Preparation method of CdSe/SiO2 quantum dot composite fluorescent nanoparticles

Abstract

The invention relates to a preparation method of CdSe/SiO2 quantum dot composite fluorescent nanoparticles, which comprises the steps of: synthesizing CdSe quantum dots in a water solution at room temperature by using EDTA as a stabilizing agent and using the electron beam irradiation method; and then, preparing core-shell type fluorescent nanoparticles of which the CdSe quantum dots are coated by silicon dioxide with amino groups on surfaces by using the water-in-oil microemulsion method and using the cohydrolysis of 3-aminopropyl trimethoxysilane (APTMS) and tetraethoxysilane (TEOS). The prepared nanoparticles which are uniformly spherical have the particle diameter of 200+/-8nm, have good monodispersity and light stability, and can not cause fluorescent molecule leakage easily. The quantum dot composite nanoparticles can be effectively absorbed by neural stem cells of a mouse, stronger fluorescence signals are detected in the cells, and a clear fluorescence imaging picture is obtained.

Description

Technical field [0001] The invention relates to a method for preparing quantum dot fluorescent nanoparticles, in particular to a CdSe / SiO 2 Preparation method of quantum dot composite fluorescent nano particles. Background technique [0002] The electron beam radiation method is a method with distinctive technical characteristics. It uses high-energy electron beams for chemical synthesis in a short reaction time. Because the reaction conditions can be controlled to create a pure reducing or pure oxidizing atmosphere, the reaction process does not require a specific reducing agent or oxidizing agent, and the purity of the reaction product is very high. For a long time, electron beam irradiation technology has been widely used in the polymerization, cross-linking and graft modification of polymers, and the anti-virus and sterilization of food and medical products, but there are not many reports on the preparation of inorganic materials. [0003] Quantum dots (QDs) have attracted peo...

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Problems solved by technology

However, quantum dots also have their own shortcomings. First, they are unstable and easily oxidized without the protection of organic solvents. Therefore, quantum dots are usually stored in organic solvents and protected from light; secondly, there are still a large number of defects on the surface of quantum dots. Its photon quantum yield, usually the photon quantum yield of organic solvent-wrapped quantum dots is between 10% and 20% at room temperature, and the photon quantum yield will increase at low temperatures, but it is not conducive to practical applications; in addition, because quantum dot semiconductor materials are usually Contains toxic heavy metal elements (such as cadmium, gallium, etc.), which may be harmful to organisms

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