Research On Detection Technology Of Quality Parameters Of Magnetic Nanoparticles

As a new type of nanomaterials,magnetic nanoparticles have unique small size effects,surface effects,good targeting,biocompatibility and other characteristics.Therefore,they have many excellent or new properties.It is widely used in many fields such as immunoassay,disease diagnosis,environmental monitoring,food industry and so on.At present,magnetic nanoparticles are mainly used as carriers to complete qualitative or semi-quantitative detection of target objects,but there are few studies on quantitative detection.How to quickly and accurately detect the quality of magnetic nanoparticles to obtain the content of the combined test substance is an urgent problem to be solved.In this paper,a new magnetic nanoparticle quality detection method based on weak magnetic signal is proposed.Because of the superparamagnetism of magnetic nanoparticles,the magnetic field excitation source is first optimized for simulation analysis of three constant magnetic field excitation sources for solenoid coil excitation source,C-type magnet excitation source,Helmholtz coil excitation source,according to Parameters such as magnetic field uniformity and uniform magnetic field range obtained from the simulation result determine the optimal magnetic field excitation source.The second is to determine the measurement direction and measurement position of the magnetic sensor.Analyze the components of the three directions of the response magnetic flux density in the three-dimensional space,and compare the peak changes of the magnetic flux density components in the three directions and the degree of signal clutter to determine the optimal measurement direction of the magnetic sensor;according to the determined magnetic sensor measurement Parameters such as the direction and the peak value of the magnetic flux density signal at different distances from the container and the degree of signal clutter determine the optimal measurement position of the magnetic sensor,and the number of magnetic sensors is determined according to the peak signal of the signal.Then analyze the response magnetic flux density signals generated by the magnetic nanoparticles in regular distribution and random distribution,analyze the advantages and disadvantages of the magnetic nanoparticle quality parameter detection methods in different distributions,and conduct in-depth research on the random distribution of magnetic nanoparticles.Linear least square method fits a linear function relationship.Afterwards,the parameters that affect the detection results in the experimental platform are studied.The main influencing parameters are the parameters of the magnetic nanoparticles,the geomagnetic field,the container material,and the base fluid.Using the control variable method,in the case of changing only one parameter factor,according to the response magnetic flux density signal generated between different parameters,analyze the advantages and disadvantages of each parameter.Finally,the neural network algorithm is used to study the data of the magnetic nanoparticle mass and response magnetic flux density signals.Three neural network algorithms,BP,RBF and PSO-RBF,are used to establish prediction models,and the results of the three prediction models are tested and analyzed,and finally a neural network prediction model with the best optimization effect is obtained.In this paper,we mainly study the method of magnetic nanoparticle quality detection,and use COMSOL Multiphysics software to simulate the detection platform.The influence of the suitable constant magnetic field excitation source and the external environment on the detection platform was analyzed through simulation data.Finally,a neural network algorithm was used to optimize the relationship between the quality of the magnetic nanoparticles and the Y component of the magnetic flux density.The magnetic signal can know the quality parameter of the magnetic nanoparticle to be measured.The results show that as the mass of magnetic nanoparticles increases,the magnetic flux density generated by them also increases,showing a linear positive correlation function.The research results have certain reference value and application prospects for the quantitative detection of the quality of magnetic nanoparticles.