Early surveillance of oral cancer demands utmost concern owing to its alarming prevalence in the modern world. An efficient electrochemical impedimetric immunosensor is fabricated based on bimetallic amino-functionalized FeCo metal–organic frameworks uniformly grown on porous nickel foam solid supports (FeCo-MOF/NF) as a transducer for the detection of oral squamous cell carcinoma (OSCC). Herein, the interleukin-1 receptor antagonist (IL-1RA) antibody is used as a biorecognition element for the first time in the determination of oral cancer in real human blood samples using electrochemical impedance spectroscopy (EIS). Furthermore, the presence of specific functional groups ensures selectivity and rapid sensitivity against the target analyte IL-1RA when compared to the other biomarkers including interleukin-6 (IL-6), interleukin-8 (IL-8), CYFRA 21-1, and so on. The immunosensor shows a wide linear dynamic detection range of IL-1RA (10 fg/mL to 10 ng/mL) with a limit of detection (LOD) of 7.30 fg/mL in buffer and 7.22 fg/mL in serum conditions and a limit of quantification (LOQ) of 22.14 fg/mL in PBS and 21.88 fg/mL in serum. For a real-life demonstration, IL-1RA in human samples is detected by the immunosensor for the first time and compared with the gold standard method. The immunosensor also displays an excellent correlation with the standard detection of IL-1RA in human samples. Altogether, this work demonstrates that the electrochemical immunosensor has a high clinical significance by being a promising alternative to conventional approaches.