CH₃NH₃Br solution as a novel platform for the selective fluorescence detection of Pb²⁺ ions

The development of a simple fluorescent sensor for detecting the Pb²⁺ heavy metal is fundamentally important. The CH₃NH₃PbBr₃ perovskite material exhibits excellent photoluminescence properties that are related to Pb²⁺. Based on the effects of Pb²⁺ on the luminescent properties of CH₃NH₃PbBr₃, we design a novel platform for the selective fluorescence detection of Pb²⁺ ions. Herein, we use a CH₃NH₃Br solution at a high concentration as the fluorescent probe. Incorporation of PbBr₂ into the CH₃NH₃Br solution results in a rapid chemical reaction to form CH₃NH₃PbBr₃. Hence, the nonfluorescent CH₃NH₃Br material displays a sensitive and selective luminescent response to Pb²⁺ under UV light illumination. Moreover, the reaction between CH₃NH₃Br and PbBr₂ could transform Pb²⁺ into CH₃NH₃PbBr₃, and therefore, CH₃NH₃Br may also be used to extract Pb²⁺ from liquid waste in recycling applications.