Poly (Biphenol/biphenoquinone - Vanadium (IV)) modified electrode as selective sensor for detection of 4-nitrophenol

Selective voltammetric detection of 4- nitrophenol. • Poly biphenol/biphenoquinone- V IV as new modifier. • Electrocatalytic activity of both BP/BQ and Vanadium (IV) redox groups. • Satisfactory results for voltammetric determination of 4-nitrophenol in real samples. In the present work, we report a new method for facile and effective synthesis of poly (biphenol/biphenoquinone-vanadium (IV)) (poly BP/BQ-V IV ) for the first time. The poly BP/BQ-V IV was applied for modification of a carbon past electrode (CPE/ poly BP/BQ-V IV ) to enhance the electro-catalytic activity towards electro-oxidation of 4-nitrophenol (4-NP) molecules in solutions. The structure and the properties of the synthesized poly BP/BQ-V IV were characterized by various techniques such as FESEM, TEM, EDX, FT-IR, UV–Vis, XPS analysis, cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy. The CPE/poly BP/BQ-V IV electrochemical sensor, exhibits a well-defined anodic peak for 4-NP molecules at 1.18 V vs. Ag/AgCl reference electrode. Under optimum experimental conditions, the CPE/ poly BP/BQ-V IV electrochemical sensor, shows a low detection limit of 60 nM, current sensitivity of 0.997 µA µM −1 and a linear response in the concentration range of 0.05 to 200 µM for quantitative measurement of 4-NP in aqueous solutions. The results verify that the CPE/ poly BP/BQ-V IV presents excellent reproducibility, appreciable repeatability, satisfactory stability, and high selectivity for detecting of 4-NP in tap and river water samples.