Sensitivity of a glassy carbon electrode covered with a chitin film improved by the addition of carbon powder.

The redox activity of a chitin film on a glassy carbon electrode was remarkably improved by the addition of carbon powder to the film in the detection of ascorbic acid, flavin adenine dinucleotide (FAD) and nicotinamide adenine dinucleotide (NADH). Although oxidation of ascorbic acid using the electrode with the chitin film did not give an appreciable voltametric response, the addition of carbon powder to the film greatly improved its activity up to a 95% level of the bare carbon electrode. For FAD and NADH, an increase in each oxidation peak was observed in a similar manner. The improvement was due to electron mediation of the carbon powder contained in the film. Thus, the electrode effectively recovers the sensitivity for some biological molecules, and thus becomes a powerful device to monitor reactions between biological molecules. Because both carbon and chitin are materials with high biocompatibility, the film can be considered as cell scaffolds. Furthermore, the film immobilized on the plate has a possibility as an electrode in itself.