Water Soluble CdTe/CdS/ZnS Quantum Dots
Product Description
Alfa Chemistry provides water-soluble CdTe/CdS/ZnS quantum dot products are CdTe as the core, CdS and ZnS as the shell layer, the surface is wrapped by hydrophilic ligands core/shell/shell type fluorescent nanomaterials, the average quantum yield ≧ 40%. Storage should avoid direct sunlight, 4 degrees sealed dark storage, can be customized for customers to produce 515nm ~ 615nm any wavelength of different grams of products. The product has the characteristics of uniform particle size, broad absorption spectrum, symmetric emission spectrum, high and stable fluorescence intensity.
Product Features
We can also provide four types of water-soluble CdTe/CdS/ZnS quantum dots for customization: (1) carboxyl group with negative charge on the surface and 3-mercaptopropionic acid as the capping agent; (2) carboxyl group with negative charge on the surface and polymer as the capping agent; (3) carboxyl group with negative charge on the surface and containing PEG chain, which has excellent biocompatibility and can be attached to antibody proteins with amino groups, etc.; (4) amino group with positive charge on the surface and containing PEG chain, which can be attached to antibody proteins with amino groups, etc. of amino groups, containing PEG chains, excellent biocompatibility, and can be attached to antibody proteins with carboxyl groups.
Applications
Na et al. successfully prepared highly luminescent, stable and low-toxicity N-acetyl-L-cysteine (NAC)-capped CdTe/CdS@ZnS-SiO2 near-infrared (NIR)-emitting quantum dots (QDs) in aqueous solution by the microwave irradiation reduction route, in which thiol-capped CdTe/CdS QDs were used as the core template, and ZnCl2, NAC and tetraethyl orthosilicate as the shell precursors. This ZnS-like cluster filled the hybrid SiO2 model, which not only greatly improved the brightness and stability of the pristine CdTe/CdS QDs, but also greatly reduced the cytotoxicity to HeLa cells. In addition, it was found that Hg2+ could effectively and selectively quench the NIR emission of QDs based on the electron transfer process. On this basis, a simple, rapid and specific method for trace Hg2+ determination was proposed. Under optimal conditions, the fluorescence intensity decreases linearly with the concentration of Hg2+ from 5.0 × 10-9 to 1.0 × 10-6 M. The detection limit of Hg2+ is 1.0 × 10-9 M (signal-to-noise ratio = 3).
Fig.1 Schematic illustration for the preparation of CdTe/CdS@ZnS-SiO2 QDs. (Na et al., 2015)
Our products are constantly updated. If the product you need is not in our catalog, please feel free to contact us, we provide relevant custom services.
Reference
- Na, et al. Microwave-assisted synthesis of high-quality CdTe/CdS@ZnS-SiO2 near infrared-emitting quantum dots and their applications in Hg2+ sensing and imaging[J]. Sensors and Actuators, B. Chemical, 2015, 207(Pt.A):74-82.
* It should be noted that our service is only used for research, not for clinical use.
