Eco-Friendly and Facile Preparation of Spherical Chitin Nanoparticles

A facile and eco-friendly procedure was established and optimized for the synthesis of spherical crystalline chitin nanoparticles (SChNPs) using the oxidizing agent Oxone®. This versatile triple-salt was effective in the cleavage of the glycosidic bonds and etching out individualization of elementary fibrils to form SChNPs. Selective oxidation occurred at the C6 primary hydroxyl group of the glucose molecule subunit to form carboxylic acid groups with a degree of oxidation of 0.10. The spherical particles are about 25 nm in diameter with enhanced aqueous solubility and amenable to bioconjugation owing to the presence of carboxylic acid groups. Both the acetamide group and the crystallinity index of the starting chitin remained intact during the treatment with Oxone®.