Preparation of magnetic imprinted polymer nanoparticle carbon paste electrode for determination of valproic acid

In this work, the modified carbon paste electrode was prepared by the nano-sized magnetic molecularly imprinted polymer (MMIP) and utilized for electrochemical determination of valproic acid. The synthesized nano-MMIP was characterized by scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FT-IR). The resulted nano-sized compound was suspended in 0.1 M HCl and then collected on the surface of a carbon paste electrode via a permanent magnet, which was situated within the carbon paste electrode. The electrochemical performance of the valproic acid sensor was investigated by cyclic voltammetry and differential pulse voltammetry techniques. All parameters influencing the electrode performance, including pH, the amount of MMIP, and the immersion time, were evaluated and optimized. Under the optimal condition, the sensor showed a dynamic linear concentration range of 0.5 nM–150.0 µM with a detection limit of 0.16 nM.