Central Composite Design for Optimizing the Biosynthesis of Silver Nanoparticles using Plantago major Extract and Investigating Antibacterial, Antifungal and Antioxidant Activity

• Published in: Scientific reports 2020-06, Vol.10 (1), p.9642, Article 9642
• Main Authors: Nikaeen, Ghazal, Yousefinejad, Saeed, Rahmdel, Samane, Samari, Fayezeh, Mahdavinia, Saeideh
• Format: Article
• Language: English
• Subjects: 639/638; 639/925; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - pharmacology; Antifungal agents; Antifungal Agents - chemistry; Antifungal Agents - pharmacology; Antioxidants; Antioxidants - chemistry; Antioxidants - pharmacology; Biological activity; Biosynthesis; Disk Diffusion Antimicrobial Tests; E coli; Fourier transforms; Fungi; Humanities and Social Sciences; Hydrogen-Ion Concentration; Infrared spectroscopy; Light scattering; Metal Nanoparticles - chemistry; Metal Nanoparticles - ultrastructure; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; multidisciplinary; Nanoparticles; pH effects; Plant Extracts; Plantago - chemistry; Plantago major; Science; Science (multidisciplinary); Seeds; Seeds - chemistry; Silver; Surface Plasmon Resonance; Temperature; Transmission electron microscopy; X-ray diffraction
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-66357-3

Central composite design (CCD) was applied to optimize the synthesis condition of silver nanoparticles (AgNPs) using the extract of Plantago major ( P. major ) seeds via a low cost and single-step process. The aqueous seed extract was applied as both reducing element and capping reagent for green production of AgNPs. Five empirical factors of synthesis including temperature ( Temp ), pH, volume of P. major extract ( V ex ), volume of AgNO 3 solution ( V Ag ) and synthesis time were used as independent variables of model and peak intensity of Surface Plasmon Resonance (SPR) originated from NPs as the dependent variable. The predicted optimal conditions was determined to be: Temp  = 55 °C, pH  = 9.9, V ex  = 1.5 mL, V Ag  = 30 mL, time  = 60 min. The characterization of the prepared AgNPs at these optimum conditions was conducted by Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), transmission electron microscopy (TEM) and X-ray diffraction (XRD) to determine the surface bio-functionalities. Bio-activity of these AgNPs against bacteria and fungi were evaluated based on its assay against Micrococcus luteus, Escherichia coli and Penicillium digitatum . Furthermore, antioxidant capacity of these NPs was checked using the ferric reducing antioxidant power (FRAP) assay.