Creatine phosphokinase (CPK-MM), is an important constituent of active muscle, acts as a vital enzyme in intracellular energy transport and is a potential biomarker for diseases like muscular dystrophy (MD), acute renal failure, and muscle damage. Herein, we report a single-step solid-state synthesis of niobium iron oxide(FeNbO4) modified nickel foam (FeNbO4/NF) for non-enzymatic detection of CPK-MM in simulated human blood serum. The X-ray diffraction (XRD) reveals an orthorhombic phase formation of FeNbO4 with (111) family of planes. The FeNbO4/NF exhibits a low limit of detection (i.e., 0.75 μg/L) and high sensitivity of 1.9 mA/x. cm−2 (x = μg/L) with a wide linear range of detection ranging from 1 μg/L to 100 μg/mL. This performance of the sensor can be attributed to the excellent electrocatalytic activity of the FeNbO4 nanomaterial facilitating the effective redox reaction of the CPK. In this mechanism, the presence of oxy functional groups on the surface of FeNbO4/NF facilitates the interaction between the electrocatalytic active sites of the electrode and the CPK-MM molecules. In addition, this sensor exhibits outstanding selectivity (in presence of different interfering species like ascorbic acid, bovine serum albumin, urea, and uric acid) with good stability as well as reproducibility. The sensor is found successful in the determination of CPK-MM concentration in simulated blood serum samples with good recovery percentages. This efficacy of the as-fabricated electrode demonstrates the FeNbO4 as a potential platform for various electrochemical-based bioanalytical applications. © 2023 Elsevier Ltd and Techna Group S.r.l.