▎ 摘　　要

The nanocomposites (Fc-GO) of ferrocene (Fc) hybridized graphene oxide (GO) were prepared by pi-pi stacking interactions. Fc-GO and Au(III) are electrochemically co-reduced to obtain Au nanoparticles (AuNPs) and Fc hybridized electrochemically reduced graphene oxide (Fc-ERGO) nanocomposites (AuNPs/Fc-ERGO). Scanning electron microscopy reveals that Au particles are about 10 nm and are dispersed uniformly on Fc-ERGO. The electrochemical behavior of AuNPs/Fc-ERGO demonstrates great electrochemical activity and stability. The AuNPs/Fc-ERGO was applied in a highly sensitive immunosensor of the biomarker carbohydrate antigen 15-3 (CA 15-3). This unique immunosensor, with AuNPs/Fc-ERGO as the immobilization platform and signal probe, exhibited significant sensitivity toward CA 15-3. Under optimal conditions, the peak current of differential pulse voltammetry (DPV) of the immunosensor decreased with increasing CA 15-3 concentration, showing two linear ranges of 2.0-25.0 U mL(-1) and 0.05-2.0 U mL(-1) with a low detection limit of 0.015 U mL(-1). The strategy developed for this immunosensor provides a promising approach for clinical research and diagnostic applications.