Meta-Phenylenediamine-Derived Silver-Containing Nanoporous Hyper-Cross-Linked Polymer: An Innovative Fluorescence Probe for S2O32- ion Detection in Aqueous Media

The meta-phenylenediamine polymer, when hyper-cross-linked, exhibits a minimal fluorescence intensity. However, the introduction of silver ions induces a significant increase in intensity, attributed to the plasmonic effect. This heightened intensity is selectively increased more upon the addition of thiosulfate ions. Capitalizing on this property, a fluorescence probe was developed. The correlation between fluorescence intensity reduction and S2O32- concentration follows a linear and consistent pattern. The precursor's response to diverse anions such as SO42-, CO32-, HPO42-, Cr2O72-, F--(-), Cl-, Br-, I-, H2PO4-, CH3COO-, NO3-, ClO-, and HCO3- was also examined. Under optimal conditions, the probe exhibited a linear range of 0.5-3 mu M with a detection limit of 0.01 mu M. Its effectiveness was demonstrated in measuring thiosulfate concentrations in aqueous media.