Cascade signal amplification using Hg 2+ -induced oxidation of silver nanoparticles and cation exchange reaction for ICP-MS bioassay.

Combining the Hg 2+ -induced oxidization of silver nanoparticles with the cation exchange reaction between Ag + and CuS nanoparticles for cascade signal amplification, a sensitive, universal and label-free ICP-MS bioassay for nucleic acids and proteins was developed. By replacing the loop sequence of the T-Hg-T hairpin structure with specific sequences or aptamers to different biomarkers, it has great promise for the early detection of biomarkers potentially for diagnosis of cancerous diseases.