Ultra-trace level chemosensing of uranyl ions; scuffle between electron and energy transfer from perovskite quantum dots to adsorbed uranyl ions

•All inorganic CsPbBr3 PQDs as fluorescent probe for sensing of UO22+ ions in organic systems.•This probe showed an ultra-low level limit of detection of 83.33 nM (19.83 ppb).•The mechanistic pathway is deeply investigated and proposed through zeta potential/DLS measurement. This work attempts to address the challenge of trace level detection of uranyl ions using highly fluorescent perovskite quantum dots. The fluorescent probe CsPbBr3 perovskite quantum dots (PQDs) in toluene, synthesized via hot-injection method allows complete fluorescence quenching within seconds detecting ppb level concentration of uranyl ions. The mechanistic pathway is deeply investigated and proposed through zeta potential/DLS measurement, the extent of spectral overlap by the change in length of ligands of PQDs, alignment of acceptor-donor energy levels, the unlikeliness of cation exchange and TRPL studies. This study opens new insights into designing the correct combination of the probe (involving PQDs) and analyte (involving metal ions) for trace level sensing of metal ions. [Display omitted]