Core-shell zinc oxide-silica nanoparticle, and preparation method and application thereof

Abstract

The invention specifically relates to a core-shell zinc oxide-silica nanoparticle, and a preparation method and application thereof, belonging to the technical field of nano-materials. The method comprises the following steps: subjecting lithium hydroxide and zinc methacrylate to hydrolysis at room temperature to produce luminous ZnO nanoparticles, adding siloxane monomers containing double bonds and azodiisobutyronitrile, carrying out heating to initiate polymerization so as to form a single organosilicon layer on the surface of the ZnO nanoparticles, then adding other siloxane and ammonia water, and carrying out hydrolysis at room temperature to form a silicon dioxide layer so as to prepare the core-shell zinc oxide-silica nanoparticles. The core of a core-shell zinc oxide-silica nanoparticle is a single zinc oxide luminous quantum dot and has a diameter of 2.7 to 4.6 nm; the shell of the nanoparticle is a thin silica layer; and the core-shell zinc oxide-silica nanoparticle is safe and nontoxic, has high quantum efficiency, stably emits light under continuous UV excitation in cells, can be used for preparing fluorescent labels for biological cells and is especially applicable to preparation of fluorescent labels for cervical carcinoma cells.

Description

technical field [0001] The invention belongs to the technical field of nanometer materials, and specifically relates to a core-shell type "zinc oxide-silicon dioxide" nanoparticle and its preparation method and application. Background technique [0002] Since the 1990s, scientists have recognized the application prospects of semiconductor luminescent quantum dots as bioluminescent markers, especially the research on the intersection of luminescent nanocrystals and biomedicine has aroused great interest of scientists and achieved remarkable results. . [0003] Semiconductor luminescent quantum dots have incomparable advantages over organic dyes in the application of bioluminescent labeling. For example, the fluorescent color of quantum dots can be adjusted by controlling their composition and particle size; the excitation peak of quantum dots is wide and the emission peak is narrow, symmetrical. Gaussian distribution, small overlap, so the same excitation light can be used t...

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Problems solved by technology

However, since the visible emission mechanism of ZnO is surface defect light emission, it is easily affected by the external environment, water, weak acid, weak base, etc. will cause fluorescence quenching, and the quantum yield of ZnO quantum dots synthesized by traditional methods is generally lower than 10%, making its application of bioluminescence labeling limited

Researchers try to adjust various conditions to increase the quantum yield of ZnO, such as replacing the reaction raw material zinc salt or alkali, or using different coating methods to protect its surface defects, such as coating with polymers and organic silicon. However, so far, the researched products are still unsatisfactory. For example, the coating protection effect is not significant, the coating process leads to a significant reduction in the quantum yield of ZnO quantum dots, or the obtained product particle size is too large, which is a shell layer. Coated multi-core structures, etc.

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