A new approach for the integration of dual contactless conductivity and amperometric detection with an electrophoresis microchip system is presented. The PDMS layer with the embedded channels was reversibly sealed to a thin glass substrate (400 microm), on top of which a palladium electrode had been previously fabricated enabling end-channel amperometric detection. The thin glass substrate serv...

A differential-type amperometric biosensor based on conventional thick-®lm technology has been developed for breath alcohol measurement. The amperometric breath alcohol biosensor utilizes the alcohol dehydrogenase (ADH) and nicotinamide adenine dinucleotide (NAD‡) cofactor which produce reduced NADH as a product of the oxidation of alcohol. The biosensor was designed in a differential format co...

Liquid chromatography with amperometric detection remains the most widely used method for acetylcholine quantification in microdialysis samples. Separation of acetylcholine from choline and other matrix components on a microbore chromatographic column (1 mm internal diameter), conversion of acetylcholine in an immobilized enzyme reactor and detection of the produced hydrogen peroxide on a horse...

A sensitive and selective amperometric sensing platform for lead (Pb(2+)) was developed based on a Pb(2+)-induced G-rich DNA conformational switch from a random-coil to G-quadruplex (G4) with crystal violet as the G4-binding indicator.

Chromaffin cells release catecholamines by exocytosis, a process that includes vesicle docking, priming and fusion. Although all these steps have been intensively studied, some aspects of their mechanisms, particularly those regarding vesicle transport to the active sites situated at the membrane, are still unclear. In this work, we show that it is possible to extract information on vesicle mot...

Nanoparticles of TiO(2) or SnO(2) on screen-printed carbon (SP) electrodes have been developed for evaluating their potential application in the electrochemical sensing of volatiles in fruits and plants. These metal oxide nanoparticle-modified electrodes possess high sensitivity and low detection limit for the detection of p-ethylguaiacol, a fingerprint compound present in the volatile signatur...

This paper describes the electrocatalytic behaviour of a glassy carbon electrode (GCE) modified with cobalt(II)phthalocyanine (CoPc) complex peripherally tetrasubstituted with cobalt(II)tetraphenylporphyrin (CoTPP) complexes via ether linkages (i.e., CoPc-(CoTPP)4). The features of the immobilised pentamer were interrogated with cyclic voltammetry and electrochemical impedance spectroscopy (EIS...

The excellent catalytic activity of a novel carbon nanomaterial, soluble carbon nanofiber (CNF) with good dispersion and wettability, to the oxidation of dihydronicotinamide adenine dinucleotide (NADH) was described for biosensing application. The edge plane sites and oxygen-rich groups presented on the CNF surface could be partially responsible for its electrocatalytic behavior, which induced ...

A cholesterol oxidase from Streptomycin sp. was immobilized onto pencil graphite rod and employed for amperometric determination of serum cholesterol. The method has the advantage over earlier amperometric methods that it requires low potential to generate electrons from H2O2, which does not allow ionization of serum substances. The optimum working conditions of amperometric determination were ...

A biosensor platform based on polyamic acid (PAA) is reported for oriented immobilization of biomolecules. PAA, a functionalized conducting polymer substrate that provides electrochemical detection and control of biospecific binding, was used to covalently attach biomolecules, resulting in a significant improvement in the detection sensitivity. The biosensor sensing elements comprise a layer of...