DNA functionalized gold nanorods/nanoplates assembly as sensitive LSPR-based sensor for label-free detection of mercury ions.

Core-satellite assembly, i.e., gold nanoplates (AuNPs) surrounded by gold nanorods (AuNRs), has been obtained by Thymine-Hg(2+)-Thymine (T-Hg(2+)-T) coordination. A novel label-free localized surface plasmon resonance (LSPR) detection of mercury ions can be performed via the core-satellite assembly. The proposed detection protocol exhibits good linear correlation between wavelength shifts of the plasmon band and concentrations of mercury ions over the range from 10nM to 0.2μM. Moreover, the detection limit (3σ) for the probes is 2.2nM, which is better than colorimetric detection via random aggregation of gold nanoparticles.