Thioglycerol-functionalized CdSe quantum dots detecting cadmium ions

Abstract

International audienceWater-soluble CdSe quantum dots (QDs) were synthesized using thioglycerol (TG) as the surface capping agent through a one-step process at low temperature T (100 degrees C). The CdSe quantum dots were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, UV-visible absorption and fluorescence spectroscopies. These measurements revealed that the TG-capped CdSe QDs possess a high crystalline quality with an average diameter in the range 2.5-2.8 nm and exhibit particular optical properties. The UV-visible absorption of CdSe QDs is enhanced by the addition of cadmium ions, with a simultaneous shift of the edge band (400 nm), while seventeen other tested metal cations have no effect on the absorption of QDs. Moreover, the binding of Cd2+ ions induces a quenching of the fluorescence emission of TG-CdSe QDs. At particular absorption wavelengths, the response is linearly proportional to the cadmium ions concentration ranging from 1.0 to 22 mu M with a detection limit of 0.32 mu M (37 mu g L-1). Based on these optical properties, the TG-CdSe QDs could be used as a highly selective probe for the detection of Cd2+ ions in aqueous solutions, a species highly toxic for cells. (C) 2015 Elsevier B.V. All rights reserved

Specific bioanalytical optical and photoelectrochemical assays for detection of methanol in alcoholic beverages

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Quantitative determination of uric acid using CdTe nanoparticles as fluorescence probes

“…In case of TGO-CdTe NPs, the peaks located at 3400 cm -1 , 2937 cm -1 , 2862 cm -1 , 1420 cm -1 , and 1083 cm -1 correspond to O-H stretching, CH 2 symmetric stretching, C-H stretching, C-H stretching, C-C stretching mode, respectively (curve (1) in Fig. S1c) (Brahim et al 2015). In all cases, the FT-IR spectra of GSH-CdTe, MPA-CdTe, and TGO-CDTe NPs (curve (1) in Fig.…”

“…S1) except that the S-H stretching vibration at 2557 cm -1 was not found. This phenomenon ascribed to the formation of a covalent bond between -SH and Cd on the surface of the NPs (Brahim et al 2015;Zhang et al 2011). The results can be considered as the direct evidences for capping ligands on CdTe NPs.…”

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