Neem root mediated-biosynthesis of silver nanoparticles: antimicrobial activities and application as detergent additive

Abstract

This study reports the biosynthesis of silver nanoparticles (AgNPs) using the aqueous extract of neem root. The synthesis was carried out under ambient conditions by reacting 1 mM silver nitrate with the aqueous extract of neem root (10:1). Characterization was done by UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The antibacterial and algicidal activities of the biosynthesized AgNPs were investigated against some clinical bacterial isolates and a bloom-forming cyanobacterial strain, respectively. Their potential application as an antimicrobial detergent additive was also evaluated. The biosynthesized AgNPs displayed maximum absorbance at wavelength of 425 nm. The particles were predominantly spherical in shape with size ranging from 10 to 40 nm. Data obtained from FTIR indicated that protein molecules in the extract played very active role in the reduction of silver ions to form AgNPs. The particles demonstrated considerable antibacterial activities against clinical isolates of E. coli, Streptococcus sp, and K. pneumoniae as they induced inhibition zone of 12-23 mm. The algicidal activity displayed by the particles against the bloom-forming cyanobacterial strain was appreciable. Similarly, the incorporation of AgNPs as additive in the locally made detergent led to total inhibition of growth of E. coli, K. pneumoniae, Candida sp, and A. flavus. Results obtained in this study therefore suggest the promising applications of the particles as an antimicrobial agent in water treatment and drug development. The particles also exhibited potential application as an antimicrobial additive in detergent production