1
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Morikawa K, Takeuchi T, Kitamori T. Local nano-electrode fabrication utilizing nanofluidic and nano-electrochemical control. Electrophoresis 2024. [PMID: 38962855 DOI: 10.1002/elps.202300002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 05/23/2024] [Accepted: 06/19/2024] [Indexed: 07/05/2024]
Abstract
Miniaturized systems have attracted much attention with the recent advances in microfluidics and nanofluidics. From the capillary electrophoresis, the development of glass-based microfluidic and nanofluidic technologies has supported advances in microfluidics and nanofluidics. Most microfluidic systems, especially nanofluidic systems, are still simple, such as systems constructed with simple straight nanochannels and bulk-scale electrodes. One of the bottlenecks to the development of more complicated and sophisticated systems is to develop the locally integrated nano-electrodes. However, there are still issues with integrating nano-electrodes into nanofluidic devices because it is difficult to fit the nano-electrode size into a nanofluidic channel at the nanometer level. In this study, we propose a new method for the fabrication of local nano-electrodes in nanofluidic devices with nanofluidic and nano-electrochemistry-based experiments. An electroplating solution was introduced to a nanochannel with control of the flow and the electroplating reaction, by which nano-electrodes were successfully fabricated. In addition, a nanofluidic device was available for nanofluidic experiments with the application of 200 kPa. This method can be applied to any electroplating material such as gold and copper. The local nano-electrode will make a significant contribution to the development of more complicated and sophisticated nanofluidic electrophoresis systems and to local electric detection methods for various nanofluidic devices.
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Affiliation(s)
- Kyojiro Morikawa
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Tomoaki Takeuchi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo, Japan
| | - Takehiko Kitamori
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo, Japan
- Institute of Nanoengineering and Microsystems, Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan
- Collaborative Research Organization for Micro and Nano Multifunctional Devices, The University of Tokyo, Tokyo, Japan
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2
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Hoang Ngoc Minh T, Kim J, Pireddu G, Chubak I, Nair S, Rotenberg B. Electrical noise in electrolytes: a theoretical perspective. Faraday Discuss 2023; 246:198-224. [PMID: 37409620 DOI: 10.1039/d3fd00026e] [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
Seemingly unrelated experiments such as electrolyte transport through nanotubes, nano-scale electrochemistry, NMR relaxometry and surface force balance measurements, all probe electrical fluctuations: of the electric current, the charge and polarization, the field gradient (for quadrupolar nuclei) and the coupled mass/charge densities. The fluctuations of such various observables arise from the same underlying microscopic dynamics of the ions and solvent molecules. In principle, the relevant length and time scales of these dynamics are encoded in the dynamic structure factors. However, modelling the latter for frequencies and wavevectors spanning many orders of magnitude remains a great challenge to interpret the experiments in terms of physical processes such as solvation dynamics, diffusion, electrostatic and hydrodynamic interactions between ions, interactions with solid surfaces, etc. Here, we highlight the central role of the charge-charge dynamic structure factor in the fluctuations of electrical observables in electrolytes and offer a unifying perspective over a variety of complementary experiments. We further analyze this quantity in the special case of an aqueous NaCl electrolyte, using simulations with explicit ions and an explicit or implicit solvent. We discuss the ability of the standard Poisson-Nernst-Planck theory to capture the simulation results, and how the predictions can be improved. We finally discuss the contributions of ions and water to the total charge fluctuations. This work illustrates an ongoing effort towards a comprehensive understanding of electrical fluctuations in bulk and confined electrolytes, in order to enable experimentalists to decipher the microscopic properties encoded in the measured electrical noise.
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Affiliation(s)
- Thê Hoang Ngoc Minh
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
| | - Jeongmin Kim
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
| | - Giovanni Pireddu
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
| | - Iurii Chubak
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
| | - Swetha Nair
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France.
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
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3
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Hoang Ngoc Minh T, Rotenberg B, Marbach S. Ionic fluctuations in finite volumes: fractional noise and hyperuniformity. Faraday Discuss 2023; 246:225-250. [PMID: 37565454 DOI: 10.1039/d3fd00031a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Observing finite regions of a bigger system is a common aim, from microscopy to molecular simulations. In the latter especially, there is ongoing interest in predicting thermodynamic properties from tracking fluctuations in finite observation volumes. However, kinetic properties have received little attention, especially not in ionic solutions, where electrostatic interactions play a decisive role. Here, we probe ionic fluctuations in finite volumes with Brownian dynamics and build an analytical framework that reproduces our simulation results and is broadly applicable to other systems with pairwise interactions. Particle number and charge correlations exhibit a rich phenomenology with time, characterized by a diversity of timescales. The noise spectrum of both quantities decays as 1/f3/2, where f is the frequency. This signature of fractional noise shows the universality of 1/f3/2 scalings when observing diffusing particles in finite domains. The hyperuniform behaviour of charge fluctuations, namely that correlations scale with the area of the observation volume, is preserved in time. Correlations even become proportional to the box perimeter at sufficiently long times. Our results pave the way to understand fluctuations in more complex systems, from nanopores to single-particle electrochemistry.
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Affiliation(s)
- Thê Hoang Ngoc Minh
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
| | - Sophie Marbach
- Sorbonne Université, CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, F-75005 Paris, France
- Courant Institute of Mathematical Sciences, New York University, NY, 10012, USA.
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4
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Grall S, Li S, Jalabert L, Kim SH, Chovin A, Demaille C, Clément N. Electrochemical Shot Noise of a Redox Monolayer. PHYSICAL REVIEW LETTERS 2023; 130:218001. [PMID: 37295112 DOI: 10.1103/physrevlett.130.218001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 04/25/2023] [Indexed: 06/12/2023]
Abstract
Redox monolayers are the base for a wide variety of devices including high-frequency molecular diodes or biomolecular sensors. We introduce a formalism to describe the electrochemical shot noise of such a monolayer, confirmed experimentally at room temperature in liquid. The proposed method, carried out at equilibrium, avoids parasitic capacitance, increases the sensitivity, and allows us to obtain quantitative information such as the electronic coupling (or standard electron transfer rates), its dispersion, and the number of molecules. Unlike in solid-state physics, the homogeneity in energy levels and transfer rates in the monolayer yields a Lorentzian spectrum. This first step for shot noise studies in molecular electrochemical systems opens perspectives for quantum transport studies in a liquid environment at room temperature as well as highly sensitive measurements for bioelectrochemical sensors.
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Affiliation(s)
- Simon Grall
- IIS, LIMMS/CNRS-IIS IRL2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo, 153-8505, Japan
| | - Shuo Li
- IIS, LIMMS/CNRS-IIS IRL2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo, 153-8505, Japan
| | - Laurent Jalabert
- IIS, LIMMS/CNRS-IIS IRL2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo, 153-8505, Japan
| | - Soo Hyeon Kim
- IIS, LIMMS/CNRS-IIS IRL2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo, 153-8505, Japan
| | - Arnaud Chovin
- Université Paris Cité, CNRS, Laboratoire d'Electrochimie Moléculaire, F-75013 Paris, France
| | - Christophe Demaille
- Université Paris Cité, CNRS, Laboratoire d'Electrochimie Moléculaire, F-75013 Paris, France
| | - Nicolas Clément
- IIS, LIMMS/CNRS-IIS IRL2820, The University of Tokyo, 4-6-1 Komaba, Meguro-ku Tokyo, 153-8505, Japan
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5
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Hoang Ngoc Minh T, Stoltz G, Rotenberg B. Frequency and field-dependent response of confined electrolytes from Brownian dynamics simulations. J Chem Phys 2023; 158:104103. [PMID: 36922117 DOI: 10.1063/5.0139258] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Using Brownian dynamics simulations, we investigate the effects of confinement, adsorption on surfaces, and ion-ion interactions on the response of confined electrolyte solutions to oscillating electric fields in the direction perpendicular to the confining walls. Nonequilibrium simulations allows to characterize the transitions between linear and nonlinear regimes when varying the magnitude and frequency of the applied field, but the linear response, characterized by the frequency-dependent conductivity, is more efficiently predicted from the equilibrium current fluctuations. To that end, we (rederive and) use the Green-Kubo relation appropriate for overdamped dynamics, which differs from the standard one for Newtonian or underdamped Langevin dynamics. This expression highlights the contributions of the underlying Brownian fluctuations and of the interactions of the particles between them and with external potentials. Although already known in the literature, this relation has rarely been used to date, beyond the static limit to determine the effective diffusion coefficient or the DC conductivity. The frequency-dependent conductivity always decays from a bulk-like behavior at high frequency to a vanishing conductivity at low frequency due to the confinement of the charge carriers by the walls. We discuss the characteristic features of the crossover between the two regimes, most importantly how the crossover frequency depends on the confining distance and the salt concentration, and the fact that adsorption on the walls may lead to significant changes both at high and low frequencies. Conversely, our results illustrate the possibility to obtain information on diffusion between walls, charge relaxation, and adsorption by analyzing the frequency-dependent conductivity.
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Affiliation(s)
- Thê Hoang Ngoc Minh
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005 Paris, France
| | | | - Benjamin Rotenberg
- CNRS, Physicochimie des Électrolytes et Nanosystèmes Interfaciaux, Sorbonne Université, F-75005 Paris, France
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6
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Sarkar S, Nieuwenhuis AF, Lemay SG. Integrated Glass Microfluidics with Electrochemical Nanogap Electrodes. Anal Chem 2023; 95:4266-4270. [PMID: 36812004 PMCID: PMC9996602 DOI: 10.1021/acs.analchem.2c04257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We present a framework for the fabrication of chip-based electrochemical nanogap sensors integrated with microfluidics. Instead of polydimethylsiloxane (PDMS), SU-8 aided adhesive bonding of silicon and glass wafers is used to implement parallel flow control. The fabrication process permits wafer-scale production with high throughput and reproducibility. Additionally, the monolithic structures allow simple electrical and fluidic connections, alleviating the need for specialized equipment. We demonstrate the utility of these flow-incorporated nanogap sensors by performing redox cycling measurements under laminar flow conditions.
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Affiliation(s)
- Sahana Sarkar
- Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Ab F Nieuwenhuis
- Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
| | - Serge G Lemay
- Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands
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7
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Pireddu G, Rotenberg B. Frequency-Dependent Impedance of Nanocapacitors from Electrode Charge Fluctuations as a Probe of Electrolyte Dynamics. PHYSICAL REVIEW LETTERS 2023; 130:098001. [PMID: 36930930 DOI: 10.1103/physrevlett.130.098001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 02/03/2023] [Indexed: 06/18/2023]
Abstract
The frequency-dependent impedance is a fundamental property of electrical components. We show that it can be determined from the equilibrium dynamical fluctuations of the electrode charge in constant-potential molecular simulations, extending in particular a fluctuation-dissipation relation for the capacitance recovered in the low-frequency limit and provide an illustration on water-gold nanocapacitors. This Letter opens the way to the interpretation of electrochemical impedance measurements in terms of microscopic mechanisms, directly from the dynamics of the electrolyte, or indirectly via equivalent circuit models as in experiments.
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Affiliation(s)
- Giovanni Pireddu
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physico-chimie des Électrolytes et Nanosystèmes Interfaciaux, PHENIX, F-75005 Paris, France
- Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, 80039 Amiens Cedex, France
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8
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Fontana M, Ivanovaitė Š, Lindhoud S, van der Wijk E, Mathwig K, Berg WVD, Weijers D, Hohlbein J. Probing DNA - Transcription Factor Interactions Using Single-Molecule Fluorescence Detection in Nanofluidic Devices. Adv Biol (Weinh) 2022; 6:e2100953. [PMID: 34472724 DOI: 10.1002/adbi.202100953] [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: 05/14/2021] [Revised: 07/16/2021] [Indexed: 01/27/2023]
Abstract
Single-molecule fluorescence detection offers powerful ways to study biomolecules and their complex interactions. Here, nanofluidic devices and camera-based, single-molecule Förster resonance energy transfer (smFRET) detection are combined to study the interactions between plant transcription factors of the auxin response factor (ARF) family and DNA oligonucleotides that contain target DNA response elements. In particular, it is shown that the binding of the unlabeled ARF DNA binding domain (ARF-DBD) to donor and acceptor labeled DNA oligonucleotides can be detected by changes in the FRET efficiency and changes in the diffusion coefficient of the DNA. In addition, this data on fluorescently labeled ARF-DBDs suggest that, at nanomolar concentrations, ARF-DBDs are exclusively present as monomers. In general, the fluidic framework of freely diffusing molecules minimizes potential surface-induced artifacts, enables high-throughput measurements, and proved to be instrumental in shedding more light on the interactions between ARF-DBDs monomers and between ARF-DBDs and their DNA response element.
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Affiliation(s)
- Mattia Fontana
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Šarunė Ivanovaitė
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Simon Lindhoud
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Elmar van der Wijk
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Klaus Mathwig
- Groningen Research Institute of Pharmacy, Pharmaceutical Analysis, University of Groningen, P.O. Box 196, 9700 AD, Groningen, The Netherlands.,Stichting Imec Nederland within OnePlanet Research Center, Bronland 10, Wageningen, 6708 WH, The Netherlands
| | - Willy van den Berg
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
| | - Johannes Hohlbein
- Laboratory of Biochemistry, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands.,Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
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9
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Le THH, Shimizu H, Morikawa K. Advances in Label-Free Detections for Nanofluidic Analytical Devices. MICROMACHINES 2020; 11:mi11100885. [PMID: 32977690 PMCID: PMC7598655 DOI: 10.3390/mi11100885] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/20/2020] [Accepted: 09/21/2020] [Indexed: 12/12/2022]
Abstract
Nanofluidics, a discipline of science and engineering of fluids confined to structures at the 1-1000 nm scale, has experienced significant growth over the past decade. Nanofluidics have offered fascinating platforms for chemical and biological analyses by exploiting the unique characteristics of liquids and molecules confined in nanospaces; however, the difficulty to detect molecules in extremely small spaces hampers the practical applications of nanofluidic devices. Laser-induced fluorescence microscopy with single-molecule sensitivity has been so far a major detection method in nanofluidics, but issues arising from labeling and photobleaching limit its application. Recently, numerous label-free detection methods have been developed to identify and determine the number of molecules, as well as provide chemical, conformational, and kinetic information of molecules. This review focuses on label-free detection techniques designed for nanofluidics; these techniques are divided into two groups: optical and electrical/electrochemical detection methods. In this review, we discuss on the developed nanofluidic device architectures, elucidate the mechanisms by which the utilization of nanofluidics in manipulating molecules and controlling light-matter interactions enhances the capabilities of biological and chemical analyses, and highlight new research directions in the field of detections in nanofluidics.
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Affiliation(s)
- Thu Hac Huong Le
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
- Correspondence: (T.H.H.L.); (H.S.); (K.M.)
| | - Hisashi Shimizu
- Collaborative Research Organization for Micro and Nano Multifunctional Devices (NMfD), The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
- Correspondence: (T.H.H.L.); (H.S.); (K.M.)
| | - Kyojiro Morikawa
- Collaborative Research Organization for Micro and Nano Multifunctional Devices (NMfD), The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656, Japan
- Correspondence: (T.H.H.L.); (H.S.); (K.M.)
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10
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Sivasankar VS, Etha SA, Sachar HS, Das S. Theoretical study on the massively augmented electro-osmotic water transport in polyelectrolyte brush functionalized nanoslits. Phys Rev E 2020; 102:013103. [PMID: 32794997 DOI: 10.1103/physreve.102.013103] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 06/08/2020] [Indexed: 11/07/2022]
Abstract
We demonstrate that functionalizing nanoslits with pH-responsive polyelectrolyte brushes can lead to extremely fast electro-osmotic (EOS) water transport, where the maximum centreline velocity and the volume flow rate can be an order of magnitude larger than these quantities in identically charged brush-free nanochannels for a wide range of system parameters. Such an enhancement is most remarkable given that the brushes have been known to retard the transport by imparting additional drag on the fluid flow. We argue that this enhancement stems from the localization of the charge density of the brush-induced electric double layer (and, hence, the EOS body force) away from the nanochannel wall (or the location of the wall-induced drag force). This ensures a much larger impact of the EOS body force triggering such fast water transport. Finally, the calculated flux values for the present brush-grafted nanochannels are found to be significantly larger than those for a wide range of nanofluidic membranes and channels, suggesting that the brush functionalization can be considered as a mechanism for enabling such superfast nanofluidic transport.
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Affiliation(s)
| | - Sai Ankit Etha
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Harnoor Singh Sachar
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
| | - Siddhartha Das
- Department of Mechanical Engineering, University of Maryland, College Park, Maryland 20742, USA
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11
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Kostiuchenko ZA, Lemay SG. Quasi-One-Dimensional Generator-Collector Electrochemistry in Nanochannels. Anal Chem 2020; 92:2847-2852. [PMID: 31934747 PMCID: PMC7003156 DOI: 10.1021/acs.analchem.9b05396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Mass transport in
fluidic channels under conditions of pressure-driven
flow is controlled by a combination of convection and diffusion. For
electrochemical measurements the height of a channel is typically
of the same order of magnitude as the electrode dimensions, resulting
in complex two- or three- dimensional concentration distributions.
Electrochemical nanofluidic devices, however, can have such a low
height-to-length ratio that they can effectively be considered as
one-dimensional. This greatly simplifies the modeling and quantitative
interpretation of analytical measurements. Here we study mass transport
in nanochannels using electrodes in a generator-collector configuration.
The flux of redox molecules is monitored amperometrically. We observe
the transition from diffusion-dominated to convection-dominated transport
by varying both the flow velocity and the distance between the electrodes.
These results are described quantitatively by the one-dimensional
Nernst–Planck equation for mass transport over the full range
of experimentally accessible parameters.
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Affiliation(s)
- Zinaida A Kostiuchenko
- MESA+ Institute for Nanotechnology and Faculty of Science and Technology , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands
| | - Serge G Lemay
- MESA+ Institute for Nanotechnology and Faculty of Science and Technology , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands
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12
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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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13
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Gravelle S, Ybert C. Flow-induced shift of the Donnan equilibrium for ultra-sensitive mass transport measurement through a single nanochannel. J Chem Phys 2019; 151:244503. [DOI: 10.1063/1.5133888] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Simon Gravelle
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
- School of Engineering and Material Science, Queen Mary University of London, London, United Kingdom
| | - Christophe Ybert
- Univ Lyon, Université Claude Bernard Lyon1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
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14
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Gravelle S, Netz RR, Bocquet L. Adsorption Kinetics in Open Nanopores as a Source of Low-Frequency Noise. NANO LETTERS 2019; 19:7265-7272. [PMID: 31466445 DOI: 10.1021/acs.nanolett.9b02858] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Ionic current measurements through solid-state nanopores consistently show a power spectral density that scales as 1/f α at low frequency f, with an exponent α ∼ 0.5-1.5, but strikingly, the physical origin of this behavior remains elusive. Here, we perform simulations of particles reversibly adsorbing at the surface of a nanopore and show that the fluctuations in the number of adsorbed particles exhibit low-frequency pink noise. We furthermore propose theoretical modeling for the time-dependent adsorption of particles on the nanopore surface for various geometries, which predicts a frequency spectrum in very good agreement with the simulation results. Altogether, our results highlight that the low-frequency noise takes its origin in the reversible adsorption of ions at the pore surface combined with the long-lasting excursions of the ions in the reservoirs. The scaling regime of the power spectrum extends down to a cutoff frequency which is far smaller than simple diffusion estimates. Using realistic values for the pore dimensions and the adsorption-desorption kinetics, this predicts the observation of pink noise for frequencies down to the hertz for a typical solid-state nanopore, in good agreement with experiments.
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Affiliation(s)
- Simon Gravelle
- School of Engineering and Material Science , Queen Mary University of London , London E1 4NS , United Kingdom
| | - Roland R Netz
- Department of Physics , Freie Universität Berlin , 14195 Berlin , Germany
| | - Lydéric Bocquet
- Laboratoire de Physique de l'Ecole Normale Supérieure , CNRS, Université PSL, Sorbonne Université, Sorbonne Paris Cité , Paris 75005 , France
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15
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Fontana M, Fijen C, Lemay SG, Mathwig K, Hohlbein J. High-throughput, non-equilibrium studies of single biomolecules using glass-made nanofluidic devices. LAB ON A CHIP 2018; 19:79-86. [PMID: 30468446 DOI: 10.1039/c8lc01175c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Single-molecule detection schemes offer powerful means to overcome static and dynamic heterogeneity inherent to complex samples. However, probing biomolecular interactions and reactions with high throughput and time resolution remains challenging, often requiring surface-immobilized entities. Here, we introduce glass-made nanofluidic devices for the high-throughput detection of freely-diffusing single biomolecules by camera-based fluorescence microscopy. Nanochannels of 200 nm height and a width of several micrometers confine the movement of biomolecules. Using pressure-driven flow through an array of parallel nanochannels and by tracking the movement of fluorescently labelled DNA oligonucleotides, we observe conformational changes with high throughput. In a device geometry featuring a T-shaped junction of nanochannels, we drive steady-state non-equilibrium conditions by continuously mixing reactants and triggering chemical reactions. We use the device to probe the conformational equilibrium of a DNA hairpin as well as to continuously observe DNA synthesis in real time. Our platform offers a straightforward and robust method for studying reaction kinetics at the single-molecule level.
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Affiliation(s)
- Mattia Fontana
- Laboratory of Biophysics, Wageningen University and Research, Stippeneng 4, Wageningen, 6708 WE, The Netherlands
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16
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Sharma P, Motte JF, Fournel F, Cross B, Charlaix E, Picard C. A Direct Sensor to Measure Minute Liquid Flow Rates. NANO LETTERS 2018; 18:5726-5730. [PMID: 30068080 DOI: 10.1021/acs.nanolett.8b02332] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Nanofluidics finds its root in the study of fluids and flows at the nanoscale. Flow rate is a quantity that is both central when dealing with flows and notoriously difficult to measure experimentally at the scale of an individual nanopore or nanochannel. We show in this letter that minute flow rate can be directly measured accumulating liquid over time within the compliant membrane of a commercial piezoresistive pressure sensor. Our flow rate sensor is versatile and can be operated independently of the nature of the liquid, flow profile, and type of nanochannel. We demonstrate this method by measuring the pressure-driven flow of silicon oil in a single nanochannel of average radius 200 nm. This approach gives reliable measurement of the flow rate up to 1 pL/min. Unlike other nanoscale flow measurements methods based, for instance, on particle tracking, our sensor delivers a direct voltage output suitable for nanoflow control applications.
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Affiliation(s)
- Preeti Sharma
- Université Grenoble Alpes, CNRS, LIPhy , 38000 Grenoble , France
| | - Jean-François Motte
- Université Grenoble Alpes, CNRS, Grenoble INP, Institut Néel , 38000 Grenoble , France
| | - Frank Fournel
- Université Grenoble Alpes, CEA, LETI , 38000 Grenoble , France
| | - Benjamin Cross
- Université Grenoble Alpes, CNRS, LIPhy , 38000 Grenoble , France
| | | | - Cyril Picard
- Université Grenoble Alpes, CNRS, LIPhy , 38000 Grenoble , France
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17
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Cui J, Mathwig K, Mampallil D, Lemay SG. Potential-Controlled Adsorption, Separation, and Detection of Redox Species in Nanofluidic Devices. Anal Chem 2018; 90:7127-7130. [PMID: 29808992 PMCID: PMC6011178 DOI: 10.1021/acs.analchem.8b01719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Nanoscale channels and electrodes for electrochemical measurements exhibit extreme surface-to-volume ratios and a correspondingly high sensitivity to even weak degrees of surface interactions. Here, we exploit the potential-dependent reversible adsorption of outer-sphere redox species to modulate in space and time their concentration in a nanochannel under advective flow conditions. Induced concentration variations propagate downstream at a species-dependent velocity. This allows one to amperometrically distinguish between attomole amounts of species based on their time-of-flight. On-demand concentration pulse generation, separation, and detection are all integrated in a miniaturized platform.
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Affiliation(s)
- Jin Cui
- MESA+ Institute for Nanotechnology , University of Twente , PO Box 217, 7500 AE Enschede , The Netherlands
| | - Klaus Mathwig
- MESA+ Institute for Nanotechnology , University of Twente , PO Box 217, 7500 AE Enschede , The Netherlands
| | - Dileep Mampallil
- MESA+ Institute for Nanotechnology , University of Twente , PO Box 217, 7500 AE Enschede , The Netherlands
| | - Serge G Lemay
- MESA+ Institute for Nanotechnology , University of Twente , PO Box 217, 7500 AE Enschede , The Netherlands
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18
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Kostiuchenko ZA, Glazer PJ, Mendes E, Lemay SG. Chemical physics of electroactive materials - the oft-overlooked faces of electrochemistry. Faraday Discuss 2017; 199:9-28. [PMID: 28654123 DOI: 10.1039/c7fd00117g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Electroactive materials and their applications are enjoying renewed attention, in no small part motivated by the advent of nanoscale tools for their preparation and study. While the fundamentals of charge and mass transport in electrolytes on this scale are by and large well understood, their interplay can have subtle manifestations in the more complex situations typical of, for example, integrated microfluidics-based applications. In particular, the role of faradaic processes is often overlooked or, at best, purposefully suppressed via experimental design. In this introductory article we discuss, using simple illustrations from our laboratories, some of the manifestations of electrochemistry in electroactive materials.
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Affiliation(s)
- Zinaida A Kostiuchenko
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
| | - Piotr J Glazer
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Eduardo Mendes
- Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Serge G Lemay
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands.
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19
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Simonnin P, Noetinger B, Nieto-Draghi C, Marry V, Rotenberg B. Diffusion under Confinement: Hydrodynamic Finite-Size Effects in Simulation. J Chem Theory Comput 2017; 13:2881-2889. [DOI: 10.1021/acs.jctc.7b00342] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pauline Simonnin
- Sorbonne Universités,
UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, Case 51, 4 Place Jussieu, F-75005 Paris, France
- IFP Energies Nouvelles, 1 & 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Benoı̂t Noetinger
- IFP Energies Nouvelles, 1 & 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Carlos Nieto-Draghi
- IFP Energies Nouvelles, 1 & 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Virginie Marry
- Sorbonne Universités,
UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, Case 51, 4 Place Jussieu, F-75005 Paris, France
| | - Benjamin Rotenberg
- Sorbonne Universités,
UPMC Univ Paris 06, CNRS, Laboratoire PHENIX, Case 51, 4 Place Jussieu, F-75005 Paris, France
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20
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Affiliation(s)
- Pradyumna S. Singh
- Intel
Labs, Intel Corporation, 2200 Mission College Boulevard, Santa Clara, California 95054, United States
| | - Serge G. Lemay
- MESA+
Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands
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21
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Gadaleta A, Biance AL, Siria A, Bocquet L. Ultra-sensitive flow measurement in individual nanopores through pressure – driven particle translocation. NANOSCALE 2015; 7:7965-70. [PMID: 25866078 DOI: 10.1039/c4nr07468h] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A challenge for the development of nanofluidics is to develop new instrumentation tools, able to probe the extremely small mass transport across individual nanochannels.
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Affiliation(s)
| | | | - Alessandro Siria
- Laboratoire de Physique Statistique
- Ećole Normale Supérieure and CNRS
- UMR 8550
- 75231 Paris, France
| | - Lyderic Bocquet
- Laboratoire de Physique Statistique
- Ećole Normale Supérieure and CNRS
- UMR 8550
- 75231 Paris, France
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22
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Bocquet L, Tabeling P. Physics and technological aspects of nanofluidics. LAB ON A CHIP 2014; 14:3143-3158. [PMID: 25046581 DOI: 10.1039/c4lc00325j] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
From a physical perspective, nanofluidics represents an extremely rich domain. It hosts many mechanisms acting on the nanoscale, which combine together or interact with the confinement to generate new phenomena. Superfast flows in carbon nanotubes, nonlinear electrokinetic transport, slippage over smooth surfaces, nanobubble stability, etc. are the most striking phenomena that have been unveiled over the past few years, and some of them are still awaiting an explanation. One may anticipate that new nanofluidic effects will be discovered in the future, but at the moment, the technological barrier is high. Fabrication of nanochannels is most often a tour de force, slow and costly. However, with the accumulation of technological skills along with the use of new nanofluidic materials (like nanotubes), nanofluidics is becoming increasingly accessible to experimentalists. Among the technological challenges faced by the field, fabricating devices mimicking natural nanometric systems, such as aquaporins, ionic pumps or kidney osmotic filtering, seems the most demanding in terms of groundbreaking ideas. Nanoflow characterization remains delicate, although considerable progress has been achieved over the past years. The targeted application of nanofluidics is not only in the field of genomics and membrane science--with disruptive developments to be expected for water purification, desalination, and energy harvesting--but also for oil and gas production from unconventional reservoirs. Today, in view of the markets that are targeted, nanofluidics may well impact the industry more than microfluidics; this would represent an unexpected paradox. These successes rely on using a variety of materials and technologies, using state-of-the-art nanofabrication, or low-tech inexpensive approaches. As a whole, nanofluidics is a fascinating field that is facing considerable challenges today. It possesses a formidable potential and offers much space for creative groundbreaking ideas.
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Affiliation(s)
- Lyderic Bocquet
- Institut Lumière Matière, UMR 5306 CNRS - University Lyon 1, 69622 Villeurbanne, France and Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, UMI 3466 CNRS-MIT, Cambridge, Massachusetts 02139, USA.
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23
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Rassaei L, Mathwig K, Kang S, Heering HA, Lemay SG. Integrated biodetection in a nanofluidic device. ACS NANO 2014; 8:8278-84. [PMID: 25105352 DOI: 10.1021/nn502678t] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The sensing of enzymatic processes in volumes at or below the scale of single cells is challenging but highly desirable in the study of biochemical processes. Here we demonstrate a nanofluidic device that combines an enzymatic recognition element and electrochemical signal transduction within a six-femtoliter volume. Our approach is based on localized immobilization of the enzyme tyrosinase in a microfabricated nanogap electrochemical transducer. The enzymatic reaction product quinone is localized in the confined space of a nanochannel in which efficient redox cycling also takes place. Thus, the sensor allows the sensitive detection of minute amounts of product molecules generated by the enzyme in real time. This method is ideally suited for the study of ultra-small-volume systems such as the contents of individual biological cells or organelles.
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24
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Lee C, Cottin-Bizonne C, Biance AL, Joseph P, Bocquet L, Ybert C. Osmotic flow through fully permeable nanochannels. PHYSICAL REVIEW LETTERS 2014; 112:244501. [PMID: 24996091 DOI: 10.1103/physrevlett.112.244501] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 06/03/2023]
Abstract
Osmosis across membranes is intrinsically associated with the concept of semipermeability. Here, however, we demonstrate that osmotic flow can be generated by solute gradients across nonselective, fully permeable nanochannels. Using a fluorescence imaging technique, we are able to measure the water flow rate inside single nanochannels to an unprecedented sensitivity of femtoliters per minute flow rates. Our results indicate the onset of a convective liquid motion under salinity gradients, from the higher to lower electrolyte concentration, which is attributed to diffusio-osmotic transport. To our knowledge, this is the first experimental evidence and quantitative investigation of this subtle interfacially driven transport, which need to be accounted for in nanoscale dynamics. Finally, diffusio-osmotic transport under a neutral polymer gradient is also demonstrated. The experiments highlight the entropic depletion of polymers that occurs at the nanochannel surface, resulting in convective flow in the opposite direction to that seen for electrolytes.
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Affiliation(s)
- C Lee
- Institut Lumière Matière, Université Claude Bernard Lyon 1-CNRS, UMR 5306, Université de Lyon, F-69622 Villeurbanne Cedex, France and School of Aerospace and Mechanical Engineering, Korea Aerospace University, Goyang 412-791, Korea
| | - C Cottin-Bizonne
- Institut Lumière Matière, Université Claude Bernard Lyon 1-CNRS, UMR 5306, Université de Lyon, F-69622 Villeurbanne Cedex, France
| | - A-L Biance
- Institut Lumière Matière, Université Claude Bernard Lyon 1-CNRS, UMR 5306, Université de Lyon, F-69622 Villeurbanne Cedex, France
| | - P Joseph
- CNRS, LAAS, 7 Avenue du Colonel Roche, F-31400 Toulouse, France and Université de Toulouse, LAAS, F-31400 Toulouse, France
| | - L Bocquet
- Institut Lumière Matière, Université Claude Bernard Lyon 1-CNRS, UMR 5306, Université de Lyon, F-69622 Villeurbanne Cedex, France
| | - C Ybert
- Institut Lumière Matière, Université Claude Bernard Lyon 1-CNRS, UMR 5306, Université de Lyon, F-69622 Villeurbanne Cedex, France
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25
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Mathwig K, Aartsma TJ, Canters GW, Lemay SG. Nanoscale methods for single-molecule electrochemistry. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2014; 7:383-404. [PMID: 25000819 DOI: 10.1146/annurev-anchem-062012-092557] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The development of experiments capable of probing individual molecules has led to major breakthroughs in fields ranging from molecular electronics to biophysics, allowing direct tests of knowledge derived from macroscopic measurements and enabling new assays that probe population heterogeneities and internal molecular dynamics. Although still somewhat in their infancy, such methods are also being developed for probing molecular systems in solution using electrochemical transduction mechanisms. Here we outline the present status of this emerging field, concentrating in particular on optical methods, metal-molecule-metal junctions, and electrochemical nanofluidic devices.
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Affiliation(s)
- Klaus Mathwig
- MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, the Netherlands; ,
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26
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Kätelhön E, Krause KJ, Mathwig K, Lemay SG, Wolfrum B. Noise phenomena caused by reversible adsorption in nanoscale electrochemical devices. ACS NANO 2014; 8:4924-4930. [PMID: 24694343 DOI: 10.1021/nn500941g] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We theoretically investigate reversible adsorption in electrochemical devices on a molecular level. To this end, a computational framework is introduced, which is based on 3D random walks including probabilities for adsorption and desorption events at surfaces. We demonstrate that this approach can be used to investigate adsorption phenomena in electrochemical sensors by analyzing experimental noise spectra of a nanofluidic redox cycling device. The evaluation of simulated and experimental results reveals an upper limit for the average adsorption time of ferrocene dimethanol of ∼200 μs. We apply our model to predict current noise spectra of further electrochemical experiments based on interdigitated arrays and scanning electrochemical microscopy. Since the spectra strongly depend on the molecular adsorption characteristics of the detected analyte, we can suggest key indicators of adsorption phenomena in noise spectroscopy depending on the geometric aspect of the experimental setup.
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Affiliation(s)
- Enno Kätelhön
- Institute of Bioelectronics (PGI-8/ICS-8) and JARA-Fundamentals of Future Information Technology, Forschungszentrum Jülich , 52425 Jülich, Germany
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27
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Kang S, Nieuwenhuis AF, Mathwig K, Mampallil D, Lemay SG. Electrochemical single-molecule detection in aqueous solution using self-aligned nanogap transducers. ACS NANO 2013; 7:10931-10937. [PMID: 24279688 DOI: 10.1021/nn404440v] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Electrochemical detection of individual molecular tags in nanochannels may enable cost-effective, massively parallel analysis and diagnostics platforms. Here we demonstrate single-molecule detection of prototypical analytes in aqueous solution based on redox cycling in 40 nm nanogap transducers. These nanofluidic devices are fabricated using standard microfabrication techniques combined with a self-aligned approach that minimizes gap size and dead volume. We demonstrate the detection of three common redox mediators at physiological salt concentrations.
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Affiliation(s)
- Shuo Kang
- MESA+ Institute for Nanotechnology, University of Twente , PO Box 217, 7500 AE Enschede, The Netherlands
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28
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29
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Laohakunakorn N, Gollnick B, Moreno-Herrero F, Aarts DGAL, Dullens RPA, Ghosal S, Keyser UF. A Landau-Squire nanojet. NANO LETTERS 2013; 13:5141-6. [PMID: 24124664 PMCID: PMC3897716 DOI: 10.1021/nl402350a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Fluid jets are found in nature at all length scales from microscopic to cosmological. Here we report on an electroosmotically driven jet from a single glass nanopore about 75 nm in radius with a maximum flow rate ~15 pL/s. A novel anemometry technique allows us to map out the vorticity and velocity fields that show excellent agreement with the classical Landau-Squire solution of the Navier-Stokes equations for a point jet. We observe a phenomenon that we call flow rectification: an asymmetry in the flow rate with respect to voltage reversal. Such a nanojet could potentially find applications in micromanipulation, nanopatterning, and as a diode in microfluidic circuits.
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30
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Limmer DT, Merlet C, Salanne M, Chandler D, Madden PA, van Roij R, Rotenberg B. Charge fluctuations in nanoscale capacitors. PHYSICAL REVIEW LETTERS 2013; 111:106102. [PMID: 25166683 DOI: 10.1103/physrevlett.111.106102] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Indexed: 05/03/2023]
Abstract
The fluctuations of the charge on an electrode contain information on the microscopic correlations within the adjacent fluid and their effect on the electronic properties of the interface. We investigate these fluctuations using molecular dynamics simulations in a constant-potential ensemble with histogram reweighting techniques. This approach offers, in particular, an efficient, accurate, and physically insightful route to the differential capacitance that is broadly applicable. We demonstrate these methods with three different capacitors: pure water between platinum electrodes and a pure as well as a solvent-based organic electrolyte each between graphite electrodes. The total charge distributions with the pure solvent and solvent-based electrolytes are remarkably Gaussian, while in the pure ionic liquid the total charge distribution displays distinct non-Gaussian features, suggesting significant potential-driven changes in the organization of the interfacial fluid.
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Affiliation(s)
- David T Limmer
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Céline Merlet
- UPMC Univ-Paris 06 and CNRS, UMR 7195, PECSA, F-75005, Paris, France and Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France
| | - Mathieu Salanne
- UPMC Univ-Paris 06 and CNRS, UMR 7195, PECSA, F-75005, Paris, France and Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France
| | - David Chandler
- Department of Chemistry, University of California, Berkeley, California 94720, USA
| | - Paul A Madden
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
| | - René van Roij
- Institute for Theoretical Physics, Utrecht University, 3584 CE Utrecht, The Netherlands
| | - Benjamin Rotenberg
- UPMC Univ-Paris 06 and CNRS, UMR 7195, PECSA, F-75005, Paris, France and Réseau sur le Stockage Electrochimique de l'Energie (RS2E), FR CNRS 3459, France
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31
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Pushing the Limits of Electrical Detection of Ultralow Flows in Nanofluidic Channels. MICROMACHINES 2013. [DOI: 10.3390/mi4020138] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Lemay SG, Kang S, Mathwig K, Singh PS. Single-molecule electrochemistry: present status and outlook. Acc Chem Res 2013; 46:369-77. [PMID: 23270398 DOI: 10.1021/ar300169d] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The development of methods for detecting and manipulating matter at the level of individual macromolecules represents one of the key scientific advancements of recent decades. These techniques allow us to get information that is largely unobtainable otherwise, such as the magnitudes of microscopic forces, mechanistic details of catalytic processes, macromolecular population heterogeneities, and time-resolved, step-by-step observation of complex kinetics. Methods based on optical, mechanical, and ionic-conductance signal transduction are particularly developed. However, there is scope for new approaches that can broaden the range of molecular systems that we can study at this ultimate level of sensitivity and for developing new analytical methods relying on single-molecule detection. Approaches based on purely electrical detection are particularly appealing in the latter context, since they can be easily combined with microelectronics or fluidic devices on a single microchip to create large parallel assays at relatively low cost. A form of electrical signal transduction that has so far remained relatively underdeveloped at the single-molecule level is the direct detection of the charge transferred in electrochemical processes. The reason for this is simple: only a few electrons are transferred per molecule in a typical faradaic reaction, a heterogeneous charge-transfer reaction that occurs at the electrode's surface. Detecting this tiny amount of charge is impossible using conventional electrochemical instrumentation. A workaround is to use redox cycling, in which the charge transferred is amplified by repeatedly reducing and oxidizing analyte molecules as they randomly diffuse between a pair of electrodes. For this process to be sufficiently efficient, the electrodes must be positioned within less than 100 nm of each other, and the analyte must remain between the electrodes long enough for the measurement to take place. Early efforts focused on tip-based nanoelectrodes, descended from scanning electrochemical microscopy, to create suitable geometries. However, it has been challenging to apply these technologies broadly. In this Account, we describe our alternative approach based on electrodes embedded in microfabricated nanochannels, so-called nanogap transducers. Microfabrication techniques grant a high level of reproducibility and control over the geometry of the devices, permitting systematic development and characterization. We have employed these devices to demonstrate single-molecule sensitivity. This method shows good agreement with theoretical analysis based on the Brownian motion of discrete molecules, but only once the finite time resolution of the experimental apparatus is taken into account. These results highlight both the random nature of single-molecule signals and the complications that it can introduce in data interpretation. We conclude this Account with a discussion on how scientists can overcome this limitation in the future to create a new experimental platform that can be generally useful for both fundamental studies and analytical applications.
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Affiliation(s)
- Serge G. Lemay
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Shuo Kang
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Klaus Mathwig
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
| | - Pradyumna S. Singh
- MESA+ Institute for Nanotechnology, University of Twente, PO Box 217, 7500 AE Enschede, The Netherlands
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