Design And Study Of Thermosensitive Anti-protein Adsorption Copolymer Coating And Near-infrared Second Region Fluorescence Imaging Molecules

The non-specific adsorption of proteins involves many research fields.In recent years,capillary electrophoresis has made great progress in proteomics,metabonomics,biomarkers and so on.In biochemical analysis,the interaction between analyte and column surface will affect the separation efficiency and migration time,and reduce the separation effect of the system.The coating can effectively solve the adsorption problem of analytes on the inner wall of the chromatographic column,improve the separation performance of the system,and has more analytical advantages.Based on the above background,we obtained a triblock copolymer peo-pnipaampspmap by atom transfer radical polymerization(ATRP).The copolymer was covalently bonded to hydrophobic substrate by photosensitizer diazoresin(DR)and applied to analytical chemistry.Sufficient hydrated groups(ether bond,amide group and sulfonic group)in the copolymers provide the basis for the adsorption performance of proteins.The conformation changes caused by the interaction of hydrophilic group and hydrophobic group(isopropyl)at different temperatures provide the possibility for the elastic self-cleaning property of the material,and can prolong the cycle life of the coating material.The antifouling performance and elastic self-cleaning function of the coating were evaluated by dynamic adsorption experiment of fluorescent protein.The coating is used for capillary electrophoresis(CE)coated column,and its excellent protein separation spectrum proves the practicability of the coating.Near infrared fluorescence imaging can greatly reduce the spontaneous fluorescence and scattering of tissues,overcome the defects of visible light in penetration depth and contrast,and provide a more advantageous platform for noninvasive biological imaging in vivo.Therefore,near infrared fluorescent materials,especially near infrared II fluorescent imaging materials,have become a research hotspot in the exploration of biological tissues/organs.Compared with other inorganic and polymer fluorescent molecules,the luminescent properties,biocompatibility and biosafety of small fluorescent molecules can be controlled and improved by reasonable structural design,so it has greater research and application potential.We use donor acceptor donor unit(D-A-D)structure design.For acceptor group,benzothiadiazole(BBTD)has a significant quinone type characteristic,which can improve the electron delocalization,and is the most popular choice.The donor,Cyclopentadithiophene(CPDT)and 3,4-ethylene dioxythiophene(EDOT)can improve the molar extinction coefficient,increase the conjugation performance,and facilitate hole transmission,reduce the band gap and improve the fluorescence performance.The introduction of alkyl chains into the molecule increases solubility.The absorption and emission peaks of the fluorescent molecule are 900 nm and 1120 nm,respectively.The quantum yield of the water-soluble nanoparticles formed by PS-MPEG is 0.98%,and its penetration depth can reach 15 mm,which has good biocompatibility.This kind of small organic molecules can be modified to increase their clinical translation,and then cooperate with biological imaging system to realize living biological imaging therapy and better guide surgery.