Determination of mercury(II) by surface-enhanced Raman scattering spectroscopy based on thiol-functionalized silver nanoparticles

Abstract

Silver nanoparticles (Ag NPs) modified with sodium 2-mercaptoethanesulfonate (mesna) exhibit strong surface-enhanced Raman scattering (SERS). Their specific and strong interaction with heavy metal ions led to a labelfree assay for Hg(II). The covalent bond formed between mercury and sulfur is stronger than the one between silver and sulfur and thus prevents the adsorption of mesna on the surface of Ag NPs. This results in a decrease of the intensity of SERS in the presence of Hg(II) ions. The Raman peak at 795 cm −1 can be used for quantification. The effect of the concentration of mesna, the concentration of sodium chloride, incubation time and pH value on SERS were optimized. Under the optimal conditions, the intensity of SERS decreases with increasing concentration of Hg(II). The decrease is linear in the 0.01 and 2 μmol L −1 concentration range, with a correlation coefficient (R 2 ) of 0.996 and detection limit (S/N03) is 0.0024 μmol L −1 . The method was successfully applied to the determination of the Hg(II) in spiked water samples.

Recent developments on nanomaterials-based optical sensors for Hg2+ detection

“…18) [105]. Similarly, an SERS determination of Hg 2+ with 2-mercaptoethanesulfonate modified Ag NPs was described by Chen et al [114]. Our group designed a colorimetric and SERS dual-signal sensor for Hg 2+ by facilely mixing Bismuthiol II and Au NPs, without dye tag [115].…”

Silver nanoparticles for separation and preconcentration processes

“…Chen et al [51] showed that AgNPs modified with sodium 2-mercaptoethanesulfonate (mesna) exhibit strong surface-enhanced Raman scattering (SERS). They used mesna as modifying agent for AgNP surfaces to form complexes of mercury(II) ions binding to reactive adsorption sites on the sorbent surface.…”

Recent progress in detection of mercury using surface enhanced Raman spectroscopy — A review

“…2C). Chen et al (2012) demonstrated a label-free assay for Hg 2+ sensing using 2-mercaptoethanesulfonate (MESNA) modified Ag NPs. The covalent bond formed between Hg 2+ and sulfur prevents the adsorption of MESNA on the Ag surface, thus led to the intensity decrease in SERS signals for MESNA (Fig.…”