Sol-gel synthesized rutile TiO₂ nanoparticles loaded with cardamom essential oil: Enhanced antibacterial activity

Nanoparticles have been recognized as a promising alternative to overcome problems associated with antibiotic-resistant bacterial strains. In the current study, the combination of TiO₂ nanoparticles with cardamom essential oil (CEO) was assessed for its antibacterial effects. First, TiO₂ nanoparticles were synthesized via sol-gel route and subjected to various physico-chemical characterizations; structural using both X-ray diffraction and Raman spectroscopy, morphological by scanning electron microscopy and elemental analysis by X-ray photoelectron spectroscopy. The synthesized nanoparticles were, then, loaded with natural CEO to form the conjugate CEO@TiO₂. The effectiveness of the conjugate CEO@TiO₂ was assessed against a standard test strain as well as against two clinical isolates using ultraviolet–visible spectrophotometry measurements. The results demonstrate that CEO@TiO₂ conjugates exhibit potent antibacterial activity against all the tested bacteria than CEO or TiO₂ nanoparticles alone. An attempt to explain the mechanism of action of the devised antibacterial agent was undertaken based on confocal microscopy observations. Overall, this proof-of-concept antibacterial system may have important implications for the development of numerous therapeutic, environmental and food industry applications.