Journal of Environmental Nanotechnology

04-10

Authors: G. GnanaJobitha1, S. Rajeshkumar1, G. Annadurai1,*, C. Kannan2,*

Today the "Green" nanoparticle synthesis has been Achieved using environmentally acceptable solvent systems and eco-friendly reducing and capping agents. The present study investigated the synthesis of silver nanoparticle using pomegranate fruit extract as reducing agent to synthesize silver nanoparticles. The formation of nanosized silver was confirmed by its characteristic surface plasmon absorption peak at around 460 nm in UV-vis spectra. The morphology and crystalline nature, were characterized by Scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX) X-ray diffraction (XRD), and conform the active functional groups present in the synthesized silver molecule by Fourier transform infra-red (FTIR) spectroscopy. Moreover, their antibacterial activity has been tested against Bacillus subtilis, (Gram positive) and Klebsiella planticolae (Gram-negative). The approach of plant-mediated synthesis appears to be cost efficient, eco-friendly and easy alternative to conventional methods of silver nanoparticles synthesis. Keywords : Biosynthesis ; Bacillus subtilis ; Klebsiella Planticolae ; Pomegranate fruit and Silver nanoparticle

16-19

Authors: A. P. Sharavana Kumaar 1,*, J. Vanitha 2, K. Venkateshwaran 3, K. Srikanth Reddy 1, D. Karthikeyan 4

The antimicrobial activity of plant extracts and phytochemicals was evaluated with antibiotic susceptible and resistant micro organisms. Methanolic extract of Opuntia dillenii (OD) was tested for its antibacterial (plate hole method) activity against fourteen different bacterial strains. From the results, it is deduced 100 % of methanolic extract were active in concentration of 1000 μg/ml, 93 % active in concentration of 500 μg/ml, 87.5 % active in concentration of 250 μg/ml, 50 % active in concentration of 125 μg/ml and no activity in lowest test concentration of 62.5 μg/ml. Antifungal activity against six different fungal organisms were studied and the results were indicated that the 1000 μg/ml & 500 μg/ ml showed good activity in all fungus (100%). The methanolic extracts in concentration of 250 μg/ml (83%) and 125 μg/ ml (33 %) showed moderate activity in all tested microorganisms. Oxy tetracycline and Amphotericin B with concentration of 1000 μg/ml were used as a standard drug for antibacterial and antifungal studies respectively. Keywords : Antibacterial ; Antifungal ; Opuntia dillenii.

28-34

Authors: Mohan Lal 1,* , BharatBhushanSharma2, PoornenduChaturvedi1, PikaJha1, Jaswant Singh Rawat1, Partap Kumar Chaudhury1

Catalytic films of FeCl3 were coated on Si using simple and highly scalable technique of dip drying of silicon in aqueous FeCl3 solution. The catalyst coated samples were pretreated at 850oC to reduce the deposited FeCl3 into iron nanoparticles. The size distribution of nanoparticles was found to be strongly dependent on initial concentration of FeCl3 in aqueous solution. The catalytic activity of nanoparticles was ascertained by growthof carbon nanotubes using Chemical Vapour Deposition. The C2H2was used as the carbon precursed along with the carrier gas of H2 and NH3.Characterization of the grown CNT revealed the direct relationship between the catalytic concentration and the diameter of carbon nanotubes. Key words : Carbon nanotubes; Catalytic films; Chemical vapour deposition; Dip dry method.

42-46

Authors: P. Khalid1,3, M. A. Hussain2, P. D. Rekha3, V. B. Suman4, A. B. Arun3*

Multi Walled Carbon Nanotubes (MWNTs) were procured from Nanoshel, USA. Covalent functionalization was accomplished with three types of oxidants: (1) 70% Nitric acid under reflux (2) Sulfuric acid and Nitric acid (v/v = 3/1) under sonication (3) 20% Sulfuric acid and Nitric acid (v/v = 3/1) by heating. The non covalent functionalization was accomplished via di-imide activated amidation using N-(3-Dimethylaminopropyl)-N2 -ethyl carbodiimides hydrochloride (EDAC) and Bovine Serum Albumin (BSA).The covalent functionlized carbon nanotubes in combination with Non Covalent functionalized Carbon Nanotubes were readily dispersed in water, DMF and cell culture media to investigate their toxicity. Characterization of functionalized and dispersed Nanotubes were carried out by using FTIR, FESEM,and UV-vis spectroscopy. Keywords : Multi-walled CNT; Covalent Funtionalization; Non-Covalent Functionalization; Nanotoxicology

52-62

Authors: Pankaj Kumar Singh,1,2* Subir Kundu2

Biosynthesis of gold nano particles (GNPs) is considered to be a novel, effective and eco-friendly method. Biosynthesis of GNPs from Benincasa hispida, Justicia gendarussa & Ocimum basilicum. Biosynthesis of stable and nearly spherical GNPs using the extract of Benincasa hispida seeds as reducing and capping agents. The particle size could be easily tuned by the reaction conditions including quantity of extract, temperature and pH. GNP shaving different sizes in the range from10-30nm could be obtained by controlling the synthesis parameters. Justicia gendarussa leaf extract mediated synthesis of GNPs by the reduction of gold ions. Three different phytochemical fractions were prepared from methanolic leaf extract by liquid-liquid extraction method using immiscible solvents. The size of the GNPs ranged from 20-42nm and 62-88nm with spherical, triangle, truncated triangle and hexagonal shapes. Ocimum basilicum (Thai Tulsi) leaf extract worked as a potential substrate for bioreduction of HAuCl4 into GNPs within 10 minutes of reaction time. It was also observed that GNPs synthesized were crystalline and uniformly spherical in shape with size range 5–40 nm which were stable even after 3 months of reaction. The gold nanoparticles were characterised by UV-Visible Spectroscopy, Transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infra red spectroscopy (FTIR), Dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS) and Atomic Absorption Spectroscopy (AAS). Keywords : Benincasa hispida; Gold nano particles (GNPs); Justicia gendarussa; Ocimum basilicum; Transmission electron microscope (TEM).

71-80

Authors: N. Srinivasan

Bioactive imidazole derivative absorbs in the UV region at 305 nm. The interaction of imidazole derivative with nanoparticulate WO3, Fe2O3, Fe3O4, CuO, ZrO2 and Al2O3 has been studied by UV-visible absorption, FT-IR and fluorescence spectroscopies. The imidazole derivative adsorbs strongly on the surfaces of nanosemiconductor, the apparent binding constants for the association between nanomaterials and imidazole derivative have been determined from the fluorescence quenching. In the case of nanocrystalline insulator, fluorescence quenching through electron transfer from the excited state of the imidazole derivative to alumina is not possible. However, a possible mechanism for the quenching of fluorescence by the insulator is energy transfer, that is, energy transferred from the organic molecule to the alumina lattice. Based on Forster’s non-radiation energy transfer theory, the distance between the imidazole derivative and nanoparticles (r0 ~2.00 nm) as well as the critical energy transfer distance (R0 ~1.70 nm) has been calculated. The interaction between the imidazole derivative and nanosurfaces occurs through static quenching mechanism. The free energy change (—Get) for electron transfer process has been calculated by applying Rehm-Weller equation. Keywords : Association constant ; Electron transfer; Imidazole; Nanoparticles; Quenching