A5083729678- Electrochemical Analysis and Applications
- Electrochemical sensors and biosensors
- Analytical Chemistry and Sensors
- Electrocatalysts for Energy Conversion
- Advanced biosensing and bioanalysis techniques
- Conducting polymers and applications
- Advanced battery technologies research
- Molecular Junctions and Nanostructures
- Force Microscopy Techniques and Applications
- nanoparticles nucleation surface interactions
- Electronic and Structural Properties of Oxides
- Carbon dioxide utilization in catalysis
- Advanced Battery Materials and Technologies
- Nanopore and Nanochannel Transport Studies
- Monoclonal and Polyclonal Antibodies Research
- Surface and Thin Film Phenomena
- Extracellular vesicles in disease
- CO2 Reduction Techniques and Catalysts
- Electrodeposition and Electroless Coatings
- Microfluidic and Capillary Electrophoresis Applications
- Machine Learning in Materials Science
- Advanced Biosensing Techniques and Applications
- Advanced Chemical Sensor Technologies
- Covalent Organic Framework Applications
- Ion-surface interactions and analysis
The University of Texas at Austin
2017-2020
Ruhr University Bochum
2012-2019
Imperial College London
2016
The measurement of key molecules in individual cells with minimal disruption to the biological milieu is next frontier single-cell analyses. Nanoscale devices are ideal analytical tools because their small size and potential for high spatial temporal resolution recordings. Here, we report fabrication disk-shaped carbon nanoelectrodes whose radius can be precisely tuned within range 5-200 nm. functionalization nanoelectrode platinum allowed monitoring oxygen consumption outside inside a brain...
In this paper, we show that Au nanoparticles (AuNPs) stabilized with either citrate or by low-generation dendrimers rapidly grow during electrocatalytic reduction of CO2. For example, citrate-stabilized AuNPs and encapsulated within sixth-generation, hydroxyl-terminated, poly(amidoamine) (G6-OH DENs) having diameters ∼2 nm substantially in size (to 6–7 nm) polydispersity just 15 min electrolysis at −0.80 V (vs RHE). This degree instability makes it impossible to correlate the structure...
Nanometric field-effect-transistor (FET) sensors are made on the tip of spear-shaped dual carbon nanoelectrodes derived from deposition inside double-barrel nanopipettes. The easy fabrication route allows semiconductors or conducting polymers to comprise transistor channel. A channel electrodeposited poly pyrrole (PPy) exhibits high sensitivity toward pH changes. This property is exploited by immobilizing hexokinase PPy nano-FETs give rise a selective ATP biosensor. Extracellular and...
Individual Ni(OH)<sub>2</sub> nanoparticles deposited on carbon nanoelectrodes are investigated in non-ensemble measurements with respect to their energy storage properties and electrocatalysis for the oxygen evolution reaction (OER).
The impact of different doping levels boron-doped diamond on the surface functionalization was investigated by means electrochemical reduction aryldiazonium salts. grafting efficiency 4-nitrophenyl groups increased with boron (B/C ratio from 0 to 20 000 ppm). Controlled nitrophenyldiazonium used adjust amount immobilized single-stranded DNA strands at and further hybridization yield in dependence level. grafted nitro functions were electrochemically reduced amine moieties. Subsequent a...
Abstract Single‐particle electrochemistry at a nanoelectrode is explored by dark‐field optical microscopy. The analysis of the scattered light allows in situ dynamic monitoring electrodeposition single cobalt nanoparticles down to radius 65 nm. Larger sub‐micrometer particles are directly sized optically super‐localization edges and contains complementary information concerning particle redox chemistry. This opto‐electrochemical approach used derive mechanistic insights about...
Local ion activity changes in close proximity to the surface of an oxygen depolarized cathode (ODC) were measured by scanning electrochemical microscopy (SECM). While operating ODC produces OH- ions and consumes O2 H2 O through electrocatalytic reduction reaction (ORR), local are detected means a positioned Pt microelectrode serving as SECM tip. Sensing at tip is based on pH-dependent PtO obviates need for prior electrode modification steps. It can be used evaluate coordination numbers O,...
Abstract Hydrogen peroxide (H 2 O ) is one of the most important reactive oxygen species, and it involved in a number cellular processes ranging from signal transduction to immune defence oxidative stress. It great interest intracellularly quantify H improve understanding its role disease processes. In this study, we present an amperometric nanosensor for quantification at single‐cell level. Deposition electrocatalyst Prussian Blue on carbon nanoelectrodes enables selective reduction mild...
Abstract The selectivity of the chlorine evolution reaction over oxygen during electrolysis aqueous NaCl is, despite being very high, still insufficient to prevent expensive separation formed Cl 2 and O by means liquefaction. We hypothesize that, decreasing local activity H near anode surface substantially increasing ionic strength electrolyte, would be suppressed, leading concomitantly a higher formation. Hence, influence on competition between electrochemical at dimensionally stable anodes...
By partially overcoming the diffraction limit, superlocalization techniques have extended applicability of optical down to nanometer size-range. Herein, cobalt oxide-based nanoparticles are electrochemically grown onto carbon nanoelectrodes and their individual catalytic properties evaluated through a combined electrochemical-optical approach. Using dark-field white light illumination, edges applied quantify changes in particle size during electrochemical activation with 20 nm precision. It...
Carbon electrodes in the sub-micrometer scale were modified with polymer/enzyme films for fabrication of miniaturized amperometric glucose sensors. The by means electrochemically induced co-deposition various polymers and converting enzymes (i) activation protected crosslinkers formation a dense crosslinker-polymer network that is able to entrap biocatalyst on electrode surface (ii) using an electrodeposition paint was deposited chemically carbon upon basic pH shift. polymer matrixes...
Abstract Catechol can be oxidized electrochemically to its corresponding o ‐benzoquinone. The electrogenerated quinone deposited by cycling the potential at surface of glassy carbon electrodes. We have studied electrochemical features films derived from catechol cyclic voltammetry. electrodeposited film shows stable reversible redox response, dependent on pH as anticipated for quinone/catechol functionalities. Glassy electrodes covered with a exhibit catalytic activity in electrooxidation...
Scanning electrochemical microscopy (SECM) is coupled with surface-enhanced Raman scattering (SERS) to characterize local surface modifications. SECM utilized for the patterning of para-nitrothiophenol self-assembled monolayers (SAMs) in direct mode a subsequent readout chemical patterns by means combined SECM-SERS. The SECM-SERS combination allows monitoring processes and provides simultaneous complementary spectroscopic information. reaction products upon SAM reduction, specifically...
Silver nanoclusters are deposited on bifunctional Θ-shaped nanoelectrodes consisting of a carbon nanoelectrode combined with hollow nanopipette. The Θ-nanoelectrodes used as model systems to study interfacial mass transport in gas diffusion electrodes and particular oxygen-depolarized cathodes (ODC) for the oxygen reduction reaction (ORR) chlor-alkali electrolysers. By local delivery O<sub>2</sub> electroactive Ag through adjacent nanopipette, enhanced currents ORR at nanoparticles recorded...
Abstract A reagentless strategy for template‐free patterning of uniformly inert surfaces is suggested. layer p ‐hydroquinone (HQ) protected by the tert ‐butyldimethylsilyl (TBDMS) group electrografted onto glassy carbon electrodes. Chemoselective activation performed through electrochemically controlled cleavage TBDMS group, which yields redox‐active surface‐confined quinone moieties. The latter are shown to undergo induced Michael addition, serves subsequent functionalization electrode...
In this paper, we report the electrosynthesis and characterization of individual, shape-controlled Pt nanocrystals electrodeposited on carbon nanoelectrodes.
Patterning of glassy carbon surfaces grafted with a layer nitrophenyl moieties was achieved by using the direct mode scanning electrochemical microscopy (SECM) to locally reduce nitro groups hydroxylamine and amino functionalities. SECM atomic force (AFM) revealed that potentiostatic pulses applied working electrode lead local destruction surface, most likely caused etchants generated at positioned tip used as counter electrode. By applying galvanostatic pulses, thus, limiting current during...
Adsorption of ceruloplasmin (Cp) at a gold electrode modified with ferromagnetic iron nanoparticles encapsulated in carbon (Fe@C Nps) leads to successful immobilization the enzyme its electroactive form. The proper placement Cp surface on top nanocapsules containing an core allowed preorientation enzyme, hence allowing direct electron transfer between and enzyme. Laser ablation coupled inductively plasma mass spectrometry indicated that was predominantly located paramagnetic nanoparticles....