A novel amperometric glucose biosensor based on poly(glycidyl methacrylate-co-(3-thienylmethylmethacrylate))

Two novel glucose oxidase (GOx) enzyme electrodes based on the copolymer of glycidyl methacrylate with 3-thienylmethyl methacrylate (poly(GMA-co-MTM)) with and without polypyrrole (PPyr) coating were prepared and employed in the amperometric determination of glucose levels. The effect of PPyr coating on the electrode properties was investigated in detail. Cyclic voltammetry studies showed that electrical conductivity of electrode B with PPyr coating (poly(GMA-co-MTM)/GOx/PPyr) was substantially higher than that of electrode A (poly(GMA-co-MTM)/GOx). On the other hand, electrode A showed better results in terms of sensitivity (10 nA/mM), limit of detection (50.2 μM), and response time (5 s). Electrodes A and B gave linear responses to the glucose concentrations in the range of 2–20 and 2–14 mM, respectively. The ranges of linearity for both enzyme electrodes are sufficient for the determination of physiological glucose concentrations in human blood. Moreover, PPyr coating of electrode B did not result in further stabilization of the enzyme electrode.

► Two enzyme electrodes (A and B) were constructed by covalent immobilization of GOx on poly(GMA-co-MTM) modified GC electrodes. ► Electrode B was electrochemically coated with polypyrrole. ► Electrode A responded much faster than electrode B. ► The response of the biosensors was linear in the range of physiological glucose concentrations in human blood.