A sensitive localized surface plasmon resonance sensor for determining mercury(II) ion using noble metal nanoparticles as probe

The noble metal nanoparticles (NPs), including gold nanorods (AuNRs), gold nanospheres (AuNSs) and silver nanoplates (AgNPTs), were synthesized and Tween 20 stabilized NPs (Tween 20-NPs) were used as the probes for determining Hg2+. Hg2+ was determined based on the strong affinity between Au (Ag) and Hg. Hg2+ was reduced to Hg in the presence of sodium borohydride. Hg interacts with the NPs and the diameter of the NPs decreases with the increase of Hg2+ concentration, which causes the shift in absorption peak of Tween 20-NPs. The peak shifts are linearly related to Hg2+ concentrations. Compared with AuNSs and AgNPTs, when the AuNRs was used, the sensitivity for determining Hg2+ was higher. The developed method shows a good selectivity for Hg2+ and can be applied to the determination of Hg2+ in water samples.

The noble metal nanoparticles (NPs), including gold nanorods (AuNRs), gold nanospheres (AuNSs) and silver nanoplates (AgNPTs), were synthesized. Hg2+ was determined using these NPs as probes. The sensitivity for determining Hg2+ obtained with AuNRs was the highest.Figure optionsDownload as PowerPoint slideHighlights
► The sensitivity for determining mercury(II) ion using different shape nanoparticles as the probes was investigated.
► The proposed method is simple and sensitive.
► Compared with gold nanospheres and silver nanoplates, the gold nanorods have higher sensitivity for determining Hg2+.