Current response to D-fructose based on electron transfer from fructose dehydrogenase incorporated in a polyion complex membrane

A polyion complex membrane containing fructose dehydrogenase (FrDH) was prepared. A FrDH solution, a polystyrene sulfonate solution and a poly-L-lysine solution were successively placed on a glassy carbon electrode; the electrode was then dried for 4 hr. The current response caused by electron transfer from FrDH to fructose was observed; the response time was short (similar to 15 s). The response current was proportional to the fructose concentration up to 10 mM, and the lower detection limit was 1 mM (S/N = 5). The electrode could detect the fructose concentration based on the current caused by the transferred electron.