Abstract
Schematic illustration of RRS detection of Hg2+ based on inhibition the peroxidase-like activity of silver nanoparticles.
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•The PVP- stabilized Ag-NPs were synthesized by microwave energy.•The morphology, size, PDI value and uniformity of the synthesized PVP- Ag-NPs were identified.•The peroxidase-like activity of the prepared PVP-Ag-NPs was confirmed by spectrophotometric and fluorescence techniques.•The catalytic activity of PVP-Ag-NPs was utilized for the detection of Hg2+ ions.•The method was applied for the detection of Hg2+ ions in river water samples by the RRS technique.
In this study, a facile nanoparticle catalytic sensor for resonance Rayleigh scattering quantification of mercury (II) ion was developed. The developed approach is relied on the selective inhibition of the peroxidase-like activity of polyvinylpyrrolidone-stabilized silver nanoparticles (PVP-Ag-NPs) by mercury (II) ions. The synthesized PVP-Ag-NPs oxidize the aqueous solution of O-Phenylenediamine (colorless) to 2,3-phenazinediamine (bright yellow) and their resonance Rayleigh scattering (RRS) activity was completely suppressed. When mercury (II) was introduced, the RRS activity of PVP-Ag-NPs was turned on combined with a reduction of the intensity of the yellow color. The enhancement in the RRS intensity was related to the concentration of mercury (II) in the linear range of 10–2000 nM. The smaller size (4.5 nm), the large surface area and the uniform size (PDI = 0.379) of the synthesized PVP-Ag-NPs offered a higher chance for interaction between mercury (II) and PVP-Ag-NPs with the advantages of high sensitivity (LOD = 4 nM) and excellent selectivity for mercury (II) detection over several metals and anions.