BSA-assisted ultrasound synthesis of water stable CsPbBr 3 nanocrystals for sensitive fluorescent detection of hydrogen sulfide in human serum.

A bovine serum albumin (BSA)-assisted ultrasonication strategy was developed for the synthesis of CsPbBr 3 nanocrystals (NCs) with stable fluorescence properties in aqueous solution. Such a preparation method is simple, fast and does not require complex equipment. The results show that the synthesized CsPbBr 3 NCs are homogeneous in particle size and have good solubility and stability in water. The CsPbBr 3 NCs have been utilized as fluorescence probe for rapid detection of hydrogen sulfide (H 2 S) in human serum. The reaction of H 2 S with the lead sites on the surface of CsPbBr 3 NCs produces lead sulfide (PbS), resulting in the decrease of fluorometric intensity of CsPbBr 3 NCs. Our designed fluorescent assay has a linear S 2- detecting range of 10 ~ 800 nM with a detection limit of 7.05 nM. The assay was used to determine H 2 S in human serum with spiked recoveries ranging from 94.98% to 102.69%. This work opens new avenues for the application of halide lead perovskite in different biosensing areas.