Green synthesis of nanoparticles by employing plant biomass is sustainable and eco-friendly as opposed to traditional chemical and physical methods. The objective of this work is to synthesize silver nanoparticles (AgNPs) using lemon (Citrus limon) leaf extract as a green reducing and capping agent, characterize their physicochemical properties, and apply the synthesized AgNPs in the fabrication of a biodegradable composite film. Lemon leaves, which are rich in bioactive compounds, were thoroughly washed, boiled, and processed to obtain the extract. Upon reaction of the resulting extract with silver nitrate (AgNO₃), a rapid color change from yellow to brownish-red was observed, providing an initial confirmation of silver nanoparticle formation. The optimal conditions for the reduction of AgNPs were determined using 0.125 M AgNO₃ at pH 5, with a 1:1 ratio of leaf extract to silver nitrate. Then polyvinyl alcohol (PVA)–Pectin composite films were prepared by dissolving the polymers in water, followed by incorporation of SiO₂ and green-synthesized AgNPs through ultrasonication and magnetic stirring; the homogeneous mixture was then cast onto Petri dishes and dried to obtain biodegradable nanocomposite films. The synthesized AgNPs were characterized using ultraviolet–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and X-ray Diffraction (XRD). The nanoparticles exhibited their highest absorption in the UV–visible spectra at around 400 nm to 450 nm. While FTIR analysis identified –OH, –C=O, and –C–O functional groups, confirming the role of polyphenols in nanoparticle reduction and stabilization. Further characterization using FESEM, Dynamic Light Scattering (DLS) and Zeta Potential analysis also revealed particle morphology, crystallinity, size distribution, and surface stability. This research provides a sustainable method to synthesizes AgNPs with not only broad antimicrobial, agricultural, and medical potential but also valorizes postharvest lemon leaf byproducts for the development of AgNPs-based antibacterial composites to enhance fruit and vegetable preservation.
Roy et al. (Thu,) studied this question.