Dual-signaling electrochemical immunosensor for ultra-sensitive detection of procalcitonin based on the hydrogen evolution and photoelectric signals of AuPt/BP.

In recent years, noble metal catalysts have been extensively studied in terms of hydrogen evolution reaction (HER), but there has been less research on the construction of immunosensor based on the catalytic signal amplification strategy of noble metal. Based on the excellent HER and photoelectric performance of AuPt nanoslices modified black phosphorus nanoflakes (AuPt/BP) in neutral medium, we reported a dual-signal electrochemical immunosensor, which uses AuPt/BP as signal amplification label for the detection of procalcitonin (PCT). Due to the charge transfer between AuPt and BP, AuPt/BP has better HER activity and photoelectric performance than single AuPt or BP, which realized the construction of dual-signal electrochemical immunosensors and the improvement of detection sensitivity. In addition, the presence of BP makes AuPt/BP has better dispersion and larger surface area, which can load more secondary antibody (Ab 2) and realize the signal amplification of the immunosensor. The linear ranges of PCT detection based on HER and photoelectric signals are 1.96 fg mL−1 ∼ 0.196 ng mL−1 and 1.96 fg mL−1 ∼ 19.6 pg mL−1, and the detection limits of PCT with HER and photoelectric signals are 0.88 fg mL−1 and 0.99 fg mL−1. [Display omitted] • A dual-signal electrochemical immunosensor has been constructed for procalcitonin detection. • AuPt/BP with excellent electrocatalytic hydrogen evolution and photoelectric signals. • The synergy of various phases improve the HER performance of AuPt and stability of BP. • This electrochemical immunosensor exhibits a satisfied linear range and detection limit. [ABSTRACT FROM AUTHOR]