Lead-Free Antimony-Based Perovskite Nanocrystals as a Fluorescent Nanoprobe for the Turn-On Detection of Trace Water in Organic Solvents

This work reported the synthesis of lead-free antimony-based perovskite nanocrystals (Cs 3 Sb 2 Br 9 PNCs) through a ligand-assisted reprecipitation method. Cs 3 Sb 2 Br 9 PNCs exhibit strong blue emission with one maximum emission peak at 423 nm when excited at a wavelength of 375 nm. Notably, it was found that the presence of trace water significantly enhances the fluorescence of Cs 3 Sb 2 Br 9 PNCs. As the result, a fluorescence nanosensor was developed for the turn-on detection of trace water. The increase in the fluorescence intensity of Cs 3 Sb 2 Br 9 PNCs at 423 nm displays a good linear relationship with the water content in the range of 0.1–4.0% (v/v) with a detection limit of 0.033% (v/v). Measurement repeatability is confirmed through parallel measurements ( n = 11) of a 2.0% (v/v) water content, resulting in a relative standard deviation of 2.1%. The efficacy of this nanosensor was successfully demonstrated for determining the water content in various commercial organic solvents, yielding satisfactory results.