Cascade signal amplification using Hg2+-induced oxidation of silver nanoparticles and cation exchange reaction for ICP-MS bioassay.

Combining the Hg2+-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. [ABSTRACT FROM AUTHOR]