压电石英晶体免疫传感器在前列腺特异抗原检测的实验研究

Study on piezoelectric quartz crystal immunosensor for determining prostate specific antigen

目的 构建一种检测前列腺特异抗原 (PSA)的新型压电石英晶体免疫传感器。方法采用AT切型、基频 10MHz的金膜电极石英晶体用金属夹具和乳胶套圈固定形成检测池 ,抗人PSA单克隆抗体采用巯基化方法固定在金膜电极表面制成抗体识别膜 ,构成压电PSA免疫传感器 ,同时对 5 6例临床血清标本进行检测 ,并与化学发光免疫分析法进行比较。结果 构建的压电PSA免疫传感器对PSA的响应特性良好 ,其线性检测范围为 1 2 5～ 5 0ng/ml,批内、批间变异系数 (CV)分别小于 4 0 %和 6 0 % ,与化学发光免疫分析法具有良好的相关性 (r =0 95 ,P >0 0 5 ) ,癌胚抗原(CEA)、甲种胎儿球蛋白 (AFP)、人绒毛膜促性腺激素 (hCG)等对PSA的检测基本无干扰 ;传感器可再生后重复使用 5次。结论 压电PSA免疫传感器具有灵敏度高、特异性好、不需标记、操作简单、省时、能实时在线检测和重复使用等优点 ,是一种检测PSA的新方法 ,适用于临床检测 ,有推广价值。

Objective To construct a new type of piezoelectric quartz crystal immunosensor to determine human prostate specific antigen (PSA). Methods The sensor pool consisted of a plastic cycle and 10 MHz quartz AT-cut with gold coated electrodes on it and the immobilization of monoclonal antibody of PSA onto the surface of gold electrode was accomplished via thiolated method. Then immunosensors were used to detect PSA of 56 serum samples in clinical laboratory.Results Experimental results showed that the piezoelectric immunosensor had good response to PSA with frequency shifts linearly dependent on PSA concentration in a range of 1.25～50 ng/ml. The variance within batch and between batch were less than 4.0% and 6.0% respectively. Correlation analysis showed there was significant correlation between this sensor and chemiluminescent immunoassay(r=0.95,P>0.05). Other antigens such as carcino embryonic antigen (CEA), alpha fetoprotein (AFP), human chorionic gonadotrpin (hCG) did not intervene in the response of sensor. The sensor could be used to detect PSA repeatedly for 5 times. Conclusion Piezoelectric immunosensor for determination of PSA is used repeatedly, in addition, of high sensitivity,high specificity,unnecessary labeling,simple operation for real-time detection. Thus, it is suitable for detecting serum PSA in clinical laboratory.