A luminescent coordination polymer for selective, sensitive, and recyclable sensing of nitrobenzene in aqueous solution

A luminescent coordination polymer, [Cd(H2biim)2SO4]·3H2O (JLNU-1, JLNU = Jilin Normal University); H2Biim = 2,2′-biimidazole, has been prepared by hydrothermal method and characterized by corresponding analytical tools. JLNU-1 exhibits outstanding chemical stability in aqueous solution and solvent-dependent luminescent behaviour. In particular, stable suspension of JLNU-1 in nitrobenzene showed highest quenching. The emission spectra were nearly completely quenched at a concentration of 100 ppm nitrobenzene in aqueous solution. JLNU-1 can be regenerative for 6 cycles by centrifugation of the solution after use and washing several times with H2O. Therefore, JLNU-1 can be used as a fluorescent probe for sensitive and recyclable sensing of small-molecule pollutant nitrobenzene in aqueous solution.