Analysis of chitosan nanoparticles synthesized from cowry and oyster shell byproducts using <i>Cymbopogon citratus</i> and silver nitrate

Purpose: To determine the properties of chitosan nanoparticles synthesized from Cymbopogon citratus and silver nitrate (AgNO3).Methods: Chitosan nanoparticles (CNPs) were synthesized using Cymbopogon citratus (Poaceae family), aqueous silver nitrate solution (AgNO3), and chitosan (synthesized via chitin deacetylation separately from oyster and cowry shells). Characterization of both chitosan and its nanoparticles was performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM).Results: X-ray diffraction (XRD) analysis showed that the chitosan extracted from the oyster and cowry shells had crystallite sizes of 30.10 and 37.48 nm, respectively, and crystallinity indices of 68.71 and 60.22 %, respectively. On the other hand, the synthesized chitosan nanoparticles from oyster and cowry shells exhibited crystallite sizes of 18.59 and 19.34 nm, respectively, with crystallinity indices of 91.65 and 83.04 %. The FTIR analysis revealed that the synthesized chitosan exhibited characteristic peaks for C=O stretching, amide I and C=O stretching in the NHCOCH₃ group, whereas the nanoparticles showed O-H stretching overlapping N-H. Scanning electron microscopy (SEM) imaging showed that the extracted chitosan had irregular, rough edges and a coarse grainy structure, while the nanoparticles displayed small, spherical particles with a grainy texture, suggesting increased porosity.Conclusion: Chitosan nanoparticles have been synthesized through a green process, providing an eco-friendly alternative. Additionally, the structural characteristics of the chitosan nanoparticles suggest their suitability for various industrial applications.