A label-free immunosensor based on PHEMA/graphene oxide nanocomposite for simultaneous electrochemical determination of alpha fetoprotein.

An electrochemical immunosensor based on poly(2-hydroxyethyl methacrylate) (PHEMA)/graphene oxide (GO) nanocomposite was designed in a simple way for the ultrasensitive detection of tumor makers (alpha-fetoprotein, AFP as a model). PHEMA with excellent biocompatibility, provides a large number of sites for connecting signal molecules. After modification with signal molecules, the functional PHEMA significantly improved the sensitivity of electrochemical detection. In order to immobilize antibodies, GO was introduced and used to construct a nanocomposite as a substrate. The designed AFP immunosensor showed favorable selectivity and excellent stability. Meanwhile, it has a low detection limit of 0.403 pg mL. Furthermore, the immunosensor was used to detect target AFP in human serum, demonstrating the feasibility of clinical diagnosis.