Fluorescence Light-Up Electrospun Membrane Incorporated with PbBr2 as a Highly Selective Fluorescence Probe for the Detection of Cs+

Abstract

This study introduces a novel fluorescent light-up electrospun membrane, integrating PbBr₂, which serves as an exceptionally selective probe for the detection of cesium ions (Cs⁺). Leveraging the superior optical properties of CsPbBr₃ perovskite nanocrystals (PNCs), the researchers employ electrospinning technology to fabricate a test strip, namely PbBr₂@polyacrylonitrile (PbBr₂@PAN) nanofiber membranes, capable of swiftly detecting Cs⁺ in water merely by observing changes in the nanocrystals' luminescence with the naked eye. By the introduction of NH₄⁺-modified montmorillonite (NH₄⁺-MMT), PbBr₂-MT@PAN nanofiber membranes is obtained. The selectivity and sensitivity to Cs⁺ can be further improved because NH₄⁺-MMT endows PbBr₂-MT@PAN nanofiber membranes with the hydrophilic property and selective adsorption toward Cs⁺ ions. The membrane's fabrication is simple, scalable, and cost-effective, with high cesium selectivity and sensitivity down to 44 ppb. This innovation enables efficient, on-site cesium monitoring critical for environmental safety and nuclear waste management.