Antibacterial activity of green gold and silver nanoparticles using ginger root extract.

Recent studies demonstrated that the speed of synthesis, biocompatibility, and antimicrobial activity of gold (Au) and silver (Ag) metals is enhanced when biosynthesized in nano-sized particles. In the present study, Au- and Ag-based nanoparticles (NPs) were synthesized via a biological process using aqueous Ginger root extract and characterized by various spectroscopic methods. The NPs have hexagonal and spherical shapes. The average particle size for Au and Ag NPs was 20 and 15 nm, respectively. The dynamic light scattering (DLS) technique has shown that the zeta potential values of synthesized NPs were 4.8 and - 7.11 mv, respectively. Gas chromatography-mass spectrometry (GC-MS) analysis of Ginger root extract revealed 25 compounds. The synthesized NPs showed significant activity against Staphylococcus aureus and Escherichia (E). coli in vitro, with IC50 and IC90 values for Au and Ag NPs, respectively, noted to be 7.5 and 7.3 µg/ml and 15 and 15.2 µg/ml for both bacterial strains. The protein leakage level was tremendous and morphological changes occurred in bacteria treated with biosynthesized NPs. These results suggest that the biosynthesized metallic NPs have the suitable potential for application as antibacterial agents with enhanced activities.

Current developments in green synthesis of metallic nanoparticles using plant extracts: a review.

Metal nanoparticles (MNPs) produced by green approaches have received global attention because of their physicochemical characteristics and their applications in the field of biotechnology. In recent years, the development of synthesizing NPs by plant extracts has become a major focus of researchers because of these NPs have low hazardous effect in the environment and low toxicity for the human body. Synthesized NPs from plants are not only more stable in terms of size and shape, also the yield of this method is higher than the other methods. Moreover, some of these MNPs have shown antimicrobial activity which is consistently confirmed in past few years. Plant extracts have been used as reducing agent and stabilizer of NPs in which we can reduce the toxicity in the environment as well as the human body only by not using chemical agents. Furthermore, the presence of some specific materials in plant extracts could be extremely helpful and effective for the human body; for instance, polyphenol, which may have antioxidant effects has the capability for capturing free radicals before they can react with other biomolecules and cause serious damages. In this article, we focused on of the most common plants which are regularly used to synthesize MNPs along with various methods for synthesizing MNPs from plant extracts.