Thioglycerol-functionalized CdSe quantum dots detecting cadmium ions

SENSORS AND ACTUATORS B-CHEMICAL

卷:220

Article

Ben Brahim, Nassim¹  Mohamed, Naim Bel Haj¹  Echabaane, Mosaab¹  Haouari, Mohamed¹  Ben Chaabane, Rafik¹  Negrerie, Michel²  Ben Ouada, Hafedh¹ 

[1] Fac Sci Monastir, Lab Interfaces & Mat Avances, Monastir 5019, Tunisia

[2] Ecole Polytech, Lab Opt & Biosci, INSERM, U1182,CNRS,UMR7645, F-91128 Palaiseau, France

关键词: CdSe quantum dots synthesis;    Absorption spectroscopy;    Electronic microscopy;    Cadmium detection;    Cation binding selectivity;   

DOI  :  10.1016/j.snb.2015.07.049

来源: Elsevier

【 摘 要 】

Water-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.

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