Glucose biosensor using fluorescence quenching with chitosan‐modified graphene oxide

Abstract

A novel graphene oxide (GO) nanomaterial, which was rapidly and simply synthesised and conjugated with low‐molecular‐weight chitosan (CS), was used to develop a simple, sensitive GO biosensor system for glucose detection by fluorescence resonance energy transfer. The GO‐CS was used to detect low concentrations of glucose based on competitive binding with maltose‐binding protein (MBP). The α‐subunit of recombinant phycocyanin (rPC), which emits far‐red fluorescence, was used to label MBP (MBP‐rPC). The rPC emission was quenched by binding between GO‐CS and MBP. However, in the presence of glucose, GO‐CS was out‐competed for binding to MBP, leading to rPC fluorescence. Glucose was sensitively and selectively detected with this biosensor, with a linear detection range of 0.1–1 mg glucose/ml. The limit of detection for glucose was ∼0.05 mg/ml.