Metal-to-ligand charge transfer chirality-based sensing of mercury ions

Chiral ligand conjugated transition metal oxide nanoparticles(NPs) are a promising platform for chiral recognition, biochemical sensing, and chiroptics. Herein, we present chirality-based strategy for effective sensing of mercury ions via ligand-induced chirality derived from metal-to-ligand charge transfer(MLCT) effects. The ligand competition effect between molybdenum and heavy metal ions such as mercury is designated to be essential for MLCT chirality. With this know-how, mercury ions, which have a larger stability constant(Kf) than molybdenum, can be selectively identified and quantified with a limit of detection(LOD) of 0.08 and 0.12 nmol/L for D-cysteine and L-cysteine(Cys) capped Mo O2 NPs. Such chiral chemical sensing nanosystems would be an ideal prototype for biochemical sensing with a significant impact on the field of biosensing, biological systems,and water research-based nanotoxicology.