Simultaneous voltammetric determination of nitrophenol isomers at ordered mesoporous carbon modified electrode

In this paper, ordered mesoporous carbons (OMCs) modified glassy carbon electrode (GCE) (OMCs/GCE) was employed to investigate the electrochemical behavior of o-nitrophenol (o-NP), m-nitrophenol (m- NP) and p-nitrophenol (p-NP) in ambient-N₂ phosphate buffer saline. Compared with bare GCE, the OMCs/GCE exhibited obvious electrocatalytic activity towards nitrophenol isomers. The electrochemical reaction mechanism of nitrophenol at the modified electrode was also studied. At OMCs/GCE, the three nitrophenol isomers could be identified and separated successfully and the simultaneous determination was realized by detecting the reduction peaks of their intermediate products (at 0.209 V vs. saturated calomel electrode for p-NP, 0.020 V for m-NP and -0.201 V for o-NP) with differential pulse voltammetry. Under the optimized experimental conditions, the linear ranges of the calibration curves were 2-90 μM for p-NP, 1-100 μM for m-NP and 0.5-90 μM for o-NP with limits of detection of 0.1 μM, 0.06 μM and 0.08 μM for p-NP, m-NP and o-NP, respectively (S/N = 3). Therefore, the proposed method is simple, rapid, stable, sensitive, specific, reproducible and cost-effective, which can be applicable for real samples detection.