A NEW CONDUCTING POLYMER GLUCOSE SENSOR-BASED ON POLYTHIANAPHTHENE

A glucose biosensor has been developed by entrapment of glucose oxidas e in a polythianaphthene film formed onto a platinum surface. Glucose has been measured by H2O2 detection at +400 mV (vs. SCE). Electrochemi cal kinetic constants for the enzyme electrode have been calculated an d indicated that in the unsaturated region the rate limiting step is t he diffusion of the substrate through the polymer. The biosensor exhib ited a linear response in the range 0.05-7.4 mmol/L with a response ti me of 30-60 s and a relative standard deviation of 5.4%. The presence of the film onto the electrode prevents the oxidation of interfering a gents such as ascorbic and uric acid. The use of additional polycarbon ate membranes onto the electrode surface extended the linearity of the response allowing the probe to be used in blood glucose analysis. The amount of glucose in two control sera was measured using the biosenso r. Results correlated well with the glucose nominal values.