A solid-state colorimetric fluorescence Pb2+-sensing scheme: mechanically-driven CsPbBr3nanocrystallization in glass

Highly toxic Pb(2+)poses a great threat to the health of human beings and ecosystems, urgently calling for an efficient Pb(2+)detection method. Herein, we demonstrated a brand-new solid-state fluorescence Pb2+-sensing scheme based on a type of Pb2+-responsive borate glass powder that is able to precipitate CsPbBr(3)nanocrystals on the glass surface upon grinding with Pb(2+)sources, following a mechanically driven glass crystallization mechanism. Pb(2+)sensing is achievedviathe Pb(2+)concentration-dependent green emission of CsPbBr(3)as an indicator signal and independent red emission of Eu(3+)as a reference signal. Under UV light irradiation, the obvious emissive color variation from red to green as Pb(2+)concentration varies enables the intuitive Pb2+-sensing by naked eyes. With the aid of a spectrometer and smartphone, Pb(2+)concentration can be quantitatively determined with the detection limit as low as similar to 70 ppm and similar to 400 ppm, respectively. The semi-quantitative Pb(2+)detection is also possible by comparing the emissive color with the calibrated color card. Hopefully, the proposed solid-state fluorescence Pb2+-sensing strategy with high selectivity can be used for portable and quick Pb(2+)analysis in daily life.