Green synthesis and antimicrobial effects of silver nanoparticles by pumpkin cucurbita maxima fruit fiber

Abstract

In the present study, for the first time, green synthesis of silver nanoparticles was carried out with the extract obtained from the fibrous structure in the pumpkin Cucurbita maxima (CM) fruit. The presence of silver nanoparticles formed by the reduction of Ag+ ions was determined with the maximum absorbance values of 442.89 nm in wavelength scans made by UV-Vis spectroscopy analysis. The functional groups of the phytochemicals involved in the reduction were examined by Fourier-transform infrared (FT-IR) spectroscopy. For the morphology of the synthesized AgNPs, they were found to be uniform in spherical appearance using atomic power microscopy (AFM), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FE-SEM) images. The surface charges of AgNPs were determined to be -16.4 mV by Zeta potential analysis. Their crystal structures and nano-sizes were evaluated by X-ray diffraction (XRD) data to be in cubic pattern, and their size was 21.20 nm using the Debye-Scherrer equation. AgNPs (CM-AgNPs) synthesized via CM provided growth suppression at concentrations of 1.00-0.12, 2.00-1.00, and 0.50 µg/mL on pathogen gram-positive, gram-negative strains and the fungus Candida albicans, respectively. These concentrations were effective against antibiotics and silver solution at a very low concentration.