Collaborative Construction of a Silver Nanocluster Fluorescent Probe Using the Pyridinium-Based Ionic Liquid...

A silver nanocluster fluorescent probe was synthesized by using the pyridinium-based ionic liquid [C₄py][DCA] as the protective agent, AgNO₃ as the precursor, and NaBH₄ as the reducing agent. The presence of pyridine group enhanced the fluorescence intensity of Ag nanoclusters and facilitated the coordination interaction between Ag nanoclusters and AsO₃ ^3-. Therefore, the collaborative construction of a silver nanocluster probe using the pyridinium-based ionic liquid [C₄py][DCA] offered outstanding selectivity and sensitivity to detect AsO₃ ^3- in water. More interestingly, the fluorescent probe quenched by AsO₃ ^3- could be recovered with the addition of H₂O₂. This fluorescent probe provided a rapid and superior method for the detection of As(III) in the linear concentration range of 0-60 ppb with the lowest detection limit of 0.60 ppb. The mechanism of fluorescence quenching was a static quenching, considered to be due to electron migration between functional groups on the surface of Ag nanoclusters constructed with [C₄py][DCA] and AsO₃ ^3-.