Improvement of amperometric glucose biosensor by the immobilization of FcCD inclusive complex and carbon nanotube

Abstract

A novel glucose biosensor was constructed by using ferrocene-carbonyl-β-cyclodextrin (FcCD) inclusive complex as electron-transfer mediator and carbon nanotubes (CNTs) as electron-transfer promoter. FcCD inclusive complex and glucose oxidase (GOx) were covalently bonded to CNTs by poly-L-lysine (PLL) to fabricate a glucose biosensor. The electrocatalytic oxidation of glucose at the biosensor occurred at low potential below 200 mV, avoiding the interference of the main interfering substances in real samples containing a 5-times higher concentration of L-cysteine, ascorbic acid, and uric acid. The biosensor showed fast response for glucose. A broad linear range of glucose concentration from 1.0 × 10⁻⁵ to 2.90 × 10⁻³ M was obtained and the detection limit was 2.2 × 10⁻⁶ M.