(549d) Functionalized Cellulose Nanocrystals in Agriculture: Synthesis and Characterization for Use As a Plant-Based Nanocarrier of Active Biomolecules

This investigation describes the development of novel bioactive molecule-conjugated cellulose nanocrystals for use as a targeted nanocarriers in agricultural applications. The United Nations estimates that agricultural food production must increase by 60% by 2050 to feed a growing world population. Herbicides and pesticides are critical to agricultural yield, but current delivery methods result in as little as 10% of the agrochemical reaching the plant with the remainder being lost to the environment. This can result in negative environmental consequences such as air, groundwater, and soil contamination. Nanocarriers are promising for increasing the efficiency of agrochemical application and reducing the potential adverse environmental effects of their use. Cellulose nanocrystals (CNCs) provide the opportunity to utilize a forestry and agricultural waste product to enhance agricultural yields. These nanocrystals have the small size for transport into plants, and surface functional groups to react with desired agricultural chemicals while maintaining crop biocompatibility and minimal environmental toxicity. This work describes the novel surface functionalization of cellulose nanocrystals with model agricultural biomarkers. Understanding biomolecule-cellulose-plant interactions is critical to the future development of agricultural bionanotechnology.

Commercially supplied sulfuric acid hydrolyzed cellulose nanocrystals were reacted with model agricultural biomolecules, such as 2,4-dichlorophenoxyacetic acid (2,4-D), using novel combinations of aqueous chemistries. The resulting functionalized CNCs were characterized using, spectroscopy, thermal analysis, elemental analysis, and microscopy techniques. The degree of substitution was calculated based on the number of available surface hydroxyl groups. Results confirmed the agricultural agents' attachment to the cellulose nanocrystals' surface. Future collaborative investigations with plant biologists will work to understand the effect and viability of cellulose nanocrystals as a nanocarrier in delivering biomolecules to plants. This investigation lays the framework for a future cyclic agricultural system, where cellulose nanocrystals can be extracted from crop waste, reacted with biomolecules of interest, and then directly delivered to plants, thus creating a more targeted effect while simultaneously reducing waste and increasing crop yield.