Amperometric l-ascorbic acid biosensors equipped with enzyme micelle membrane

Ascorbate oxidase (ASOD) bound to polymaleimidostyrene (PMS) forms stable ASOD micelle structure in polystyrene (PS) membrane. The oxygen permeable hydrophobic ASOD micelle membrane were coated on both aminated glassy carbon electrode (AGCE) and gold electrode (AuE) for the amperometric detections of l-ascorbic acid (AsA) based on the consumption of oxygen. These AsA sensors have good sensitivities with short response time (within 1 min.). A good linear relationship was observed in the concentration range of 5 μM to 0.4 mM when AGCE was used and the applied potential was −0.5 V vs. Ag/AgCl. Interferences from the reducing agents can be avoided because the detections were conducted at cathodic potential.