Highly sensitive detection of Hg2+ using ruthenium complex-based probe in water

Abstract A new ruthenium complex using 2-(2-thienyl)pyridine as cyclometalating ligand and 2,2’-bipyridine-5,5’-dicarboxylic acid as anchoring ligands was successfully synthesized and used as an Hg2+ colorimetric probe. Upon adding Hg2+ into the aqueous solution of the complex, a significant absorption spectral change with a blue shift of 142 nm can be observed accompanied by an obvious color change. The detection limit of Hg2+ was calculated to be as low as 4.7 × 10−8 M in neutral aqueous medium by using UV-Vis absorption technology. Then, it was loaded onto mesoporous silica nanoparticles, which was characterized by TEM, XPS and TG. The new composite material Ru-COOH@NH2-MSNs displayed abilities to enrich and separate Hg2+ in water, which demonstrates a potential application in environmental system.