γ-干扰素DNA传感器组装过程的表面等离子体子共振研究

The Study on Assembling Process of IFN - γ DNA Sensor by Surface Plasmon Resonance

自行设计并组装了一套简便实用的多波长表面等离子体子共振DNA传感装置,用于γ-干扰素DNA的检测.以人工合成γ-干扰素(interferon gamma,IFN-γ)寡聚核苷酸片段作为DNA探针,用化学法标记生物素探针,利用生物素-亲和素系统相互作用在传感器表面固定DNA探针,使用该SPR传感装置实时监测了DNA探针的固定过程及DNA杂交反应的进行.用于IFN-γ寡聚核苷酸的检测,测定范围为50～400ng/mL;用于IFN-γ的聚合酶链反应(polymerase chain reaction,PCR)扩增产物的检测,其测定范围为5～40ng/mL.同时研究了DNA传感器的稳定性、可逆性及干扰情况.实验结果表明,该传感器可成功地用于检测目的DNA.

A practical and simple DNA sensor based on surface plasmon resonance (SPR) has been developed to determine the interferon gamma (IFN -γ) . This SPR instrument was designed on the basis of simultaneous multi - wavelength detection. IFN - γ oligonucletide DNA chemically labeled with biotin was used as the probe. Biotin- avidin system was used to immobilize the bio - DNA on the sensor surface. The assembling process and condition of the DNA sensor were examined in detail. The SPR sensor can be used to monitor the process of the immobility of the bio - DNA and DNA hybridization in real - time. The determination range of IFN - γ oligonucleotide (24 bases) is 50 - 400 ng/mL. The detennination range of polymerase chain reaction (PCR) product of IFN -γ (247 bases) is 5- 40ng/mL. The stability, reversibility and specificity of the DNA sensor were also investigated. It is found from the experiment that the sensor can be applied for longer time (about 100 times). The relative standard deviation (RSD) for determination DNA and PCR product of DNA was 1.2% and 1.4%, respectively. The interference of noncomplementary DNA sequence with the determination of DNA was examined. It is found that noncomplementary 20 - mer and 21 - mer DNA (ICE - F and ICE - R) do not affect the determination of DNA.