Flexible hand-made carbon electrode decorated with metronidazole imprinted polymer

Carbon paper was used as a cost-effective electrode material for flexible electrode fabrication. These electrodes were coated with polypyrrole film imprinted with metronidazole. SEM imaging indicated successful covering of the carbon paper fibers. Structure of the pre-polymerization complex was optimized via DFT simulations. This imprinted polymer-modified electrode responded linearly to the logarithm of metronidazole concentration in 0.2 to 200 nM range with the LOD of 0.4 nM in the DPV experiments in the presence of the Ru(NH₃)₆Cl₃ redox probe. Selectivity of the fabricated sensor was appreciably high, and the apparent imprinting factor was equal to IF = 38. Such high selectivity and the imprinting factor confirmed successful imprinting in the polypyrrole matrix. The sensor was validated by metronidazole determination in honey samples. Moreover, robustness of the MIP-coated carbon paper electrode was proven. Only a slight loss of recorded current values was observed when the electrode was bent to approx. 45° and straightened multiple times.