This paper describes a diffusion-controlled electrolysis of glucose with mediated bioelectrocatalysis at microdisk-electrodes. Under conditions of an extremely fast enzyme reaction, compared with the diffusion of glucose, the current in potential-step chronoamperometry reaches an almost steady state within 10 s, and is proportional to the glucose concentration. The current can be detected at +0...

A facile hydrothermal route for the synthesis of ordered NiWO4 nanocrystals, which show promising applications as high performance non-enzymatic glucose sensor is reported. The NiWO4-modified electrodes showed excellent sensitivity (269.6 μA mM(-1 )cm(-2)) and low detection limit (0.18 μM) for detection of glucose with desirable selectivity, stability, and tolerance to interference, rendering t...

electrochemically generated iron can remove most contaminants present in water and wast water, by precipitation, adsorption, electrostatic interaction, and complex formation (generally called electrocoagulation-ec). in the present paper, pretreatment of brackish water having high total hardness (th), alkalinity (a),  and cl¯ ions, is studied by application of a dc-electrical current ot the iron...

Optical sensor arrays typically require a large set of chemically responsive colorants to enhance discrimination capability. Conversely, we have proven that by using multiple concentrations of one indicator, the discrimination of various analytes could be realized.

• Grafting of glucose oxidase to carbon nanotubes improves enzyme activity. Design-of-experiments used evaluate optimum component amount for electrode preparation. Higher current density compared one-factor-at-a-time approach. Enzymatic electrodes based on mediated electron transfer have potential application as semi-implantable or implantable sensors. Enzyme consisting adsorbed osmium-based re...

We demonstrate a glucose sensor based on an organic electrochemical transistor (OECT) in which the channel, source, drain, and gate electrodes are made from the conducting polymer poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate) (PEDOT:PSS). The OECT employs a ferrocene mediator to shuttle electrons between the enzyme glucose oxidase and a PEDOT:PSS gate electrode. The device...

Laccase, a multicopper oxidase, catalyses the four electron reduction of oxygen to water. Upon adsorption to an electrode surface, laccase is known to reduce oxygen at overpotentials lower than the best noble metal electrocatalysts usually employed. While the electrocatalytic activity of laccase is well established on carbon electrodes, laccase does not typically adsorb to better defined noble ...

Self-assembled DNA nanostructures with precise sizes allow a programmable "soft lithography" approach to engineer the interface of electrochemical DNA sensors. By using millimeter-sized gold electrodes modified with several types of tetrahedral DNA nanostructures (TDNs) of different sizes, both the kinetics and thermodynamics of DNA hybridization were profoundly affected. Because each DNA probe...

An investigation on nano-structured electrodes to detect different metabolites is proposed in this paper. Three different metabolites are considered: glucose, lactate, and cholesterol. The direct detection of hydrogen peroxide is also considered since it does not involve any enzyme. The metabolites and the peroxide were detected by using screen-printed electrodes modified by using multi-walled ...

The fabrication of ultrathin-ring electrodes with a diameter of 2 mm and a thickness of 100 nm is established. The ultrathin-ring electrodes provide a large density of pseudo-steady-state currents, and realize pseudo-steady-state amperometry under quiescent conditions without a Faraday cage. Under the limiting current conditions, the current response at the ultrathin-ring electrode can be well ...