适配子型压电传感器的实验研究

Aptamer-based Piezoelectric Quartz Crystal Biosensor

目的建立适配子型压电传感器阵列检测人免疫球蛋白E,对适配子型压电石英传感器的各项参数进行初步探索。方法用生物素-亲和素法将针对人IgE的适配子探针固定在压电传感器的金膜表面,通过压电传感器对适配子与IgE的反应进行实时监测,观察不同浓度IgE的反应趋势及所引起的频率变化,获得IgE检测标准曲线;通过检测BSA、IgG、IgE非特异信号,并与特异性信号相比较对适配子检测的特异性进行检验。结果亲和素法固定适配子对IgE进行检测,最低检出限0.055mg/L,线性范围0.1～2.5mg/L,非特异性信号响应小,不超过同浓度特异性信号的5%。结论构建的适配子压电传感器可检测ng级物质且非特异性信号小,显示该平台在临床检测中有较好的应用前景。

OBJECTIVE To establish an aptamer-based piezoelectric .sensor assay to detect human immunoglobulin E （IgE） and acquire the parameters about this kind of biosensor. METHODS Anti-IgE aptamers were immobilized on the gold surface of piezoelectric quartz crystal sensor with biotin-avidin method. The reaction between anti-IgE aptamers and IgE was monitored in time on piezoelectric sensor. Different concentrations of IgE were detected and the calibration curve of IgE was drawn. Non-specific response signals of BSA, IgG and IgE were monitored to show the detecting specificity of aptamer-based sensor. RESULTS For the aptamer-based sensor, the lowest limit of detection was 0. 055mg/L and the linear range was 0.1-2. 5mg/L. Non-specific signals of this sensor were less than 5M of specific signals of IgE at the same concentration. CONCLUSIONS The aptamer-based piezoelectric sensor can detect 5.5 ng IgE while the non-specific signals are very low. So this aptamer-based sensor is hopeful to be applied to clinical laboratory diagnosis.