磁性无机-生物复合粒子敏感膜新型电流型免疫传感器的研究

Amperometric Immunosensor Based on Magnetic Inorganic Bio-nanoparticles Sensing Films

合成了磁性Fe3O4纳米粒子，利用3-氨基丙基三乙氧基硅烷（APS）进行硅烷化，形成表面带有氨基的磁性Fe3O4纳米复合粒子，再用戊二醛将羊抗人免疫球蛋白G抗体（anti-IgG）固定在该磁性粒子表面，通过磁力将其修饰于固体石蜡碳糊电极表面制作成免疫传感器。与标记HRP的二抗体anti-IgG结合，以对苯二酚作为电子媒介体，实现对人免疫球蛋白G（IgG）的定量检测。IgG测定线性范围为2．5～400μ/L，检出限为0．75μ/L。该免疫传感器制作简单，成本低，表面更新方便，可用于临床血清检测。

Fe3O4 magnetic nanoparticles were prepared using co-precipitation technology by the reaction between FeSO4 and FeCl3 , and then the surface of the magnetic nanoparticles were functionalized with 3-aminopropyhriethoxysilane （APS）. The goat anti-human immunoglobulin G antibody was covalently linked to amino-modified particles using glutaraldehyde to form magnetic bio-nanoparticles. The resulting magnetic bio-nanoparticles were attached onto the surface of solid paraffin carbon paste electrode （SPCE） with the help of a permanent magnet to construct a new amperometic immunosensor. This immunosensor was used to analyze human immunoglobulin G （IgG）. The linear range was from 2.5 to 400 μg/L. The detection limit was 0.75μg/L. The simple manipulations of construction, low cost and easy regeneration of the sensing platform were main advantages of proposed immunosensor. It can be applicable to serum detection in clinical diagnosis.