Mediated by tea polypeptides: A green synthesis approach for selenium nanoparticles exhibiting potent antioxidant and antibacterial properties

This study presents an ecologically conscious methodology for synthesizing tea polypeptides-selenium nanoparticles (TP-SeNPs) exhibiting antioxidant and antibacterial properties, utilizing polypeptides (TP). Proteins were extracted from leaves using alkali extraction-acid precipitation method, response surface (RSM) was employed to optimize the preparation processes both TP TP-SeNPs. The extract obtained with highest content of 28.12% at a pH 6, temperature 50°C, duration 3 h, enzyme concentration 4%. TP-SeNPs minimum particle size 98 nm biosynthesized by adding 3% 4 reaction 55°C 6 h. UV spectrum showed absorption peak 285 nm. EDS 1.37 keV confirmed presence selenium in Electron microscopy revealed thin layer coating on Infrared analysis changes C=O, NH, C-N bonds. XRD indicated formation crystalline structure absorbance ratio peptide nanoparticle colloidal solution remained stable over 7 days 25°C 4°C. exhibited higher activity than SeNPs high concentrations. contain selenium, carbon, oxygen, nitrogen, plays role stabilizing encapsulating may involve physical adsorption, covalent interactions, other unknown preventing aggregation or degradation. improves their material properties enhances abilities.