Highly Sensitive Immunosensing of Carcinoembryonic Antigen Based on Gold Nanoparticles Functionalized PB@PANI Core-Shell Nanocubes as a Novel Signal Amplification Strategy

Abstract

Herein, a novel strategy to amplify electrochemical signal by gold nanoparticles functionalized prussian blue@polyanline core-shell nanocures (Au NPs/PB@PANI) was proposed for the sensitive monitoring of carcinoembryonic antigen (CEA). Firstly, a facile low-temperature method was used to prepare the uniform PB@PANI core-shell nanocubes with the assistance of PVP, where PB acted as the electron transfer mediator to provide electrochemical signals, and the PANI with excellent conductive and desirable chemical stability not only played the role of a protective layer to prevent etching of PB in basic media but also effectively improved electron transfer. Importantly, the incorporation of highly conductive Au NPs could further enhance the electrochemical signal and capture a large amount of Ab 2 . Subsequently, by virtue of the novel redox-active nanoprobe advantages and the involvement of gold-platinum bimetallic nanoflower (AuPt NFs, behaved as electrode material), a novel sandwich-type electrochemical immunosensor was constructed for ultrasensitive determination of CEA. The as-developed immunosensor could obtain a dynamic working range of 0.01 pg mL −1 -100.0 ng mL −1 at a detection limit of 3.3 fg mL −1 via DPV (at 3σ). Furthermore, the new redox-active nanoprobe-based electrochemical immunosensor exhibited remarkable analytical performance, which brought about feasible ideas in disease diagnosis in future.