Cost-effective chlorpyrifos detection via smartphone-based colorimetry and microextraction method

This study presents a novel, cost-effective, portable, and environmentally friendly smartphone-based method for on-site detection of chlorpyrifos (CPF) pesticide residues in water samples. The approach combines a simple colorimetric reaction with an eco-friendly dispersive liquid-liquid microextraction (DLLME) method, using a deep eutectic solvent (DES) derived from choline chloride (ChCl) and decanoic acid (DA). To better understand the extraction mechanism, molecular dynamics (MD) simulations were conducted, revealing strong hydrogen bonding and C-H...pi interactions as key factors driving the extraction of the CPF derivative (DHPQ). The method exhibits high selectivity, as confirmed by its tolerance to interfering ions and compounds without affecting CPF measurement. It employs a smartphone app for quantification, eliminating the need for expensive laboratory equipment. The optimized procedure delivers exceptional analytical performance, with a detection limit of 25.4 ng mL- 1, precision below 3.3 %, and recovery rates ranging from 94.4 % to 106.0 % in real-world samples. This innovative approach offers a rapid, accurate, and sustainable solution for monitoring chlorpyrifos contamination in water bodies, offering significant advantages over traditional methods in terms of cost, portability, and simplicity.