Impedimetric identification of heteroMOFs modified porous nickel foam self-supports as robust electrodes for CA 19-9 pancreatic tumor marker in human serum

An impedance-based electrochemical immunosensor for direct and binder-free target recognition of carbohydrate antigen (CA 19-9) tumor biomarker for the early diagnosis of pancreatic cancer was reported. This study uses an in situ solvothermal process to develop a simple method for the one-pot construction of Ni-Fe heteroMOFs (HFNMOFs,) self-supported on conductive nickel foam (NicFm). Utilizing HFNMOFs@NicFm developed in this study, the electrochemical performance of the biosensor was studied for the first time. The as-prepared mixed MOFs decorated NicFm electrodes displayed potential electrochemical outputs. They demonstrated the potential for developing binder-free non-enzymatic immunosensors with wide linear limits, high selectivity, stability, and excellent sensitivity. The bifunctional MOFs exhibit improved electrochemical conductivity owing to the highly exposed metal sites and hierarchical porosity. The changes in the charge transfer resistance present a linear response against increasing target concentrations. The immunosensor developed in this study exhibited its detection limit of 2.56 U/mL. Further, the bioelectrodes produced were validated against real human spiked serum with good results of percentage recovery, indicating the immunosensor is well-suitable to be tested in real-time analysis.