CdSe/ZnS Quantum Dots-Carboxyl & Alkyl
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Product Description
Alfa Chemistry offers CdSe/ZnS quantum dots in the emission range of 450 nm to 650 nm. Our CdSe/ZnS quantum dots are gradient-alloyed semiconductor materials with size-dependent optical/electronic properties, high fluorescence efficiency, low toxicity, and easy cellular uptake. The low luminescence efficiency caused by defects and surface trap states can be greatly reduced by surface passivation of the high band gap ZnS shell. Our CdSe/ZnS quantum dots can be used for highly sensitive cell imaging, drug delivery, and luminescence devices.
Alfa Chemistry provides quantum dots products including follwing:
CdSe/ZnS Quantum Dots - Carboxyl are CdSe/ZnS core/shell quantum dots coated with carboxyl, with the emission peaks ranging from 500 nm to 650 nm, quantum yield > 20%.
CdSe/ZnS Quantum Dots - Alkyl are CdSe/ZnS core/shell quantum dots coated with alkyl, with the emission peaks ranging from 450 nm to 650 nm, quantum yield > 40%.
Applications
Fluorescent Probes
Quantum dots (QDs) are inorganic semiconductor nanocrystals composed of group II-IV or III-V elements with a particle size between 1 and 100 nm and a restricted three-dimensional shape, similar to a sphere. Compared with traditional organic fluorescent dyes, quantum dots have high fluorescence quantum yield, wide excitation spectrum, narrow emission spectrum, strong resistance to photobleaching, good optical stability and easy to modify. Currently, quantum dots have been widely used in frontier scientific fields such as bioimaging analysis, heavy metal ion detection, biomarker, drug determination, and DNA and protein detection. Due to more defects on the surface of single-core quantum dots, the fluorescence efficiency is lower and the stability of photo-oxidation is also poor. In comparison with mononuclear quantum dots, core-shell quantum dots (e.g., CdSe/ZnS) have better luminescence efficiency and stability, and their lower toxicity makes core-shell quantum dots very promising for applications. Cheng et al. established a simple, sensitive, selective and low-cost method for the fluorescence of oil-soluble core-shell CdS/ZnS QDs based on the sensitive bursting property of acetylmethamidophos. This method can be applied to the rapid detection of acetamiprid in fruits and vegetables, which expands the application of fluorescent quantum dots.
Fig.1 TEM image of Cdse/ZnS QDs(a)and the photo of Cdse/Zns QDs under ultraviolet light(b). (Cheng et al, 2021)
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References
- Cheng Y., et al. Fluorometric Determination of Acephate Based on CdSe/Zns Quantum Dots. Journal of Analytical Science, 2021,37(05):606-610.
- Wen, S. H. , et al. CdSe/ZnS quantum dots coated with carboxy-PEG and modified with the terbium(III) complex of guanosine 5’-monophosphate as a fluorescent nanoprobe for ratiometric determination of arsenate via its inhibition of acid phosphatase activity. Microchimica Acta,2019, 186(1).
* It should be noted that our service is only used for research, not for clinical use.
