Enhanced urease inhibitory activity of quercetin via conjugation with silver nanoparticles: synthesis, characterization, and DFT study.

Urease plays a crucial role in the survival and colonization of Helicobacter pylori (H. pylori). Consequently, urease inhibitors are important in managing various diseases associated with H. pylori infection. Given the widespread use of silver nanoparticles (AgNPs) as antibacterial agents and quercetin's known urease inhibitory properties, we sought to develop a potent urease inhibitor by conjugating quercetin onto AgNPs. In fact, this study aimed to enhance the urease inhibitory activity of quercetin through its conjugation with AgNPs. Quercetin-loaded silver nanoparticles (Ag@QNPs) were successfully synthesized using the Frens method and characterized using various techniques, including UV-Vis spectroscopy, FT-IR spectroscopy, XRD analysis, DLS, and TEM. The urease inhibitory activity of Ag@QNPs was significantly higher (approximately 250 times) than that of pure quercetin, demonstrating a synergistic effect. In contrast, AgNPs alone exhibited minimal inhibitory activity against urease. Density functional theory (DFT) calculations revealed a favorable interaction energy between quercetin and the silver surface. These findings suggest the potential of Ag@QNPs as promising nanomaterials for applications in urease-related diseases.