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目的利用电化学DNA生物传感器技术,建立一种简单快速的沙门氏菌检测方法。方法利用循环伏安法将新蒸单体吡咯和羧基多壁碳纳米管聚合到电极表面,形成均匀牢固、富含羧基的修饰膜。导电聚合物薄膜使电极获得了大的比表面积和优异的电子传递能力。在偶联剂1-乙基-(3-二甲基氨基丙基)碳化二亚胺盐酸盐(EDAC)的作用下,亲和素与电极表面的羧基发生共价反应,进而与生物素标记的DNA探针结合,使探针固定到电极表面。结果采用电化学阻抗法对目的基因进行检测,线性范围为1.0×10-9mol/L~1.0×10-7mol/L,检测下限为5.0×10-10mol/L。结论用聚吡咯/羧基多壁碳纳米管修饰玻碳电极,通过生物素-亲和素体系固定探针,制备一种电化学DNA生物传感器,可实现对沙门氏菌毒力基因invA的特异性基因片段的快速检测。
Objective To establish a simple and rapid Salmonella detection method using electrochemical DNA biosensor technology. Methods Cyclic voltammetry was used to polymerize freshly synthesized pyrrole and carboxyl multiwalled carbon nanotubes onto the electrode surface to form a uniform and carboxyl-rich modified membrane. Conductive polymer film electrode to obtain a large specific surface area and excellent electron transfer ability. Under the action of coupling agent 1-ethyl- (3-dimethylaminopropyl) carbodiimide hydrochloride (EDAC), avidin covalently reacted with carboxyl groups on the electrode surface, Labeled DNA probes bind to fix the probe to the electrode surface. Results The target gene was detected by electrochemical impedance spectroscopy. The linear range was 1.0 × 10-9mol / L to 1.0 × 10-7mol / L, and the detection limit was 5.0 × 10-10mol / L. CONCLUSION: An electrochemical DNA biosensor was prepared by poly (pyrrole / carboxy) multi-walled carbon nanotubes modified glassy carbon electrode and biotin-avidin system immobilized probe. The electrochemical DNA biosensor could be used to detect the specific gene fragment of invA in virulence gene of Salmonella Quick test.