Collaborative Construction of a Silver Nanocluster Fluorescent Probe Using the Pyridinium-Based Ionic Liquid [C(4)py][DCA]

[Image: see text] A silver nanocluster fluorescent probe was synthesized by using the pyridinium-based ionic liquid [C(4)py][DCA] as the protective agent, AgNO(3) as the precursor, and NaBH(4) 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 AsO(3)(3–). Therefore, the collaborative construction of a silver nanocluster probe using the pyridinium-based ionic liquid [C(4)py][DCA] offered outstanding selectivity and sensitivity to detect AsO(3)(3–) in water. More interestingly, the fluorescent probe quenched by AsO(3)(3–) could be recovered with the addition of H(2)O(2). 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 [C(4)py][DCA] and AsO(3)(3–).