Design Of Low-Fouling Gold Magnetic Particles And Its Application In High-Risk HPV Gene Detection Of Cervical Cancer

Gold magnetic particles with unique physical and chemical properties have been widely used in the detection of disease markers.However,the resistance encountered at present is that there are a lot of interfering substances in the actual samples,and their influence on the measured results can not be effectively eliminated.What’s more,they directly lead to the agglomeration and deposition of gold magnetic particles,which leads to the failure of research and development.The current solution is the modification of anti-fouling materials,the most used are poly（ethylene glycol）（PEG）,peptides,poly（carboxybetaine methacrylate）and choline phosphate due to their remarkable properties.However,product design involving only these materials is unlikely to meet the requirements of increasingly complex detection environments.Two gold magnetic particles with excellent anti-pollution properties have been designed and successfully applied to disease detection.The article consists of the following three parts:（1）Preparation and characterization of Fe₃O₄@Au nanoparticles:Firstly,superparamagnetic Fe₃O₄ nanoparticles with particle size of 7-10 nm were synthesized by chemical co-precipitation method,and then the core-shell Fe₃O₄@Au nanoparticles were prepared by direct reduction.Finally,it was characterized by UV spectrophotometer（UV-Vis）,X-ray powder diffractometer（XRD）and transmission electron microscopy（TEM）.The results show that the prepared spherical gold magnetic particles are uniform in size,uniform in dispersion,and have a good magnetic response shape with a particle size of about 50 nm.（2）Preparation of Fe₃O₄@Au@PEI nanoparticles and its application in HPV DNA detection:Polyethyleneimine（PEI）was modified on the surface of Fe₃O₄@Au nanoparticles by self-assembly method to obtain excellent dispersibility and stain resistance.The Fe₃O₄@Au@PEI nanoparticles were applied to 1%serum for detection of HPV DNA.The results showed that the fluorescence signal and the concentration of HPV DNA showed good linearity,and the detection limit for HPV DNA was 16.7 nM,and the linear range was 50-1000 nM.（3）Preparation of Fe₃O₄@Au@PEI@HPP nanoparticles and its application in HPV DNA detection:Hyperbranched polyether polyol（HPP）molecules were covalently grafted onto Fe₃O₄@Au@PEI nanoparticles.We have successfully prepared a new type of magnetic nanoparticles with excellent stability,biocompatibility and anti-pollution properties,and successfully applied to the rapid and direct diagnosis of disease markers in 100%serum.The experimental results showed that the detection limit of HPV DNA in 100%serum was 1.23 nM,and the linear range was 5 nM-1μM.Predicting the commercial value of the material.