2D/3D Copper-Based Metal-Organic Frameworks for Electrochemical Detection of Hydrogen Peroxide

Metal-organic frameworks (MOFs) have been extensively used as modified materials of electrochemical sensors in the food industry and agricultural system. In this work, two kinds of copper-based MOFs (Cu-MOFs) with a two dimensional (2D) sheet-like structure and three dimensional (3D) octahedral structure for H₂O₂ detection were synthesized and compared. The synthesized 2D and 3D Cu-MOFs were modified on the glassy carbon electrode to fabricate electrochemical sensors, respectively. The sensor with 3D Cu-MOF modification (HKUST-1/GCE) presented better electrocatalytic performance than the 2D Cu-MOF modified sensor in H₂O₂ reduction. Under optimal conditions, the prepared sensor displayed two wide linear ranges of 2 μM-3 mM and 3-25 mM and a low detection limit of 0.68 μM. In addition, the 3D Cu-MOF sensor exhibited good selectivity and stability. Furthermore, the prepared HKUST-1/GCE was used for the detection of H₂O₂ in milk samples with a high recovery rate, indicating great potential and applicability for the detection of substances in food samples. This work provides a convenient, practical, and low-cost route for analysis and extends the application range of MOFs in the food industry, agricultural and environmental systems, and even in the medical field.