Recent developments on nanomaterials-based optical sensors for Hg2+ detection

Abstract

Mercuric ion (Hg 2+), released from both natural and industrial sources, has severe adverse effects on human health and the en-vironment even at very low concentrations. It is very important to develop a rapid and economical method for the detection of Hg 2+ with high sensitivity and selectivity. Nanomaterials with unique size and shape-dependent optical properties are at-tractive sensing materials. The application of nanomaterials to design optical sensors for Hg 2+ provides a powerful method for the trace detection of Hg 2+ in the environment, because these optical sensors are simple, rapidly responsive, cost-effective and highly sensitive. This review summarizes the recent advances on the development of optical assays for Hg 2+ in aqueous solu-tion by using functionalized nanomaterials (including noble metal nanoparticles, fluorescent metal nanoclusters, semicon-ductor quantum dots and carbon nanodots). Detection strate-gies based on the Hg 2+ -induced changes in spectral absorbance, fluorescence intensity and surface-enhanced Raman scattering signals were described. And the design principles for each opti-cal assay were presented. In addition, the future challenge and the prospect of the development of nanomaterial optical sen-sors for Hg 2+ detection were also discussed.