Glucose Oxidase-Instructed Fluorescence Amplification Strategy for Intracellular Glucose Detection

The accurate detection of glucose at cellular level remains a big challenge. In this study, a signal amplification strategy mediated by silver nanocube (AgNC), glucose oxidase (GOx), and silver ion fluorescence probe (denoted as AgNC–GOx/Ag+-FP) is proposed for amplified intracellular glucose detection. The AgNC is oxidized into Ag+ by H2O2 generated from GOx-catalyzed glucose oxidation reaction, and Ag+ remarkably enhances the red fluorescence of Ag+-FP. Our results show that AgNC–GOx/Ag+-FP is highly sensitive and specific to glucose and H2O2. Afterward, the feasibility of using AgNC–GOx/Ag+-FP to detect intracellular glucose is verified in five different cell lines. In summary, a sensitive and specific fluorescence amplification strategy has been developed for intracellular glucose detection.