基于DNA构象折叠的三聚氰胺电化学传感器  

Construction of an Electrochemical Sensor for Melamine Based on Melamine Inducing Conformation Folding of T-rich Oligonucleotide

作　　者：张韬顺 陈国良[1] 高凤[1] 汪庆祥[1] ZHANG Taoshun;CHEN Guoliang;GAO Feng;WANG Qingxiang(College of Chemistry and Environment,Minnan Normal University,Zhangzhou,Fujian 363000,China;College of Food Engineering,Zhangzhou Institute of Technology,Zhangzhou,Fujian 363000,China)

机构地区：[1]闽南师范大学化学与环境学院,福建漳州363000 [2]漳州职业技术学院食品工程学院,福建漳州363000

出　　处：《闽南师范大学学报（自然科学版）》2018年第1期36-44,共9页Journal of Minnan Normal University：Natural Science

基　　金：国家自然科学基金(21275127);青岛科技大学肿瘤标志物传感分析教育部重点实验室开放课题

摘　　要：利用胸腺嘧啶(T)能与三聚氰胺(Mel)特异性结合成T-Mel-T结构的原理,构建了基于富T碱基寡聚核苷酸(TRO)为识别探针的三聚氰胺电化学传感器.采用循环伏安法(CV)、电化学阻抗谱法(EIS)和原子力显微技术(AFM)对传感器的构建进行了表征,结果表明Mel能有效诱导富T碱基核苷酸序列(TRO)折叠成发夹结构,从而改变电极表面的形貌和电化学性能.采用电化学阻抗谱对固定探针浓度及三聚氰胺作用时间进行了优化,实验结果表明,在最佳条件下,传感器的阻抗变化值ΔR_(ct)与三聚氰胺的浓度对数值logC_(Mel)在10.0 pM到1.0μM范围内呈现良好的线性关系.根据3倍信噪比原则,计算得传感器对Mel检测限为1.2 pM.由于T-Mel-T的特异性结构,传感器在氨水、半胱氨酸、尿素、L-苯丙氨酸、牛血清白蛋白、葡萄糖、氯化钠等干扰物质存在时呈现很好的选择性,并可用于实际牛奶样品中Mel的检测,回收率为96.4%~104.4%.Based on the principle that thymine(T)could be specifically combined with melamine(Mel)to form T-Mel-T structure,a novel electrochemical sensor for melamine based on T-rich oligonucleotide(TRO)was constructed.The fabrication process of the sensor was characterized by cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS)and atomic force microscopy(AFM).The results showed that Mel could effectively induce the TRO sequence to fold into the hairpin structure,thereby changing the morphology and the electrochemical performance of the electrode surface.After optimizing the immobilization probe concentration and interaction time of melamine by electrochemical impedance spectroscopy,the impedance variation value(ΔRct)of the sensor had a good linear relationship with the logarithm values of the concentration of melamine(lgCMel)over the range from 10.0 pM to 1.0μM.According to the signal-to-noise ratio of 3,the detection limit of the sensor to Mel was estimated to be 1.2 pM.Due to the specific structure of T-Mel-T,the sensor also showed excellent selectivity in the presence of aqueous ammonia,cysteine,urea,L-phenylalanine,bovine serum albumin,glucose and sodium chloride.Most importantly,it can be used to measure the Mel in real milk samples,and the recoveries were in the range from 96.4%to 104.4%.

关 键 词：三聚氰胺 富T寡聚核苷酸TRO 电化学阻抗谱 电化学传感器 

分 类 号：O656.31[理学—分析化学]