Dual-signaling and ultrasensitive detection for PCT based on the photoelectric and electrocatalytic hydrogen evolution signals of Pt/Mo-CoFeS.

Few study has been carried out on the construction of immunesensors utilized the photoelectric and catalytic signal of nanomaterial. Here, a dual-signal electrochemical immunosensor was constructed for procalcitonin (PCT) detection based on the excellent photoelectric and hydrogen evolution performance of molybdenum-doped cobalt-iron sulfur nanosheets modified by platinum nanoparticles (Pt/Mo-CoFeS). Due to the electronic structure regulation between Pt and Mo-CoFeS, Pt/Mo-CoFeS exhibits superior photoelectric and hydrogen evolution performance compared to single Mo-CoFeS, which improved the sensitivity of the electrochemical immunosensor. Furthermore, the presence of Pt improves surface area and biocompatibility, achieving more antibodies loading and signal amplification. The linear range of PCT detection are 0.002-20 ng mL and 0.002-50 ng mL, the detection limits are 0.0015 and 0.0012 ng mL. In addition, this electrochemical immunosensor was applied to the PCT analysis in human serum samples with high recoveries. F-test and t-test show that there is no significant difference in the test results between the HER and photoelectric signals, the mutual verification between above two signals can effectively improve the accuracy of detection result.