Biologically inspired experimental process in synthesising nanoparticles is of great interest in present scenario. Biosynthesis of nanoparticles is considered to be one of the best green techniques in synthesising metal nanoparticles. Here, an in situ green biogenic synthesis of gold nanoparticles using aqueous extracts of Terminalia chebula as reducing and stabilizing agent is reported. Gold nanoparticles were confirmed by surface plasmon resonance in the range of 535 nm using UV-visible spectrometry. TEM analysis revealed that the morphology of the particles thus formed contains anisotropic gold nanoparticles with size ranging from 6 to 60 nm. Hydrolysable tannins present in the extract of T. chebula are responsible for reductions and stabilization of gold nanoparticles. Antimicrobial activity of gold nanoparticles showed better activity towards gram positive S. aureus compared to gram negative E. coli using standard well diffusion method. © 2011 Elsevier B.V. All rights reserved.

Mohan Kumar P

Department of Digital Communications

School of Information Technology and Engineering

Vellore Campus

Badal Kumar Mandal

Department of Chemistry

School of Advanced Sciences

Sinha M

Krishnakumar V.

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy

An antimicrobial agent kills microorganisms or inhibits their growth. Antimicrobial agents may be antibacterial, which work against bacteria; antifungal, against fungi; microbiocides, which kill microbes; or microbiostatic, growth inhibitors of microbes. Generally it is defined as disinfectants or antiseptics or antibiotics or bactericidal or bacteriostatic agent. An antimicrobial therapy is a treatment modality that attacks the microorganisms responsible for a specific disease or condition. Many bulk metals such as copper and its alloys (brasses, bronzes, cupronickel, copper-nickel-zinc, and others) are natural antimicrobial materials. Also, ions of copper, silver, mercury, lead, iron, bismuth, aluminum, zinc, and gold act as antimicrobial agents. In addition, numerous phytochemicals and synthetic compounds have been used as antimicrobial agents. After the discovery of penicillin, actinomycin, and streptomycin, medical sciences tried to use antibiotics instead of antimicrobial agents like silver. Nowadays, due to increasing drug-resistance and growing concern regarding the over-prescribing of antibiotics, the scientific community is searching for antimicrobial agents which can solve the above problems. Hence nanobiomaterials are coming up as emerging materials of the future in medical science. A thorough literature survey on nanobiomaterials used as antimicrobial agents showed that nanomaterials such as silver, gold, iron, copper, iron oxide (FeO, Fe2O3, Fe3O4), copper oxide (Cu2O, CuO), zinc oxide (ZnO), titanium dioxide (TiO2), silver oxide (Ag2O), cadmium oxide (CdO), alumina (Al2O3), nickel oxide (NiO), silica (SiO2), tin oxide (SnO2), and cadmium telluride (CdTe) quantum dots show antimicrobial activity toward various bacteria and microbes. Also, this chapter will provide a brief highlight of other nonmetallic carbon-based nanomaterials for their antimicrobial activity. Finally, this chapter will provide a brief highlight of a mechanistic approach for all. © 2016 Elsevier Inc. All rights reserved.

Nanobiomaterials in Antimicrobial Therapy

Scopes of green synthesized metal and metal oxide nanomaterials in antimicrobial therapy

In past decades, the possibility of using high atomic number nanoparticle has gained interest in gel dosimetry to enhance the dose deposited in the tumor while using low radiation as well as for better imaging purposes. Sparing of healthy tissues and targeting the tumor part have become much more captivating with the help of these systems. The gel dosimetry is a the three-dimensional dosimeter for extracting the dose, which can be used along with the nanoparticles like gold, platinum, and silver, for better therapeutic efficiency for modern radiotherapy techniques. These nanoparticles of different size prepared either by chemical route or green synthesis and incorporated into the gel system respond in a different manner. Having wide applications in therapeutic field, this study reviews the use of gel dosimeters in the therapeutic procedures and also with the aid of nanoparticles so as to achieve dose enhancement. The biological activity of the various nanoparticles has been discussed.

Applied Microbiology and Biotechnology

Current scenario of biomedical aspect of metal-based nanoparticles on gel dosimetry

A green one step facile synthesis of graphene nanosheets by Terminalia chebula (T. chebula) extract mediated reduction of graphite oxide (GO) is reported in this work. This method avoids the use of harmful toxic reducing agents. The comparative results of various characterizations of GO and T. chebula reduced graphene oxide (TCG) provide a strong indication of the exclusion of oxygen containing groups from graphene oxide and successive stabilization of the formed reduced graphene oxide (RGO). The functionalization of reduced graphene oxide with the oxidized polyphenols causes their stability by preventing the aggregation. We also have proposed how the oxidized polyphenols are accountable for the stabilization of the formed graphene sheets. © 2015 Elsevier B.V. All rights reserved.

Bioinspired reduced graphene oxide nanosheets using Terminalia chebula seeds extract

Synthesis of metal nanoparticles (NPs) using plant extracts as reducing agents is of great interest due to its ease and environmental friendly process. Reports show biogenic green synthesis reaction times in forming gold metal nanoparticles (Au NPs) varying from minutes to several hours. In this article, an instantaneous (less than 10 s) method for the green synthesis of gold NPs using aqueous extract of Terminalia bellirica as a reducing and stabilising agent has been reported. Formation of Au NPs was instantaneous and confirmed by UV-Vis spectroscopy where surface plasmon resonance band centred at 530 nm. Formation of anisotropic Au NPs was evidenced from transmission electron microscope studies. High levels of polyphenols in T. bellirica were responsible for the rapid reduction and stabilisation. The Au NPs did not display toxicity when tested by the brine shrimp (Artemia salina) assay. © 2014 Copyright Taylor &amp; Francis Group, LLC.

Fulltext

Journal of Experimental Nanoscience

Gold nanoparticles byTerminalia belliricaaqueous extract – a rapid green method

(Chemical Equation Presented) A facile rapid green eco-friendly method to synthesize gold nanoparticles (Au NPs) of tunable size using aqueous Terminalia arjuna fruit extracts has been demonstrated herein. Formation of Au NPs was confirmed by Surface Plasmon Resonance (SPR) study at 528 nm using UV-visible spectrophotometer. The time of reduction, size and morphological variations of Au NPs were studied with varying quantities of T. arjuna fruit aqueous extracts. Synthesized Au NPs were characterized using UV-visible spectroscopy, Fourier transformed infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and Energy dispersive X-ray spectroscopy (EDAX). Polyphenols responsible for reduction of Au3+ to Au 0 were identified using High Performance Liquid Chromatography (HPLC) as ascorbic acid, gallic acid and pyrogallol. The oxidized forms of polyphenols formed coordination with surface of Au NPs which protected their further growth and aggregation. We also propose a plausible mechanism how to tune size and shape of Au NPs by varying the quantity of extracts. Thus obtained Au NPs were stable for more than four months. © 2013 Elsevier B.V. All rights reserved.

Green synthesis of size controllable gold nanoparticles

Colloids and Surfaces B: Biointerfaces

Biosynthesis of anisotropic gold nanoparticles using Maduca longifolia extract and their potential in infrared absorption

Facile green synthesis of gold nanoparticles using leaf extract of antidiabetic potent Cassia auriculata

Process Biochemistry

Green synthesis of gold nanoparticles with Zingiber officinale extract: Characterization and blood compatibility

Phytosynthesis of Au, Ag and Au–Ag bimetallic nanoparticles using aqueous extract and dried leaf of Anacardium occidentale

Biosynthesis of gold nanowires using sugar beet pulp

Terminalia chebula mediated green and rapid synthesis of gold nanoparticles

Journal	Data powered by TypesetSpectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publisher	Data powered by TypesetElsevier BV
ISSN	1386-1425
Open Access	0