无标记电化学生物传感平台用于癌胚抗原的检测

Construction of label-free electrochemical biosensing platform and its application for carcinoembryonic antigen detection

基于目标物诱导DNA杂交链式反应(HCR)及银纳米颗粒(Ag NPs)自组装过程构建了无标记型电化学生物传感平台,并将其应用于癌胚抗原(CEA)的检测.在目标物存在的情况下,适配体对CEA进行特异性识别并结合,释放出与之互补的触发DNA链(t DNA).该t DNA能够被金电极上的捕获探针(c DNA)捕获,并启动HCR过程,使得两条发夹DNA链被相继打开并串联成长的DNA双链结构,带正电的Ag NPs通过与该DNA结构之间的静电作用大量自组装到电极表面,并产生强的电化学信号.在优化的实验条件下,该电化学生物传感平台能够在0.5 ng·L^(-1)到50μg·L^(-1)的浓度范围内实现对CEA的良好响应.

A label-free electrochemical biosensing platform for sensitive detection of carcinoembryonic antigen(CEA)was constructed by using target-induced hybridization chain reaction(HCR)and self-assembly of Ag nanoparticles(Ag NPs).Upon addition of CEA,the analyte attacked the aptamer and released trigger DNA,which was captured by capture DNA immobilized on the electrode.Then,HCR process was triggered to form a long and nicked double-helix structure,which could capture large amount of Ag NPs through electrostatic interaction to generate electrochemical signal.Under optimal conditions,the currents of the biosensor were linearly dependent on the logarithm of CEA concentrations from0.5ng·L^-1to50μg·L^-1.