Simple method for O-GlcNAc sensitive detection based on graphene quantum dots

Abstract

Recent studies have reported that abnormal levels of O-GlcNAc are involved in several diseases (e.g. cancer, diabetes and Alzheimer's disease, etc.). Therefore, the detection of O-GlcNAc has attracted numerous researchers' attention for the early clinical diagnosis of these diseases. Recently, graphene quantum dots (GQDs) have been widely used for the analysis of biomolecules because of their easy preparation and strong and stable fluorescence signal. Herein, we describe a simple and sensitive method for O-GlcNAc detection that first uses the GQDs in combination with wheat germ agglutinin (WGA) as fluorescence probes. The recognition between O-GlcNAc and WGA resulted in the decrease of fluorescence intensity, the signal decreased with the increased concentration of O-GlcNAc. The linear response range is from 5 to 200 pg mL⁻¹ with a detection limit of 0.8 pg mL⁻¹. The selectivity of this method has also been investigated. Finally, this sensing system was used to detect O-GlcNAc on α-crystallin protein and cancer cells lysate. The result suggests the potential application of this simple, high sensitivity sensing system to directly diagnose O-GlcNAc-related diseases that are a serious threat to the human health.