Simultaneous Determination of Catechol and Hydroquinone Using Nickel Nanoparticles\Poly-4-Nitroaniline Nanocomposite Modified Glassy Carbon Electrode

In this paper, a simple procedure has been developed to fabricate sensor based on Ni nanoparticles and poly-4-nitroaniline (P4NA) modified glassy carbon electrode (GCE) for simultaneous detection of catechol and hydroquinone. The formed composite film was characterized by scanning electron microscopy (SEM), UV-visible spectroscopy, electrochemical impedance spectroscopy (EIS) and DPV measurements. The modified electrode showed high sensitivity and selectivity towards catechol (CC) and hydroquinone (HQ). Under optimized conditions, the modified GCE showed two sharp redox peaks for CC and HQ in differential pulse voltammetry (DPV) voltammograms with a peak potential separation of 112 mV in pH 7.0 phosphate buffer solution (PBS). The detection limits for HQ and CC were calculated to be 2.3 and 3.9 μM, respectively. Good linearity was observed for a concentration range from 10
^-9
-10
^-4
M and 10
^-3
-10
^-4
M for CC and HQ respectively. Furthermore, the newly made electrode was successfully evaluated in the detection of both analytes CC and HQ in seawater as a real sample.