Magnetic Carbon Paste Electrode Modified with a High Performance Composite Based on Molecularly Imprinted Carbon Nanotubes for Sensitive Determination of Levofloxacin

A selective electrochemical sensor based on molecularly imprinted magnetite decorated carbon nanotubes (MCNTs@MIP) was developed for the determination of levofloxacin (Lv). The preparation of molecularly imprinted polymers was performed using Lv as template, MCNTs as support, methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross-linker. Fourier transform infrared spectroscopy and scanning electron microscopy were used to characterize the composites structures. The resulting MCNTs@MIP were suspended in Lv solution and then collected on the surface of a carbon paste electrode via a permanent magnet, situated within the carbon paste electrode and then the voltammetry signals were recorded. Under the optimized experimental conditions, a linear response was obtained in the range of 0.003–0.440 μM with a detection limit of 0.8 nM. The applicability of the method for complex matrix analysis was also evaluated and the modified electrode showed good stability and reproducibility.