Design of CsPbBr3 NCs/MnO2 based sensing system for multi-mode detection of D-penicillamine

Herein, a multi-mode assay platform was constructed for the detection of D-penicillamine based on perovskite nanocrystals (CsPbBr3 NCs) and MnO2 nanosheets. The water-dispersible CsPbBr3 NCs synthesized via aqueous emulsion process has a strong fluorescence emission at 520 nm. The electrostatic interaction between positively charged CsPbBr3 NCs and negatively charged MnO2 nanosheets would lead to the fluorescence quenching of CsPbBr3 NCs on account of the inner filter effect (IFE). The addition of D-penicillamine could convert MnO2 nanosheets to Mn2+ and weaken inner filter effect, resulting in distinct recovery of fluorescence at 520 nm and the decrease of the absorption of CsPbBr3 NCs/MnO2 at 375 nm. Therefore, the fluorescence and colorimetric assay system for D-penicillamine was developed. The fluorescence and colorimetric sensing system could detect D-penicillamine ranging from 0.1 to 40 µM and 0.5 to 40 µM with the limits of detection (LOD) were 0.061 µM and 0.24 µM, respectively. The developed assay system could be applied to analyze D-penicillamine in real samples and acquired satisfactory results. Furthermore, a portable intelligent detection device was developed based on the mobile phone and RGB analysis software, demonstrating the practicability and potential of the sensing system.