A Novel Co(II) Coordination Compound Fluorescent Probe for Visual, Rapid, and Selective Detection of Hydrazine Hydrate

A novel Co(II) coordination compound fluorescent probe [Co(bim)2(SCN)2] (bim = benzimidazole, SCN− = thiocyanate) 1 was synthesized by the room-temperature diffusion method using benzimidazole (bim) and amine thiocyanate (NH4SCN) as ligands. The suspension of compound 1 exhibited good fluorescence stability. In addition, compound 1 exhibited a visual fluorescence quenching effect on hydrazine hydrate (N2H4·H2O), with a high quenching constant, a low detection limit (LOD) of 0.544 μM, a high quenching efficiency, a response time of only 4 s, and good cycling stability. Furthermore, the quenching mechanism for N2H4·H2O was discussed, which is attributed to the energy transfer between bim of compound 1 and N2H4·H2O.