Biocompatible Graphene Oxide-Based Glucose Biosensors

TLDR

Microporous graphene oxide is biocompatible and supports cell attachment, making it promising for clinical biosensor applications. The study aims to develop a covalently bonded glucose oxidase–graphene oxide enzyme electrode and to evaluate its biocompatibility with retinal pigment epithelium cells. The electrode is fabricated by covalently linking glucose oxidase to graphene oxide sheets via carboxyl–amine chemistry, and biocompatibility is assessed on retinal pigment epithelium cells. The biosensor shows a linear response up to 28 mM·mm⁻² with a sensitivity of 8.045 mA cm⁻² M⁻¹, and demonstrates reproducibility and good storage stability, indicating practical applicability.

Abstract

This letter demonstrates that a novel, highly efficient enzyme electrode can be directly obtained using covalent attachment between carboxyl acid groups of graphene oxide sheets and amines of glucose oxidase. The resulting biosensor exhibits a broad linear range up to 28 mM·mm−2 glucose with a sensitivity of 8.045 mA·cm−2·M−1. The glucose oxidase-immobilized graphene oxide electrode also shows a reproducibility and a good storage stability, suggesting potentials for a wide range of practical applications. The biocompatibility of as-synthesized graphene oxide nanosheets with human cells, especially retinal pigment epithelium (RPE) cells, was investigated for the first time in the present work. Microporous graphene oxide exhibits good biocompatibility and has potential advantages with respect to cell attachment and proliferation, leading to opportunities for using graphene-based biosensors for the clinical diagnosis.