DIAMOND-LIKE CARBON-FILMS FOR ENZYME ELECTRODES - CHARACTERIZATION OFNOVEL OVERLYING PERMSELECTIVE BARRIERS

Diamond like carbon (DLC) coated microporous polycarbonate membranes h ave been studied for use as novel composite permselective barriers mem branes for a glucose enzyme electrode. Permeability coefficients, P, f or key electrochemically active interferents across uncoated and DLC c oated polycarbonate membranes has been compared. Interferent responses have then been assessed for sensors incorporating such membranes, and their relationship to differing DLC depositions assessed. Membranes w ith smaller pore sizes (0.03 and 0.01 mu m) and extended DLC depositio ns (up to 7 min coating), while imparting some enhanced selectivity to wards glucose, failed to show major discrimination for glucose over in terferents as shown by P values: maximum glucose-to-interferent P rati os being 1.36 and 1.25 for ascorbate and urate, respectively. The impl ications of these findings are discussed.