Valorization of tomato stem waste: Lignin nanoparticles as eco-friendly platforms for 2,4-D and antimicrobial applications

This study explores the valorization of organosolv lignin extracted from tomato stems (tOL) and its transformation into tomato lignin nanoparticles (tLNP) via a hydrotropic synthesis method using sodium p-toluenesulfonate (p-TSA). The structural and chemical properties of tOL and tLNP were thoroughly characterized using SEM, FTIR, UV-Vis, DLS, Zeta potential, and NMR analyses, confirming successful nanoparticle formation with favorable physicochemical properties. Both tOL and tLNP exhibited strong antimicrobial activity, achieving maximum inhibition of Escherichia coli within 4 h of contact. Furthermore, tLNP were employed as carriers for the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and tested in field trials, demonstrating effective herbicide delivery and enhanced performance under practical agricultural conditions. These results highlight the potential of tomato stem-derived lignin nanoparticles as multifunctional, sustainable materials for agrochemical applications, offering simultaneous waste valorization, antimicrobial protection, and environmentally friendly pesticide delivery.