Nanosensor-based on TiO₂ nanoparticles coated with cationic surfactant for the determination of 2,4-D in fruits and vegetables

This study engineered an electrochemical electrode designed for the susceptible detection of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) through sophisticated electrochemical methodologies. The electrode, denoted as CTAB/TiO₂-CPE, was synthesized by integrating titanium oxide (TiO₂) nanoparticles into a carbon paste electrode (CPE) and introducing cetyltrimethylammonium bromide (CTAB) as a surfactant to the electrolyte solution. Comparative analysis revealed that the CTAB/TiO₂-CPE exhibited superior sensitivity compared to the unmodified CPE, showcasing an impressive lower limit of detection at 0.23 × 10⁻⁸ M. A meticulous examination of pH influence demonstrated that the phosphate buffer saline (PB) induced the highest peak current at a pH of 3.0. Exploring scan rate variations enabled the quantitative assessment of various physicochemical attributes. The fabricated electrode was systematically employed to quantify 2,4-D levels across diverse environmental samples, including soil, fruits, vegetables, and water. The results, characterized by a high degree of precision, underscore the reliability of the proposed electrode, demonstrating a commendable success rate in sample recoveries. Graphical Abstract: (Figure presented.)