Antimicrobial activity of the metals and metal oxide nanoparticles

Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications.

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Green Synthesis of Metallic Nanoparticles via Biological Entities

Nanoparticles and their antimicrobial properties against pathogens including bacteria, fungi, parasites and viruses.

Plant-mediated green synthesis of nanomaterials has been increasingly gaining popularity due to its eco-friendly nature and cost-effectiveness. In the present study, we synthesized silver nanoparticles (AgNPs) by using an aqueous solution of Saudi Origanum vulgare L. plant extract as a bioreducing agent. The as-synthesized AgNPs were characterized using various microscopic and spectroscopic techniques. The results indicated the formation of crystalline face-centered cubic (fcc) AgNPs. Additionally, FT-IR study confirmed that the O. vulgare L. extract not only functioned as a bioreductant but also stabilized the surface of the AgNPs by acting as a capping agent. Moreover, the effect of the amount of the plant extract on the size and the antimicrobial activity of the NPs was also assessed. It was found that with increasing amounts of plant extract, the size of the NPs was decreased. Moreover, as-synthesized AgNPs as well as O. vulgare L. plant extract were separately tested to examine their antimicrobial activities. The activities were tested against various bacterial and fungal microorganisms including Shigella sonnei, Micrococcus luteus, Escherichia coli, Aspergillus flavus, Alternaria alternate, Paecilomyces variotii, Phialophora alba, and so on. These results evidently show that the inclusion of O. vulgare L. extracts improves the solubility of AgNPs, which led to a significant enhancement in the toxicity of the NPs against the assessed microorganisms.

https://www.mdpi.com/2071-1050/10/4/913/pdf

Plant-Extract-Assisted Green Synthesis of Silver Nanoparticles Using Origanum vulgare L. Extract and Their Microbicidal Activities

Bactericidal activity of silver nanoparticles: A mechanistic review

Development of a green chemistry process for the synthesis of silver nanoparticles has become a focus of interest. This would offer numerous benefits, including ecofriendliness and compatibility for biomedical applications. Here we report the synthesis of silver nanoparticles from the reduction of silver nitrate and an aqueous extract of the lichen Parmotrema praesorediosum as a reductant as well as a stabilizer. The physical appearance of these silver nanoparticles was characterized using ultraviolet-visible spectroscopy, electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction techniques. The results show that silver nanoparticles synthesized using P. praesorediosum have an average particle size of 19 nm with a cubic structure. The antibacterial activity of the synthesized silver nanoparticles was tested against eight micro-organisms using the disk diffusion method. The results reveal that silver nanoparticles synthesized using P. praesorediosum have potential antibacterial activity against Gram-negative bacteria.

/pdf/synthesis-of-silver-nanoparticles-with-antibacterial-53qz5mypmi.pdf

Synthesis of silver nanoparticles with antibacterial activity using the lichen Parmotrema praesorediosum.

Chemical synthetic method in synthesizing silver nanoparticle was quite expensive, toxic and flammable. In order to enhance green technology, we develop a simple biological method for the green synthesis of silver nanoparticles using two lichens species, Parmotrema praesorediosum and Ramalina dumeticola. Silver nanoparticles were characterized using UV-Vis absorption spectroscopy and TEM. Within 72 hours reaction time, absorption spectra of silver nanoparticles formed in R. dumeticola and P. praesorediosum has absorbance peak at 407 nm and 423 nm, respectively. TEM analysis showed the average size of 20 nm of silver nanoparticles obtained in R. dumeticola and the average size of 42 nm of silver nanoparticles obtained in P. praesorediosum. These two lichens species are able to synthesize silver nanoparticles through green chemistry method, which are environmental friendly and cost effective. This is for the first time that any species of lichens was used for the synthesis of silver nanoparticles.

Green synthesis of silver nanoparticles using two lichens species: Parmotrema praesorediosum and ramalina dumeticola

The aim of the study is to elucidate chemical compositions of the lichen Ramalina dumeticola and to evaluate the ability of the extract to produce silver nanoparticles. The sample was soaked in different polarities of solvent namely hexane, acetone, methanol and water. Isolation work on the acetone extract gave a despite which was identified as sekikaic acid (1). The structure was elucidated by spectroscopic methods. For the production of silver nanoparticles (AgNPs), metabolites from the acetone extract and water extract show potential as reducing agents for silver ions.

Secondary metabolite isolated from Ramalina dumeticola and its application for silver nanoparticles production

The development of reliable and eco-friendly metallic nanoparticles needs some consideration on the chemical procedures involved in the synthesis of nanomaterials. The conventional methods in the production of metallic nanoparticles generate a large amount of hazardous byproducts. Thus, there is a need for ‘green chemistry’ that includes a clean, nontoxic and environment-friendly method of nanoparticle synthesis [1]. As an alternative, biological methods are considered safe and ecologically sound for the nanomaterial fabrication [2]. Therefore, in this review special attention is focused on the biosynthesis of nanoparticles from natural resources as compared as ordinary chemical method. Biosynthesis of nanoparticles using plant is a new development of green nanotechnology beneficial to environmental and to the plant itself. It also plays a significant role in the field of biology and medicine.

Ropisah Mie

Papers

Synthesis of silver nanoparticles with antibacterial activity using the lichen Parmotrema praesorediosum.

Green synthesis of silver nanoparticles using two lichens species: Parmotrema praesorediosum and ramalina dumeticola

Secondary metabolite isolated from Ramalina dumeticola and its application for silver nanoparticles production

A Review on Biosynthesis of Nanoparticles Using Plant Extract: An Emerging Green Nanotechnology

Sintesis biomimetik nanozarah perak menggunakan liken ramalina dumeticola dan aktiviti antibakteria