Highly soluble polythiophene-based strontium-doped NiO nanocomposite for effective electrochemical detection of catechol in contaminated water

Abstract

Water-soluble conductive polymers are crucial for the development of sensor fabrication materials for the detection of water-soluble analytes. Polythiophene was considered as an excellent candidate because of its admirable optoelectronic properties. This work describes the synthesis of strontium-doped NiO nanocomposite (Sr-NiO) with water-soluble polythiophene (P3ThA). Improved interaction between Sr-NiO and polythiophene was achieved with acetic acid pendant group functionalization onto the polymer, and the resultant polymer nanocomposite was examined with various analytical tools. The as-synthesized Sr-NiO@P3ThA nanocomposite was employed as an effective nanocomposite electrode material for the electrochemical detection of ecotoxic catechol (CC). The modified screen-printed carbon electrode (SPCE) exhibited an exceptional electrocatalytic performance because of its synergistic effect of Sr-NiO nanoparticles with water-soluble P3ThA. The Sr-NiO@P3ThA-modified electrode showed the calibration curve for CC detection using the differential pulse voltammetry (DPV) technique, with a linear range of 0.009–14.1 and 14.1–404 µM and a detection limit of 6.5 nM (S/N = 3). Moreover, the Sr-NiO@P3ThA-modified electrode demonstrated good selectivity and sensitivity and was not influenced by interference moieties. The fabricated material was successfully utilized to detect catechol in river water and tap water in Taiwan. Overall, an eco-friendly, water-soluble, simple, sensitive, and selective approach was established to determine catechol contaminations in water resources.