Biosynthesis of silver nanoparticles using aqueous extract of silky hairs of corn and investigation of its antibacterial and anticandidal synergistic activity and antioxidant potential

Abstract

This paper investigated the green synthesis of silver nanoparticles (AgNPs) using aqueous extract of silky hairs of corn (Zea mays L.) which is a waste material of the crop, as both a reducing and stabilising/capping agent. The AgNPs were characterised by UV-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The average size of AgNPs was found to be 249.12 nm. The AgNPs displayed strong antibacterial activity against five different foodborne pathogenic bacteria with diameter of inhibition zones ranged between (9.23 - 12.81 mm). It also exhibited potent synergistic antibacterial activity together with standard antibiotics, kanamycin (10.6 - 13.65 mm inhibition zones) and rifampicin (10.02 - 12.86 mm inhibition zones) and anticandidal activity with amphotericin b (10.57 - 13.63 mm inhibition zones). The AgNPs exhibited strong antioxidant activity in terms of nitric oxide scavenging (IC50 91.56 mu g/mL), ABTS (2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging (IC50 115.75 mu g/mL), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging (IC50 385.87 mu g/mL), and reducing power (IC0.5 23.14 mu g/mL). This study demonstrated the synthesis of spherical AgNPs with strong antibacterial, anticandidal and antioxidant properties that could potentially be utilised in the biomedical, cosmetic, food and pharmaceutical industries.