Green synthesis of silver nanoparticles from Hibiscus tiliaceus L. Leaves and their applications in dye degradation, antioxidant, antimicrobial, and anticancer activities

Abstract

The present study reports the green synthesis of silver nanoparticles (AgNPs) from aqueous extract of Hibiscus tiliaceus L. leaves and their application in dye degradation, antioxidant, antimicrobial, and anticancer activities. Analysis using Fourier transform infrared (FT-IR) spectroscopy revealed that plant metabolite functional groups had a role in the reduction and stability of AgNPs, and X-ray crystallography (XRD) demonstrated that the AgNPs were in crystal form. The UV–vis spectroscopy, dynamic light scattering (DLS), and zeta potential investigations revealed that the AgNPs were formed with an average size of 88.10 nm in colloidal form and were stable (-49 mV). The field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM) confirmed the shape and size of the AgNPs as spherical with a particle size of 30 - 35 nm, respectively. The AgNPs exhibited potential antioxidant activity by total antioxidant, DPPH, and reducing power assays. The biosynthesized AgNPs displayed a wide range of antibacterial activity on Gram-ve and Gram+ve bacteria by the zone of inhibition assay. AgNPs showed good anticancer activity on MCF-7 cells with an IC50 value of 65.83 µg/mL. Furthermore, AgNPs acted as potential catalysts in combination with the reducing agent sodium borohydride (NaBH4) for the degradation of methylene blue (MB), methylene orange (MO), and methylene green (MG) dyes. The degradation efficiency of catalyst AgNPs in the attendance of NaBH4 for 15 min was noted to be 12.8 %, 26.92 %, and 47.56 % for MO, MB, and MG, respectively. The study concluded that green synthesized AgNPs could be highly applicable as an antioxidant, antimicrobial, and anticancer agents in the biomedical field. Furthermore, AgNPs could be helpful in the remediation of dye effluents.