOI: 10.1073/pnas.2014139118] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Proteins are commonly known to transfer electrons over distances limited to a few nanometers. However, many biological processes require electron transport over far longer distances. For example, soil and sediment bacteria transport electrons, over hundreds of micrometers to even centimeters, via putative filamentous proteins rich in aromatic residues. However, measurements of true protein conductivity have been hampered by artifacts due to large contact resistances between proteins and electrodes. Using individual amyloid protein crystals with atomic-resolution structures as a model system, we perform contact-free measurements of intrinsic electronic conductivity using a four-electrode approach. We find hole transport through micrometer-long stacked tyrosines at physiologically relevant potentials. Notably, the transport rate through tyrosines (105 s-1) is comparable to cytochromes. Our studies therefore show that amyloid proteins can efficiently transport charges, under ordinary thermal conditions, without any need for redox-active metal cofactors, large driving force, or photosensitizers to generate a high oxidation state for charge injection. By measuring conductivity as a function of molecular length, voltage, and temperature, while eliminating the dominant contribution of contact resistances, we show that a multistep hopping mechanism (composed of multiple tunneling steps), not single-step tunneling, explains the measured conductivity. Combined experimental and computational studies reveal that proton-coupled electron transfer confers conductivity; both the energetics of the proton acceptor, a neighboring glutamine, and its proximity to tyrosine influence the hole transport rate through a proton rocking mechanism. Surprisingly, conductivity increases 200-fold upon cooling due to higher availability of the proton acceptor by increased hydrogen bonding.
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20
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Tang L, Nadappuram BP, Cadinu P, Zhao Z, Xue L, Yi L, Ren R, Wang J, Ivanov AP, Edel JB. Combined quantum tunnelling and dielectrophoretic trapping for molecular analysis at ultra-low analyte concentrations. Nat Commun 2021; 12:913. [PMID: 33568635 PMCID: PMC7876030 DOI: 10.1038/s41467-021-21101-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 01/06/2021] [Indexed: 01/04/2023] Open
Abstract
Quantum tunnelling offers a unique opportunity to study nanoscale objects with atomic resolution using electrical readout. However, practical implementation is impeded by the lack of simple, stable probes, that are required for successful operation. Existing platforms offer low throughput and operate in a limited range of analyte concentrations, as there is no active control to transport molecules to the sensor. We report on a standalone tunnelling probe based on double-barrelled capillary nanoelectrodes that do not require a conductive substrate to operate unlike other techniques, such as scanning tunnelling microscopy. These probes can be used to efficiently operate in solution environments and detect single molecules, including mononucleotides, oligonucleotides, and proteins. The probes are simple to fabricate, exhibit remarkable stability, and can be combined with dielectrophoretic trapping, enabling active analyte transport to the tunnelling sensor. The latter allows for up to 5-orders of magnitude increase in event detection rates and sub-femtomolar sensitivity. Probes that effectively utilize quantum tunneling are sought after for high-resolution study of nanoscale objects. Here the authors present an easily fabricated probe of two nanoelectrodes that enables highly sensitive quantum-tunneling-based sensing of single molecules.
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Affiliation(s)
- Longhua Tang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering; International Research Center for Advanced Photonics, Zhejiang University, Hangzhou, China. .,Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK. .,Innovation Institute for Artificial Intelligence in Medicine, Zhejiang University, Hangzhou, China.
| | | | - Paolo Cadinu
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Zhiyu Zhao
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
| | - Liang Xue
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Long Yi
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Ren Ren
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK
| | - Jiangwei Wang
- Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou, China
| | - Aleksandar P Ivanov
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK.
| | - Joshua B Edel
- Department of Chemistry, Molecular Science Research Hub, Imperial College London, London, UK.
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