Copper-based Metal-organic Framework Applied in the Development of an Electrochemical Biomimetic Sensor for Catechol Determination

In this study, the synthesis and characterization of a Cu-based metal-organic framework (MOF) [Cu-3(BTC)(2)(H2O)(3)](n) (where BTC=benzene-1,3,5-tricarboxylate), known as HKUST-1, were performed. The Cu-MOF was applied in the modification of a carbon paste to obtain a biomimetic sensor for the electrochemical determination of catechol. Kinetic assays confirmed that the Cu-MOF acts as a catalyst for the oxidation of catechol and it can be considered as a catechol oxidase mimetic. Under optimized conditions, the calibration curve for catechol presented a linear range of 8.0x10(-7) to 3.2x10(-5)molL(-1), with detection limit of=1.0x10(-7)molL(-1). The sensor demonstrated good intra-day repeatability and inter-electrode reproducibility (relative standard deviations of 3.8% (n=10) and 4.3% (n=6), respectively). In the selectivity study, an adequate peak-to-peak separation was observed for hydroquinone and uric acid in relation to catechol, demonstrating that this sensor has the potential for use in the simultaneous determination of these compounds. This sensor was successfully applied in the determination of catechol in water samples.