Glucose Sensor Using Fe3O4 Functionalized MXene Nanosheets as a Promising Sensing Platform: Exploring the Potential of Electrochemical Detection of Glucose

Enzymatic electrochemical sensors are promising for real-time glucose monitoring due to their high sensitivity and continuous detection capability. In this work, a magnetic Fe3O4@MXene nanocomposite was synthesized hydrothermally. The introduction of Fe3O4 not only reduced MXene’s inherent negative surface charge, improving interaction with glucose oxidase (GOD), but also formed a porous structure that enhances enzyme immobilization via physical adsorption. Based on these properties, a Fe3O4@MXene/GOD/Nafion/GCE electrode was fabricated. The composite’s high specific surface area, excellent conductivity, and good biocompatibility significantly promoted the direct electron transfer (DET) of GOD. Meanwhile, the apparent electron transfer rate constant (ks) was calculated to be 9.57 s−1, representing a 1.26-fold enhancement over the MXene-based electrode (7.57 s−1) and confirming faster electron transfer kinetics. The sensor showed a bilinear glucose response in the ranges of 0.05–15 mM, with sensitivity of 120.47 μA·mM−1·cm−2 and a detection limit of 38 μM. It also exhibited excellent selectivity, reproducibility and stability. Satisfactory recovery rates were achieved in artificial serum samples while demonstrating comparable detection performance to commercial blood glucose meters.