A doped core-shell nanomaterial and preparation method thereof

Abstract

The invention discloses a doped core-shell nanometer material and a preparation method thereof. The chemical general formula of the material is Cd1-xMxSe / ZnS, and M is one of Cr, Mn, Fe, Co, Ni, Cu, Zn, Bi, Ce, Pr, Nd, Eu and Er. The preparation method comprises the steps that 1, a positive ion aqueous solution is prepared, a surface finishing agent is added, the pH value is adjusted, and positive ion precursor liquid is obtained; 2, Se powder is added to a NaBH4 aqueous solution, a reaction is carried out under protection of nitrogen, and negative ion precursor liquid is obtained; 3, at constant temperature, the negative ion precursor liquid and the positive ion precursor liquid are mixed for reacting, and core layer Cd1-xMxSe nanocrystalline precursor liquid is obtained; 4, a Zn<2+> and S<2-> ion aqueous solution is added through titrimetry, the reaction continues to be carried out, cooling is carried out under protection of nitrogen, detergent is added for centrifugation and washing, and the doped core-shell nanometer material is obtained. The material is free of toxins or low in toxin, and the preparation method is simple in step; the size is easy to control, and large-scale production can be achieved. A novel method is provided for preparing efficient and cheap biomedical materials.

Description

technical field [0001] The invention belongs to the field of nanometer materials and their preparation, in particular to a doped core-shell nanometer material and its preparation method. Background technique [0002] II-VI semiconductor nanomaterials have excellent optical properties such as wide excitation spectrum, narrow emission spectrum, and high photochemical stability, and have extremely broad application prospects in light-emitting diodes, photodetectors, solar cells, and field-effect transistors. Especially as a biomarker, its performance surpasses the widely used organic dye markers in many aspects, and it has become a new research hotspot in the field of biomedicine. [0003] Among them, CdTe, CdSe and other cadmium-based nanomaterials are the most widely studied due to their excellent optical properties, but Cd elements belong to the A-type toxic elements, which may bring toxicity to organisms, which greatly limits their applications in cell imaging, immune analy...

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Problems solved by technology

[0005] At present, there are many methods for preparing high-quality nanocrystals, such as metal-organic methods, hydrothermal methods, and single-molecule precursor methods. For example, the patent document CN101891162A discloses "a low-cost synthetic Zn x Cd 1-x Se(0≤x≤1) and its related core-shell structure semiconductor nanocrystal method", patent document CN101948686B discloses "a method for synthesizing manganese-doped zinc selenide color-tunable fluorescent quantum dots in aqueous phase", patent document CN102517025B discloses "a method for preparing ZnSe / ZnS core-shell quantum dots", and patent document CN104974742A discloses "a method for preparing CdTeSeS / ZnTe core-shell quantum dots by aqueous phase microwave", but most of these preparation methods have harsh reaction conditions, If the reaction temperature is high, equipment such as an autoclave is required, the reaction steps are relatively complicated, and the reaction reagent still uses a large amount of organic matter, which is highly toxic and harmful to the health of researchers and developers, and is expensive and expensive.

Most importantly, most of the nanocrystals synthesized by these methods are oil-soluble nanocrystals, which have poor water solubility and low biocompatibility, which seriously limit their application in the field of biomedicine.

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