Silicon dioxide surfaces, both bulk and porous, were used to anchor the enzyme glucose oxidase. The immobilization protocol was optimized and the samples characterized using X-ray Photoelectron Spectroscopy, Energy Dispersive X-rays coupled to scanning electron microscopy and enzymatic activity measurements. We show that a uniform layer was obtained by activating the oxide before immobilization...

Scanning Electrochemical Microscopy is a tool for imaging and investigate surfaces by meaning of chemical reactivity, electric conductivity, and enzymatic activity. This technique is typical electrochemical cell plus three axis positioner. Positioner allows to measure typical electrochemical measurements, like Cyclic Voltammetry, Chronoamperometry, Impedance Spectroscopy, etc. in the vicinity o...

Glucose oxidase (GOx) is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state) to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H₂O₂). GOx has found...

Glucose, as the major energy source in cellular metabolism, plays an important role in the natural growth of cells. Herein, a simple, rapid and low-cost method for the glucose determination by utilizing glucose oxidase and CdTe/thioglycolic acid (TGA) quantum dots (QDs) on a thin layer chromatography (TLC) plate has been described. The detection was based on the combination of the glucose enzym...

Co-precipitation of enzymes in metal-organic frameworks is a unique enzyme-immobilization strategy but challenged by weak acid-base stability. To overcome this drawback, we discovered that Ca2+ can co-precipitate with carboxylate ligands and under ambient aqueous conditions form [email protected] material composites stable wide range pHs (3.7–9.5). We proved on four varied isoelectric points, m...

We have tested the tumoricidal potency of enzyme immunotoxins constructed of antibodies conjugated to glucose oxidase and to lactoperoxidase. Murine plasmacytoma cells were targeted in vitro with the use of affinity-purified rabbit anti-plasmacytoma membrane antibodies (conjugated to glucose oxidase or lactoperoxidase) or rabbit serum raised against plasmacytoma microsome membranes followed by ...

A diffusion-kinetic model is presented for an enzyme-modified microcylinder electrode, where the enzyme reaction generates an electro-active product. Simple, approximate expressions are derived for the steady-state current in cases where the enzyme is immobilized in a metallically conducting, or a non-conducting matrix. The model is also extended to the chemical sensor case, of a conducting pol...

background and objectives : the attempts were made to describe the development of a whole cell immobilization of p. pastoris by entrapping the cells in polyacrylamide gel beads. the alcohol oxidase activity of the whole cell pichia pastoris was evaluated in comparison with yeast biomass production. materials and methods : methylotrophic yeast p. pastoris was obtained from collection of standard...

A cellulose-based glucose oxidase membrane was prepared on a glassy carbon (GC) electrode. The current response of the electrode to glucose was measured by applying a potential of 1.0 V vs. Ag/AgCl on the base GC and was proportional to the concentration of glucose up to 1 mM. The long-term stability of the electrode was examined by measuring the daily glucose response. Over four months, the re...

Glucose oxidase (/3-n-glucose : 02 oxidoreductase, EC 1.1.3.4) has been highly purified from the extracts of three fungi, Penicillium not&urn (1, 2), Penicillium amagasakiense (3, 4), and Aspergillus niger (5, 6). It has also been identified and sometimes partially purified from a number of other sources. Some of these sources are reviewed by Schepartz and Subers (7). Recently Pazur and Kleppe ...