A Simple and Rapid Resonance Scattering Spectral Method for Detection of Trace Hg2+ Using Aptamer-Nanogold as Probe

Single-strand deoxyribonucleic acid (ssDNA) were used to modified nanogold particle to obtain a aptamer-nanogold probe (NGssDNA) for Hg(II). The probe is not aggregated in high concentration of NaCl. In the pH 7.0 Na2HPO4-NaH2PO4 buffer solution and in the presence of high concentration of NaCl, NGssDNA interact with Hg (II) to form stable double-strand T-Hg(II)-T mismatches and to release nanogold particles from the probe. The released nanogold particles aggregated to form bigger clusters which leaded the resonance scattering (RS) intensity at 540 nm enhanced linearly with the concentration of Hg2+ in the range of 0.39-1666.7 nM, with detection of 0.1 nM. This simple, rapid, and sensitive aptamer-nanogold RS assay was applied to determination of Hg2+ in wastewater, with satisfactory results.