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Plačkić A, Neubert TJ, Patel K, Kuhl M, Watanabe K, Taniguchi T, Zurutuza A, Sordan R, Balasubramanian K. Electrochemistry at the Edge of a van der Waals Heterostructure. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2306361. [PMID: 38109121 DOI: 10.1002/smll.202306361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 10/19/2023] [Indexed: 12/19/2023]
Abstract
Artificial van der Waals heterostructures, obtained by stacking two-dimensional (2D) materials, represent a novel platform for investigating physicochemical phenomena and applications. Here, the electrochemistry at the one-dimensional (1D) edge of a graphene sheet, sandwiched between two hexagonal boron nitride (hBN) flakes, is reported. When such an hBN/graphene/hBN heterostructure is immersed in a solution, the basal plane of graphene is encapsulated by hBN, and the graphene edge is exclusively available in the solution. This forms an electrochemical nanoelectrode, enabling the investigation of electron transfer using several redox probes, e.g., ferrocene(di)methanol, hexaammineruthenium, methylene blue, dopamine and ferrocyanide. The low capacitance of the van der Waals edge electrode facilitates cyclic voltammetry at very high scan rates (up to 1000 V s-1), allowing voltammetric detection of redox species down to micromolar concentrations with sub-second time resolution. The nanoband nature of the edge electrode allows operation in water without added electrolyte. Finally, two adjacent edge electrodes are realized in a redox-cycling format. All the above-mentioned phenomena can be investigated at the edge, demonstrating that nanoscale electrochemistry is a new application avenue for van der Waals heterostructures. Such an edge electrode will be useful for studying electron transfer mechanisms and the detection of analyte species in ultralow sample volumes.
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Affiliation(s)
- Aleksandra Plačkić
- L-NESS, Department of Physics, Politecnico di Milano, Via Anzani 42, Como, 22100, Italy
- BioSense Institute, University of Novi Sad, Dr Zorana Đinđića 1, Novi Sad, 21000, Serbia
| | - Tilmann J Neubert
- School of Analytical Sciences Adlershof (SALSA), IRIS Adlershof & Department of Chemistry, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Kishan Patel
- L-NESS, Department of Physics, Politecnico di Milano, Via Anzani 42, Como, 22100, Italy
| | - Michel Kuhl
- School of Analytical Sciences Adlershof (SALSA), IRIS Adlershof & Department of Chemistry, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan
| | - Amaia Zurutuza
- Graphenea Semiconductor SLU, Mikeletegi Pasealekua 83, San Sebastián, 20009, Spain
| | - Roman Sordan
- L-NESS, Department of Physics, Politecnico di Milano, Via Anzani 42, Como, 22100, Italy
| | - Kannan Balasubramanian
- School of Analytical Sciences Adlershof (SALSA), IRIS Adlershof & Department of Chemistry, Humboldt-Universität zu Berlin, Unter den Linden 6, 10099, Berlin, Germany
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2
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Lu SM, Vannoy KJ, Dick JE, Long YT. Multiphase Chemistry under Nanoconfinement: An Electrochemical Perspective. J Am Chem Soc 2023; 145:25043-25055. [PMID: 37934860 DOI: 10.1021/jacs.3c07374] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Most relevant systems of interest to modern chemists rarely consist of a single phase. Real-world problems that require a rigorous understanding of chemical reactivity in multiple phases include the development of wearable and implantable biosensors, efficient fuel cells, single cell metabolic characterization techniques, and solar energy conversion devices. Within all of these systems, confinement effects at the nanoscale influence the chemical reaction coordinate. Thus, a fundamental understanding of the nanoconfinement effects of chemistry in multiphase environments is paramount. Electrochemistry is inherently a multiphase measurement tool reporting on a charged species traversing a phase boundary. Over the past 50 years, electrochemistry has witnessed astounding growth. Subpicoampere current measurements are routine, as is the study of single molecules and nanoparticles. This Perspective focuses on three nanoelectrochemical techniques to study multiphase chemistry under nanoconfinement: stochastic collision electrochemistry, single nanodroplet electrochemistry, and nanopore electrochemistry.
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Affiliation(s)
- Si-Min Lu
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P.R. China
| | - Kathryn J Vannoy
- Department of Chemistry, Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Jeffrey E Dick
- Department of Chemistry, Elmore Family School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Yi-Tao Long
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, P.R. China
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Godeffroy L, Shkirskiy V, Noël JM, Lemineur JF, Kanoufi F. Fuelling electrocatalysis at a single nanoparticle by ion flow in a nanoconfined electrolyte layer. Faraday Discuss 2023; 246:441-465. [PMID: 37427498 DOI: 10.1039/d3fd00032j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
We explore the possibility of coupling the transport of ions and water in a nanochannel with the chemical transformation of a reactant at an individual catalytic nanoparticle (NP). Such configuration could be interesting for constructing artificial photosynthesis devices coupling the asymmetric production of ions at the catalytic NP, with the ion selectivity of the nanochannels acting as ion pumps. Herein we propose to observe how such ion pumping can be coupled to an electrochemical reaction operated at the level of an individual electrocatalytic Pt NP. This is achieved by confining a (reservoir) droplet of electrolyte to within a few micrometres away from an electrocatalytic Pt NP on an electrode. While the region of the electrode confined by the reservoir and the NP are cathodically polarised, operando optical microscopy reveals the growth of an electrolyte nanodroplet on top of the NP. This suggests that the electrocatalysis of the oxygen reduction reaction operates at the NP and that an electrolyte nanochannel is formed - acting as an ion pump - between the reservoir and the NP. We have described here the optically imaged phenomena and their relevance to the characterization of the electrolyte nanochannel linking the NPs to the electrolyte microreservoir. Additionally, we have addressed the capacity of the nanochannel to transport ions and solvent flow to the NP.
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Affiliation(s)
| | | | - Jean-Marc Noël
- Université Paris Cité, CNRS, ITODYS, F-75013 Paris, France.
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4
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Levey KJ, Edwards MA, White HS, Macpherson JV. Simulation of the cyclic voltammetric response of an outer-sphere redox species with inclusion of electrical double layer structure and ohmic potential drop. Phys Chem Chem Phys 2023; 25:7832-7846. [PMID: 36857676 DOI: 10.1039/d3cp00098b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A finite-element model has been developed to simulate the cyclic voltammetric (CV) response of a planar electrode for a 1e outer-sphere redox process, which fully accounts for cell electrostatics, including ohmic potential drop, ion migration, and the structure of the potential-dependent electric double layer. Both reversible and quasi-reversible redox reactions are treated. The simulations compute the time-dependent electric potential and ion distributions across the entire cell during a voltammetric scan. In this way, it is possible to obtain the interdependent faradaic and non-faradaic contributions to a CV and rigorously include all effects of the electric potential distribution on the rate of electron transfer and the local concentrations of the redox species Oz and Rz-1. Importantly, we demonstrate that the driving force for electron transfer can be different to the applied potential when electrostatic interactions are included. We also show that the concentrations of Oz and Rz-1 at the plane of electron transfer (PET) significantly depart from those predicted by the Nernst equation, even when the system is characterised by fast electron transfer/diffusion control. A mechanistic rationalisation is also presented as to why the electric double layer has a negligible effect on the CV response of such reversible systems. In contrast, for quasi-reversible electron transfer the concentrations of redox species at the PET are shown to play an important role in determining CV wave shape, an effect also dependant on the charge of the redox species and the formal electrode potential of the redox couple. Failure to consider electrostatic effects could lead to incorrect interpretation of electron-transfer kinetics from the CV response. Simulated CVs at scan rates between 0.1 and 1000 V s-1 are found to be in good agreement with experimental data for the reduction of 1.0 mM Ru(NH3)63+ at a 2 mm diameter gold disk electrode in 1.0 M potassium nitrate.
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Affiliation(s)
- Katherine J Levey
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK. .,Centre for Diamond Science and Technology, University of Warwick, Coventry, CV4 7AL, UK
| | - Martin A Edwards
- Department of Chemistry & Biochemistry, University of Arkansas, Fayetteville, AR 72701, USA
| | - Henry S White
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, UT 84112, USA.
| | - Julie V Macpherson
- Department of Chemistry, University of Warwick, Coventry, CV4 7AL, UK. .,Centre for Diamond Science and Technology, University of Warwick, Coventry, CV4 7AL, UK
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Weiß LJK, Music E, Rinklin P, Banzet M, Mayer D, Wolfrum B. On-Chip Electrokinetic Micropumping for Nanoparticle Impact Electrochemistry. Anal Chem 2022; 94:11600-11609. [PMID: 35900877 DOI: 10.1021/acs.analchem.2c02017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Single-entity electrochemistry is a powerful technique to study the interactions of nanoparticles at the liquid-solid interface. In this work, we exploit Faradaic (background) processes in electrolytes of moderate ionic strength to evoke electrokinetic transport and study its influence on nanoparticle impacts. We implemented an electrode array comprising a macroscopic electrode that surrounds a set of 62 spatially distributed microelectrodes. This configuration allowed us to alter the global electrokinetic transport characteristics by adjusting the potential at the macroscopic electrode, while we concomitantly recorded silver nanoparticle impacts at the microscopic detection electrodes. By focusing on temporal changes of the impact rates, we were able to reveal alterations in the macroscopic particle transport. Our findings indicate a potential-dependent micropumping effect. The highest impact rates were obtained for strongly negative macroelectrode potentials and alkaline solutions, albeit also positive potentials lead to an increase in particle impacts. We explain this finding by reversal of the pumping direction. Variations in the electrolyte composition were shown to play a critical role as the macroelectrode processes can lead to depletion of ions, which influences both the particle oxidation and the reactions that drive the transport. Our study highlights that controlled on-chip micropumping is possible, yet its optimization is not straightforward. Nevertheless, the utilization of electro- and diffusiokinetic transport phenomena might be an appealing strategy to enhance the performance in future impact-based sensing applications.
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Affiliation(s)
- Lennart J K Weiß
- Neuroelectronics - Munich Institute of Biomedical Engineering, Department of Electrical Engineering, TUM School of Computation, Information and Technology, Technical University of Munich, Boltzmannstrasse 11, Garching 85748, Germany
| | - Emir Music
- Neuroelectronics - Munich Institute of Biomedical Engineering, Department of Electrical Engineering, TUM School of Computation, Information and Technology, Technical University of Munich, Boltzmannstrasse 11, Garching 85748, Germany
| | - Philipp Rinklin
- Neuroelectronics - Munich Institute of Biomedical Engineering, Department of Electrical Engineering, TUM School of Computation, Information and Technology, Technical University of Munich, Boltzmannstrasse 11, Garching 85748, Germany
| | - Marko Banzet
- Institute of Biological Information Processing, Bioelectronics (IBI-3), Forschungszentrum Jülich, Jülich 52425, Germany
| | - Dirk Mayer
- Institute of Biological Information Processing, Bioelectronics (IBI-3), Forschungszentrum Jülich, Jülich 52425, Germany
| | - Bernhard Wolfrum
- Neuroelectronics - Munich Institute of Biomedical Engineering, Department of Electrical Engineering, TUM School of Computation, Information and Technology, Technical University of Munich, Boltzmannstrasse 11, Garching 85748, Germany
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6
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Jaugstetter M, Blanc N, Kratz M, Tschulik K. Electrochemistry under confinement. Chem Soc Rev 2022; 51:2491-2543. [PMID: 35274639 DOI: 10.1039/d1cs00789k] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Although the term 'confinement' regularly appears in electrochemical literature, elevated by continuous progression in the research of nanomaterials and nanostructures, up until today the various aspects of confinement considered in electrochemistry are rather scattered individual contributions outside the established disciplines in this field. Thanks to a number of highly original publications and the growing appreciation of confinement as an overarching link between different exciting new research strategies, 'electrochemistry under confinement' is the process of forming a research discipline of its own. To aid the development a coherent terminology and joint basic concepts, as crucial factors for this transformation, this review provides an overview on the different effects on electrochemical processes known to date that can be caused by confinement. It also suggests where boundaries to other effects, such as nano-effects could be drawn. To conceptualize the vast amount of research activities revolving around the main concepts of confinement, we define six types of confinement and select two of them to discuss the state of the art and anticipated future developments in more detail. The first type concerns nanochannel environments and their applications for electrodeposition and for electrochemical sensing. The second type covers the rather newly emerging field of colloidal single entity confinement in electrochemistry. In these contexts, we will for instance address the influence of confinement on the mass transport and electric field distributions and will link the associated changes in local species concentration or in the local driving force to altered reaction kinetics and product selectivity. Highlighting pioneering works and exciting recent developments, this educational review does not only aim at surveying and categorizing the state-of-the-art, but seeks to specifically point out future perspectives in the field of confinement-controlled electrochemistry.
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Affiliation(s)
- Maximilian Jaugstetter
- Analytical Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany.
| | - Niclas Blanc
- Analytical Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany.
| | - Markus Kratz
- Analytical Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany.
| | - Kristina Tschulik
- Analytical Chemistry II, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Bochum, Germany.
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7
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A direct comparison of 2D versus 3D diffusion analysis at nanowire electrodes: A finite element analysis and experimental study. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.139890] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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8
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Wang Z, Ma R, Meng Q, Yang Y, Ma X, Ruan X, Yuan Y, Zhu G. Constructing Uranyl-Specific Nanofluidic Channels for Unipolar Ionic Transport to Realize Ultrafast Uranium Extraction. J Am Chem Soc 2021; 143:14523-14529. [PMID: 34482686 DOI: 10.1021/jacs.1c02592] [Citation(s) in RCA: 53] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
High-speed capturing of uranyl (UO22+) ions from seawater elicits unprecedented interest for the sustainable development of the nuclear energy industry. However, the ultralow concentration (∼3.3 μg L-1) of uranium element leads to the slow ion diffusion inside the adsorbent particle, especially after the transfer paths are occupied by the coexisted interfering ions. Considering the geometric dimension of UO22+ ion (a maximum length of 6.04-6.84 Å), the interlayer spacing of graphene sheets was covalently pillared with phenyl-based units into twice the ionic length (13 Å) to obtain uranyl-specific nanofluidic channels. Applying a negative potential (-1.3 V), such a charge-governed region facilitates a unipolar ionic transport, where cations are greatly accelerated and co-ions are repelled. Notably, the resulting adsorbent gives the highest adsorption velocity among all reported materials. The adsorption capacity measured after 56 days of exposure in natural seawater is evaluated to be ∼16 mg g-1. This novel concept with rapid adsorption, high capacity, and facile operating process shows great promise to implement in real-world uranium extraction.
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Affiliation(s)
- Zeyu Wang
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Rongchen Ma
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Qinghao Meng
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Yajie Yang
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Xujiao Ma
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Xianghui Ruan
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Ye Yuan
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
| | - Guangshan Zhu
- Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education, Northeast Normal University, Changchun 130012, China
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9
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Sopoušek J, Věžník J, Houser J, Skládal P, Lacina K. Crucial factors governing the electrochemical impedance on protein-modified surfaces. Electrochim Acta 2021. [DOI: 10.1016/j.electacta.2021.138616] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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10
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Baek S, Kwon SR, Fu K, Bohn PW. Ion Gating in Nanopore Electrode Arrays with Hierarchically Organized pH-Responsive Block Copolymer Membranes. ACS APPLIED MATERIALS & INTERFACES 2020; 12:55116-55124. [PMID: 33222437 DOI: 10.1021/acsami.0c12926] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Inspired by biological ion channels, artificial nanopore-based architectures have been developed for smart ion/molecular transport control with potential applications to iontronics and energy conversion. Advances in nanofabrication technology enable simple, versatile construction methods, and post-fabrication functionalization delivers nanochannels with unique ion transport-control attributes. Here, we characterize a pH-responsive, charge-selective dual-gating block copolymer (BCP) membrane composed of polystyrene-b-poly(4-vinylpyridine) (PS48400-b-P4VP21300), capable of self-organizing into highly ordered nanocylindrical domains. Because the PS-b-P4VP membrane exhibits pH-dependent structural transitions, it is suitable for designing intelligent pH-gated biomimetic channels, for example, exhibiting on-off transport switching at pH values near the pKa of P4VP with excellent anion permselectivity at pH < pKa. Introducing the BCP membrane onto nanopore electrode arrays (BCP@NEAs) allows the BCP to serve as a pH-responsive gate controlling ion transfer into the NEA nanopores. Such selectively transported and confined ions are detected by using a 100 nm gap dual-ring nanoelectrode structure capable of enhancing current output by efficient redox cycling with an amplification factor >102. In addition, BCP@NEAs exhibit extraordinary pH-gated ion selectivity, resulting in a 3380-fold current difference between anion and cation probes at pH 3.0. This hierarchically organized BCP-gated NEA system can serve as a template for the development of other stimulus-responsive ion gates, for example, those based on temperature and ligand gating, thus exploiting the intrinsic advantages of NEAs, such as enhanced sensitivity based on redox cycling, which may lead to technological applications such as engineered biosensors and iontronic devices.
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Affiliation(s)
- Seol Baek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Seung-Ryong Kwon
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Kaiyu Fu
- Department of Radiology, Stanford University, Stanford, California 94306, United States
- Department of Electrical Engineering, Stanford University, Stanford, California 94306, United States
| | - Paul W Bohn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
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11
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Abstract
We present the results of acid–base experiments performed at the single ion (H+ or OH−) limit in ∼6 aL volume nanopores incorporating electrochemical zero-mode waveguides (E-ZMWs). At pH 3 each E-ZMW nanopore contains ca. 3600H+ ions, and application of a negative electrochemical potential to the gold working electrode/optical cladding layer reduces H+ to H2, thereby depleting H+ and increasing the local pH within the nanopore. The change in pH was quantified by tracking the intensity of fluorescein, a pH-responsive fluorophore whose intensity increases with pH. This behavior was translated to the single ion limit by changing the initial pH of the electrolyte solution to pH 6, at which the average pore occupancy 〈n〉pore ∼3.6H+/nanopore. Application of an electrochemical potential sufficiently negative to change the local pH to pH 7 reduces the proton nanopore occupancy to 〈n〉pore ∼0.36H+/nanopore, demonstrating that the approach is sensitive to single H+ manipulations, as evidenced by clear potential-dependent changes in fluorescein emission intensity. In addition, at high overpotential, the observed fluorescence intensity exceeded the value predicted from the fluorescence intensity-pH calibration, an observation attributed to the nucleation of H2 nanobubbles as confirmed both by calculations and the behavior of non-pH responsive Alexa 488 fluorophore. Apart from enhancing fundamental understanding, the approach described here opens the door to applications requiring ultrasensitive ion sensing, based on the optical detection of H+ population at the single ion limit. Visualizing dynamic change in the number of protons during electroreduction of protons in attoliter volume zero-mode waveguides.![]()
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Affiliation(s)
- Vignesh Sundaresan
- Department of Chemical and Biomolecular Engineering, University of Notre Dame Notre Dame IN 46556 USA
| | - Paul W Bohn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame Notre Dame IN 46556 USA .,Department of Chemistry and Biochemistry, University of Notre Dame Notre Dame IN 46556 USA
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13
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Fu K, Kwon SR, Han D, Bohn PW. Single Entity Electrochemistry in Nanopore Electrode Arrays: Ion Transport Meets Electron Transfer in Confined Geometries. Acc Chem Res 2020; 53:719-728. [PMID: 31990518 PMCID: PMC8020881 DOI: 10.1021/acs.accounts.9b00543] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Electrochemical measurements conducted in confined volumes provide a powerful and direct means to address scientific questions at the nexus of nanoscience, biotechnology, and chemical analysis. How are electron transfer and ion transport coupled in confined volumes and how does understanding them require moving beyond macroscopic theories? Also, how do these coupled processes impact electrochemical detection and processing? We address these questions by studying a special type of confined-volume architecture, the nanopore electrode array, or NEA, which is designed to be commensurate in size with physical scaling lengths, such as the Debye length, a concordance that offers performance characteristics not available in larger scale structures.The experiments described here depend critically on carefully constructed nanoscale architectures that can usefully control molecular transport and electrochemical reactivity. We begin by considering the experimental constraints that guide the design and fabrication of zero-dimensional nanopore arrays with multiple embedded electrodes. These zero-dimensional structures are nearly ideal for exploring how permselectivity and unscreened ion migration can be combined to amplify signals and improve selectivity by enabling highly efficient redox cycling. Our studies also highlight the benefits of arrays, in that molecules escaping from a single nanopore are efficiently captured by neighboring pores and returned to the population of active redox species being measured, benefits that arise from coupling ion accumulation and migration. These tools for manipulating redox species are well-positioned to explore single molecule and single particle electron transfer events through spectroelectrochemistry, studies which are enabled by the electrochemical zero-mode waveguide (ZMW), a special hybrid nanophotonic/nanoelectronic architecture in which the lower ring electrode of an NEA nanopore functions both as a working electrode to initiate electron transfer reactions and as the optical cladding layer of a ZMW. While the work described here is largely exploratory and fundamental, we believe that the development of NEAs will enable important applications that emerge directly from the unique coupled transport and electron-transfer capabilities of NEAs, including in situ molecular separation and detection with external stimuli, redox-based electrochemical rectification in individually encapsulated nanopores, and coupled sorters and analyzers for nanoparticles.
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Affiliation(s)
- Kaiyu Fu
- Department of Radiology, Stanford University, Stanford, CA, 94306
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94306
| | - Seung-Ryong Kwon
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556
| | - Donghoon Han
- Department of Chemistry, The Catholic University of Korea, Bucheon, Gyeonggi-do, 14662 Republic of Korea
| | - Paul W. Bohn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556
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14
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Sassa F, Biswas GC, Suzuki H. Microfabricated electrochemical sensing devices. LAB ON A CHIP 2020; 20:1358-1389. [PMID: 32129358 DOI: 10.1039/c9lc01112a] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Electrochemistry provides possibilities to realize smart microdevices of the next generation with high functionalities. Electrodes, which constitute major components of electrochemical devices, can be formed by various microfabrication techniques, and integration of the same (or different) components for that purpose is not difficult. Merging this technique with microfluidics can further expand the areas of application of the resultant devices. To augment the development of next generation devices, it will be beneficial to review recent technological trends in this field and clarify the directions required for moving forward. Even when limiting the discussion to electrochemical microdevices, a variety of useful techniques should be considered. Therefore, in this review, we attempted to provide an overview of all relevant techniques in this context in the hope that it can provide useful comprehensive information.
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Affiliation(s)
- Fumihiro Sassa
- Graduate School of Information Science and Electrical Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
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15
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The Sealing Step in Aluminum Anodizing: A Focus on Sustainable Strategies for Enhancing Both Energy Efficiency and Corrosion Resistance. COATINGS 2020. [DOI: 10.3390/coatings10030226] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Increasing demands for environmental accountability and energy efficiency in industrial practice necessitates significant modification(s) of existing technologies and development of new ones to meet the stringent sustainability demands of the future. Generally, development of required new technologies and appropriate modifications of existing ones need to be premised on in-depth appreciation of existing technologies, their limitations, and desired ideal products or processes. In the light of these, published literature mostly in the past 30 years on the sealing process; the second highest energy consuming step in aluminum anodization and a step with significant environmental impacts has been critical reviewed in this systematic review. Emphasis have been placed on the need to reduce both the energy input in the anodization process and environmental implications. The implications of the nano-porous structure of the anodic oxide on mass transport and chemical reactivity of relevant species during the sealing process is highlighted with a focus on exploiting these peculiarities, in improving the quality of sealed products. In addition, perspective is provided on plausible approaches and important factors to be considered in developing sealing procedures that can minimize the energy input and environmental impact of the sealing step, and ensure a more sustainable aluminum anodization process/industry.
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16
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Kostiuchenko Z, Cui JZ, Lemay SG. Electrochemistry in Micro- and Nanochannels Controlled by Streaming Potentials. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2020; 124:2656-2663. [PMID: 32030113 PMCID: PMC6996092 DOI: 10.1021/acs.jpcc.9b08584] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/20/2019] [Indexed: 06/10/2023]
Abstract
Fluid and charge transport in micro- and nanoscale fluidic systems are intrinsically coupled via electrokinetic phenomena. While electroosmotic flows and streaming potentials are well understood for externally imposed stimuli, charge injection at electrodes localized inside fluidic systems via electrochemical processes remains to a large degree unexplored. Here, we employ ultramicroelectrodes and nanogap electrodes to study the subtle interplay between ohmic drops, streaming currents, and faradaic processes in miniaturized channels at low concentrations of supporting electrolyte. We show that electroosmosis can, under favorable circumstances, counteract the effect of ohmic losses and shift the apparent formal potential of redox reactions. This interplay can be described by simple circuit models, such that the results described here can be adapted to other micro- and nanofluidic electrochemical systems.
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17
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Edwards MA, Robinson DA, Ren H, Cheyne CG, Tan CS, White HS. Nanoscale electrochemical kinetics & dynamics: the challenges and opportunities of single-entity measurements. Faraday Discuss 2019; 210:9-28. [PMID: 30264833 DOI: 10.1039/c8fd00134k] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The development of nanoscale electrochemistry since the mid-1980s has been predominately coupled with steady-state voltammetric (i-E) methods. This research has been driven by the desire to understand the mechanisms of very fast electrochemical reactions, by electroanalytical measurements in small volumes and unusual media, including in vivo measurements, and by research on correlating electrocatalytic activity, e.g., O2 reduction reaction, with nanoparticle size and structure. Exploration of the behavior of nanoelectrochemical structures (nanoelectrodes, nanoparticles, nanogap cells, etc.) of a characteristic dimension λ using steady-state i-E methods generally relies on the well-known relationship, λ2 ∼ Dt, which relates diffusional lengths to time, t, through the coefficient, D. Decreasing λ, by performing measurements at a nanometric length scales, results in a decrease in the effective timescale of the measurement, and provides a direct means to probe the kinetics of steps associated with very rapid electrochemical reactions. For instance, steady-state voltammetry using a nanogap twin-electrode cell of characteristic width, λ ∼ 10 nm, allows investigations of events occurring at timescales on the order of ∼100 ns. Among many other advantages, decreasing λ also increases spatial resolution in electrochemical imaging, e.g., in scanning electrochemical microscopy, and allows probing of the electric double layer. This Introductory Lecture traces the evolution and driving forces behind the "λ2 ∼ Dt" steady-state approach to nanoscale electrochemistry, beginning in the late 1950s with the introduction of the rotating ring-disk electrode and twin-electrode thin-layer cells, and evolving to current-day investigations using nanoelectrodes, scanning nanocells for imaging, nanopores, and nanoparticles. The recent focus on so-called "single-entity" electrochemistry, in which individual and very short redox events are probed, is a significant departure from the steady-state approach, but provides new opportunities to probe reaction dynamics. The stochastic nature of very fast single-entity events challenges current electrochemical methods and modern electronics, as illustrated using recent experiments from the authors' laboratory.
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Affiliation(s)
- M A Edwards
- Department of Chemistry, University of Utah, 315 South 1400 East, Salt Lake City, Utah 84112-0850, USA.
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Al-Kutubi H, Voci S, Rassaei L, Sojic N, Mathwig K. Enhanced annihilation electrochemiluminescence by nanofluidic confinement. Chem Sci 2018; 9:8946-8950. [PMID: 30647886 PMCID: PMC6301198 DOI: 10.1039/c8sc03209b] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 09/30/2018] [Indexed: 12/30/2022] Open
Abstract
The generation of stable enhanced light emission by electrochemiluminescence in microfabricated nanofluidic electrochemical devices is demonstrated for the first time by exploiting nanogap amplification.
Microfabricated nanofluidic electrochemical devices offer a highly controlled nanochannel geometry; they confine the volume of chemical reactions to the nanoscale and enable greatly amplified electrochemical detection. Here, the generation of stable light emission by electrochemiluminescence (ECL) in transparent nanofluidic devices is demonstrated for the first time by exploiting nanogap amplification. Through continuous oxidation and reduction of [Ru(bpy)3]2+ luminophores at electrodes positioned at opposite walls of a 100 nm nanochannel, we compare classic redox cycling and ECL annihilation. Enhanced ECL light emission of attomole luminophore quantities is evidenced under ambient conditions due to the spatial confinement in a 10 femtoliter volume, resulting in a short diffusion timescale and highly efficient ECL reaction pathways at the nanoscale.
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Affiliation(s)
- Hanan Al-Kutubi
- University of Groningen , Groningen Research Institute of Pharmacy , Pharmaceutical Analysis , P.O. Box 196 , 9700 AD Groningen , The Netherlands .
| | - Silvia Voci
- University of Bordeaux , Bordeaux INP , Institut des Sciences Moléculaires , UMR CNRS 5255 , 33607 Pessac , France .
| | - Liza Rassaei
- Rotterdam School of Management , Erasmus University , Burgemeester Oudlaan 50 , 3062 PA Rotterdam , The Netherlands.,Delft University of Technology , Van der Maasweg 9 , 2629 HZ Delft , The Netherlands
| | - Neso Sojic
- University of Bordeaux , Bordeaux INP , Institut des Sciences Moléculaires , UMR CNRS 5255 , 33607 Pessac , France .
| | - Klaus Mathwig
- University of Groningen , Groningen Research Institute of Pharmacy , Pharmaceutical Analysis , P.O. Box 196 , 9700 AD Groningen , The Netherlands .
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Fu K, Han D, Kwon SR, Bohn PW. Asymmetric Nafion-Coated Nanopore Electrode Arrays as Redox-Cycling-Based Electrochemical Diodes. ACS NANO 2018; 12:9177-9185. [PMID: 30080388 DOI: 10.1021/acsnano.8b03751] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Inspired by the functioning of cellular ion channels, pore-based structures with nanoscale openings have been fabricated and integrated into ionic circuits, for example, ionic diodes and transistors, for signal processing and detection. In these systems, the nonlinear current responses arise either because asymmetric nanopore geometries break the symmetry of the ion distribution, creating unequal surface charge across the nanopore, or by coupling unidirectional electron transfer within a nanopore electrode. Here we develop a high-performance redox-cycling-based electrochemical diode by coating an asymmetric ion-exchange membrane, that is, Nafion, on the top surface of a nanopore electrode array (Nafion@NEA), in which each pore in the array exhibits one or more annular electrodes. Nafion@NEAs exhibit highly sensitive and charge-selective electroanalytical measurements due to efficient redox-cycling reaction, the permselectivity of Nafion, and the strong confinement of redox species in the nanopore array. In addition, the top electrode of dual-electrode Nafion@NEAs can serve as a voltage-controlled switch to gate ion transport within the nanopore. Thus Nafion@NEAs can be operated as a diode by switching voltages applied to the top and bottom electrodes of the NEA, leading to a large rectification ratio, fast response times, and simplified circuitry without the need for external electrodes. By taking advantage of closely spaced and individually addressable electrodes, the redox-cycling electrochemical diode has the potential for application to large-scale production and electrochemically controlled circuit operations, which go well beyond conventional electronic diodes or transistors.
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Affiliation(s)
- Kaiyu Fu
- Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Donghoon Han
- Department of Chemical and Biomolecular Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Seung-Ryong Kwon
- Department of Chemical and Biomolecular Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
| | - Paul W Bohn
- Department of Chemistry and Biochemistry , University of Notre Dame , Notre Dame , Indiana 46556 , United States
- Department of Chemical and Biomolecular Engineering , University of Notre Dame , Notre Dame , Indiana 46556 , United States
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20
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Fu K, Han D, Ma C, Bohn PW. Electrochemistry at single molecule occupancy in nanopore-confined recessed ring-disk electrode arrays. Faraday Discuss 2018; 193:51-64. [PMID: 27711896 DOI: 10.1039/c6fd00062b] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Electrochemical reactions at nanoscale structures possess unique characteristics, e.g. fast mass transport, high signal-to-noise ratio at low concentration, and insignificant ohmic losses even at low electrolyte concentrations. These properties motivate the fabrication of high density, laterally ordered arrays of nanopores, embedding vertically stacked metal-insulator-metal electrode structures and exhibiting precisely controlled pore size and interpore spacing for use in redox cycling. These nanoscale recessed ring-disk electrode (RRDE) arrays exhibit current amplification factors, AFRC, as large as 55-fold with Ru(NH3)62/3+, indicative of capture efficiencies at the top and bottom electrodes, Φt,b, exceeding 99%. Finite element simulations performed to investigate the concentration distribution of redox species and to assess operating characteristics are in excellent agreement with experiment. AFRC increases as the pore diameter, at constant pore spacing, increases in the range 200-500 nm and as the pore spacing, at constant pore diameter, decreases in the range 1000-460 nm. Optimized nanoscale RRDE arrays exhibit a linear current response with concentration ranging from 0.1 μM to 10 mM and a small capacitive current with scan rate up to 100 V s-1. At the lowest concentrations, the average pore occupancy is 〈n〉 ∼ 0.13 molecule establishing productive electrochemical signals at occupancies at and below the single molecule level in these nanoscale RRDE arrays.
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Affiliation(s)
- Kaiyu Fu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Donghoon Han
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Chaoxiong Ma
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
| | - Paul W Bohn
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA. and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, USA
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21
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Wang Y, Shan X, Tao N. Emerging tools for studying single entity electrochemistry. Faraday Discuss 2018; 193:9-39. [PMID: 27722354 DOI: 10.1039/c6fd00180g] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Electrochemistry studies charge transfer and related processes at various microscopic structures (atomic steps, islands, pits and kinks on electrodes), and mesoscopic materials (nanoparticles, nanowires, viruses, vesicles and cells) made by nature and humans, involving ions and molecules. The traditional approach measures averaged electrochemical quantities of a large ensemble of these individual entities, including the microstructures, mesoscopic materials, ions and molecules. There is a need to develop tools to study single entities because a real system is usually heterogeneous, e.g., containing nanoparticles with different sizes and shapes. Even in the case of "homogeneous" molecules, they bind to different microscopic structures of an electrode, assume different conformations and fluctuate over time, leading to heterogeneous reactions. Here we highlight some emerging tools for studying single entity electrochemistry, discuss their strengths and weaknesses, and provide personal views on the need for tools with new capabilities for further advancing single entity electrochemistry.
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Affiliation(s)
- Yixian Wang
- Center for Biosensors and Bioelectronics, Biodesign Institute and School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA.
| | - Xiaonan Shan
- Center for Biosensors and Bioelectronics, Biodesign Institute and School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA.
| | - Nongjian Tao
- Center for Biosensors and Bioelectronics, Biodesign Institute and School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, USA. and State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093, China
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22
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Fu K, Han D, Crouch GM, Kwon SR, Bohn PW. Voltage-Gated Nanoparticle Transport and Collisions in Attoliter-Volume Nanopore Electrode Arrays. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2018; 14:e1703248. [PMID: 29377558 PMCID: PMC8287793 DOI: 10.1002/smll.201703248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/28/2017] [Indexed: 06/07/2023]
Abstract
Single nanoparticle analysis can reveal how particle-to-particle heterogeneity affects ensemble properties derived from traditional bulk measurements. High-bandwidth, low noise electrochemical measurements are needed to examine the fast heterogeneous electron-transfer behavior of single nanoparticles with sufficient fidelity to resolve the behavior of individual nanoparticles. Herein, nanopore electrode arrays (NEAs) are fabricated in which each pore supports two vertically spaced, individually addressable electrodes. The top ring electrode serves as a particle gate to control the transport of silver nanoparticles (AgNPs) within individual attoliter volume NEAs nanopores, as shown by redox collisions of AgNPs collisions at the bottom disk electrode. The AgNP-nanoporeis system has wide-ranging technological applications as well as fundamental interest, since the transport of AgNPs within the NEA mimics the transport of ions through cell membranes via voltage-gated ion channels. A voltage threshold is observed above which AgNPs are able to access the bottom electrode of the NEAs, i.e., a minimum potential at the gate electrode is required to switch between few and many observed collision events on the collector electrode. It is further shown that this threshold voltage is strongly dependent on the applied voltage at both electrodes as well as the size of AgNPs, as shown both experimentally and through finite-element modeling. Overall, this study provides a precise method of monitoring nanoparticle transport and in situ redox reactions within nanoconfined spaces at the single particle level.
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Affiliation(s)
- Kaiyu Fu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, US
| | - Donghoon Han
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, US
| | - Garrison M. Crouch
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, US
| | - Seung-Ryong Kwon
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, IN 46556, US
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23
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Fu K, Bohn PW. Nanopore Electrochemistry: A Nexus for Molecular Control of Electron Transfer Reactions. ACS CENTRAL SCIENCE 2018; 4:20-29. [PMID: 29392173 PMCID: PMC5785767 DOI: 10.1021/acscentsci.7b00576] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Indexed: 05/12/2023]
Abstract
Pore-based structures occur widely in living organisms. Ion channels embedded in cell membranes, for example, provide pathways, where electron and proton transfer are coupled to the exchange of vital molecules. Learning from mother nature, a recent surge in activity has focused on artificial nanopore architectures to effect electrochemical transformations not accessible in larger structures. Here, we highlight these exciting advances. Starting with a brief overview of nanopore electrodes, including the early history and development of nanopore sensing based on nanopore-confined electrochemistry, we address the core concepts and special characteristics of nanopores in electron transfer. We describe nanopore-based electrochemical sensing and processing, discuss performance limits and challenges, and conclude with an outlook for next-generation nanopore electrode sensing platforms and the opportunities they present.
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Affiliation(s)
- Kaiyu Fu
- Department
of Chemistry and Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Paul W. Bohn
- Department
of Chemistry and Biochemistry and Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- E-mail: . Tel: +1 574 631 1849. Fax: +1 574 631 8366
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24
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Wang Y, Narayanan SR, Wu W. Field-Assisted Splitting of Pure Water Based on Deep-Sub-Debye-Length Nanogap Electrochemical Cells. ACS NANO 2017; 11:8421-8428. [PMID: 28686412 DOI: 10.1021/acsnano.7b04038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Owing to the low conductivity of pure water, using an electrolyte is common for achieving efficient water electrolysis. In this paper, we have fundamentally broken through this common sense by using deep-sub-Debye-length nanogap electrochemical cells to achieve efficient electrolysis of pure water (without any added electrolyte) at room temperature. A field-assisted effect resulted from overlapped electrical double layers can greatly enhance water molecules ionization and mass transport, leading to electron-transfer limited reactions. We have named this process "virtual breakdown mechanism" (which is completely different from traditional mechanisms) that couples the two half-reactions together, greatly reducing the energy losses arising from ion transport. This fundamental discovery has been theoretically discussed in this paper and experimentally demonstrated in a group of electrochemical cells with nanogaps between two electrodes down to 37 nm. On the basis of our nanogap electrochemical cells, the electrolysis current density from pure water can be significantly larger than that from 1 mol/L sodium hydroxide solution, indicating the much better performance of pure water splitting as a potential for on-demand clean hydrogen production.
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Affiliation(s)
- Yifei Wang
- Ming Hsieh Department of Electrical Engineering, and ‡Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
| | - S R Narayanan
- Ming Hsieh Department of Electrical Engineering, and ‡Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
| | - Wei Wu
- Ming Hsieh Department of Electrical Engineering, and ‡Department of Chemistry, University of Southern California , Los Angeles, California 90089, United States
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25
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Fu K, Bohn PW. Nanochannel Arrays for Molecular Sieving and Electrochemical Analysis by Nanosphere Lithography Templated Graphoepitaxy of Block Copolymers. ACS APPLIED MATERIALS & INTERFACES 2017; 9:24908-24916. [PMID: 28661651 DOI: 10.1021/acsami.7b06794] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The ability to design, fabricate, and manipulate materials at the nanoscale is fundamental to the quest to develop technologies to assemble nanometer-scale pieces into larger-scale components and materials, thereby transferring unique nanometer-scale properties to macroscopic objects. In this work, we describe a new approach to the fabrication of highly ordered, ultrahigh density nanochannel arrays that employs nanosphere lithography to template the graphoepitaxy of polystyrene-polydimethylsiloxane, diblock copolymers. By optimizing the well-controlled solvent vapor annealing, overcoating conditions, and the subsequent reactive ion etching processes, silica nanochannel (SNC) arrays with areal densities, ρA, approaching 1000 elements μm-2, are obtained over macroscopic scales. The integrity and functionality of the SNC arrays was tested by using them as permselective ion barriers to nanopore-confined disk electrodes. The nanochannels allow cations to pass to the disk electrode but reject anions, as demonstrated by cyclic voltammetry. This ion gating behavior can be reversed from cation-permselective to anion-permselective by chemically inverting the surface charge from negative to positive. Furthermore, the conformal SNC array structures obtained could easily be lifted, detached, and transferred to another substrate, preserving the hierarchical organization while transferring the nanostructure-derived properties to a different substrate. These results demonstrate how nanoscale behavior can be replicated over macroscale distances, using electrochemical analysis as a model.
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Affiliation(s)
- Kaiyu Fu
- Department of Chemistry and Biochemistry and ‡Department of Chemical and Biomolecular Engineering, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Paul W Bohn
- Department of Chemistry and Biochemistry and ‡Department of Chemical and Biomolecular Engineering, University of Notre Dame , Notre Dame, Indiana 46556, United States
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26
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Jiang J, Zhang L. Nanostructured Platinum-iridium Alloy Microelectrode for Ammonia Determination. ELECTROANAL 2017. [DOI: 10.1002/elan.201700265] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Junhua Jiang
- Illinois Sustainable Technology Center; University of Illinois at Urbana-Champaign; IL 61820 USA
- Fuel Design and Development Department; Idaho National Laboratory, Idaho Falls; ID 83415 USA
| | - Lei Zhang
- Illinois Sustainable Technology Center; University of Illinois at Urbana-Champaign; IL 61820 USA
- Department of Electronics and Information Materials, School of Materials Science and Engineering; Shanghai University; Shanghai 200444 China
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27
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Fu K, Han D, Ma C, Bohn PW. Ion selective redox cycling in zero-dimensional nanopore electrode arrays at low ionic strength. NANOSCALE 2017; 9:5164-5171. [PMID: 28393950 DOI: 10.1039/c7nr00206h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Surface charge characteristics and the electrical double layer (EDL) effect govern the transport of ions into and out of nanopores, producing a permselective concentration polarization, which dominates the electrochemical response of nanoelectrodes in solutions of low ionic strength. In this study, highly ordered, zero-dimensional nanopore electrode arrays (NEAs), with each nanopore presenting a pair of recessed electrodes, were fabricated to couple EDL effects with redox cycling, thereby achieving electrochemical detection with improved sensitivity and selectivity. These NEAs exhibit current amplification as high as 55-fold due to the redox cycling effect, which can be further increased by ∼500-fold upon the removal of the supporting electrolyte. The effect of nanopore geometry, which is a key factor determining the magnitude of the EDL effect, is fully characterized, as is the effect of the magnitude and sign of the charge of the redox-active species. The observed changes in limiting current with the concentration of the supporting electrolyte confirm the accumulation of cations and repulsion of anions in NEAs presenting negative surface charge. Exploiting this principle, dopamine was selectively determined in the presence of a 3000-fold excess of ascorbic acid within the NEA.
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Affiliation(s)
- Kaiyu Fu
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
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28
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Adly N, Feng L, Krause KJ, Mayer D, Yakushenko A, Offenhäusser A, Wolfrum B. Flexible Microgap Electrodes by Direct Inkjet Printing for Biosensing Application. ACTA ACUST UNITED AC 2017. [DOI: 10.1002/adbi.201600016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Nouran Adly
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
| | - Lingyan Feng
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
- Materials Genome Institute; Shanghai University; 200444 Shanghai China
| | - Kay J. Krause
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
| | - Dirk Mayer
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
| | - Alexey Yakushenko
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
| | - Andreas Offenhäusser
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
| | - Bernhard Wolfrum
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA - Fundamentals of Future Information Technology; Forschungszentrum Jülich; 52425 Jülich Germany
- Neuroelectronics; Munich School of Bioengineering; Department of Electrical and Computer Engineering; Technical University of Munich (TUM) & BCCN Munich; Boltzmannstrasse 11 85748 Garching Germany
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29
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ZHU X, HUANG M, LI J, HE H, ZHANG X, WANG S. A Novel Electrochemical Sensor Based on [Ru(NH<sub>3</sub>)<sub>6</sub>]Cl<sub>3</sub> as a Redox Indicator for the Detection of G-G Mismatched DNA. ANAL SCI 2017; 33:585-590. [DOI: 10.2116/analsci.33.585] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Affiliation(s)
- Xiaoqian ZHU
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
| | - Min HUANG
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
| | - Jiao LI
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
| | - Hanping HE
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University
| | - Xiuhua ZHANG
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University
| | - Shengfu WANG
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University
- Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Hubei University
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30
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Dual-Plate Gold-Gold Microtrench Electrodes for Generator-Collector Voltammetry without Supporting Electrolyte. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.11.103] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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31
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Adly NY, Bachmann B, Krause KJ, Offenhäusser A, Wolfrum B, Yakushenko A. Three-dimensional inkjet-printed redox cycling sensor. RSC Adv 2017. [DOI: 10.1039/c6ra27170g] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Electrochemical amplification through redox cycling in an all-inkjet-printed device utilizing four different functional inks.
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Affiliation(s)
- N. Y. Adly
- Institute of Bioelectronics (PGI-8/ICS-8)
- JARA—Fundamentals of Future Information Technology
- Forschungszentrum Jülich
- 52425 Jülich
- Germany
| | - B. Bachmann
- Neuroelectronics
- MSB
- Department of Electrical and Computer Engineering
- Technical University of Munich (TUM) & BCCN Munich
- Garching
| | - K. J. Krause
- Institute of Bioelectronics (PGI-8/ICS-8)
- JARA—Fundamentals of Future Information Technology
- Forschungszentrum Jülich
- 52425 Jülich
- Germany
| | - A. Offenhäusser
- Institute of Bioelectronics (PGI-8/ICS-8)
- JARA—Fundamentals of Future Information Technology
- Forschungszentrum Jülich
- 52425 Jülich
- Germany
| | - B. Wolfrum
- Institute of Bioelectronics (PGI-8/ICS-8)
- JARA—Fundamentals of Future Information Technology
- Forschungszentrum Jülich
- 52425 Jülich
- Germany
| | - A. Yakushenko
- Institute of Bioelectronics (PGI-8/ICS-8)
- JARA—Fundamentals of Future Information Technology
- Forschungszentrum Jülich
- 52425 Jülich
- Germany
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Redox cycling with ITO electrodes separated by an ultrathin silica nanochannel membrane. Electrochem commun 2016. [DOI: 10.1016/j.elecom.2016.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Wolfrum B, Kätelhön E, Yakushenko A, Krause KJ, Adly N, Hüske M, Rinklin P. Nanoscale Electrochemical Sensor Arrays: Redox Cycling Amplification in Dual-Electrode Systems. Acc Chem Res 2016; 49:2031-40. [PMID: 27602780 DOI: 10.1021/acs.accounts.6b00333] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Micro- and nanofabriation technologies have a tremendous potential for the development of powerful sensor array platforms for electrochemical detection. The ability to integrate electrochemical sensor arrays with microfluidic devices nowadays provides possibilities for advanced lab-on-a-chip technology for the detection or quantification of multiple targets in a high-throughput approach. In particular, this is interesting for applications outside of analytical laboratories, such as point-of-care (POC) or on-site water screening where cost, measurement time, and the size of individual sensor devices are important factors to be considered. In addition, electrochemical sensor arrays can monitor biological processes in emerging cell-analysis platforms. Here, recent progress in the design of disease model systems and organ-on-a-chip technologies still needs to be matched by appropriate functionalities for application of external stimuli and read-out of cellular activity in long-term experiments. Preferably, data can be gathered not only at a singular location but at different spatial scales across a whole cell network, calling for new sensor array technologies. In this Account, we describe the evolution of chip-based nanoscale electrochemical sensor arrays, which have been developed and investigated in our group. Focusing on design and fabrication strategies that facilitate applications for the investigation of cellular networks, we emphasize the sensing of redox-active neurotransmitters on a chip. To this end, we address the impact of the device architecture on sensitivity, selectivity as well as on spatial and temporal resolution. Specifically, we highlight recent work on redox-cycling concepts using nanocavity sensor arrays, which provide an efficient amplification strategy for spatiotemporal detection of redox-active molecules. As redox-cycling electrochemistry critically depends on the ability to miniaturize and integrate closely spaced electrode systems, the fabrication of suitable nanoscale devices is of utmost importance for the development of this advanced sensor technology. Here, we address current challenges and limitations, which are associated with different redox cycling sensor array concepts and fabrication approaches. State-of-the-art micro- and nanofabrication technologies based on optical and electron-beam lithography allow precise control of the device layout and have led to a new generation of electrochemical sensor architectures for highly sensitive detection. Yet, these approaches are often expensive and limited to clean-room compatible materials. In consequence, they lack possibilities for upscaling to high-throughput fabrication at moderate costs. In this respect, self-assembly techniques can open new routes for electrochemical sensor design. This is true in particular for nanoporous redox cycling sensor arrays that have been developed in recent years and provide interesting alternatives to clean-room fabricated nanofluidic redox cycling devices. We conclude this Account with a discussion of emerging fabrication technologies based on printed electronics that we believe have the potential of transforming current redox cycling concepts from laboratory tools for fundamental studies and proof-of-principle analytical demonstrations into high-throughput devices for rapid screening applications.
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Affiliation(s)
- Bernhard Wolfrum
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
- Neuroelectronics,
IMETUM, Department of Electrical and Computer Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching, Germany
| | - Enno Kätelhön
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Alexey Yakushenko
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Kay J. Krause
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Nouran Adly
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Martin Hüske
- Institute
of Bioelectronics (PGI-8/ICS-8), Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Philipp Rinklin
- Neuroelectronics,
IMETUM, Department of Electrical and Computer Engineering, Technical University of Munich, Boltzmannstr. 11, 85748 Garching, Germany
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