A highly sensitive and selective resonance Rayleigh scattering method for Hg2+ based on the nanocatalytic amplification

In 0.2mol/L HCl–0.22mol/L HNO3 medium, trace Hg2+ catalyzed NaH2PO2 reduction of HAuCl4 to form gold nanoparticles (AuNPs), which exhibited a strong resonance Rayleigh scattering (RRS) effect at 370nm. With increasing of [Hg2+], the RRS effect enhanced due to more AuNP generated from the catalytic reaction. Under the chosen conditions, the enhanced RRS intensity at 370nm is linear to Hg2+ concentration in the range of 5.0–450×10−9mol/L, with a detection limit of 0.1nmol/L. This RRS method was applied for the determination of Hg in water samples, with high sensitivity and good selectivity, and its results were agreement with that of atomic fluorescence spectrometry.