无标记的电化学免疫传感器检测早期肝癌血清标志物

A label-free immunosensor for electrochemical detection of serum biomarker for early stage hepatocellular carcinoma

目的高尔基蛋白73(Golgi protein 73,GP73)是一种高尔基糖蛋白,是近年来发现的一种与早期肝癌相关的血清标志物。GP73在早期肝癌患者的血液中呈现出高表达,所以GP73的检测对早期肝癌的诊断具有重要的指导意义。本工作制备了一种无标记的电化学免疫传感器用于GP73的检测。方法首先利用3-巯基丙酸(MPA)中的巯基在金电极表面形成自组装单层,而GP73多克隆抗体则与MPA上的羧基通过共价键被固定在电极上,最后利用牛血清白蛋白对电极表面的非特异性结合位点进行封闭。最终以获得的修饰电极作为工作电极,通过交流阻抗法(EIS)对GP73抗原进行定量检测。结果其响应信号-电子转移电阻(R et)在0.001~0.1 ng·mL-1范围内,随GP73浓度呈线性增加,检测限为0.0021 ng·mL-1(S/N=3)。结论该电化学免疫传感器具有较高的灵敏度、特异性和良好的重复性,可为肝癌的早期诊断提供了一个有用而可靠的平台。

Objective Golgi protein 73(GP73),a resident Golgi glycoprotein,is discovered as a serum marker for early hepatocellular carcinoma(HCC)recently.GP73 is strongly up-regulated and expressed in HCC with both high sensitivity and specificity.Methods A label-free immunosensor for electrochemical detection of GP73 was prepared,in which GP73 antibody was immobilized on a gold electrode and GP73 antigen was detected quantitatively by electrochemical impedance spectroscopy.Results Electron transfer resistance(R et)increased linearly with GP73 concentration in the range of 0.001~0.1 ng·mL-1 with the detection limit of 0.0021 ng·mL-1(S/N=3).Conclusion The GP73 immunosensor also showed high sensitivity,specificity and good reproducibility,thereby serving as a useful and reliable platform for early diagnosis of HCC.