Screen-printed graphite electrode modified with Co 3 O 4 nanoparticles and 2D graphitic carbon nitride as an effective electrochemical sensor for 4-aminophenol detection.

We fabricated a new electrochemical 4-aminophenol sensor based on a nanocomposite of Co 3 O 4 nanoparticles and graphite carbon nitride (Co 3 O 4 @g-C 3 N 4 ), used for the modification of a screen-printed electrode (Co 3 O 4 @g-C 3 N 4 /SPE). The synthesized nanocomposite was characterized using field-emission scanning electron microscopy, energy-dispersive x-ray spectroscopy, x-ray diffraction and Fourier transform-infrared (FT-IR) techniques. The electro-oxidation of 4-aminophenol in phosphate buffer solution (pH = 7.0) was investigated via cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The peak current of oxidation in the optimized conditions had a linear relationship with various 4-aminophenol contents (0.05-780.0 μ M) with a correlation coefficient of 0.9996 and the limit of detection (S/N = 3) of 1.5 × 10 -8 M. The developed method was successful to determine 4-aminophenol in real specimens, with acceptable outcomes.