Chitin nanofibers derived from deep eutectic solvent extraction and ammonium persulfate oxidation as a seed nanopriming agent for microgreen growth enhancement

Chitin nanofibers (ChNFs) were successfully prepared from lobster shells using deep eutectic solvents (DESs) and ammonium persulfate oxidation (APS), offering a sustainable approach for marine waste utilization. DES-treated chitin (DES-Chitin) with a yield of 26.22% and 94.78% purity retained a high degree of acetylation (96%), while APS oxidation improved crystallinity, introduced carboxyl content, and enhanced dispersibility. The resulting ChNFs obtained after 5 hours of APS oxidation (5h-ChNFs) exhibited superior transparency, dispersion stability, and morphological refinement, with thermal stability comparable to DES-Chitin. In germination studies, 5h-ChNFs significantly improved physiological characteristics, nitrogen assimilation, and chlorophyll synthesis in broccoli and radish microgreens. Optimal concentrations of 20 μg mL⁻¹ for broccoli and 75 μg mL⁻¹ for radish enhanced protein, polyphenol, and flavonoid contents, alongside elevated DPPH and ABTS radical scavenging capacities. These findings demonstrated the potential of ChNFs as a bioactive seed nanopriming agent, bridging nanomaterial science and agricultural biotechnology to increase microgreen production sustainably.