基于石墨烯-依来铬青蓝R的新型免标记电化学免疫传感器用于CA19-9检测

目的构建石墨烯-依来铬青蓝R(GO-ECR)免标记电化学免疫传感器高灵敏检测CA19-9的新技术。方法化学法合成氧化石墨烯并滴涂于电极表面，通过循环伏安法电沉积制作GO-ECR修饰玻碳电极，在偶联剂EDC和NHS作用下以共价键合方式将CA19-9抗体固定于修饰电极表面，固定的抗体与CA19-9发生免疫反应形成抗原-抗体复合物。铁氰化钾溶液作为检测探针，对比免疫反应前后铁氰化钾响应信号的差异，利用信号降低程度与CA19-9浓度正相关，实现对CA19-9的特异性高灵敏检测。结果该电化学免疫传感器检测CA19-9的线性范围为0.05～500 U/mL，检测限为0.01 U/mL，且能准确测定临床血清样本CA19-9的浓度。结论构建的GO-ECR免标记电化学免疫传感器可以简单、准确、特异地检测CA19-9。

Novel Electrochemical Label-free Immunosensor Based on Graphen-Eriochrome Cyanine R for the Detection of CA19-9

ObjectiveTo construct the new technique of electrochemical label-free immunosensor based on GO-ECR for the detection of CA19-9.MethodGraphene prepared from chemical routine was used to modify glassy carbon electrode, and then the GO-ECR film modified electrode was fabricated by cyclic voltammetry deposition.With the help of EDC and NHS, anti-CA19-9 was immobilized on the modified electrode through covalent bond.The fixed anti-CA19-9 reacted with CA19-9 to form immunocomplex.Using K3\Fe(CN)6\] as electrochemical probe, the variable current response before and after the immobilized CA19-9 implied the concentration of CA19-9.And the different current responses were used to specifically quantify the concentrations of CA19-9.ResultThe electrochemical immunosensor can be applied to accurately detect the CA19-9, and the clinical serum CA19-9 concentration can also be precisely detected.ConclusionThe constructed electrochemical label-free immunosensor based on GO-ECR for the detection of CA19-9 shows the characteristics of high accuracy and specificity.