Abstract
An amperometric glucose-sensing electrode was prepared by immobilizing glucose oxidase (GOx) on a polyion complex-modified glassy carbon (GC) electrode. First, a GC electrode was anodized in a 1, 5-pentanediol solution to introduce carboxyl groups on the electrode surface. Next, aqueous solutions of poly-L-lysine and poly (4-styrenesulfonate) were successively placed on the electrode and allowed to dry. Finally a GOx layer was formed on the poly-L-lysine/poly(4-styrenesulfonate)-complex layer by crosslinking the enzyme by the addition of glutaraldehyde. The use of the thin bilayer system with inner, polyion complex membrane, which showed permselectivity based on the solute size with molecular cut-off of ca. 100, brought about high performance characteristics, such as rapid response and low interference level, to the glucose-sensing electrode. The enzyme electrode was useful for the measurement of glucose in beverages involving vitamin C-enriched drinks.
