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（K f ） 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(C ys ) capped Mo O 2 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.