适配子型压电石英晶体传感器探针固定方法的研究

Immobilization methods for probes of aptamer-based piezoelectric quartz crystal sensor

目的比较金膜表面两种探针固定法的优劣，选择适配子型压电传感器探针固定的最佳方法。方法用巯基固定法及生物素-亲和素固定法将针对人IgE的适配子探针固定在压电传感器的金膜表面，对不同浓度IgE引起的频率变化进行检测。结果与巯基法相比，生物素-亲和素法固定探针压电传感器频率下降更为明显，检出限低，线性范围宽，0．1-2．5mg／L浓度范围内IgE浓度与频率变化呈明显的线性相关，相关系数0．9945。结论在压电基因传感器探针固定中效果良好的巯基法在适配子探针固定中并不适用，生物素-亲和素法在适配子压电传感器探针固定中有明显优势。

Objective To compare 2 methods to immobilize probes on the surface of gold membrane and select the better one for aptamer immobilization of aptamer-based piezoelectric quartz crystal sensor. Methods Anti-IgE aptamers were immobilized on the gold surface of piezoelectric quartz crystal sensor with thiol method or biotin-avidin method. The changes of frequency were compared in reactions with different concentrations of IgE. Results Biotin-avidin method obtained higher frequency changes in the reactions of IgE, lower limit of detection and wider liner range than thiol method. For biotin-avidin method, there was significant linear correlation between frequency changes and the concentration of IgE with the correlation coefficient of 0. 994 5. Conclusion The thiol method which is proved effective for probe immobilization on gene sensor is unfit for aptamer immobilization. Biotin-avidin method has a better ability to immobilize probe on the surfaces of aptamer-based piezoelectric quartz crystal sensor.