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Bangalore, India

Nagaraju D.H.,Linkoping University | Suresh G.S.,NMKRV College for Women
ECS Electrochemistry Letters | Year: 2012

In this article, we have demonstrated the synthesis of palladium nanoparticles decorated on reduced graphene oxide (RGO-Pd NPs) film via green chemistry route, one pot electrochemical reduction of graphene oxide and palladium ions without using any chemical reducing agents. Cyclic voltammetry in acid medium shows the characteristic nanosized palladium nanoparticles. The RGO-Pd NPs poses very high electrochemically active surface area and shows good catalytic properties for the elctrooxidation of ethanol in alkaline medium. © 2012 The Electrochemical Society.

Shashikala Devi K.,Kuvempu University | Vaidya V.P.,Government First Grade College | Ramaiah M.,NMKRV College for Women | Saqib A.,Mahranis Science College for Women
Research Journal of Pharmaceutical, Biological and Chemical Sciences | Year: 2013

Synthesis of novel heterocyclic system encompassing four different heterocycles viz., naphtho[2,1-b]furan, 1,2,4-triazole, azetidinone and pyrrole has been carried out to obtain novel antibacterial agents. Ethyl 3-(2,5-dimethylpyrrol)naphtho[2,1-b]furan-2-carboxylate 2, synthesized by the reaction between ethyl 3-aminonaphtho[2,1-b]furan-2-carboxylate 1 and acetonyl acetone, was converted in to corresponding hydrazide 3. The hydrazide 3 on treatment with carbon disulphide and hydrazine hydrate in presence of alkali produced 3-(2,5-dimethylpyrrol)-4-aminonaphtho[2,1-b]furan-2-yl-4H-1,2,4-triazole-3-thiol 4. The reaction of triazole 4 with various substituted aromatic aldehydes resulted in the formation of respective Schiff bases 5a-e. Synthesis of the desired compounds i.e. 3-(2,5-dimethylpyrrol)-4-{(4-aryl)methylene}amino-5-naphtho[2,1-b]-2-yl-4H-1,2,4-triazole-4-yl)-4-arylazetidin-2-ones 6a-e was accomplished by reacting Schiff bases 5a-e with chloroacetyl chloride. The structures of the newly synthesized compounds were established by IR, 1H NMR and 13C NMR spectral studies. The antibacterial activity of the synthesized compounds, at the concentration of 100 μg/ml, has been evaluated against four bacterial strains using Gentamycin and Amphicillin as standard drugs. Some of the compounds showed promising antibacterial activity.

Prasannakumar S.,M.R.Research | Manjunatha R.,M.R.Research | Nethravathi C.,Materials Research Group | Suresh G.S.,M.R.Research | And 3 more authors.
Portugaliae Electrochimica Acta | Year: 2012

A modified electrode is fabricated by the electrodeposition of polyaniline-polystyrene sulphonate composite onto the carboxylated graphene modified graphite electrode for the detection of hydrogen peroxide (H2O2). The modified electrode displayed excellent catalytic response to the reduction of hydrogen peroxide in neutral pH. It was found that the presence of carboxylated graphene in the sensor system could effectively increase the electron transfer rate and stability. The modified electrode was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and atomic force microscopy. Chronoamperometric studies showed the linear relationship between the reduction peak current and the concentration of H2O2 in the range 25 to 350 μM (R = - 0.995) with the detection limit of 1×10-6 mol/L (S/N=3). Further, electrochemical analysis of H2O2 in the presence of common interferents such as dopamine, uric acid and ascorbic acid with the modified electrode reveals that there is no overlapping signal from the interferents.

Veena K.,Maharanis Science College for Women | Ramaiah M.,NMKRV College for Women | Vanita G.K.,Maharanis Science College for Women | Avinash T.S.,University of Mysore | Vaidya V.P.,Kuvempu University
E-Journal of Chemistry | Year: 2011

The starting material 3-nitro-2-acetylnaphtho[2,1-b]furan (2) was obtained by nitration of 2-acetylnaphtho[2,1-b] furan (1), under mild condition. The compound 1 was synthesized by the reaction of 2-hydroxy-1-naphthaldehyde with chloroacetone, where in both condensation and cyclization took place in single step. The reaction of 3-nitro-2-acetylnaphtho[2,1-b]furan (2) with hydrazine hydrate produced corresponding hydrazone (3) in excellent yield, which on treatment with various aromatic aldehydes under different reaction conditions resulted in the formation of symmetrical azines (4a-e) and unsymmetrical azines (5a-e). All the newly synthesized compounds have been characterized by analytical and spectral studies and were screened for antibacterial antibacterial activity against Bacillus subtilus and Alcaligenes fecalies and antifungal activity against Aspergillus nidulans, Aspergillus parasiticus and Aspergillus terrus. The Second Harmonic Generation (SHG) efficiency of some of the synthesized compounds was measured by powder technique using Nd:YAG laser.

Nagaraju D.H.,National University of Singapore | Kuezma M.,National University of Singapore | Suresh G.S.,NMKRV College for Women
Journal of Materials Science | Year: 2015

One of the challenges in incorporating reduced graphene oxide (rGO) in energy storage material is to synthesize the homogenized mixtures of rGO with the electrode active materials at molecular level. In this direction, we have synthesized flexible, thin sheets of rGO-wrapped LiFePO4 plates using aqueous GO solution and precursors of LiFePO4. The in situ rGO provides necessary conductivity required for the charge storage performance. The LiFePO4/rGO composite was used as a active material without using any conductive carbon additive. The composite could be able to deliver the energy as high as about 161 mAh/g at C/10 rate and posses good cyclability. The high energy storage capabilities of LiFePO4 is due to the wrapping of highly conductive thin rGO sheets, which increases the electronic conductivity of the LiFePO4. © 2015, Springer Science+Business Media New York.

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