Two-channel electrochemical immunosensor based on one-step-synthesized AuPt-boron-doped graphene electrode for CA153 detection

Herein, a novel dual-channel electrochemical immunosensor was fabricated via vertical growth of AuPt-decorated boron-doped graphene (AuPt-BG) nanosheets as a signal amplification platform to detect cancer antigen 153 (CA153). Highly open, porous AuPt-BG films were synthesized using one-step electron-assisted hot-filament chemical vapor deposition. The Au-Pt alloy nanoparticles were dispersed on BG nanosheets to improve their biocompatibility, and antibodies (Ab) were directly bonded to the AuPt-BG electrode. The architectures enlarged the loading of CA153Ab and efficiently catalyzed the Fe(CN)63-/4- reaction, ultimately amplifying the signals. This novel strategy allows the simultaneous detection of CA153 in the oxidation and reduction channels, improving the reliability of the detection results. The AuPt-BG-based immunosensor exhibited a lower detection limit (0.0012 mU mL-1, S/N = 3) and wider linear range (0.1-4 × 104 mU mL-1) along with improved reproducibility, selectivity, and stability for the assay of CA153. Owing to the high process controllability of AuPt-BG films, a large-area electrode for in-vitro analyses and a flexible microelectrode for in-vivo analyses were prepared, which confirmed that the AuPt-BG-based sensor is an ideal CA153 detection platform for clinical diagnosis and practical applications.