CsPbBr₃ perovskites: A dual fluorescence sensor to distinguish ethanol from methanol

In recent years, lead halide perovskites have emerged as a promising material with defect tolerance, thermally stable, and optoelectronic properties. However, the instability is the major factor which hinder their potential applications in various fields. This work demonstrates the chemical stability of Cesium Lead Bromide (CsPbBr₃) under different passivation condition with an objective to develop alcohol sensor. Cetyltrimethyl ammonium bromide (CTAB) passivated CsPbBr₃ demonstrated as a turn off fluorescent probe for alcohols and more significantly turn on fluorescent probe for ethanol. Herein, it is shown that CTAB passivated CsPbBr₃ can effectively discriminate ethanol from methanol owing to its different mode of interaction with ethanol and methanol. The outstanding optical properties of halide perovskites with an ultra-low detection limit of 7.3 ppb was obtained for ethanol detection. The sensing performance of the material is also validated with petrol and cough syrup samples showing excellent performance for future implementation with practical applications.