Assessment of antimicrobial efficacy of leather coating using chitosan modified TiO₂-CuO nanocomposites

This research investigates the microbial inactivation potential of ternary TiO₂-CuO-chitosan nanocomposites (TCC NCs) applied as surface coatings on cowhide leather. Initially, bare TiO₂ nanoparticles (NPs) and binary TiO₂-CuO (TC) NCs, with varying CuO NPs content, were prepared using an in situ sol-gel method. These binary TC NCs were then modified with chitosan at varying weight percentages (2%, 4%, 6%, and 8%). The resulting NCs were analyzed using various spectral tools. XRD analysis revealed the dominance of the anatase form of TiO₂ in both binary and ternary NCs. UV-visible DRS measurements were used to study the optical properties of the NCs and compare these to those of individual components. Microscopic analysis indicated the formation of grain clusters with irregular shapes, with particle sizes ranging between 10 and 20 nm. FT-IR analysis studied the interconnectivity between TC and chitosan through different functional moieties, while Raman analysis confirmed the phases of the different constituents. BET analysis showed that TCC 8 NCs (having 8% OF chitosan in TC NCs) had a surface area 1.4 times greater than bare TiO₂ NPs. Antibacterial and antifungal studies were conducted using standard protocols to test the prepared NCs against representative microbes. When coated on cowhide leather as microbicidal agents, the TCC 8 NCs-coated leather exhibited the highest microbicidal activity against E. coli, S. aureus, B. cereus, P. vulgaris, C. albicans, and A. niger in comparison to other ternary NCs, including TCC 2, TCC 4, and TCC 6, as well as binary NCs such as TC 10, TC 20, TC 30, and TC 50. This study showcases the effectiveness of these functional NCs for the surface disinfection of leather coatings.