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

Authors: Nam, Sunghyun; Olanya, Ocen; Jordan, Jacobs; Uknalis, Joseph; He, Zhongqi; KASHEM, MD NAYEEM HASAN - US Department Of Agriculture (USDA); Fang, David

Submitted to: Frontiers in Nanotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/23/2025
Publication Date: 5/6/2025
Citation: Nam, S., Olanya, O.M., Jordan, J.H., Uknalis, J., He, Z., Kashem, M., Fang, D.D. 2025. From cotton gin byproduct to nano-in-nano structured hybrid composite for effective pathogen control. Frontiers in Nanotechnology. 7: 1567693. https://doi.org/10.3389/fnano.2025.1567693.
DOI: https://doi.org/10.3389/fnano.2025.1567693

Interpretive Summary: Nanotechnology offers transformative solutions across various fields including pathogen control by enhancing the efficiency of antimicrobial materials. In this study, a nano-in-nano structured hybrid composite was developed using CGB as a renewable resource for CNF and leveraging the unique capability of CNF as a reagent-free platform for the in situ synthesis of Ag NPs. This approach achieved a uniform dispersion of Ag NPs within the CNF matrix, enhancing surface reactivity for antimicrobial performance. The Ag NP-embedded CNF exhibited superior antibacterial activity against opportunistic and foodborne pathogens, achieving as high as >6.8 Log CFU/mL in as little as 10 min at a concentration of 0.5 wt%. Electron microscopic analysis confirmed the stability of embedded NPs and revealed that their antimicrobial mechanism involves ionization rather than nanomechanical attack. These findings show the potential of Ag-CNF for diverse antimicrobial applications, such as wound dressings, food safety, and agricultural disease management, while addressing environmental waste challenges by transforming agricultural byproducts into high-performance functional materials.

Technical Abstract: 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). The 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 antimicrobial efficacy, achieving >99.99% reductions of P. aeruginosa, S. aureus, S. Typhimurium, and L. monocytogenes within 1 h, 24 h, 10 min, and 10 min, respectively, 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.