Ratiometric fluorescent probe based on AuNCs induced AIE for quantification and visual sensing of glucose

Blood glucose measurement plays a very important role in clinical diagnosis and fluorescence analysis has attracted extensive attention. A novel ratiometric fluorescent system with aggregation induced emission (AIE) property for the detection of glucose was established in this work. In this system, bovine serum albumin-stabilized Au nanoclusters (BSA-AuNCs) served both as the fluorescent detection probe and the AIE inducer. An AIE molecule, named sodium 1,2-bis [4-(3-sulfonatopropoxyl) phenyl]-1,2-diphenylethene (BSPOTPE), served as fluorescent reference probe. In the presence of H2O2, the fluorescence intensity of BSPOTPE/BSA-Au NCs at 680 nm progressively decreased while that at 490 nm remained constant. Glucose can be catalyzed by glucose oxidase (GOx) and produces H2O2. Therefore, glucose detection can be conveniently achieved by the proposed strategy. The fluorescence intensity change ratio increased linearly with the glucose concentration in the range 1-8 mM. Moreover, the proposed method exhibits a consecutive fluorescence color change ("from red to cyan") to glucose concentration in the range of 1-8 mM under a 365 nm UV lamp and exhibits bright "red" or bright "cyan" in lower glucose concentrations (lower than 3 mM) or high glucose concentrations (higher than 7 mM), respectively. The work offers an ideal rapid clinical diagnostic method for both normal and abnormal blood glucose screening.