Enhancement of amperometric response of glucose biosensor by electrodeposition of silver nanoparticles onto chitosan-modified electrode

Abstract

A highly sensitive biosensor based on silver nanoparticles (AgNPs) was fabricated for glucose detection in aqueous phase. Firstly, a platinum (Pt) electrode was modified with the mixture of glucose oxidase and chitosan. AgNPs were electrodeposited into the modified electrode by single pulse potentiostatic method at –0.4 V. The electrochemical performance of the modified electrode was evaluated by cyclic voltammetry and amperometry. The fabricated biosensor had a high sensitivity of 58.6 μA mM−1 cm−2 and detection limit of 4.4 μM glucose at a signal to noise ratio of 3. In addition, the biosensor showed a short response time less than 5 s and a wide linear range of 0.05-11.5 mM. The apparent Michaelis–Menten constant (KM) was found to be 9.14 mM. In addition, thermal stability and anti-interference ability of the biosensor were investigated. The results demonstrated that AgNPs enhanced the analytical performance of the biosensor.