Quick preparation of water-soluble perovskite nanocomposite via cetyltrimethylammonium bromide and its application.

A good water-soluble and stable nanocomposite has been facilely prepared by the encapsulation of CsPbBr 3 QDs via cetyltrimethylammonium bromide and mineral oil through sonication, namely CsPbBr 3 @CMO nanocomposite. Such method is very quick and simple without complicated instruments and strict conditions. The results reveal that the synthesized CsPbBr 3 @CMO nanocomposite is spherical with uniform size and shows remarkably good solubility and stability in water. Specifically, the fluorescent intensity of CsPbBr 3 @CMO nanocomposite in water is decreased by 0.76% after 3 h; this result is comparable with those in earlier studies, and the good stability in water might be owned to the hydrophobic core of the CsPbBr 3 @CMO nanocomposite. The prepared CsPbBr 3 @CMO nanocomposite has been applied as a sensitive fluorescent probe for monitoring hydrogen sulfide (H 2 S), and the fluorescence intensity (~ 524 nm) has a linear relationship with the concentration of H 2 S in the range 0.15-105 µM with a detection limit of 53 nM, demonstrating application for monitoring H 2 S in rat brain coupled with microdialysis apparatus with satisfied results. The present study not only provides a simple but sensitive approach for the detection of H 2 S in living body, but also paves the way for expanding the application of CsPbBr 3 QDs to aqueous medium.