The green synthesis of nanoparticles (NPs) using living cells is a promising and novelty tool in bionanotechnology. Chemical and physical methods are used to synthesize NPs; however, biological methods are preferred due to its eco-friendly, clean, safe, cost-effective, easy, and effective sources for high productivity and purity. High pressure or temperature is not required for the green synthesis of NPs, and the use of toxic and hazardous substances and the addition of external reducing, stabilizing, or capping agents are avoided. Intra- or extracellular biosynthesis of NPs can be achieved by numerous biological entities including bacteria, fungi, yeast, algae, actinomycetes, and plant extracts. Recently, numerous methods are used to increase the productivity of nanoparticles with variable size, shape, and stability. The different mechanical, optical, magnetic, and chemical properties of NPs have been related to their shape, size, surface charge, and surface area. Detection and characterization of biosynthesized NPs are conducted using different techniques such as UV-vis spectroscopy, FT-IR, TEM, SEM, AFM, DLS, XRD, zeta potential analyses, etc. NPs synthesized by the green approach can be incorporated into different biotechnological fields as antimicrobial, antitumor, and antioxidant agents; as a control for phytopathogens; and as bioremediative factors, and they are also used in the food and textile industries, in smart agriculture, and in wastewater treatment. This review will address biological entities that can be used for the green synthesis of NPs and their prospects for biotechnological applications.

Green Synthesis of Metallic Nanoparticles and Their Prospective Biotechnological Applications: an Overview

Metal nanoparticles have received great attention from researchers across the world because of a plethora of applications in agriculture and the biomedical field as antioxidants and antimicrobial compounds. Over the past few years, green nanotechnology has emerged as a significant approach for the synthesis and fabrication of metal nanoparticles. This green route employs various reducing and stabilizing agents from biological resources for the synthesis of nanoparticles. The present article aims to review the progress made in recent years on nanoparticle biosynthesis by microbes. These microbial resources include bacteria, fungi, yeast, algae and viruses. This review mainly focuses on the biosynthesis of the most commonly studied metal and metal salt nanoparticles such as silver, gold, platinum, palladium, copper, cadmium, titanium oxide, zinc oxide and cadmium sulphide. These nanoparticles can be used in pharmaceutical products as antimicrobial and anti-biofilm agents, targeted delivery of anticancer drugs, water electrolysis, waste water treatment, biosensors, biocatalysis, crop protection against pathogens, degradation of dyes etc. This review will discuss in detail various microbial modes of nanoparticles synthesis and the mechanism of their synthesis by various bioreducing agents such as enzymes, peptides, proteins, electron shuttle quinones and exopolysaccharides. A thorough understanding of the molecular mechanism of biosynthesis is the need of the hour to develop a technology for large scale production of bio-mediated nanoparticles. The present review also discusses the advantages of various microbial approaches in nanoparticles synthesis and lacuna involved in such processes. This review also highlights the recent milestones achieved on large scale production and future perspectives of nanoparticles.

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A review on the biosynthesis of metal and metal salt nanoparticles by microbes

Green synthesis of nanoparticles has many potential applications in environmental and biomedical fields. Green synthesis aims in particular at decreasing the usage of toxic chemicals. For instance, the use of biological materials such as plants is usually safe. Plants also contain reducing and capping agents. Here we present the principles of green chemistry, and we review plant-mediated synthesis of nanoparticles and their recent applications. Nanoparticles include gold, silver, copper, palladium, platinum, zinc oxide, and titanium dioxide.

Green synthesis of nanoparticles using plant extracts: a review

Advanced materials are essential to the quality of modern day life, but the synthesis of these compounds is often inefficient in terms of energy, time and resources; especially when considering the hydrothermal batch methods used to prepare many such compounds – often requiring week-long reaction times with variable yields and product quality. In contrast, Continuous flow synthesis (CFS) provides a more readily scalable means for the efficient, effective and reproducible synthesis of inorganic compounds. This publication demonstrates the novel CFS of several metal ammonium phosphates and compare the effect of synthesis route on particle size, size distribution, and crystallinity.

Genesis of Pure Se(0) Nano- and Micro- structures in Wastewater

During the last decade, metal nanoparticles (MtNPs) have gained immense popularity due to their characteristic physicochemical properties, as well as containing antimicrobial, anti-cancer, catalyzing, optical, electronic and magnetic properties. Primarily, these MtNPs have been synthesized through different physical and chemical methods. However, these conventional methods have various drawbacks, such as high energy consumption, high cost and the involvement of toxic chemical substances. Microbial flora has provided an alternative platform for the biological synthesis of MtNPs in an eco-friendly and cost effective way. In this article we have focused on various microorganisms used for the synthesis of different MtNPs. We also have elaborated on the intracellular and extracellular mechanisms of MtNP synthesis in microorganisms, and have highlighted their advantages along with their challenges. Moreover, due to several advantages over chemically synthesized nanoparticles, the microbial MtNPs, with their exclusive and dynamic characteristics, can be used in different sectors like the agriculture, medicine, cosmetics and biotechnology industries in the near future.

https://www.mdpi.com/1422-0067/19/12/4100/pdf

Biosynthesis of Metal Nanoparticles via Microbial Enzymes: A Mechanistic Approach.

Green synthesis of palladium nanoparticles using Chlorella vulgaris

The presence of Arsenic in drinking water is the greatest threat to health effects especially in water. The purpose of this study is application of green palladium nanoparticles for removal of trivalent Arsenic from aqueous solutions and also the impact of some factors such as retention time, pH, concentration of palladium nanoparticles and Arsenic concentrations was studied. The values for Arsenic removal from aqueous solutions were measured by furnace atomic adsorption spectrometry (Conter AA700). In the study, Langmuir and Freundlich isotherm models and pseudo-second order kinetic model were studied. The results of  optimization is shown that 0.5 g of nanoparticles can removed %99.8 of Arsenic with initial concentration of  0.5 g/l, in 5 minutes at pH=4. Langmuir model, Freundlich model (R2=0.94) and pseudo-second order kinetic model (R2=0.99) shown high correlation for removing of Arsenic from aqueous solutions. It was found, palladium nanoparticles can be used as an efficient method to remove Arsenic from aqueous solutions in a short time.

http://www.jwent.net/article_26541_654e1d07c44066a316de1a6414ed29b6.pdf

Farzaneh Arsiya

Papers

Green synthesis of palladium nanoparticles using Chlorella vulgaris

Arsenic (III) Adsorption Using Palladium Nanoparticles from Aqueous Solution