Sensitive Chemiluminescent Sensing Method for Mercury(II) Ions Based on Monolayer Molybdenum Disulfide.

A simple and sensitive chemiluminescent (CL) sensing platform for mercury(II) ions (Hg) in water was developed based on monolayer molybdenum disulfide (MoS). The layered MoS can catalyze the oxidation of luminol by HO, producing an enhanced CL signal because of the peroxidase-like activity of the layered MoS. In addition, MoS has a good adsorption ability to Hg because of the inherent affinity of Hg to sulfur contained in MoS. Interestingly, the pre-incubation of Hg with layered MoS inhibited the catalytic activity of MoS on the luminol-HO-MoS CL reaction, leading to CL quenching. The CL intensity decreased linearly with increasing concentration of Hg from 0.005 - 40 μM. The limit of detection (LOD) was estimated to be 1 nM. The relative standard deviation (RSD) was found to be 3.71%, indicating good reproducibility. The recoveries of Hg spiked in tap water were from 100.0 to 116.0% with RSD from 2.7 to 5.6%, detected by the standard addition method, and demonstrated good applicability.