Design and Application of a Non-enzymatic Sensor Based on Metal-organic Frameworks for the Simultaneous Determination of Carbofuran and Carbaryl in Fruits and Vegetables

A novel, stable and sensitive non-enzymatic sensor was developed with metal-organic frameworks (MOFs) that have attracted great attention in electrochemical sensors applications in recent years. The pore structures of MIL (Fe)-101 and MIL (Fe)-53 are the families of MOFs that were constructed via a simple solvothermal procedure. The 35MIL-101(Fe)-reduced graphene oxide nanocomposite has been used for modification of glassy carbon electrode for the determination of carbofuran (CBF) and carbaryl (CBR). The porosity of the composites increased the voltammetric responses significantly for CBF and CBR in a mixed solution that makes the simultaneous determination of both carbamate pesticides possible. Characterization of MIL (Fe)-101 and MIL (Fe)-53 were performed with FT-IR, XRD, BET and SEM. Finally, the introduced sensor under the optimal conditions showed low detection limits of 1.2 and 0.5 nM within the linear ranges of 5.0-200.0 nM and 1.0-300.0 nM for CBF and CBR, respectively. The non-enzymatic sensor was successfully used to monitoring of carbamates residue in vegetable and fruit samples.