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.