Development of a Bienzymatic Amperometric Glucose Biosensor Using Mesoporous Silica (MCM-41) for Enzyme Immobilization and Its Application on Liquid Pharmaceutical Formulations

This paper describes the development and optimization of an amperometric bienzymatic biosensor for glucose, based on glucose oxidase (GOX) and peroxidase (HRP), immobilized on mesoporous silica with hexagonal symmetry (MCM‐41). The mesoporous material was immobilized by Nafion assisted adsorption on a glassy carbon electrode, which was used as working electrode. Measurements were performed in a conventional three electrode cell using a Ag/AgCl reference electrode and platinum wire as counter electrode. Operating parameters such as GOX/HRP enzyme ratio, mediator (catechol) concentration, applied potential and pH were optimized. The proposed biosensor showed excellent analytical performance with detection and quantification limits of 8.6×10−6 M and 2.5×10−5 M, respectively; analytical sensitivity of 4.67×10−4 AM−1, repeatability