A fluorescence-based method for the determination of both Cr(iii) and Cr(vi) using unmodified gold nanoparticles.

Amitava Mukherjee

Centre for Nanobiotechnology

Vellore Campus

Chandra Sekaran N

Elavarasi M

Alex S.A

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Anal. Methods

AuNP aggregation by Cr(iii) causes the reduction of the fluorescence emission intensity at 582 nm (λex = 490 nm).

Analytical Methods

Reply to the ‘Comment on “Simple fluorescence-based detection of Cr(iii) and Cr(vi) using unmodified gold nanoparticles”’ by M. R. Hormozi-Nezhad, J. Mohammadi and A. Bigdeli, Anal. Methods, 2015, 7, DOI: 10.1039/c5ay00005j

In this study we present a colorimetric detection method for Cr (VI) in aqueous solution based on as synthesized silver nanoparticles (Ag NPs) without surface functionalization. The method principle involves reduction of Cr (VI) to Cr (III) by excess reductant present in as synthesized Ag NP dispersion, and subsequent aggregation of Ag NPs by Cr (III) leading to red-shift of the surface plasmon resonance (SPR) peak. The UV-vis absorption spectra, Zeta potentials, dynamic light scattering measurements, and scanning electron microscopy (SEM) confirmed the aggregation of the Ag NPs. Under the optimized conditions, a good linear relationship (correlation coefficient r = 0.981) was obtained between the ratio of the absorbance at 550 nm to that at 390 nm (A 550/390) and the concentration of Cr (VI) over the range of 10 -3-10 -9 M [50 mg/L to 50 ng/L]. The reported probe has a limit of detection down to 1 nM, which, to the best of our knowledge, is the lowest ever reported for the colorimetric detection of Cr (VI). Furthermore, a remarkable feature of this method is that it involves a simple technique exhibiting high selectivity to Cr (VI) over other tested heavy metal ions. © 2012 Elsevier B.V. All rights reserved.

Sensors and Actuators B: Chemical

Selective colorimetric detection of nanomolar Cr (VI) in aqueous solutions using unmodified silver nanoparticles

In the current study we present a fluorescence probe for Cr(iii) in aqueous solution employing as-synthesized silver nanoparticles (Ag NPs) without surface labeling by any extrinsic fluorophore. The principle of the method involves aggregation of Ag NPs by Cr(iii) leading to a red-shift of the fluorescence emission peak from 420 to 684 nm for a corresponding excitation wavelength of 340 nm. The UV-visible absorption spectral studies, dynamic light scattering measurements, and scanning electron microscopy (SEM) corroborated the aggregation of the Ag NPs upon interaction with Cr(iii). Under the optimized conditions, a good linear relationship (correlation coefficient r = 0.975) was observed between concentration of Cr(iii) and the fluorescence intensity at 684 nm in the range of 1 × 10 -3 to 2 × 10 -9 M (50 mg L -1 to 100 ng L -1). The reported probe has a limit of detection as low as 2 nM, which, to the best of our knowledge, is the lowest ever reported for the fluorescence detection of Cr(iii). The developed sensor was successfully tested with chromium containing real samples, such as groundwater and fresh water, demonstrating potential application in the field of environmental sensing. © The Royal Society of Chemistry. 2012.

Studies on fluorescence determination of nanomolar Cr(iii) in aqueous solutions using unmodified silver nanoparticles

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

Silver and gold nanoparticles for sensor and antibacterial applications

Analytica Chimica Acta

Facile preparation of glutathione-stabilized gold nanoclusters for selective determination of chromium (III) and chromium (VI) in environmental water samples

Sensitive and selective detection of trivalent chromium using hyper Rayleigh scattering with 5,5′-dithio-bis-(2-nitrobenzoic acid)-modified gold nanoparticles

Journal	Data powered by TypesetAnal. Methods
Publisher	Data powered by TypesetRoyal Society of Chemistry (RSC)
ISSN	1759-9660
Open Access	0