Polycarbonate-based ordered arrays of electrochemical nanoelectrodes obtained by e-beam lithography.
TL;DR: Electrochemical results showed satisfactory agreement between experimental voltammograms and suitable theoretical models, and the peculiarities of NEAs versus ensembles of nanoelectrodes, obtained by membrane template synthesis, are critically evaluated.
Abstract: Ordered arrays of nanoelectrodes for electrochemical use are prepared by electron beam lithography (EBL) using polycarbonate as a novel e-beam resist. The nanoelectrodes are fabricated by patterning arrays of holes in a thin film of polycarbonate spin-coated on a gold layer on Si/Si3N4 substrate. Experimental parameters for the successful use of polycarbonate as high resolution EBL resist are optimized. The holes can be filled partially or completely by electrochemical deposition of gold. This enables the preparation of arrays of nanoelectrodes with different recession degree and geometrical characteristics. The polycarbonate is kept on-site and used as the insulator that separates the nanoelectrodes. The obtained nanoelectrode arrays (NEAs) exhibit steady state current controlled by pure radial diffusion in cyclic voltammetry for scan rates up to approximately 50 mV s − 1. Electrochemical results showed satisfactory agreement between experimental voltammograms and suitable theoretical models. Finally, the peculiarities of NEAs versus ensembles of nanoelectrodes, obtained by membrane template synthesis, are critically evaluated.
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01 Jul 2017
TL;DR: In this paper, the authors present the last advances related to analytical and bioanalytical applications of electrochemiluminescence achieved by exploiting the special optical or electrochemical properties of quantum dots and nanoelectrodes, respectively.
Abstract: This review presents the last advances related to analytical and bioanalytical applications of electrochemiluminescence (ECL) achieved by exploiting the special optical or electrochemical properties of quantum dots and nanoelectrodes, respectively. After a brief introduction which covers the basic concepts of ECL detection, the review presents relevant examples dealing with in the use of quantum dots and arrays of nanoelectrodes to improve the analytical and bioanalytical capabilities of ECL. Finally, prospects and limits derived from the application of the above advanced nanomaterials to stimulate ECL emission are discussed.
65 citations
TL;DR: The design of a novel immunosensor and its application for celiac disease diagnosis, based on an electrogenerated chemiluminescence (ECL) readout, using membrane-templated gold nanoelectrode ensembles (NEEs) as a detection platform, showing to be suitable to discriminate between healthy and celiac patients.
Abstract: We report here the design of a novel immunosensor and its application for celiac disease diagnosis, based on an electrogenerated chemiluminescence (ECL) readout, using membrane-templated gold nanoelectrode ensembles (NEEs) as a detection platform. An original sensing strategy is presented by segregating spatially the initial electrochemical reaction and the location of the immobilized biomolecules where ECL is finally emitted. The recognition scaffold is the following: tissue transglutaminase (tTG) is immobilized as a capturing agent on the polycarbonate (PC) surface of the track-etched templating membrane. It captures the target tissue transglutaminase antibody (anti-tTG), and finally allows the immobilization of a streptavidin-modified ruthenium-based ECL label via reaction with a suitable biotinylated secondary antibody. The application of an oxidizing potential in a tri-n-propylamine (TPrA) solution generates an intense and sharp ECL signal, suitable for analytical purposes. Voltammetric and ECL analy...
60 citations
TL;DR: In this paper, the Schottky barrier height (SBH) is successfully tuned by triboelectric nanogenerator (TENG) and the same device is made to achieve reversible conversion between Schottkey contact and Ohmic contact.
Abstract: Schottky and Ohmic contacts–based electronics play an important role in highly sensitive detection of biomolecules and neural electric impulses, respectively. The reversible conversion between these two contacts appears especially important for multifunctional sensing by just one biosensor. Here, Schottky barrier height (SBH) is successfully tuned by triboelectric nanogenerator (TENG) and the same device is made to achieve reversible conversion between Schottky contact and Ohmic contact. In the same Schottky to Ohmic reversible (SOR) biosensor, highly sensitive detections of biomolecule (i.e., neurotransmitter) and neural electric signal are achieved at different contact states. The SOR biosensor reveals the feasibility of using one device to realize multifunctional detection. This work proposes a simple and significant method to achieve reversible tuning between the Schottky contact and Ohmic contact on one device by TENG, which exhibits great potential in developing multifunctional and high-sensitivity biosensors, rectifiers, and other functional electronic devices.
59 citations
TL;DR: This review deals with recent advances in bioelectroanalytical applications of nanostructured electrodes, in particular nanoelectrode ensembles (NEEs) and arrays (NEAs), and nanofabrication techniques, principles of function, and specific advantages and limits of NEEs and NEAs.
Abstract: This review deals with recent advances in bioelectroanalytical applications of nanostructured electrodes, in particular nanoelectrode ensembles (NEEs) and arrays (NEAs). First, nanofabrication techniques, principles of function, and specific advantages and limits of NEEs and NEAs are critically discussed. In the second part, some recent examples of bioelectroanalytical applications are presented. These include use of nanoelectrode arrays and/or ensembles for direct electrochemical analysis of pharmacologically active organic compounds or redox proteins, and the development of functionalized nanoelectrode systems and their use as catalytic or affinity electrochemical biosensors.
47 citations
Cites background from "Polycarbonate-based ordered arrays ..."
...However, it is worth stressing that, because of the nanolithographic process itself, quite often the nanoelectrodes obtained are slightly recessed, so that theoretical model for such geometry must be taken into account [50, 55]....
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...5, because the properties of PC enable its use as a high-resolution e-beam resist, it is possible to obtain a perfectly ordered array of nano-holes, of controlled diameter, as small as 50 nm [55]....
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...[55]) Bioelectroanalysis with nanoelectrode arrays 3719...
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...for arrays including a very large number of electrodes [47, 55, 60]....
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...A recent study [55] demonstrated that PC, also, can be used as a high-resolution resist for e-beam lithography....
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TL;DR: A novel and low cost nanofabrication process is proposed for producing hybrid polydimethylsiloxane (PDMS) nanostructured arrays with great promise as a robust nanoreplication method for functional applications.
Abstract: In the study, a novel and low cost nanofabrication process is proposed for producing hybrid polydimethylsiloxane (PDMS) nanostructured arrays. The proposed process involves monolayer self-assembly of polystyrene (PS) spheres, PDMS nanoreplication, thin film coating, and PDMS to PDMS (PDMS/PDMS) replication. A self-assembled monolayer of PS spheres is used as the first template. Second, a PDMS template is achieved by replica moulding. Third, the PDMS template is coated with a platinum or gold layer. Finally, a PDMS nanostructured array is developed by casting PDMS slurry on top of the coated PDMS. The cured PDMS is peeled off and used as a replica surface. In this study, the influences of the coating on the PDMS topography, contact angle of the PDMS slurry and the peeling off ability are discussed in detail. From experimental evaluation, a thickness of at least 20 nm gold layer or 40 nm platinum layer on the surface of the PDMS template improves the contact angle and eases peeling off. The coated PDMS surface is successfully used as a template to achieve the replica with a uniform array via PDMS/PDMS replication process. Both the PDMS template and the replica are free of defects and also undistorted after demoulding with a highly ordered hexagonal arrangement. In addition, the geometry of the nanostructured PDMS can be controlled by changing the thickness of the deposited layer. The simplicity and the controllability of the process show great promise as a robust nanoreplication method for functional applications.
44 citations
References
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01 Jan 2006
TL;DR: In this article, the authors present an overview of the basic fundamentals and applications of electrochemistry in small places and at novel interfaces, including the following: 1. Fundamentals Part Two: Laboratory Practical 2. Practical Electrochemical Cells 3. Solvents and Supporting Electrolytes 4. Reference Electrodes 5. Solid Electrode Materials: Pretreatment and Activation 6. Ultramicroelectrodes 7. Potentiometric Ion-Selective Electrodes 8. Chemically Modified Electrodes 9. Semiconductor Electrodes 10.
Abstract: Part One: Fundamentals 1. Fundamentals Part Two: Laboratory Practical 2. Practical Electrochemical Cells 3. Solvents and Supporting Electrolytes 4. Reference Electrodes 5. Solid Electrode Materials: Pretreatment and Activation 6. Ultramicroelectrodes 7. Potentiometric Ion-Selective Electrodes 8. Chemically Modified Electrodes 9. Semiconductor Electrodes 10. Microelectrode Arrays Part Three: Techniques 11. Classical Experiments 12. Scanning Electrochemical Microscopy 13. Electrogenerated Chemiluminesence 14. Spectroelectrochemistry Part Four: Applications 15. Determination of Electrode Kinetics 16. Metal Deposition 17. Electrochemistry in Small Places and at Novel Interfaces Part Five: Data 18. Electrode Potentials 19. Diffusion Coefficients 20. Liquid Junction Potentials
704 citations
TL;DR: In this article, an electroless deposition procedure for filling the pores in nanoporous filtration membranes with metal (gold) nanowires is described, which allows us to routinely prepare ensembles of gold nanodisk electrodes in which the nanodisks have diameters as small as 10 nm.
Abstract: : An electroless deposition procedure for filling the pores in nanoporous filtration membranes with metal (gold) nanowires is described. This method allows us to routinely prepare ensembles of gold nanodisk electrodes in which the nanodisks have diameters as small as 10 nm. Results of electrochemical experiments at ensembles of 30 nm-diameter and 10 nm-diameter gold-disk electrodes are described. The electrochemical response characteristics of these nanoelectrode ensembles are in agreement with predictions of the relevant electrochemical theories. Cyclic voltammetric detection limits for electroactive species at ensembles containing 10 nm-diameter gold disks can be as much as 3 orders of magnitude lower than at a large-diameter gold-disk electrode.
699 citations
TL;DR: Track membrane (TM) technology is an example of industrial application of track etching technique as discussed by the authors, and it has been used in many applications, such as process filtration, cell culture, and laboratory filtering.
593 citations
TL;DR: Benefits that accrue from use of very small working electrodes within electrochemical cells are discussed, followed by a review of methods for the preparation of such electrodes.
Abstract: This review deals with the topic of ultrasmall electrodes, namely nanoelectrodes, arrays of these and discusses possible applications, including to analytical science. It deals exclusively with the use of nanoelectrodes in an electrochemical context. Benefits that accrue from use of very small working electrodes within electrochemical cells are discussed, followed by a review of methods for the preparation of such electrodes. Individual nanoelectrodes and arrays or ensembles of these are addressed, as are nanopore systems which seek to emulate biological transmembrane ion transport processes. Applications within physical electrochemistry, imaging science and analytical science are summarised.
437 citations
TL;DR: In this paper, the authors examined the currently accepted guidelines on center-to-centre separation and identified the key factors involved in the voltammetry of both regular and random arrays of microdisc (and nanodisc) electrodes.
352 citations