From cotton gin byproduct to nano-in-nano structured hybrid composite for effective pathogen control

Cotton gin byproduct (CGB), a high-volume byproduct of cotton processing composed of discarded plant materials, is often underutilized despite its abundance and potential value. In this study, CGB was upcycled into a nano-in-nano structured composite with potent antimicrobial properties, offering a sustainable solution for agricultural waste management and pathogen control. Cellulose nanofibers (CNF) were extracted from CGB and used as an active biotemplate for the in situ synthesis of antimicrobial silver nanoparticles (Ag NPs). CNF inherently facilitated the formation of Ag NPs (17.2 ± 4.7 nm, 6.8 wt%) without the need for external reducing or stabilizing agents, resulting in a hybrid nanocomposite (Ag-CNF). This embedded nanostructure demonstrated stability and potent antimicrobial efficacy, achieving >99.99% reduction of S. Typhimurium and Listeria monocytogenes within 10 min, Pseudomonas aeruginosa within 1 h, and Staphylococcus aureus within 24 h at a 0.5 wt% concentration. These findings suggest the potential of Ag-CNF as an eco-friendly antimicrobial material with applications in disease prevention and sustainable waste utilization.