Antimicrobial activities and evaluation of biogenic silver nanoparticles as antimicrobial additive in paint

Abstract

In the present study, aqueous seed extract of bitter kola (Garcinia kola) was utilized for biological synthesis of silver nanoparticles (AgNPs) under the influence of solar irradiation. Antimicrobial activities and potential application of the biogenic AgNPs as antimicrobial additive in emulsion paint were examined. The AgNPs were characterized by UV-vis spectroscopy, fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The particles displayed brown coloration with maximum absorbance at wavelength 437nm. The FTIR spectrum showed distinct peaks at 3267 and 1635 cm-1 indicating the role of biomolecules in the capping and stabilization of the biogenic AgNPs. The particles were spherical in shape with sizes of 20-60 nm. Furthermore, the biogenic AgNPs exhibited moderate antibacterial activity against clinical isolates of Staphylococcus aureus and Salmonella Typhi while a very remarkable antifungal efficacy was also demonstrated against strains of Aspergillus niger and Aspergillus fumigatus. The AgNPs when incorporated as an additive into white emulsion paint completely inhibited the growth of Staphylococcus aureus, Bacillus subtilis, Aspergillus niger and Aspergillus flavus. Hence, the results obtained suggest that the biogenic AgNPs have promising biomedical application and could also serve as an essential ingredient in the manufacture of novel nanopaint.