Trace colorimetric detection of Pb2 + using plasmonic gold nanoparticles and silica–gold nanocomposites

Thatai, Sheenam and Kurana, Parul and Prasad, Surendra and Soni, Sarvesh K. and Kumar, Dinesh (2016) Trace colorimetric detection of Pb2 + using plasmonic gold nanoparticles and silica–gold nanocomposites. Microchemical Journal, 124 . pp. 104-110. ISSN 0026-265X

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Abstract

A novel, simple and highly sensitive plasmonic colorimetric method is developed for the detection of Pb2 + in aqueous samples. The method is based on the aggregation of gold nanoparticles (AuNPs) or SiO2core–Aushell nanocomposites (SiO2@Au NCs) in the presence of Pb2 + ions. It was found that the colour of AuNPs or SiO2@Au NCs changes in the presence of Pb2 + ions and the intensity of surface plasmon resonance (SPR) peak of AuNPs or SiO2@Au NCs decreased. Thus, the synthesis of sensitive surface enhanced Raman scattering (SERS) materials; ~ 20 nm spherical AuNPs and ~ 360 nm SiO2@Au NCs leads to the development of nanosensor for the detection of Pb2 + ions. Both AuNPs and SiO2@Au NCs by virtue of their versatility show localized surface plasmon resonance (LSPR) peaks at 522 nm and 541 nm respectively. The synthesized AuNPs, SiO2@Au NCs and analyte samples prepared were characterised using a scanning electron microscope, a transmission electron microscope and a UV–vis spectrophotometer. The SERS study was also used to compare sensitivities of both AuNPs and SiO2@Au NCs towards Pb2 + ions using crystal violet (CV) as a target molecule. The analyte Pb2 + was detected as low as 500 nM using 20 nm AuNPs and 50 nM using 360 nm SiO2@Au NCs. It was confirmed that SiO2@Au NCs were found ten times more sensitive as compared to AuNPs for the detection of Pb2 + ions.

Item Type:	Journal Article
Subjects:	Q Science > Q Science (General) Q Science > QD Chemistry
Divisions:	Faculty of Science, Technology and Environment (FSTE) > School of Biological and Chemical Sciences
Depositing User:	Fulori Nainoca - Waqairagata
Date Deposited:	11 Apr 2016 03:55
Last Modified:	04 May 2017 23:55
URI:	https://repository.usp.ac.fj/id/eprint/8807

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