Molecular sensitivity of DNA-Ag-PATP hybrid on optical activity for ultratrace mercury analysis.

The para-aminothiophenol (PATP), in which the thiol groups adsorbed on the Ag surface and the amino groups coordinated with Hg(2+), can mediate the aggregation of sunlight-reduced λ-DNA-templated Ag nanoparticles, resulting in high molecular sensitivity of this hybrid on optical activity. Sub-pM levels of Hg(2+) assays were achieved based on this molecular stepwise assembly.