All-inorganic CsPbBr3 perovskite quantum dots as a photoluminescent probe for ultrasensitive Cu2+ detection

Abstract

Pollution triggered by highly toxic heavy metal ions has become a worldwide issue of concern, and has aroused increasing research interest, but it is still a challenge to carry out its trace detection in the organic phase using inorganic fluorescent colloidal nanocrystals (NCs). Herein, we report fully inorganic CsPbBr₃ perovskite quantum dots (PQDs), which were synthesized via a hot-injection method, as a fluorescent probe for the selective detection of copper ions in hexane. The photoluminescence (PL) intensity of CsPbBr₃ PQDs is significantly quenched within several seconds after the addition of Cu²⁺ due to effective electron transfer from the PQDs to the added Cu²⁺, which is experimentally verified via analyzing absorption spectra and PL decay lifetime. The sensor, in turn-off mode, has a detection range from 0 to 100 nM with a limit of detection (LOD) as low as 0.1 nM, indicating great potential for practical applications. This study paves the way for PQD-based fluorescent probes for heavy metal detection in the organic phase.