Optical sensing of ultra-trace As3+ species using 2-mercaptoethanol capped CdTe Quantum Dots in aqueous medium

Aman, Gyanan and Khatei, Jayakrishna and Mondal, Sandip and Kumar, Arvind and Mallik, Ramesh Chandra (2019) Optical sensing of ultra-trace As3+ species using 2-mercaptoethanol capped CdTe Quantum Dots in aqueous medium. In: MATERIALS RESEARCH EXPRESS, 6 (12).

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Abstract

This work describes the optical response of luminescent colloidal CdTe quantum dots (QDs) stabilized with 2-mercaptoethanol (ME) and thioglycolic acid (TGA) synthesized by a one-pot hydrothermal method for sensing As3+ ions in aqueous solution. The sensing behavior of CdTe QDs was determined by examining the fluorescence spectra with the varying molar concentration of As3+ ions in the solution. The fluorescence peaks of TGA-CdTe QDs (?=648 nm) depreciated in the presence of As3+ ions. However, ME-CdTe QDs (?=610 nm) peaks got enhanced in the presence of As3+ ions. The quenching responses of TGA-CdTe fluorescence peak is attributed to a non-radiative relaxation process due to the presence of traps states on the surface. On the other hand, luminescence enhancement of ME-CdTe QDs can be ascribed to the active surface related radiative decay, owing to surface passivation of dangling bonds in QDs or due to the formation of higher bandgap AsTe shell structure formed on the ME-CdTe QDs. The detection limit in this method was found to be 10 nM l(?1). Hence, establishing ME-CdTe as a suitable probe for ultra-trace detection of As3+ ion in aqueous solution.

Item Type:	Journal Article
Publication:	MATERIALS RESEARCH EXPRESS
Publisher:	IOP PUBLISHING LTD
Additional Information:	Copyright of this article belongs to IOP PUBLISHING LTD.
Keywords:	quantum dots; luminescence; mercaptoethanol; sensing; arsenic
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	31 Dec 2019 11:20
Last Modified:	31 Dec 2019 11:20
URI:	http://eprints.iisc.ac.in/id/eprint/64100

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