A novel label-free electrochemical immunosensor based on aldehyde-terminated ionic liquid.

In this paper, aldehyde-terminated ionic liquid was synthesized and used to fabricate a novel label-free electrochemical immunosensor for the determination of hepatitis B surface antigen. This sensor was formed from a gold electrode which was modified with a composite film containing the aldehyde-functionalized ionic liquid incorporated into nafion and anti-hepatitis B surface antigen antibody probes. Aldehyde-functionalized ionic liquid was used not only as a substrate for antibody immobilization, but also as a good material with high electrical conductivity, which greatly simplified the process of sensor fabrication. The proposed sensor exhibited a good performance in a linear range from 0.05 to 15ngmL-1 with a detection limit of 20pgmL-1 (S/N=3) and provided a novel strategy for clinical detection due to satisfying stability, selectivity and reproducibility.