Green Synthesis of Silver Nanoparticles for Preparation of Gelatin Films with Antimicrobial Activity

Abstract

Silver nanoparticles were successfully synthesized using Thuja orientalis aqueous extract and AgNO3 as a precursor. UV–Vis showed a distinct absorption peak at 424 nm attributed to silver nanoparticles due to their surface plasmon resonance. Atomic absorption analysis reflected an increase in the concentration of nanoparticles in relation to the progress of the synthesis, obtaining a peak concentration value of 15.7 mg/L at 50 min. The FTIR spectra revealed the characteristic functional groups of phytomolecules involved in the silver–ion binding process, such as R–O–H (3335 cm−1) O=C–OH (2314 cm−1) and C—C=C (1450 cm−1). At 50 min, zeta potential showed the stability of the nanoparticles with the value of −21.73 mV. TEM micrographs revealed the formation of spherical nanoparticles with an average size of about 85.77 nm. Furthermore, films incorporated with nanoparticles exhibited a Tg from 66.42 °C to 73.71 °C and Tm at 103.31 °C. Films from the G22 formulation presented excellent antibacterial properties inhibiting the growth of Staphylococcus aureus. Thuja orientalis aqueous extract could be a low-cost, eco-friendly, and efficient reducing and capping agent for the synthesis of nanometric-sized Ag particles. Gelatin films with nanoparticles are expected to have high potential as an active food packaging system.

Kaolin-Supported Silver Nanoparticles as an Effective Catalyst for the Removal of Methylene Blue Dye from Aqueous Solutions

“…Figure depicts the UV–Vis spectra of beneficiated kaolin and fabricated Ag-NPs/kaolin composites. The absorption peak at around 400 nm is attributed to the SPR of Ag-NPs, indicating the growth of Ag-NPs on the kaolin surface. − The SPR band arises due to the combined oscillations of nanoparticle conduction electrons in visible light. It is greatly influenced by the size and morphology of the nanoparticles .…”