甲胎蛋白压电免疫传感器的研究

Studies on the Piezoelectric Immunosensor for the Determination of α-Fetoprotein (AFP)

以合成的甲基丙烯酸甲酯和甲基丙烯酸羟乙酯共聚物作载体，在压电石英晶体表面涂覆共聚物涂层，经ＣＮＢｒ活化后固定ＡＦＰ抗体，研制成ＡＦＰ压电晶体免疫传感器。研究了固定化方法、载体量、抗原抗体结合时间、重现性、选择性等实验条件和参数的影响。压电晶体的频移值与ＡＦＰ浓度在１００ｎｇ／ｍＬ～８００ｎｇ／ｍＬ的范围内有良好的线性关系。将此传感器初步用于人体血清样品的测定，并与放射免疫法对照，结果令人满意．

A piezoelectric immunosensor has been developed for the determination of AFP.The crystal is AT-cut and has a basic resonant frequency of 9 MHz.Immobilization of theantibody of AFP(anti-AFP) to the crystal's surface is accomplished via a CNBr-activatedcopolymer coating of hydroxyethyl-methacrylate (HEMA )and methyl-methacrylate(MMA).The effects of immobilization method,the amount of copolymer coating and the reaction time between antigen and antibody are studied. Under the optimized conditions, the frequency shifts are linearly dependent on the AFP concentrations in the range of 100￣800ng/mL. Experimental results show that the piezoimmunosensor has good reproducibility, selectivity and sensitivity.Other antigens presented in human serum do not interfere with the sensor's response.Further, the valent value of AFP and anti-AFP and the affinity constant of immunoreaction in this experimental system are calculated. The analytical results given by this approach are in satisfactory agreement with those given by Radial Immunoassay(RIA).