Triazole-Coupled Benzimidazole-Based Fluorescent Sensor for Silver, Bromide, and Chloride Ions in Aqueous Media.

A triazole-coupled benzimidazole-based fluorescent probe S1 with nitrogen and oxygen binding sites was synthesized and its properties as a probe for cations were investigated. Probe S1 was found to be highly selective toward Ag+ ions in aqueous media. The fluorescence intensity of S1 was quenched as a function of the concentration of Ag+ ions in the presence of potential interfering cations with a detection limit of 2.70 μM. The resulting S1-Ag+ complex was subsequently studied for its anion recognition abilities and found to recognize Br- and Cl- ions, revealing the concentration-dependent fluorescence enhancement with detection limits of 22.2 and 23.0 μM, respectively. Revival of the fluorescence profile of probe S1 indicated that Ag+ ion was released from the S1-Ag+ complex. Probe S1 is a sensor that can be single-handedly utilized for the qualitative and quantitative determination of Ag+, Br-, and Cl- ions in aqueous media.