Glucose amperometry

Total glucose Amperometry 10-600nmol - Fermentation process... 

Enzyme sensors are based primarily on the immobilization of an enzyme onto an electrode, either a metallic electrode used in amperometry (e.g., detection of the enzyme-catalyzed oxidation of glucose) or an ISE employed in potentiometry (e.g., detection of the enzyme-catalyzed liberation of hydronium or ammonium ions). The first potentiometric enzyme electrode, which appeared in 1969 due to Guilbault and Montalvo [140], was a probe for urea with immobilized urease on a glass electrode. Hill and co-workers [141] described in 1986 the second-generation biosensor using ferrocene as a mediator. This device was later marketed as the glucose pen . The development of enzyme-based sensors for the detection of glucose in blood represents a major area of biosensor research. 

Tubular electrodes. Blaedel et al.161 were the first to introduce the TBE, a tubular electrode. It was constructed by melting a Pt cylinder in a glass capillary (see Fig. 5.25), the total length of Pt being 25.5 mm and its diameter 0.75 mm. The authors originally used it for an enzymatic determination of glucose by means of differential amperometry based on the following sequential reactions"12 ... 

In amperometry, the current at the working electrode is proportional to analyte concentration. The amperometric glucose monitor generates H202 by enzymatic oxidation of glucose and the H202 is measured by oxidation at an electrode. A mediator is employed to rapidly shuttle electrons between electrode and analyte. 

Arg, Met-Gly, glucose PDMS DC amperometry End-channel (off-chip) Copper [122]... 

Enzymeassays Glucose, creatinine, uric and Glass DC amperometry... 

Fig. 3-105. Separation of various sugar alcohols and saccharides. - Separator column CarboPac PA-1 eluent 0.15 mol/L NaOH flow rate 1 mL/min detection pulsed amperometry at a Au working electrode injection volume 50 pL solute concentrations 10 ppm xylitol, 5 ppm sorbitol, 20 ppm each of rhamnose, arabinose, glucose, fructose, and lactose, 100 ppm sucrose and raffmose, 50 ppm maltose.

Fig. 3-110. Gradient elution of various mono- and disaccharides. - Separator column IonPac AS6A eluent (A) water, (B) 0.05 mol/L NaOH gradient linear, from 7% B to 100% B in 15 min flow rate 0.8 mL/min detection pulsed amperometry at a Au working electrode with post-column addition of NaOH injection volume 50 pL solute concentrations 15 ppm inositol (1), 40 ppm sorbitol (2), 25 ppm fucose (3) and deoxyribose (4), 20 ppm deoxyglucose (5), 25 ppm arabinose (6), rhamnose (7), galactose (8), glucose (9), xylose (10), mannose (11), fructose (12), melibiose (13), isomaltose (14), gentiobiose (15), and cellubiose (16), 50 ppm turanose (17), and maltose (18).

Figure 4. (A) Current-time trace recorded upon introduction of [Fe(CN)6] , menadione and glucose to S. cerevisiae cells on an electrode microchip. (B) A silicon microchip for mediated amperometry (upper panel) and a microscope image of S. cerevisiae cells on a microband electrode (widtMength 25/1,000 pm). (Reprinted with permission from Ref. [8], 2009 Elsevier BV.) (Lower panel).

D-Glucose oxidase has been immobilized for use in a number of analytical systems. Immobilization of the enzyme onto nonporous glassy carbon electrodes by carbodi-imide-mediated coupling to superficial oxides generated by anodic oxidation has afforded an immobilized enzyme electrode with which hydrogen peroxide released enzymically from D-glucose may be measured amperometri-cally. Properties of the enzyme immobilized on amino-organo-sylochrome have been studied. 

Glucose Glucose oxidase Polypyrrole Amperometry Potentiometry... 

Glucose determination Glucose oxidase Injection of sample in enzyme containing running electrolyte, electrophoretic separation from interferents Amperometry (Au electrode)... 

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