Electrochemical Sensing of Glucose at a Platinum Electrode with a Chitin/Glucose Oxidase Film

Chitin powder was dissolved in a mixed solution of N,N-dimethylacetoamide and 1-methyl-2-pyrrolidone with lithium chloride. The chitin solution was adhered to the film. Glucose oxidase having a negative charge was immobilized to the protonated chitin film in 0.1 mol dm-3 acetate buffer (pH 5.0), based on electrostatic interaction. The interaction is useful and convenient for an immobilization of the enzyme. In this study, glucose sensor was developed at a platinum electrode with a chitin/glucose oxidase film as an application of chitin in analytical chemistry. An oxidation peak of H2O2 from the enzyme reaction was observed at +0.5 V (vs. Ag/AgCl) in 0.1 mol dm-3 acetate buffer (pH 6.2). The calibration curve of glucose was linear in the range from 5×10-7 to 3×10-5 mol dm-3. The sensor was applied to determination of glucose in sports drinks.