Bacterial responses to stem extract and green-synthesized Ag-TiO and Ag-SeO core/shell nanocomposites: unveiling antimicrobial and antioxidant properties.

This study reports an efficient and green protocol for the green synthesis of Ag-TiO and Ag-SeO nanocomposites using the extracted stems of . Results of spectroscopic and analytical analyses confirmed the successful synthesis, stability, and crystalline nature of the nanomaterials. The phytochemical profile and antioxidant and antimicrobial activities of the extract and the nanocomposites were also studied. extract and both the nanomaterials exhibited significant levels of active phytochemical compounds. These compounds contributed to their potent antioxidant activity, with extract and Ag-TiO NC demonstrating the highest antioxidant activity. Besides, Ag-SeO NC displayed remarkable antibacterial properties against different pathogenic bacteria with 31.0 ± 1.27 mm against , 31.0 ± 1.72 mm against , and 44.0 ± 1.09 mm against , and antifungal properties against and . The enhanced antimicrobial activity of Ag-SeO NC can be attributed to the synergistic effects of silver and selenium nanoparticles, which can disrupt cell membranes, induce oxidative stress, and interfere with essential cellular processes. The minimum inhibitory concentration values of Ag-SeO NC against and were found to be 0.2956 mg mL and 4.73 mg mL, respectively. The mechanism of action of Ag-SeO NC against both fungal strains was investigated using FTIR and HR-TEM analyses.