A carboxyl-functionalized poly(arylene ether sulfone)–terbium(iii) coordination polymer-based fluorescent fibrous membrane for highly sensitive detection of Cr(vi) ions

Abstract

Hexavalent chromium (Cr(VI)), a widely utilized yet highly toxic industrial heavy metal, is a frequently found contaminant in industrial wastewater, thereby posing significant risks to ecosystems and human health. Therefore, the development of a rapid and highly sensitive method for detecting Cr(VI) is crucial. In this study, we constructed a novel fluorescent fibrous membrane by utilizing carboxyl-functionalized poly(arylene ether sulfone) (CPES) as a polymer ligand to form Tb(III) coordination polymers. The resulting fibrous membrane emits intense green fluorescence under ultraviolet light and exhibits excellent fluorescence stability across a broad range of NaCl concentrations (0–1.0 M) and pH values (1–14), attributable to the inherent chemical robustness of the CPES backbone. The presence of Cr(VI) induces significant fluorescence quenching of the membrane, with a detection limit of 8.6 µM in aqueous solution. Importantly, the membrane demonstrates remarkable reusability, with no significant decrease in fluorescence intensity even after eight consecutive detection–regeneration cycles. In summary, the CPES–Tb(III) fibrous membrane combines high selectivity, sensitivity, anti-interference capability, and reusability, making it a highly promising material for detecting Cr(VI) in industrial wastewater and providing a solid foundation for the development of next-generation portable sensors.