CsBr film as a stable flexible fluorescent probe for selective detection of Pb2+

Researchers have been working to develop stable and convenient test strips for detecting heavy metals. This paper reports a new portable lead ion test strip based on the exceptional photoluminescence properties of CsPbBr3. The CsBr films deposited on different substrates (rigid, semi-rigid, and flexible substrates) display highly selective luminescent response to Pb2+. For the flexible substrate, CsBr fluorescent probe not only shows lightweight, easy to use in large-scale manufacturing but also exhibits long detection lifetime. In comparison to organometallic perovskite fluorescence sensing of Pb2+, the CsBr fluorescent probe displays better stability and higher detection limit. Moreover, the used test strip can be reused to detect Cl- in solution, the CsBr fluorescent probe also shows a potential for multi-testing in recycling applications.