Green Biosynthesis of Spherical Silver Nanoparticles by Using Date Palm (Phoenix Dactylifera) Fruit Extract and Study of Their Antibacterial and Catalytic Activities.

Saeed Farhadi,Ajerloo Mohammadi,Bahram Ajerloo

doi:10.17344/acsi.2016.2956

Abstract

In this work, we have synthesized spherical silver nanoparticles (Ag NPs) by a low-cost, rapid, simple and ecofriendly approach using Date palm fruit extract as a novel natural reducing and stabilizing agent. The product was characterized by UV-visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), energy-dispersive X-ray (EDX) spectroscopy and Zeta potential measurements. The reaction conditions including time, content of reducing agent and silver nitrate, temperature and pH were investigated. The optimum yield of Ag NPs was obtained when 10 mM of silver nitrate was reacted with Date fruit extract at pH 11 and heated it to 55 °C within 10 minutes. The elemental and crystalline nature of Ag NPs were confirmed from EDX and XRD analysis. SEM and TEM images showed that the Ag NPs were spherical and with sizes in the range of 25-60 nm. On the base of FT-IR analysis, it can be stated that the functional groups present in bio-molecules of Date fruits are responsible for the reduction and stabilization of Ag NPs, respectively. The Ag NPs showed good antibacterial activity against a few human pathogenic bacteria. The catalytic activity of the Ag NPs for rapid and efficient reduction of toxic nitro compounds into less toxic corresponding amines by using NaBH4 was also investigated.

Highlights

Among various transition metal nanoparticles, silver nanoparticles (Ag NPs) have attracted considerable attention in nanoscience and nanotechnology due to their excellent optical and electronic properties as well as their wide applications in various fields such as catalysis,[1] surface enhanced Raman scattering,[2] degradation of environmental pollutants,[3] biosensors[4] cancer therapy[5] and antibacterial effects.[6]
Silver nitrate treated with date fruit extract showed a color change from yellow to brown within 20 min whereas no color change could be observed in silver nitrate solution without date extract (Figure 2)
Date fruit extract was used as an effective reducing as well as capping agent for the biosynthesis Ag NPs in aqueous solution

Summary

Introduction

Among various transition metal nanoparticles, silver nanoparticles (Ag NPs) have attracted considerable attention in nanoscience and nanotechnology due to their excellent optical and electronic properties as well as their wide applications in various fields such as catalysis,[1] surface enhanced Raman scattering,[2] degradation of environmental pollutants,[3] biosensors[4] cancer therapy[5] and antibacterial effects.[6]. Biosynthesis of metal nanoparticles has received considerable attention due to the growing need to develop clean and nontoxic chemicals, environmentally friendly solvents and renewable materials.[12] The selection of a non-toxic reducing agent, a cost-effective and renewable stabilizing agent and an environmentally benign solvent system are the three main criteria for a greener metal nanoparticles synthesis. A great deal of effort has been devoted toward the biosynthesis of silver nanoparticles using bacteria,[13,14,15,16,17] fungi,[18,19,20] actinomycetes,[21,22,23] yeast[24] and viruses[25,26,27] but the rate of nanoparticle synthesis is faster using fruits and plants extracts than microbes, and the pro-

Methods

Results

Conclusion