Preparation Of Chemiluminescence Immunoprobes For Magnetic Nanoparticles And Their Detection Of Acetamiprid

Acetamiprid（ACE）is a common new insecticide,which is widely used to control pests.However,due to the excessive use and abuse of acetamiprid,there is a problem of acetamiprid residue in food and water,which has potential adverse effects on human health and living environment.At present,chemiluminescence immunoassay technology has made some progress in the detection of pesticide residues,but its sensitivity and specificity are low.Therefore,it is an urgent problem to establish a simple,rapid,sensitive and low detection limit detection method.In this paper,the sensitivity of immunoassay is combined with the specific recognition of magnetic molecular imprinting,and a new method for trace detection of pesticides by magnetic molecular imprinting chemiluminescence immunoassay is developed,which provides a new way for food and water quality detection.The main contents and conclusions of this paper are as follows:（1）Magnetic nanoparticles were prepared by hydrothermal synthesis,and Fe₃O₄@BSA MIPs were prepared by oscillating reaction with EDC as crosslinking agent,BSA as functional monomer,acetamiprid as template molecule and PBS buffer solution as solvent.The results of SEM,magnetic response diagram,XRD and FT-IR show that the imprinted materials are spherical with a size of about 300nm.The thermodynamic and kinetic adsorption experiments show that Fe₃O₄@BSA MIPs has excellent magnetism and good adsorption performance.A direct competitive ELISA method was established to detect acetamiprid.Firstly,the best reaction conditions were explored.Secondly,horseradish peroxidase（HRP）was activated and enzyme-linked antigen,namely enzyme-linked acetamiprid,was prepared by covalent binding.The standard curve was established by direct competitive enzyme-linked immunoassay.The four-parameter equation was established to explore the chemiluminescence intensity,and the lowest detection limit was 1.57×10^-8 mg L^-1,and the cross-reaction rate of structural analogues was explored.（2）Magnetic nanoparticles were prepared by coprecipitation method,and PS@Fe₃O₄ was prepared by the interaction between positive and negative charges.With acetamiprid as a template molecule,APTS as a functional monomer,TEOS as a crosslinking agent,ethanol as a solvent,the imprinted materials were swollen with tetrahydrofuran to obtain hollow Fe₃O₄@SiO₂ MIPs.SEM,magnetic response diagram,XRD,EDX and XPS show that the imprinted material is spherical with uniform size,and thermodynamic and kinetic adsorption experiments show that hollow Fe₃O₄@SiO₂MIPs has excellent adsorption performance.Hollow Fe₃O₄@SiO₂ MIPs material has higher adsorption performance than Fe₃O₄@SiO₂ MIPs material,which is due to the larger specific surface area of hollow structure and more recognition sites.According to the optimal reaction conditions,a direct competitive ELISA method was established to detect acetamiprid.The four-parameter equation was established to explore the chemiluminescence intensity,and the lowest detection limit was 1.98×10^-9 mg L^-1,and the cross-reaction rate of structural analogues was explored.（3）Magnetic nanoparticles were prepared by coprecipitation method,successfully loaded on the surface of UCNP by solvothermal method,and UCNP@Fe₃O₄@SiO₂was synthesized by microemulsion method.UC@Fe₃O₄@SiO₂ MIPs was prepared by acetamiprid as template molecule,methacrylic acid as functional monomer,ethylene glycol dimethacrylate as crosslinking agent,azodiisobutyronitrile as initiator and acetonitrile as solvent.The results of SEM,XRD and FT-IR show that the imprinted material has uniform particle size,good dispersibility and high crystallinity.Thermodynamic and kinetic adsorption experiments show that UC@Fe₃O₄@SiO₂MIPs has excellent adsorption performance.According to the above-mentioned optimal reaction conditions,a direct competitive ELISA method was established to detect acetamiprid,and a four-parameter equation was established to explore the chemiluminescence intensity.The lowest detection limit was 1.64×10^-10 mg L^-1,and the cross-reaction rate of structural analogues was explored.The above results show that the method is simple,rapid,sensitive and selective,which provides a new idea for the detection of acetamiprid pesticide residues.