High-magnetic micro-particle-size nano magnetic beads and preparation method thereof

Abstract

The invention discloses a preparation method of high-magnetic micro-particle-size nano magnetic beads. The preparation method comprises the following steps: mixing iron chloride, cobalt chloride and nickel chloride in an equal ratio to obtain a metal salt mixture; mixing ethylene glycol with the metal salt mixture sufficiently under the condition of mechanical stirring to obtain a mixture of the ethylene glycol and metal salt; adding sodium acetate into the mixture of the ethylene glycol and the metal salt, and continuing to stir to obtain a mixed solution; pouring the mixed solution into a non-metallic reaction kettle; placing the reaction kettle in a temperature-controlled oven, and controlling the oven to operate according to a preset procedure to make the mixed solution be subjected toa thermal reaction to form iron-cobalt-nickel alloy Fe-Co-NiOx magnetic nanoparticles; magnetically separating the iron-cobalt-nickel alloy Fe-Co-NiOx magnetic nanoparticles, and washing and drying;coating the surface layers of the iron-cobalt-nickel alloy Fe-Co-NiOx magnetic nanoparticles with a carbon layer and a silicon dioxide layer sequentially, and covalently grafting polyethylene glycol onto an outermost layer. The preparation method disclosed by the invention solves the technical problems of relatively large particle size, wide distribution range, small specific surface area and lowmagnetic response of magnetic beads in the prior art.

Description

technical field [0001] The invention relates to the field of DNA detection, in particular to a nano magnetic bead with a high magnetic particle diameter and a preparation method thereof. Background technique [0002] Cell-free DNA (nucleic acid) research is a hot field in genome molecular diagnosis research. It has been gradually applied clinically to all stages of tumors from initial diagnosis to treatment and development, including: early screening, evaluation of tumor heterogeneity, metastasis and recurrence Risk and prognosis assessment, real-time monitoring of treatment response and drug resistance, tumor staging and grading, and guidance of treatment options, etc. [0003] At present, the methods of extracting free DNA mainly include the magnetic bead method. The principle of the magnetic bead method to extract nucleic acid is: using superparamagnetic nanoparticles, using the method of absorbing nucleic acid under high-salt conditions and low pH, and then separating nu...

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Problems solved by technology

[0005] The main purpose of the present invention is to propose a nano-magnetic bead with high magnetic particle size and its preparation method, aiming

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