基于双醛基功能化离子液体构建电化学免疫传感器

Electrochemical immunosensor based on dialdehyde-functionalized ionic liquid

合成了含双醛基的离子液体,此离子液体一端的醛基与修饰在电极表面的氨基发生共价键作用,将离子液体修饰在电极表面,另一端的醛基可用来固定抗体,构建电化学免疫传感器,实现对心肌肌钙蛋白I(cTnI)的检测。离子液体通过共价键作用固定在电极表面,不仅减少了从电极表面向检测溶液的渗透,提高传感器的稳定性,而且还可以直接固定抗体,不需要使用其他交联试剂;同时,离子液体可增强传感界面的导电性,提高传感器的灵敏度。在优化的实验条件下,传感器的线性范围为0.1~40 ng/mL,检出限为0.06 ng/mL。

Dialdehyde-functionalized ionic liquid was synthesized.The aldehyde group of this ionic liquid could react with the amino group of cysteamine which self-assembled on the surface of electrode,resulting in the immobilization of ionic liquid on the electrode surface.The rest aldehyde group of ionic liquid could be used to bind antibody for the fabrication electrochemical immunosensor for cardiac troponin I(cTnI).The covalent reaction prevented ionic liquid to leach out from electrode surface to electrolyte solution,resulting in a stable sensing interface.In addition,this multifunctional ionic liquid could be used as substrate for direct antibody immobilization,in which no other link reagents were required.In the meantime,the intraduction of ionic liquid improved the conductivity of electrode surface and enhanced the sensitivity of the immunosensor.The proposed immunosensor had good performance in linear range of 0.1-40 ng/mL with detection limit of 0.06 ng/mL.