Morphology-engineered MnO2-incorporated CuZn-MOF microstructures for sensitive enzyme-free electrochemical glucose detection in human serum

초록

Monitoring blood glucose levels is essential for diabetes management; however, traditional enzymatic electrochemical sensors encounter various problems, such as high costs, narrow operating conditions, and low stability. To address these limitations, we design and fabricate an enzyme-free electrochemical sensor based on a copper‑zinc metal-organic framework combined with manganese dioxide (CuZn-MOF@MnO2). The bimetallic MOF@MnO2 composites, formed through an interfacial nucleation growth mechanism, exhibit three distinct morphologies [rectangular microbricks (RMBs), hexagonal microplates (HMPs), and hexagonal microrods (HMRs)] depending on the MnO2 content. Their morphological and structural properties were analyzed using typical physicochemical characterization studies. The CuZn-MOF@MnO2-modified screen-printed carbon electrodes (RMBs-MOF@MnO2/SPCE, HMPs-MOF@MnO2/SPCE, and HMRs-MOF@MnO2/SPCE) are employed as novel electrochemical glucose sensors and evaluated by standard voltammetry and chronoamperometry techniques. The performances of CuZn-MOF@MnO2/SPCEs were found to be superior to that of CuZn-MOF/SPCE and MnO2/SPCE individually, but to be dependent on the morphology of the composite. Noticeably, the HMPs-MOF@MnO2/SPCE exhibited the highest performance, including a wide linear concentration range (4.90 μM to 4.75 mM), a low detection limit (1.1 μM), and high sensitivity (117 μA/mM/cm2). Furthermore, the novel nonenzymatic sensor showed excellent selectivity, stability, and reproducibility, with outstanding recovery responses in human serum samples. © 2026 Elsevier B.V.

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