Core-shell type magnetic quantum-dot nanometer particle and preparation method thereof

Abstract

The invention relates to a core-shell type magnetic quantum-dot nanometer particle and a preparation method thereof. The quantum-dot nanometer particle is formed by a core and an epitaxially-grown shell; the core is a magnetic nanometer particle with the particle size more than 1 nm and less than 20 nm; the epitaxially-grown shell is a three-composition semiconductor shell with the thickness more than 0.5 nm and less than 5 nm; and the magnetic quantum-dot nanometer particle is a hydrophobic magnetic quantum-dot nanometer particle, and the fluorescent quantum yield is more than 1% and less than 99%. The preparation method is capable of adjusting the photoluminescence spectra of the magnetic quantum-dot nanometer particle by controlling the relative proportions of all chemical element compositions in the fluorescence semiconductor shell, and enabling the photoluminescence spectra to be adjustable in the scope of 450-900 nm. The preparation method is mild in conditions and is capable of repeatedly preparing the magnetic quantum-dot nanometer particle with superparamagnetism and the same emission wavelength in large scale.

Description

technical field [0001] The invention relates to a quantum dot nanoparticle, in particular to a novel core-shell magnetic quantum dot nanoparticle and a preparation method thereof, belonging to the technical field of biological and medical materials. Background technique [0002] Quantum dot nanoparticles can also be called quasi-zero-dimensional semiconductor nanocrystals. Due to the nanoscale effect, electrons and holes are quantum-confined. When the diameter is smaller than the Bohr diameter, quantum dot nanoparticles change from a continuous energy level to a discrete energy level structure with molecular characteristics. Therefore, after receiving energy (excitation), it can emit light of a specific wavelength. Compared with traditional fluorescent dyes, the advantages of quantum dot nanoparticles include (Bruchez et al.1998): (1) Quantum dot nanoparticles with the same chemical composition can emit light of different colors according to different scales, that is, photo...

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Problems solved by technology

These multifunctional nanoparticles are all formed by combining magnetic nanoparticles with binary semiconductor materials, which have the following disadvantages and deficiencies: (1) It is difficult to overcome the luminous efficiency due to lattice differences and the fluorescence quenching effect of the magnetic core on the semiconductor part. low

(2) The scale distribution is not uniform and difficult to control; (3) Controlling the emission wavelength by particle size is not easy to operate, and the repeatability is not good, which is not conducive to large-scale preparation and application; (4) Nanoparticles synthesized by scale control, Due to the inconsistent size of quantum dot nanoparticles of different colors, it is limited in biomedical applications. For example, when studying the motion of different molecules in parallel, the problem of different degrees of motion restriction caused by different quantum dot scales must be considered.

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