Nanocrystalline chitin thin films

Elucidating the interactions between crystalline chitin and various biomacromolecules is of fundamental importance for designing and fabricating chitin-based biomaterials. This work highlights a simple method to prepare ultrathin films of chitin nanocrystals (chitin NC) by spincoating chitin NCs from a colloidal suspension onto a gold surface modified by an amine-terminated self-assembled monolayer. Atomic force microscopy confirmed that chitin NC films are reasonably smooth and homogeneous, and quartz crystal microbalance with dissipation monitoring (QCM-D) solvent exchange experiments demonstrated that chitin NC films have twice as much water as amorphous regenerated chitin (RChitin) films of similar thickness. QCM-D data also showed that chitinase-catalyzed hydrolysis of chitin NC films was much slower than that of RChitin films. Chitinase not only degraded, but also caused the swelling of the chitin nanocrystals. BSA adsorption studies demonstrated that chitin NC films have high protein loading capacity, and thus show potential applications for enzyme immobilization.