A L-ascorbic acid biosensor based on ascorbate oxidase has been developed. The enzyme was extracted from the mesocarp of cucumber (Cucumis sativus) by using 0.05 mol L phosphate buffer, pH 5.8 containing 0.5 mol L NaCl. After the dialysis versus phosphate buffer 0.05 mol L pH 5.8, the enzyme was immobilized onto nylon net through glutaraldehyde covalent bond. The membrane was coupled to an O 2 ...

carbon nanotubes are regarded as promising building blocks for the construction of novel biosensors due to their unique properties like fast electron transfer, high electrocatalytic effect and good biocompatibility. in the present study, the effect of different chemical oxidation’s methods of multi-walled carbon nanotubes (mwcnts) on the electrochemical behavior of modified graphite electrodes ...

Studies on the possible r&e of reduced glutathione (GSH) in the conversion of the drugs nitroglycerin and erythritol tetranitrate to nitrites (1) and in the reduction of methemoglobin to hemoglobin (2) have led to the need for a method of determining GSH in the presence of nitrite. The common methods for GSH cannot be employed for this purpose because nitrite interferes with the analyses. This ...

In this paper, the hemoglobin (Hb)-collagen microbelt modified electrode with three-dimensional configuration was fabricated via the electrospinning method. Direct electron transfer of the Hb immobilized into the electrospun collagen microbelts was greatly facilitated. The apparent heterogeneous electron transfer rate constant (k(s)) was calculated to be 270.6s⁻¹. The electrospun Hb-collagen mi...

A novel exogenous time-temperature integrator (TTI) based on an amperometric glucose oxidase biosensor is presented. The TTI consists of the enzyme entrapped within an electrochemically generated poly(o-phenylenediamine) (PoPD) thin film deposited on the interior wall of a platinum (Pt) or a platinized stainless steel (Pt-SS) capsule. After thermal treatment, the TTI is mounted in a continuous ...

A simple amperometric detection (AD) method based on mesoporous platinum (Pt) electrodes has been developed for the determination of sugars (glucose, fructose, and sucrose) with high-performance anion-exchange chromatography (HPAEC). The amperometric detection is based on the direct oxidation of sugars on mesoporous Pt films formed on a gold electrode. The mesoporous Pt electrode (roughness fac...

A sensitive and selective amperometric procedure, based on a glassy carbon electrode (GCE) modified with a thin multi-wall carbon nanotube (MWNT) film, for the determination of ascorbic acid (AA) was developed. The modified electrode showed excellent electrocatalytic activity towards the oxidation of AA. The oxidation potential of AA shifted negatively by as much as 460 mV to –18 mV (vs. SCE) a...

The purpose of this study was to develop novel nanoscale biosensors using titania nanotubes (TNTs) made by anodization. Titania nanotubes were produced on pure titanium sheets by anodization at room temperature. In this research, the electrolyte composition ethylene glycol 250 mL/NH4F 1.5 g/DI water 20 mL was found to produce the best titania nanotubes array films for application in amperometri...

The preparation of a cholesterol amperometric biosensor using a platinized Pt electrode as a support for the electropolymerization of a polypyrrole film, in which cholesterol oxidase and ferrocene monocarboxylic acid (electron-transfer mediator) were co-entrapped, is described. All the biosensor preparation steps (platinization and electropolymerization) and the cholesterol determination take p...

The roles of nonmuscle myosin II and cortical actin filaments in chromaffin granule exocytosis were studied by confocal fluorescence microscopy, amperometry, and cell-attached capacitance measurements. Fluorescence imaging indicated decreased mobility of granules near the plasma membrane following inhibition of myosin II function with blebbistatin. Slower fusion pore expansion rates and longer ...