Glow-discharge-treated cellulose acetate (CA) membrane for a high linearity single-layer glucose electrode in the food industry

The aim of this study was to develop a single-layer glucose enzyme electrod e with extended linearity to be used in the food industry in order to deter mine the glucose content. An amperometric-based probe-type glucose enzyme e lectrode with Pt working electrode and Ag/AgCl reference electrode polarise d at + 650 mV was used. In this study, permselective behaviour of different polymeric membranes, which were prepared in our laboratory (cellulose acet ate, polyurethane, polyetersulphone) and commercially available tract-etche d pulycarbonate, were investigated at different pH values (pH 4, 6, 7.4, 10 ) to estimate the magnitude of interferences caused by a group of different electroactive compounds. The selectivity tests showed that cellulose aceta te membranes were the most convenient structure to establish a single-membr ane recognition layer. The single surface of the cellulose acetate membrane s was then modified with a plasma polymerisation technique at different glo w-discharge parameters with amylamine monomer in order to show the effect o f plasma polymerisation. The plasma-treated surface of the membranes was ac tivated with glutaraldehyde then glucose oxidase (GOD) immobilised onto thi s site. The linearity and response time of these electrodes were investigat ed at pH 4 and 6. According to the results of linearity and response time t ests, cellulose acetate membranes treated with amylamine: at 5 W/20 min sho wed the best result. The linearity acid response time of this electrode wer e found to be 320 mM glucose and 500 s, respectively at pH 4. Finally, the GOD electrode which was prepared with the most convenient membrane was used to determine the glucose content of some food stuff. Similar results were observed with the conventional measurement method. (C) 2000 Published by El sevier Science Ltd. All rights reserved.