Antibacterial and cytotoxic activities of a green synthesized silver nanoparticles using corn silk aqueous extract

Abstract

The present work described an ecofriendly method for the synthesis of silver nanoparticles (AgNPs) by aqueous extract of corn silk. Bio-reduction of silver was complete when the mixture (AgNO3 + extract) changed its color from light yellow to reddish-brown. Corn silk aqueous extracts were screened for Total Phenolic contents (TPC), Total Flavonoid contents (TFC) and total reducing sugar content with the values of 106.4 ± 9.6 mg/g, 42.8 ± 3.7 mg/g, 96.0 ± 4.4 mg/g, respectively. AgNPs were characterized by UV–vis spectroscopy, dynamic light scattering (DLS), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) analysis. Different pH value, temperature and AgNO3 concentration were optimized by UV–vis spectroscopy and the mean particle size was in the range of 10−30 nm. FT-IR spectroscopy scrutinized the involvement of various functional groups during nanoparticle synthesis. SEM analysis confirmed the morphology of the synthesized nanoparticles. XRD also confirmed the formation of small spherical silver nanoparticles. In addition, green synthesized AgNPs showed efficient antimicrobial activities against both Gram-positive and Gram-negative bacteria. Further, dose response cytotoxicity on HepG2 cell was found by MTT assay with the inhibitory concentrations (IC50) value of 53 μg/mL. The study suggested that this green and simple procedure for preparing AgNPs had an underestimated potential in biomedical, antimicrobial and nanotechnological applications.