Colorimetric Sensing of Hydrogen Peroxide Based on the Wavelength-Shift of CsPbBr3 Perovskite Nanocrystals on Water–Oil Interface

In this study, the halogen exchange reactions are investigated between KI or methylamine iodide in aqueous solution and CsPbBr 3 NCs in toluene. The mass transfer process on the interface between water and toluene affects the halogen exchange time and efficiency. Stirring and heating can effectively improve the halogen exchange efficiency and increases the sensing sensitivity. The photoluminescence wavelength shift of CsPbBr 3 NCs shows good linear relationship with the concentration of I − in the range from 0 to 20 nmol/L with the detection limit of 0.2 nmol/L I − . Taking H 2 O 2 as a typical water-soluble oxide, the method is applied to the colorimetric sensing of H 2 O 2 in water solution. After the optimization of sensing conditions, the obvious wavelength shift could be observed with the different concentration range of H 2 O 2 . A good linear relationship between the wavelength shift and the H 2 O 2 concentration from 0 to 1.0 mmol/L with the detection limit of 0.05 mmol/L H 2 O 2 could be found.