Production method of probe molecule for recognizing tumor cell by specificity

Abstract

The invention relates to a preparing method for a probe molecule which identifies tumor cells specifically, belonging to the nanometer material and biology technical field; the method comprises the following steps: (1) biocompatible folate is used for modifying PEG with the two sides being amino groups; (2) the PEG connected with the folate is modified to the surface of dendrimer PAMAM; (3) oil-soluble ligand on the surface of a quantum dot is replaced by a ligand exchange method, thus preparing a water-soluble quantum dot; the invention can lead the quantum dot to identify cancer cells expressed with high-level folate receptors, thus being capable of being used as a fluorescent probe used for the study of cytology; at the same time, the PAMAM and the PEG are modified to the surface of the quantum dot, thus improving the stability of the quantum dot greatly; furthermore, the PAMAM and the PEG have good biocompatibility and little toxicity, thus providing feasibility for the application thereof in the biology.

Description

technical field [0001] The invention belongs to the field of nanomaterials and biotechnology; it relates to a method for preparing dendritic polyamide-amine coated oil-soluble quantum dots connected with folic acid, and prepares a water-soluble probe for specific recognition of tumor cells molecular. Background technique: [0002] Quantum dots refer to semiconductor nanocrystals, mainly nanoparticles composed of II-VI or III-IV elements. Due to its quantum size effect, it has unique properties, including controllable fluorescence emission wavelength, wide and continuous excitation spectrum, strong fluorescence, good photostability, resistance to photobleaching, and the ability to realize one-element excitation and multiple emission at the same time. Make up for the shortage of existing organic fluorescent dyes, and even replace organic fluorescent dyes in some cases. The unique properties of quantum dots will facilitate their application in medical experiments and clinical...

AI Technical Summary

Problems solved by technology

However, the particle size of the quantum dots coated by this method is relatively large, which is not conducive to the application in biology.

(4) Encapsulation is achieved through the hydrophobic interaction between the amphiphilic polymer and the alkyl chain on the surface of the quantum dot. Since this method does not destroy the organic molecules on the surface of the quantum dot, its optical properties are basically not affected, but a large amount of organic solvent is used. , the process is complex and difficult to purify

However, the surface of the quantum dots is modified by using a small molecular compound of mercapto, which cannot effectively protect the quantum dots; in addition, the mercapto groups on the surface of the quantum dots are easy to generate disulfides under the condition of light, and the disulfides cannot be combined with The surface of the quantum dot interacts, which will fall off the surface of the quantum dot

Therefore, the surface modification of quantum dots with mercapto small molecule compounds will lead to poor stability of quantum dots.

Images