High Sensitive Sandwich-type Electrochemical IgG Immunosensor Based on a Nanocomposite of Carbon Nanotube and Multifunctional Ionic Liquid Containing Aldehyde and Ferrocene Groups as Labels

摘要

Using a nanocomposite of carbon nanotube and multifunctional ionic liquid as labels and chitosan asplatform, we fabricated a sandwich-type electrochemical immunosensor. The multifunctional ionicliquid was anchored with both aldehyde groups and ferrocene groups. Aldehyde groups were used tobond the second antibody and ferrocene groups were used as signal probes. Due to the large surfacearea of carbon nanotube, increased-loading of ferrocene was obtained, which improved the sensitivityof the immunosensor. In addition, the high conductivity of carbon nanotube and ionic liquid alsoenhanced the sensitivity of the immunosensor. The fabricated immunosensor showed a goodperformance. The linear range was from 0.05 to 30 ng mL-1 with a detection limit of 0.01 ng ml-1(S/N=3), which is 40 times higher than that of reported immunsensor for human IgG based onferrocene as labels. We anticipate this strategy may provide a new platform for the clinic application.