Amperometric glucose biosensor based on immobilization of glucose oxidase in electropolymerized o-aminophenol film at copper-modified gold electrode

Abstract

Amperometric glucose biosensor is developed, based on immobilization of glucose oxidase (GOD), in an electrochemically polymerized non-conducting poly( o-aminophenol) (POAP) film at copper (Cu)-modified gold (Au) electrode. The rough surface and the ability to electrochemically oxidize glucose of Cu nanoparticles result in the improvement of the detection limit and the increase of the maximum response current and sensitivity. The biosensor based on Au/Cu/POAP/GOD electrode has two times lower detection limit, three times larger maximum current and 2.5 times higher sensitivity than those of the biosensor based on Au/POAP/GOD electrode. Additionally, the fast response time, large response current and good selectivity for ascorbic acid, uric acid and acetaminophen can also be obtained. On the other hand, effects of electrochemical deposition time of Cu, applied potential used in the determination and electroactive compounds on the amperometric response of the enzymatic sensor were investigated and discussed. Excellent reproducibility and stability of biosensor are also observed.