Ultrasensitive label-free electrochemical immunosensor based on core-shell Au@PtNPs functionalized rGO-TEPA/PB nanocomposite for HBsAg detection

In this study, a sensitive and quantitative label-free electrochemical immunosensor based on bimetallic [email protected] nanoparticles , Prussian blue (PB), and reduced graphene oxide-tetraethylene pentamine nanocomposite (rGO-TEPA) was constructed to achieve sensitive detection of HBsAg. A one-pot green method was used to synthesize interlocked rGO-TEPA/PB hybrid composites as high-performance materials with good conductivity . PB was the electron transfer mediator used to provide electrochemical signals. By utilizing rGO-TEPA as supporting material , the stability and intensity of PB were greatly improved. The incorporation of highly conductive [email protected] nanoparticles could further amplify the electrochemical signal, and the high adsorption capacity could provide an efficient substrate for hepatitis B surface antibody (HBsAb) immobilization. Under optimal conditions, the immunoassay had a wide linear range from 0.25 pg mL −1 to 400 ng mL −1 and a low detection limit of 0.08 pg mL −1 (S/N = 3). This method was also applied to the analysis of human serum samples, and the obtained results were on par with those of electrochemiluminescence immunoassay (ECLIA), suggesting significant potential for this new method in clinical research.