Coating of wallpaper with green synthesized silver nanoparticles from Passiflora foetida fruit and its illustrated antifungal mechanism

Abstract Indoor walls are constantly exposed to fungal aerosols, resulting in the highest indoor fungal pollutant. The antifungal activity of silver nanoparticles (AgNPs) synthesized using Passiflora foetida fruit extract and coated with liner wallpaper was investigated against indoor fungus, Fusarium sp. Successful biosynthesis of AgNPs was observed by ultraviolet-visible (UV-Vis) spectroscopy showing surface plasma resonance (SPR) peak at 450 nm. The X-ray diffraction (XRD) analysis and selected area electron diffraction (SAED) confirmed the face-centered cubic crystalline AgNPs. The transmission electron microscopy (TEM) technique confirmed the spherical shape with an average size of 12 nm. The energy dispersive spectroscopy (EDS) confirmed the existence of elemental silver. The Fourier transform infrared spectroscopy (FTIR) was analyzed for the presence of capping and stabilizing agents in AgNPs, and further, it was confirmed by gas chromatography-mass spectroscopy (GC-MS). Finally, the synthesized AgNPs were coated in the wallpaper by the bar-coating method and tested against a common indoor fungus, Fusarium sp. which displayed an excellent antifungal activity with a zone of inhibition of 22 ± 0.3 mm at 80 µg/mL of AgNPs coated liner wallpaper. The application of the synthesized AgNPs to building materials could effectively protect indoor environments from fungal development. This study will open a new avenue to control indoor fungi by coating the synthesized AgNPs on the wallpaper.