Integration of a glucose biosensor based on an epoxy-graphite-TTF·TCNQ-GOD biocomposite into a FIA system

An amperometric glucose biosensor based on graphite and non-conducting epoxy resin biocomposite was constructed. Glucose oxidase (GOD) and the tetrathiafulvalene-tetracyanoquinodimethane (TTF·TCNQ) conducting organic salt were incorporated into the bulk of the composite to form a renewable biosensor. Several graphite-TTF·TCNQ ratios (w/w) were studied in order to select the best biosensor to be integrated in a FIA system for the automated detection of glucose. The optimal amount of GOD in the composite was studied as well. The selection was based on the analytical response of the electrodes. Best results were obtained by an electrode whose composition was 5% GOD, 76% polymer, 9.5% graphite and 9.5% TTF·TCNQ. An especially designed flow amperometric cell was constructed so that the biosensor could be integrated into a FIA system and glucose in beverage samples could be determined.