A nonfouling voltammetric immunosensor for the carcinoembryonic antigen based on the use of polyaniline nanowires wrapped with hyaluronic acid

A non-fouling electrochemical immunosensor is described for determination of the tumor biomarker carcinoembryonic antigen (CEA). It is based on the use of composite wires made by chemical grafting of hyaluronic acid onto polyaniline nanowires. The modified nanowires possess excellent antifouling property both in single protein solutions and in dilute serum samples. The current of immunoelectrode exhibits a linear response in the 0.01 pg mL −1 to 10,000 pg mL −1 CEA concentration range and 0.0075 pg mL −1 detection limit. This work demonstrates that coating an electrode with hyaluronic acid can largely reduce unspecific adsorption of proteins on the electrode surface. Schematic of a nonfouling electrochemical immunosensor for the carcinoembryonic antigen. It is based on novel composite wires made through the chemical grafting of easily available hyaluronic acid (HA) onto polyaniline (PANI) nanowires. The HA/PANI demonstrated excellent antifouling property both in single protein solutions and human serum samples.