基于离子液体修饰碳纳米管电极的碱性磷酸酶电化学检测

利用自制的离子液体修饰碳纳米管电极(CNTs-ILE),在对CNTs-ILE的特性及对碱性磷酸酶(AP)酶促反应的底物磷酸对硝基苯酯(PNPP)和产物对硝基苯酚(PNP)进行电化学研究的基础上,采用安培法对酶促反应进程实现了持续动态的检测.实验表明,CNTs-ILE的循环伏安特性优于传统玻碳电极,且它在检测PNP时呈现出良好的抗钝化特性.当AP浓度范围在1.0～100 U/L时,电流大小与AP的浓度呈良好的线性关系.本方法可快速检测AP浓度,检测时间在20 min内.CNTs-ILE具有良好的抗钝化、操作简单及制作成本低等特点,在碱性磷酸酶的检测领域中有望得到进一步发展.在传统ELISA基础上,利用CNTs-ILE对具体样本最终的AP酶促反应产物进行电化学检测,通过峰值电流大小确定抗原浓度,为检测以AP为标记酶的抗原和抗体提供了理论依据.

Electrochemical Detection of Alkaline Phosphatase Using Ionic Liquid Modified Carbon Nanotubes Electrode

An electrochemical assay of a steady and dynamic detection method of alkaline phosphatase(AP) was investigated.Using a new composite electrode fabricated with carbon nanotubes and ionic liquids(CNTs-ILE),after working on the characteristics of the electrode,and the electrochemical research of the catalytic reaction substrate p-nitrophenyl phosphate(PNPP) and product p-nitrophenol(PNP),continuous dynamic amperometric detection of the enzymatic reaction was achieved.The results indicated that the cyclic voltammetry characteristics of the CNTs-ILE were better than those of glassy carbon electrode,and the CNTs-ILE had good anti-fouling property when detected PNP.When the concentration range of AP was 1 U/L to 1×102 U/L,the current had a good proportional relationship with the concentration of AP.This method could be used to detect AP within 20 min.CNTs-ILE′s good anti-fouling and low production cost properties made this electrode expect to have a further development in detection of AP.This technique can also be used to analyze a specific sample,which was,on basis of the traditional ELISA method,using CNTs-ILE to electrochemically detect the catalytic reaction product of AP.This method can be used to determine the concentrations of antigen through the current peak,and provide theory basis for the future detection of AP marked antigen or antibody.