Oil Phase CdSe/ZnS Quantum Dot Solution
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Product Description
The dependence of optical properties on particle size is the unique and most attractive feature of quantum dots. For example, by controlling the particle size, the emission wavelength of CdSe quantum dots can be continuously tunable over the entire visible range. However, two-element quantum dots, such as CdSe quantum dots, have two drawbacks. First, its surface defects form a surface trap state, which reduces the luminescence efficiency and stability. The surface defects can be reduced by encapsulating ZnS on the quantum dot surface to form a Core-shell structure, but the mismatch between the CdSe and ZnS lattices greatly affects its luminescence efficiency and optical stability. Second, the extinction coefficient of quantum dots is proportional to the volume of the particles. Materials labeled with 6 nm (red light) CdSe quantum dots have an emission intensity thirty times higher than that of 2 nm (green light) quantum dots, which will cause a difference in detection sensitivity.
Unlike two-element quantum dots, Alfa Chemistry offers alloyed CdSe quantum dots with a transitional component hydrophobic material in the emitting core and ZnS shell, which brings the following advantages:
1. Controlling the optical properties by adjusting the composition of alloy elements to prepare quantum dots with the same volume but different luminescence frequencies, thus reducing the difference in detection sensitivity due to the application of quantum dots of different colors.
2. The alloy quantum dots have strong lattice strength and stable performance.
3. The gradual transition of the lattice is realized, which effectively reduces the internal pressure caused by the lattice defects of quantum dots, so that the quantum dots have higher luminescence efficiency and stability.
Applications
Fluorescent Probes
Adamczak et al. embedded CdSe/ZnS hydrophobic quantum dots in polyelectrolyte nanocapsules. The core of the capsule consists of a mixture of linseed oil and chloroform, prepared by a spontaneous emulsification technique. The resulting emulsions were stabilized with lecithin and encapsulated using layer-by-layer (LbL) adsorption of polyelectrolytes. The emulsions and capsules were deposited on mica surfaces and the deposition topography was examined by atomic force microscopy (AFM). The presence of quantum dots in the oil cores was confirmed by recording the fluorescence spectra of the samples containing CdSe/ZnS. To assess the cytotoxicity of the capsules, their effect on the viability of mouse embryonic fibroblasts was examined using the MTT test, followed by observation of the cell morphology by light microscopy after hematoxylin-eosin staining.
Fig. 1 Scheme of the multilayer nanocapsules formation using the layer-by-layer adsorption of polyelectrolytes on the liquid emulsion core. (Adamczak et al, 2013)
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Reference
- Adamczak, M. , et al. Linseed oil based nanocapsules as delivery system for hydrophobic quantum dots[J]. Colloids Surf B Biointerfaces, 2013, 110:1-7.
* It should be noted that our service is only used for research, not for clinical use.
