An ultrasensitive nanobiohybrid platform for glucose electrochemical biosensing based on ferrocenyl iminopropyl-modified silica nanoparticles

Abstract

A novel nanobiohybrid platform based on ferrocenyl iminopropyl-modified silica nanoparticle conjugates (fap-SiNPs), entrapped in glucose oxidase (GOx) and bovine serum albumin cross-linked with glutaraldehyde, was developed. The as-synthesized nanobiohybrid composite was cast onto a p-aminothiophenol-modified gold electrode surface to form the platform for glucose electrochemical biosensing. Under optimal conditions, the device was able to detect glucose with a detection limit of 0.68 nM and a linear range from 1 nM to 100 μM. The proximity of these three components: fap-SiNPs, aminothiophenol and GOx enhanced the electron-transfer between film and electrode. The applicability of the platform was tested on glucose detection in saliva. Furthermore, using HRP instead of GOx, the platform can be used to detect 1 pM of H₂O₂.