Voltammetric determination of vanillin in commercial food products using overoxidized poly(pyrrole) film-modified glassy carbon electrodes

In this work, a very simple, rapid, cheap, sensitive, and selective polymer film-modified electrode for vanillin determination in commercial food products was developed via electrochemical polymerization and overoxidation of pyrrole. The formation of both poly(pyrrole) and overoxidized poly(pyrrole) films on a glassy carbon electrode surface was characterized by electrochemical impedance spectroscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. Under optimized conditions, the calibration graph comprises two linear segments of 0.032-1.500 $\mu $mol L$^{-1}$ and 3.00--150.00 $\mu $mol L$^{-1}$ with a detection limit of 0.012 $\mu $mol L$^{-1}$. The selectivity of the modified electrode was examined in the presence of metals, inorganic ions, and organic substances. Moreover, the proposed method was successfully used for the assessment of vanillin contents in commercial food products with satisfactory results.