Electrochemical and Spectroscopic Characterization of Glucose Oxidase Immobilized in Polyvinyl Alcohol and Applications in Glucose Detection

摘要

A simple and novel amperometric biosensor for glucose detection is proposed. It is based on the immobilization of glucose oxidase in a poly(vinyl alcol) matrix drop casted on a platinum electrode surface (Pt/GOx-PVA). The composite material GOx-PVA has been characterized by UV-vis spectroscopy to verify the preservation of enzyme structural integrity and of the enzymatic activity in PVA membrane. X-ray Photoelectron Spectroscopy (XPS) characterization revealed a homogeneous film deposited on Pt whose structure is preserved under operative conditions. Glucose was determined in the absence of a mediator used to transfer electrons between the electrode and the enzyme. Amperometric characterization has been performed at -400 mV by using pulsed amperometric detection (PAD). Under the selected optimal conditions, the biosensor showed wide dynamic range (0.1-37 mM) yielding a low limit of detection (10 μM). Biosensor performance was satisfactory also in terms of repeatability, reproducibility and anti-interference ability.