Nanoparticles cadmium telluride

Nanoparticles such as those of the heavy metals, like cadmium selenide, cadmium sulfide, lead sulfide, and cadmium telluride are potentially toxic [14,15]. The possible mechanisms by which nanoparticles cause toxicity inside cells are schematically shown in Fig. 2. They need to be coated or capped with low toxicity or nontoxic organic molecules or polymers (e.g., PEG) or with inorganic layers (e.g., ZnS and silica) for most of the biomedical applications. In fact, many biomedical imaging and detection applications of QDs encapsulated by complex molecules do not exhibit noticeable toxic effects [16]. One report shows that the tumor cells labeled with QDs survived in circulation and extravasated into tissues... 

Many other systems based on different nanoparticles have been introduced, such as copper indium disulfide (CuInS2) [263-265], copper indium diselenide (CuInSe2) [266,267], cadmium telluride (CdTe) [268], lead sulfide (PbS) [269,270], lead selenide (PdSe) [271], and mercury telluride (HgTe) [272]. Some of these systems show enhanced spectral response well into the infrared part of the solar spectrum [271,272]. In most cases the absorption of the nanocrystals was, however, quantitatively small as compared to the conjugated polymers. 

Nanomaterials in the form of a colloidal solution or quantum dots are attributed to have a tremendous impact in analytical chemistry for their unique physical and chemical properties (Alivisatos 2004 Katz and Willner 2004). A different methodology has been adopted to analyse vitamin Bi spectro-fluorimetrically by using cadmium selenide quantum dots (CdSe QDs), cadmium telluride (CdTe) nanorods, and silica and gold nanoparticles. A fluorescence resonance Rayleigh scattering (RRS) method was applied for determining vitamin Bi at sub-nanomolar level (Liu et al. 2006). In this technique, vitamin Bi was mixed with acidic buffer and prepared gold nanoparticles. After incubation, the solution mixture was excited in synchronous mode to obtain RRS spectra. The RRS spectral intensity correlated with the concentration of vitamin Bi. 

Cd (II) complex of bis-(isopropyl telluro) propane is prepared and decomposed to obtain CdTe nanoparticles. Briefly, bis-(isopropyl)di-telluride is first synthesized by the reduction of tellurium powder, synthesis of SSMP pale yellow Cd (II) complex of bis-(isopropyltelluro)propaneis followed by reacting the compound with cadmium chloride in acetonitrile finally pyrolysis of precursor molecule in hot quinoline at 205°C generated grey colored CdTe nanoparticles (Fig. 7). 

Fig. 8 X-ray diffraction pattern of CdTe nanoparticles synthesized from SSMP (a) Cadmium (II) complex of bis-(aminopropyl)telluride, and (b) Cd (II) complex of bis-isopropyltelluro propane...

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