基于金-铂纳米颗粒修饰的碳纳米管构建免标记电化学免疫传感器用于CEA检测

A label-free electrochemical immunoassay for CEA detection based on Au-Pt hybrid nanoparticles functionalized carbon nanotubes

本文将金-铂双金属纳米颗粒(Au-PtNPs)沉积在羧基化的单壁碳纳米管表面作为基底材料,用以固载癌胚抗原抗体(anti-CEA)。利用anti-CEA与癌胚抗原(CEA)间的特异性识别作用将CEA固载于电极表面,用于降低Au-PtNPs对底物对苯二酚的催化作用,以改变电化学响应信号。通过对比CEA作用前后的电化学信号变化强弱可实现CEA的定量检测。研究发现,在最优实验条件下,CEA的浓度与电化学响应信号呈良好的线性关系。在0.05~80ng·mL^-1范围内其检测限为5 pg·mL^-1。该免疫传感器不仅展现出良好的选择性、重现性和稳定性,同时能成功用于人体血清样本的分析检测,其结果与酶联免疫方法(ELISA)检测结果相吻合。

In this work,a labeled-free electrochemical immunoassay biosensor was fabricated for carcino-embryonic antigen(CEA)detection based on gold-platinum hybrid nanoparticles functionalized carbon nanotubes.The Au-Pt hybrid nanoparticles(Au-PtNPs)functionalized carbon nanotubes were employed as the substrate for anti-CEA immobilization.With the assistant of immunological recognition,the target CEA was selectively immobilized on the surface of the electrode.As the result,the catalysis between Au-PtNPs and hydroquinone was significantly inhibited,which directly reflect in electrochemical response signals.Therefore,the concentration of CEA could be easily obtained by comparing the electrochemical responses before and after incubation CEA.Under the optimal conditions,the peak current changes increased with increasing CEA concentration in the range of0.05 to 80 ng·mL^-1,and exhibited a linear response with a detection limit of 5 pg·mL^-1.Furthermore,this electrochemical immunosensor not only showed good selectivity,reproducibility and stability,but also successfully applied to the clinical serum samples analysis,which matched well with enzyme-linked immunosorbent assay(ELISA).