Optical sensing of ultra-trace As3+ species using 2-mercaptoethanol capped CdTe Quantum Dots in aqueous medium. (27th November 2019)

• Record Type: Journal Article
• Authors: Aman, Gyanan; Khatei, Jayakrishna; Mondal, Sandip; Kumar, Arvind; Mallik, Ramesh Chandra
• Is Part Of: Materials research express. Volume 6:Number 12(2019)
• Publication Date: 2019-11-27
• Subjects: quantum dots -- luminescence -- mercaptoethanol -- sensing -- arsenic; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/ab57d7
• Languages: English
• ISSNs: 2053-1591

Abstract

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 As 3+ ions in aqueous solution. The sensing behavior of CdTe QDs was determined by examining the fluorescence spectra with the varying molar concentration of As 3+ ions in the solution. The fluorescence peaks of TGA-CdTe QDs ( λ = 648 nm) depreciated in the presence of As 3+ ions. However, ME-CdTe QDs ( λ = 610 nm) peaks got enhanced in the presence of As 3+ 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 As 3+ ion in aqueous solution.