Electrochemical biosensors at the nanoscale

Wei, Di; Bailey, Marc J. A.; Andrew, Piers; Ryhänen, Tapani

doi:10.1039/b903118a

Cited by 128 publications

(81 citation statements)

References 95 publications

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“…[21][22][23][24][25] Different methodologies allow following the concentration influence on the electrochemical responses of conducting polymers coating metal electrodes. Laslau et al used modified scanning ion conductance microscopy.…”

Section: Introductionmentioning

confidence: 99%

Effect of the Electrolyte Concentration and Substrate on Conducting Polymer Actuators

2014

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ABSTRACT:The effect of the electrolyte concentration (NaCl aqueous electrolyte) on the dimensional variations of films of polypyrrole doped with dodecylbenzenesulphonate PPy(DBS) on Pt and Au wires was studied. Any parallel reaction that occurs during the redox polymeric reaction that drives the mechanical actuation, as detected from the coulovoltammetric responses, was avoided by using Pt wires as substrate and controlling the potential limits, thus significantly increasing the actuator lifetime. The NaCl concentration of the electrolyte, when studied by cyclic voltammetry or chronoamperometry, has a strong effect on the performance as well. A maximum expansion was achieved in 0.3 M aqueous solution. The consumed oxidation and reduction charges control the fully reversible dimensional variations: PPy(DBS) films are faradaic polymeric motors. Parallel to the faradaic exchange of the cations, osmotic, electrophoretic, and structural changes play an important role for the water exchange and volume change of PPy(DBS).

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Section: Introductionmentioning

confidence: 99%

Effect of the Electrolyte Concentration and Substrate on Conducting Polymer Actuators

2014

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“…In comparison with that on IL-ERGO/ACF, the PtAu electrodeposited on bare ACF shows a much lower particle density and a larger size ranging from 30 to 70 nm (Supplementary Figure S5). This phenomenon can be explained as 4 ] molecules may act as templates for the formation of nanostructures, such as supramolecular structures formed via hydrogen bonds. 33,34 Alternatively, the nucleation of PtAu alloy nanoparticles occurs at the dense edge-plane-like defects on ERGO nanosheets, which stabilizes the PtAu alloy nanoparticles on the ERGO scaffold.…”

Section: Morphological and Structural Characterizationmentioning

confidence: 99%

“…[1][2][3] In addition, the high temporal resolution for fast electron/mass transfer due to nonplanar diffusion [4][5][6] and the intrinsic mechanical and deformational characteristics enable such electrodes to be rolled up and incorporated into compact electrochemical sensor systems. The miniaturized integrated sensor devices based on fiber microelectrodes open the possibility of measuring miniscule body fluid sample volumes for in vitro analysis and minimally invasive in vivo clinical analysis; [7][8][9] such devices also provide new insight into near-cell and even intracellular biological signals that can be isolated from the surroundings.…”

Section: Introductionmentioning

confidence: 99%

PtAu alloy nanoflowers on 3D porous ionic liquid functionalized graphene-wrapped activated carbon fiber as a flexible microelectrode for near-cell detection of cancer

et al. 2016

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Recent advances in flexible fiber-based microelectrodes have opened a new horizon for sensitive real-time near-cell and even intracellular measurements. In this work, we develop a new type of hierarchical nanohybrid microelectrode based on three-dimensional (3D) porous graphene-wrapped activated carbon fiber (ACF) via a facile and effective electrodeposition of graphene oxide (GO) nanosheets on ACF using a green ionic liquid (IL) as the electrolyte. This technique enables the simultaneous electrodeposition and electrochemical reduction of GO nanosheets on ACF to form 3D porous IL functionalized electrochemically reduced GO (ERGO)-wrapped ACF (IL-ERGO/ACF). The adsorbed IL molecules on the ERGO surface provide sufficient active sites and act as the template for the in situ electrodeposition of highly dense and well-dispersed bimetal PtAu nanoflowers on the 3D IL-ERGO scaffold. By virtue of the unique array of structural and chemical properties of bimetal PtAu nanocatalysts and 3D porous IL-ERGO on ACF, the resultant PtAu nanoflowers-decorated IL-ERGO/ACF (PtAu/IL-ERGO/ACF) microelectrode demonstrates a variety of excellent sensing performances, including high sensitivity, a wide linear range and good selectivity in the electrochemical detection of a newly emerged cancer biomarker, hydrogen peroxide (H 2 O 2 ). When used for the real-time tracking of H 2 O 2 secreted from female cancer cells, such as breast cancer cells and gynecological cancer cells, the electrochemical sensor based on the PtAu/IL-ERGO/ACF microelectrode provides important information for distinguishing between different cancer cells and normal cells and for evaluating the therapeutic activity of antitumor drugs towards live cancer cells, which are of great clinical significance for cancer diagnosis and management.

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“…The exploration of new materials, including gold nanoparticles, carbon nanotubes or quantum dots is an extremely promising route to achieve this goal. Essential progress has also been made in recent years in the miniaturization of transducers (nanoelectrodes, nanowaveguides, BioMEMS) and will contribute to reduce significantly the amount of biological entity required, but also to improve integration of the systems in labs on chips (Ligler, 2009;Wei et al, 2009 …”

Section: Resultsmentioning

confidence: 99%