Poly(p-aminobenzene sulfonic acid)-modified graphite electrode [poly(p-ABSA)/GE] was prepared via a straightforward one-step electropolymerization and was employed to investigate the electrochemical behavior of o-nitrophenol (o-NP), m-nitrophenol (m-NP) and p-nitrophenol (p-NP), for the purpose of realizing the simultaneous determination of nitrophenol isomers. Semi-derivative voltammetry (SDV) was adopted to enhance the resolution and sensitivity. Compared with the bare GE, poly(p-ABSA)/GE exhibited excellent electrocatalytic activity towards the oxidation process of the intermediate products of nitrophenol isomers. Thus, o-, m- and p-NP can be clearly identified and successfully separated at 0.119V, -0.125V and 0.027V (vs. saturated calomel electrode). Under the optimized experimental conditions, the linear ranges of the calibration curves were 3 similar to 800 mu mol L-1 for o-NP, and 3 similar to 700 mu mol L-1 for both m-NP and p-NP. In addition, the low detection limits for o-, m- and p-NP were 0.28, 0.5 and 0.3 mu mol L-1, respectively (S/N = 3). The proposed method is novel and has many advantages such as simple, sensitive, selective, reproducible and cost-effective. Therefore, it can be considered a promising sensing platform for direct simultaneous determination of nitrophenol isomers in water samples. (C) 2015 Published by Elsevier Ltd.