Green Synthesis of Silver Nanoparticles - A review

International Journal of Nanomedicine

Background: Nanotechnology explores a variety of promising approaches in the area of material sciences on a molecular level, and silver nanoparticles (AgNPs) are of leading interest in the present scenario. This review is a comprehensive contribution in the field of green synthesis, characterization, and biological activities of AgNPs using different biological sources. Methods: Biosynthesis of AgNPs can be accomplished by physical, chemical, and green synthesis; however, synthesis via biological precursors has shown remarkable outcomes. In available reported data, these entities are used as reducing agents where the synthesized NPs are characterized by ultraviolet-visible and Fourier-transform infrared spectra and X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Results: Modulation of metals to a nanoscale drastically changes their chemical, physical, and optical properties, and is exploited further via antibacterial, antifungal, anticancer, antioxidant, and cardioprotective activities. Results showed excellent growth inhibition of the microorganism. Conclusion: Novel outcomes of green synthesis in the field of nanotechnology are appreciable where the synthesis and design of NPs have proven potential outcomes in diverse fields. The study of green synthesis can be extended to conduct the in silco and in vitro research to confirm these findings.

Nanoparticle biosynthetic discipline is still under development and is known to have a big impact on numerous manufactures for a long time. Nowadays, biosynthesis of silver nanoparticles (AgNPs) had gained so much attention in developed countries due to development demand of environmental friendly technology for material synthesis. The use of green chemistry is environmental friendly, non-toxic, and cheap. This review focused on the recent scientific publications in the green synthesis field of AgNPs and its applications. A number of microorganisms including bacteria, fungi, yeasts, algae, and plants either intra-or extracellular have been found to be capable of synthesizing AgNPs. All scientific reports reflect the unique properties AgNPs possess that find myriad applications such as antibacterial, antifungal, antivirus, and anticancer drugs, larvicidal excellent catalytic natural action towards degradation of dyes, very good antioxidants, treatment of diabetes-related complications, and wound healing activities. The recent strategy for improving the efficacy of antibiotics is to combine them with AgNPs in order to control the microbial infections as confirmed by the damage action of AgNPs on microbial deoxyribonucleic acid. This review describes also the microorganism/plant extract and the reaction parameters used in synthesis of the AgNPs, which hold prominent impact on their size, shape, and application. Recently published information on AgNP synthesis and its applications are summarized in this review.

Turkish Journal of Engineering and Environmental Sciences

In this work, the synthesis of stable silver nanoparticles by the bioreduction method was investigated. Aqueous extracts of the manna of hedysarum plant and the soap-root (Acanthe phylum bracteatum) plant were used as reducing and stabilizing agents, respectively. UV-Vis absorption spectroscopy was used to monitor the quantitative formation of silver nanoparticles. The characteristics of the obtained silver nanoparticles were studied using X-ray diffraction analysis (XRD), energy-dispersive spectroscopy (EDX), and scanning electron microscopy (SEM). The EDX spectrum of the solution containing silver nanoparticles confirmed the presence of an elemental silver signal without any peaks of impurities. The average diameter of the prepared nanoparticles in solution was about 29-68 nm.

ChemInform, 2015

Nanotechnology is an escalating field that has made its contribution to all spheres of human life. The green synthesis of nanoparticles has paved for better methodologies and approaches in the medicinal field. Nowadays silver, gold and other metallic nanoparticles are used as an efficient carrier for drug molecules for developing novel drug delivery systems. In course of synthesizing these nanoparticles various chemicals, solvents and reagents are used which harms our eco system directly or indirectly. Silver nanoparticles (Ag NPs) have been widely used as a novel therapeutic agent extending its use as antibacterial, antifungal, anti-viral and anti-inflammatory agent. Silver nanoparticles (Ag NPs) prepared by green synthesis have many advantages over conventional methods involving chemical agents associated with environmental toxicity. Green synthetic methods include polysaccharide method, irradiation method, biological method, polyoxometallates method and tollens method. Green synthesis of nanoparticles is found to be an emerging branch of nanotechnology. The use of environmentally benign materials like plant leaf extract for the synthesis of nanoparticles offers numerous benefits of eco-friendliness and compatibility for pharmaceutical and biomedical applications as they do not use toxic chemicals in the synthesis protocols. Rapid and green synthetic methods using various plant extracts have shown a great potential in silver nanoparticles (Ag NPs) synthesis. This review article describes the bio-inspired synthesis of nanoparticles that provides advancement over chemical and physical methods as it is cost effective, eco-friendly and more effective in a variety of applications.

Journal of Bionanoscience, 2017

Green chemistry is a branch of chemistry that deals with natural materials such as plants, fungi, bacteria, algae, and rocks rather than chemical components. Advantages of green chemistry rather than chemical are that no toxic components are released, inexpensive, available anytime, easy to get, and eco-friendly. Metallic nanoparticles have received great attention from chemists, physicists, biologists and engineers who wish to use them for the development of a new generation of nanodevices. One of the important metal nanoparticles is the silver nanoparticles (AgNPs). Silver is a nontoxic agent having an antibacterial, antifungal, and antioxidant properties. AgNPs have been used in many applications such as catalysis, biotechnology, biomedical applications, electronics, and in the treatment of burns and wounds. The green synthesis of AgNPs involves three main steps: the selection of the solvent medium, the selection of environmentally reducing agents, and the selection of non-toxic substances for the stability of AgNPs. In this review, we will discuss some green chemistry methods to synthesize AgNPs via plant extracts and other natural agents, such as fungi, bacteria, and algae. In addition, we will compare between these methods, according to their applications and stabilities.

--Indus script graphemes Brāhmī word majhitha, कणण क du. the two legs spread out (AV. xx , 133), ayo 'fish' (on chest), mẽḍhā ram (horns), badhi 'boar' (head) + unicorn (on chest) જ ંગડિયો jangaḍiyo 'maritime treasure-guard'

The current paper reviews various pricing strategies adopted by the modern businesses. It further states various merits and demerits of each of the pricing strategies. The main objective of the paper is to compile some of the popular pricing strategies and their pros and cons at one place. The topic not only relates to marketing management but also extends to managerial economics. The paper has been classified into six parts. The first section introduces the purpose of the paper. The second section examines the importance of the pricing strategies. The third section describes the main objectives behind pricing strategies. The fourth section explains various pricing strategies whereas the next section discusses advantages and disadvantages of various pricing strategies. The paper ends with a conclusion about how the businesses should select the most suitable pricing strategy for themselves.

Acta Geologica Sinica-english Edition, 2019

Fundamental scientific questions about the tectonics of continental subduction during collisional orogenesis include: 1) the maximum depth from which the continental crust can be exhumed along the subduction channel, and 2) the evolution and role of fluid and melt in the deformation and metamorphism of the crust during burial and exhumation. To address these questions, we have studied one of the most deeply subducted slabs of continental crust to retrieve information about deformation and metamorphism at extreme pressures. In this presentation we summarize the results of our studies conducted during the past ten years from the Yangkou Bay-General's Hill area in the central Sulu belt. Here we have integrated structural mapping with microstructural, petrological, geochemical and geochronological studies on the most deeply-subducted (possibly >200 km [1]) UHP metamorphic rocks in the Sulu belt. The rocks preserve evidence of fluid evolution from nominally anhydrous minerals and partial melting during exhumation. Our studies have led to a new understanding of the structural history, P-T-t path and melting of UHP rocks during continental subduction and exhumation associated with collisional orogenesis.

AMCIS 2001 …, 2001

This paper describes a project which is developing a simulated economic environment in which operates a virtual supply chain based on the manufacturing and sales of personal computers. The supply chain is modeled in SAP R/3. The project is called the SAP Student Marketplace for the Advancement of Research and Training (SAP SMART). The aim of the project is to develop a richly populated simulation environment in which participating institutes of higher learning will be able to develop and deliver world-class, technology-enabled business and management education programs utilizing the mySAP.com e-business applications to their full extent.

Bolgov R. et al. (eds) Proceedings of Topical Issues in International Political Geography. Cham, Switzerland: Springer, 2021, pp. 337-354., 2021

The paper explores the political and ideological evolution of the mainstream left thought collective in the West. Heavily influenced by the classical Marxian paradigm prior to the 1950s, this collective gradually shifted to the matters of culture and identity between the 1950s and the 1980s. In the left ideological paradigm, this transformation became known as the “cultural turn”; some early left authors also referred to this shift as “Cultural Marxism.” Later, the latter became a favorite word of choice for scholars and writers on the right. Social scholarship on both sides of the political spectrum have frequently stressed the important role of the so-called Frankfurt School in pioneering the abovementioned transformation. This paper argues that, as far as the mainstreaming of the cultural turn, there were more important intellectual sources than that school. Among others, these sources included racialized Marxism of C.L.R James, William Dubois, and Frantz Fanon (1940s-1960s), W. Right Mills, and British Cultural Studies, which gradually phased out economic determinism and the class-based approach of classical Marxism by shifting attention to culture, identity, the Third World, race, and gender.