Antibacterial Activity of Ag@HKUST-1-Encapsulated Cinnamomum sintoc Essential Oil Against Salmonella typhi

Typhoid fever, caused by Salmonella typhi ( S. typhi ), remains a pressing public health issue in developing regions, due to rising antimicrobial resistance and poor sanitation. In response to this challenge, this study explores the antibacterial potential of Cinnamomum sintoc ( C. sintoc ) essential oil, a traditional medicinal plant used by indigenous Dayak communities, by encapsulating it into a silver-doped metal-organic framework, Ag@HKUST-1, and evaluates its antibacterial activity against S. typhi . C. sintoc oil was extracted via steam distillation, and its chemical profile was analyzed using GC-MS. The Ag@HKUST-1 composite was synthesized through solvothermal assembly of HKUST-1, followed by in situ incorporation of silver nanoparticles (AgNPs). Characterization via XRD, FTIR, nitrogen physisorption, SEM-EDS, TEM, and UV-Vis, confirmed successful formation and integration of AgNPs into the HKUST-1 framework. Encapsulation efficiency was highest at 1.5 mL of oil (16.82%), indicating an optimal loading threshold. Antibacterial assays using the agar disk diffusion method showed that the supernatant of the encapsulated system had the strongest inhibition at 1.5 mL (4.0 mm), while the solid fraction exhibited a sustained release effect, with stable inhibition up to 2.7 mm (3 mL). These results suggest that Ag@HKUST-1 serves as an effective carrier for volatile bioactives, enabling controlled delivery and enhanced antibacterial performance. This approach highlights a promising strategy for combating drug-resistant typhoid infections through MOF-assisted phytochemical delivery systems.