title: Sensitive and selective detection of trivalent chromium using Hyper Rayleigh Scattering with 5,5'-dithio-bis-(2-nitrobenzoic acid)-modified gold nanoparticles.
abstract: Hyper Rayleigh Scattering (HRS) and absorption spectral assays using surface-modified gold nanoparticles (AuNP) have been developed for sensitive and selective detection of trivalent chromium (Cr3+) from other metal ions including hexavalent chromium (as Cr2O72-). Gold nanoparticles of 13 nm, covalently attached with 5,5'-dithio-bis-(2-nitrobenzoic acid) (AuNP-DTNBA), is used as a probe for both the absorption and HRS assays. AuNP-DTNBA is able to detect Cr3+at 20 ppb level at pH 6.0 using absorption spectral change of the AuNP-DTNBA. Visible color change can be observed when mixed with 250 ppb of Cr3+, while there is no color change when mixed with 2 ppm level of some of the most common metal ions such as Cr2O72-, Hg2+, Ba2+, Fe3+, Pb2+, Na+, Zn2+, Cd2+, Co2+, Mn2+, Ca2+, and Ni2+. However, a color change is observed when mixed with Ni2+, Zn2+, and Cd2+at a concentration higher than 2 ppm. The detection limit for the HRS assay is on a remarkable 25 ppt level, and there is no detectable HRS signal at 2 ppm level for Cr2O72-, Hg2+, Ba2+, Fe3+, Pb2+, Na+, Zn2+, Cd2+, Co2+, Mn2+, Ca2+, and Ni2+.
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Shantelle I
authors.initials: SI
authors.lastname: Hughes
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Samuel S R
authors.initials: SS
authors.lastname: Dasary
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Anant K
authors.initials: AK
authors.lastname: Singh
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Zachery
authors.initials: Z
authors.lastname: Glenn
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Hakim
authors.initials: H
authors.lastname: Jamison
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Paresh C
authors.initials: PC
authors.lastname: Ray
authors.affiliation: Department of Chemistry and Biochemistry, Jackson State University, Jackson, Mississippi 39217.
authors.forename: Hongtao
authors.initials: H
authors.lastname: Yu
keywords: 5,5’-dithio-bis-(2-nitrobenzoic acid); Gold nanoparticles; Hyper Rayleigh Scattering; colorimetric; pH dependence; trivalent chromium