Perovskite nanocrystals fluorescence nanosensor for ultrasensitive detection of trace melamine in dairy products by the manipulation of inner filter effect of gold nanoparticles
2020
Li, Qian | Wang, Hongbo | Yue, Xuanfeng | Du, Jianxiu
Barium sulfate-coated CsPbBr₃ perovskite nanocrystals (CsPbBr₃ NCs@BaSO₄) was successfully synthesized that exhibited stable and intense fluorescence property in aqueous buffer. With the CsPbBr₃ NCs@BaSO₄ as signal readout, an ultrasensitive fluorescence nanosensor was developed for turn-on determination of melamine by the manipulation of inner filter effect of citrate-protected gold nanoparticles (AuNPs). The fluorescence of the CsPbBr₃ NCs@BaSO₄ was remarkably quenched by the AuNPs due to inner filter effect. This inner filter effect could be weakened by the addition of melamine as a result of melamine-triggering aggregation of the AuNPs and subsequently led to a recovery in the fluorescence of the CsPbBr₃ NCs@BaSO₄. The recovery ratio was proportional to the concentration of melamine in the range of 5.0–500.0 nmol/L. The limit of detection was 0.42 nmol/L and the relative standard deviation was 4.0% for the repetitive determination of 500.0 nmol/L melamine solution (n = 11). The nanosensor was successfully applied to analysis of melamine in dairy product samples.
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