Molecular imprinted polymer modified carbon ultramicroelectrode for a selective detection of 3-methyl-4-nitrophenol and its bioremediation in a fungal microbial fuel cell

In the present work, we have developed for the first time a carbon ultramicroelectrode modified by a molecular imprinted polymer (MIP) for selective determination of 3-methyl-4-nitrophenol (MNP) in aqueous media. The polymeric film based on a non-covalent approach was obtained by electropolymerization of ortho -phenylenediamine in the presence of MNP to generate a template-polymer association on the electrode surface. Cyclic Voltammetry (CV) was used for MIP elaboration, performing 20 cycles in the range from 0 to 0.7 V versus Ag/AgCl/Cl − sat . After removing the template, we obtained a specific MNP recognition site on the modified microelectrode. The surfaces of the modified and unmodified microelectrodes were observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Many parameters influencing the electropolymerization process were optimized. Square Wave Voltammetry (SWV) was used for the quantitative analysis of MNP with the optimized following parameters: frequency 50 Hz, potential amplitude 70 mV, and scan increment 15 mV. The peak current increased linearly with the MNP concentration in the range from 1 to 17 mg L −1 , and the limit of detection (LoD) for MNP was calculated to be 0.69 mg L −1 . The elaborated UME-MIP was applied to study the bioremediation of MNP in a fungal microbial fuel cell using a ligninolytic fungus Trametes trogii (strain CLBE 55). The obtained results showed a zero-order kinetic with a kinetic constant of 10.5 mg L −1 h −1 at 22 °C and a half-time degradation of 4.5 h under an optimal external resistance of 20,950 Ohm and a power density of 1.2 mW m −3 . Graphical abstract