CsPbBr₃ Perovskite Nanocrystals Decorated with Cu Nanoclusters for Ratiometric Detection of Glucose

A dual-emitting fluorescent nanoprobe was constructed through hybridizing green emission CsPbBr3 perovskite nanocrystals (CsPbBr3 PNCs) and red emissive copper nanoclusters (Cu NCs). The CsPbBr3@Cu nanohybrid was formed during the in situ reduction of cupric ions with d-penicillamine with the co-existence of CsPbBr3 PNCs. Hydrogen peroxide can dramatically quench the red fluorescence of Cu NCs at 645 nm, whereas it has no perceptible impact on the green emission of CsPbBr3 PNCs at 517 nm. With CsPbBr3 PNCs as a reference unit, a ratiometric fluorescent nanosensor was developed for the determination of glucose because hydrogen peroxide can be generated during glucose oxidation under the enzymatic catalytic action of glucose oxidase. This ratiometric fluorescent nanoprobe presented a good linear response range for glucose from 2.0 to 170.0 μM with a detection limit of 0.8 μM. The glucose amount in human serums was successfully determined with satisfactory results.