Amphiphilic macromolecular modified oil-soluble nuclear/shell quantum dots and preparation method

Abstract

The invention relates to amphiphilic macromolecular modified oil-soluble nuclear/shell quantum dots and a preparation method. A nuclear layer is of CdSe quantum dots; and a shell layer comprises CdS, an alloy layer, ZnS, an amphiphilic polymer layer from the inside to the outside in turn. The structure of the alloy layer is: Cd0.4Zn0.6S, Cd0.45Zn0.55S or Cd0.6Zn0.4S; the structure of the amphiphilic polymer layer is that: an inner layer is an alkyl chain hydrophobic layer; a connecting layer is aliphatic long carbon chains; and an outer layer is a carboxyl hydrophilic layer; and the particle size range of the quantum dots is between 200 and 1,000 nm. By covering different shell layers with appropriate thickness on the surface of the CdSe nuclear quantum dots, the nuclear/shell quantum dots with high fluorescence efficiency and stable fluorescent properties are synthesized; by performing self-assembly water-solubility modification on self-made amphiphilic polymer and amphiphilic polymer, a formed amphiphilic polymer layer protects the surface structure and fluorescence properties of the nuclear quantum dots, can restrain cadmium ions and selenium ions from diffusing outwards and reduces the toxicity of the quantum dots to organisms; and the modified quantum dots cannot generate fluorescence resonance energy transfer in multi-flux detection.

Description

technical field [0001] The invention relates to the field of nanomaterial preparation and biochemical multi-flux detection, in particular to an amphiphilic polymer modified oil-soluble core / shell quantum dot and a preparation method thereof. Background technique [0002] Quantum dots (Quantum Dots, QDs), due to their unique optical and electrical properties, have attracted widespread attention from scientists and have become a bright spot in nanotechnology. With the continuous improvement of preparation technology, quantum dots have shown more and more broad application prospects in the biological field, especially as fluorescent probes for biomarkers, biodetection, and bioimaging. Compared with organic fluorescent molecules, quantum dots have many unique optical properties: their emission peak wavelength can be adjusted by the composition material and particle size, their excitation light wavelength range is very wide, they have a large Stokes shift and narrow symmetry. Fl...

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Problems solved by technology

[0004] At present, there are many literature reports on the hydrophilic modification of quantum dots, such as patent CN101104806, which uses hydrophilic silicate to coat quantum dots, but the reaction conditions are not easy to control, the reproducibility is poor, and the yield is low. In the later application, non-specific adsorption Serious; patent CN101250403 uses long-chain mercapto compounds to coat quantum dots, but the combination of mercaptocarboxylic acid and quantum dots is not stable, and under the condition of a physiological solution with a pH of 7-8.5, the carboxyl groups on the surface of quantum dots will dissociate and cause Severe non-specific bonding; patents CN1712489 and CN101012373A both use core / shell quantum dots for hydrophilic modification, but the difference in lattice parameters between the core and shell affects the crystal structure and fluorescence efficiency of quantum dots, and The polymer used may destroy the surface structure of quantum dots and affect the uniformity of the surface of quantum dots

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