A novel electrochemical immunosensor based on rifter-like Ni-TCPP(Fe) nanosheets and PSS-functionalized graphene for ultrasensitive detection of H-FABP

In terms of medicine, the prevention, diagnosis, and assessment of acute myocardial infarction (AMI) as well as the effectiveness of therapy all depend on the sensitive and early detection of human heart-type fatty acid–binding protein (H-HABP). The synthetic material used in this study, Ni-TCPP(Fe), has a unique structure that resembles a rifter with many thorns. When exposed to PSS-Gr, Ni-TCPP(Fe) would unfold into a sheet structure, exposing a lot of active sites and improving the catalytic active surface area, making it easier to detect H-FABP. We have successfully synthesized an electrochemical immunosensor based on Ni-TCPP(Fe)@PSS-Gr and Ag@Au/Pt as a signal label which demonstrated excellent sensor performance. A broad linear range of 10 fg/mL to 100 ng/mL with a low detection limit of 5.75 fg/mL (S/N = 5) for detecting H-FABP was obtained under ideal conditions. Furthermore, the detection results from the human serum samples were positive, suggesting that the made-up immunosensor could be useful for early clinical analysis.