An interference-free glucose biosensor based on a novel low potential redox polymer mediator

A highly sensitive and interference-free glucose biosensor based on a novel ruthenium complex-tethered redox polymer (Ru-RP) mediated enzymatic oxidation of glucose at −0.15 V (vs. Ag/AgCl) is described in this report. Through the co-immobilization of the Ru-RP and glucose oxidase (GOx) on a glassy carbon electrode (GCE) via a simple one-step chemical crosslinking process with glutaraldehyde, the crosslinked membrane displays excellent catalytic activity toward the oxidation of glucose with a current sensitivity of 24.3 μA mM−1 cm−2 and a linear correlation between the oxidation current and glucose concentration up to 10 mM. More importantly, owing to the low operating potential of −0.15 V (vs. Ag/AgCl), potential interferences from naturally occurring interfering species in blood such as ascorbic acid, dopamine, uric acid, and common drug acetaminophen are effectively alleviated. Furthermore, the hydrophilic nature of the crosslinked membrane also effectively retards the diffusion of molecular oxygen. This glucose biosensor could be an attractive candidate in the development of miniaturized glucose biosensors.