Gargi Dinda; Dipankar Halder; Atanu Mitra
Abstract
We report the successful synthesis of copper nanoparticle (CuNP)-starch composite employing low cost green protocol without inert gas protection. UV-Vis spectroscopy, X-Ray diffraction (XRD) and Transmission electron microscopy (TEM) were used to characterize the CuNP-starch composite. Mono-disperse ...
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We report the successful synthesis of copper nanoparticle (CuNP)-starch composite employing low cost green protocol without inert gas protection. UV-Vis spectroscopy, X-Ray diffraction (XRD) and Transmission electron microscopy (TEM) were used to characterize the CuNP-starch composite. Mono-disperse almost spherical CuNP having average diameter 4.02 ± 0.076 nm was obtained. The catalytic activity of the as-synthesized CuNP-starch composite during reduction of pollutants, like, 4-nitrophenol (4-NP) and dyes, Eosine Blue (EB), Eriochrome Black T (EBT) and Brilliant Cresyl Blue (BCB by NaBH4 has been investigated. High catalytic efficiency of the composite was demonstrated by rapid decrease of the intensity of the UV-Vis absorption peaks at respective λmax of the pollutants with time when reaction mixture contained NaBH4 and small quantity of CuNP-starch composite. The rate constant of each processes was calculated by considering that the reactions follow pseudo-first-order kinetics with respect to substrate. The obtained rate constants for 4-NP, EB, EBT and BCB are 0.021S-1, 0.011S-1, 0.036S-1 and 0.032S-1 respectively. The other application, antibacterial activity was tested against Gm positive and Gm negative bacteria. Plate count and minimum inhibitory concentration (MIC) studies show higher susceptibility of Gm positive bacteria towards CuNP-starch composite. The as-synthesized CuNP-starch composite may find potential application in the field of environmental remedies and antibacterial formulations. Copyright©2018 VBRI Press.
Rachna .; Baljeet S. Saharan .; Mahender S. Yadav .; Nisha Sharma .
Abstract
A simple and efficient synthesis of silver nanoparticles (AgNPs) is reported here using red Dianthus caryophyllus flower, acting both as reducing and capping agent. The resultant silver colloids were characterized using UV-visible spectrophotometer, X-ray Diffractometer (XRD) and Transmission electron ...
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A simple and efficient synthesis of silver nanoparticles (AgNPs) is reported here using red Dianthus caryophyllus flower, acting both as reducing and capping agent. The resultant silver colloids were characterized using UV-visible spectrophotometer, X-ray Diffractometer (XRD) and Transmission electron microscope (TEM). The surface absorption plasmon response and kinematics of reduction of silver ions were observed by UV-visible spectroscopy. The crystalline fcc structure of AgNPs was confirmed by its XRD pattern. Their morphological study was done with TEM, showing spherically shaped AgNPs in the range 10-20 nm. The antibacterial action was also studied using Agar well diffusion method against pathogenic bacteria cultures (Staphylococcus aureus, Bacillus cereus and Escherichia coli). AgNPs showed better antimicrobial activity against S. aureus culture. Copyright © 2018 VBRI Press.
Arehalli S Santhosh; Shadakshari Sandeep; Ningappa Kumara Swamy; Gurukar S Suresh; Jose S Melo
Abstract
In the present work, we report on green synthesis of hybrid silver nano structures using a solution of AgNO3 and leaf broth of Cassia occidentalis plant as reducing agent. The incubation of AgNO3 solution and leaf broth for 48 hrs under neutral pH and constant stirring at 150 rpm resulted in the formation ...
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In the present work, we report on green synthesis of hybrid silver nano structures using a solution of AgNO3 and leaf broth of Cassia occidentalis plant as reducing agent. The incubation of AgNO3 solution and leaf broth for 48 hrs under neutral pH and constant stirring at 150 rpm resulted in the formation of hybrid silver nanostructures comprised of silver nano particles (AgNPs) and silver nanorods (AgNRs). The bio reduction of Ag+ ions to AgNPs and AgNRs is confirmed via appearance of surface plasmon resonance peaks at 420 and 370 nm in the UV visible spectrum. The synthesized nanostructures are purified and further characterized using XRD and FT-ATR. The morphology of nanostructures is examined by SEM studies which further revealed the formation of spherical shaped AgNPs and rod shaped AgNRs. The study therefore concludes that it is possible to synthesize the AgNRs and AgNPs effectively using silver nitrate (AgNO3) solution and the leaf broth of Cassia occidentalis. However, further work is needed to establish the employability of these nanostructures in various applications. Copyright © 2017 VBRI Press.
Ravi Jon; Vipul Singh; D.P Jayapandian
Abstract
The main aim of this research is to propose the various green reducing agents for extract the green gold nanoparticles from Gold Chloride (HAucl4) solution. Green reducing agents are safe and eco-friendly for the extraction of the gold nanoparticles. The green gold nanoparticles were synthesized using ...
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The main aim of this research is to propose the various green reducing agents for extract the green gold nanoparticles from Gold Chloride (HAucl4) solution. Green reducing agents are safe and eco-friendly for the extraction of the gold nanoparticles. The green gold nanoparticles were synthesized using plant and fruit extract, and green Gold nanoparticles were characterized using SEM, TEM, and UV-Vis. Spectroscopy. The absorption peak was observed at 530-540 nm, which proved the green gold nanoparticles. Green Gold nanoparticles in the size of 30 nm in the spherical shape were confirmed by transmission electron microscopy. The toxicity of green gold nanoparticles is less than gold nanoparticles. These green gold nanoparticles can be used in various biomedical applications. Green reducing agents are the best alternative for the synthesis of the gold nanoparticles. Copyright © 2017 VBRI Press.
Abhishek K. Bhardwaj; Abhishek Shukla; S. C. Singh; Kailash N. Uttam; Gopal Nath; Ram Gopal
Abstract
Green synthesis of nanoparticles (NPs) from biological constituents extracts have emerged as potential methods for the fabrication of metallic NPs. In the present study, Cuprous oxides hallow microspheres (Cu2O-HMs) have been synthesized using D. carota pulp waste extract (CPWE). This Cu2O hollow microsphere ...
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Green synthesis of nanoparticles (NPs) from biological constituents extracts have emerged as potential methods for the fabrication of metallic NPs. In the present study, Cuprous oxides hallow microspheres (Cu2O-HMs) have been synthesized using D. carota pulp waste extract (CPWE). This Cu2O hollow microsphere (Cu2O-HMs) synthesis is environmental friendly, at room temperature. The aqueous copper ions are reduced into Cu2O-NPs, when these ions interact with active reducing constituents of CPWE and very little amount of sodium hydroxide for enhancing rate of reaction. The Cu2O-NPs have been characterized by UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Transmission electron microscopy (TEM). XRD measurements contain average size of Cu2O-NPs are approx 12 nm which is responsible to form Cu2O-HMs. UV-VIS spectra show that the surface Plasmon resonance peak of copper is observed at 490 nm. FTIR measurements indicate the presence of different reducing constituents in D. carota extract which is responsible for reducing and capping bioreduced Cu2O-HMs. TEM measurement shows that most Cu2O-HMs are spherical in shape and are responsible to form microsphere and nanotubes. Antibacterial activity of Cu2O-HMs tested on S. aureus shows a comparable zone of inhibition. These interesting results may be applicable for the cost-effective, environmental friendly, surface disinfectant and biomedical fields. Copyright © 2017 VBRI Press.
