Analyte-triggered autocatalytic amplification combined with gold nanoparticle probes for colorimetric detection of heavy-metal ions.

This work reports a new colorimetric nanosensor for the detection of heavy-metal ions that initially integrates analyte-triggered autocatalytic amplification with o-phenylenediamine-mediated aggregation of label-free gold nanoparticles. Its utility is well demonstrated with the simple, rapid, sensitive, and specific detection of Hg2+, Cu2+, and Ag+ targets with detection limits less than 3 nM.