Green synthesis, chracterization, and antioxidant properties of silver nanoparticles capped chestnut shell extract

Abstract

Bionanotechnology is a promising field for the development of novel nanomaterials designed for different applications. Biogenic synthesis of nanoparticles is carried out with natural resources such as plants and microorganisms. Chestnut fruits are known for their nutritional benefits such as high carbohydrate content and low-fat content but their shells have been underutilized despite containing significant antioxidants, anti-inflammatory and antimicrobial properties. In this study, it was aimed at synthesizing of silver nanoparticles (SNPs) using the extract obtained from chestnut shells, a by-product rich in bioactive compounds such as flavonoids and polyphenols, and to determine the antioxidant properties of the synthesized nanoparticles for various applications. In the proposed method, silver ions (I) were reduced to silver (0) via phytochemicals of chestnut shell extract (CSE). The synthesized CSE-SNPs were characterized by ultraviolet (UV) spectrophotometry, infrared (IR) spectrophotometry, dynamic light scattering (DLS) and wet-STEM (scanning transmission electron microscope). The antioxidant capacities/activities of the synthesized CSE-SNPs were determined using Cupric Reducing Antioxidant Capacity (CUPRAC) and DPPH (2,2-diphenyl-1-picrylhydrazyl) assays. The synthesized light-yellow CSE-SNPs have a maximum absorption at 430 nm wavelength. The CSE-SNPs with an average size of 15 nm are spherical, monodisperse, and homogeneous. The polydispersity index of the synthesized silver nanoparticles was determined as 0.28. The antioxidant capacity and radical scavenging activity values of the CSE-SNPs were found to be 0.051 ± 0,002 mmol-TR, and 0.026 ± 0,004 mmol-TR according to the CUPRAC method and DPPH assay, respectively. Nano-sized, monodispersed, antioxidant CSE-SNPs were produced using an eco-friendly, sustainable, and simple technique.