Volume 2, Issue 4, October 2011


Editorial Of INDIAS 2010, India Special Issue

Avinash C. Pandey;Prashant K. Sharma

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 245-245
DOI: 10.5185/amlett.indias.100

This special issue of Advanced Materials Letters contains selected peer-reviewed papers presented in the “4th International Conference, INDIAS 2010”, which was held during September 19-21, 2010 at the Nanotechnology Application Centre, University of Allahabad, Allahabad 211002, India. This conference was supported by the Department of Science and Technology (DST), Government of India, Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE), India, Indian Farmers Fertilizers Cooperative Limited (IFFCO) and University of Allahabad, India.

Advances in multifunctional magnetic nanoparticles

Prashant K. Sharma; Ranu K. Dutta; Avinash C. Pandey

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 246-263
DOI: 10.5185/amlett.2011.indias214

Multifunctional magnetic nanoparticles have emerged as one of the important futuristic material for variety of applications starting from data storage, security/sensors to biomedical applications. The application of multifunctional magnetic nanoparticles in biological organisms has fashioned noteworthy advances in research, diagnosis and therapy of various diseases. The multifunctional magnetic nanoparticles, capable of theragnosis, drug delivery and monitoring of therapeutic response, are expected to play a significant role in the emergence of the era of personalized medicine with much of research efforts devoted toward that goal. The present review recapitulates the development of state-of-the-art multifunctional magnetic nanoparticles and the foremost applications of these multifunctional magnetic nanoparticles in magnetic targeting, drug delivery, separation, and contrast agents in magnetic resonance imaging, hyperthermia and sensors. The biocompatibility requirements and functionalization approach for multifunctional magnetic nanoparticles used in these applications are also reviewed.

Biomimetic piezoelectric quartz sensor for folic acid based on a molecular imprinting technology

Rashmi Madhuri; Mahavir Prasad Tiwari; Deepak Kumar; Aparna Mukharji; Bhim Bali Prasad

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 264-267
DOI: 10.5185/amlett.indias.194

A novel molecularly imprinted polymer (MIP)-modified quartz crystal microbalance (QCM) sensor with high selectivity has been developed for the determination of folic acid via activator generated-atom transfer radical polymerization (AGET-ATRP) technique. It requires an alkyl halide (R-X) as an initiator, a transition metal complex as a catalyst, and an amine as reducing agent. Herein, chlorosilane was used as initiator which was grafted onto the self assembled monolayer modified-quartz crystal surface followed by the addition of pre-polymer mixture which latter underwent thermal cross-linking resulting in MIP-modified QCM sensor. The linear working range (quantification) was found to be 0.6-26.0 μg L-1, with the detection limit as low as 0.08 μg L-1 (S/N=3).

Assessing the conformational and cellular changes of ZnO nanoparticles impregnated Escherichia coli cells through molecular fingerprinting

Ranu K. Dutta; Prashant K. Sharma; Avinash C. Pandey

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 268-275
DOI: 10.5185/amlett.indias.195

Here is an insight into the effects of interaction of ZnO nanoparticles and the various cellular level changes that are brought about by the help of Raman spectroscopy on individual Escherichia coli cells. Raman vibrational signatures show variation in peak intensities of some of the cellular components of E coli cells with increase in nanoparticles concentration. This can be attributed to the cellular and molecular changes associated with bacterial cell growth, as the cells proceed from lag phase to stationary phase, which indicates that ZnO interferences with bacterial growth. Growth kinetics studies show mitigation in growth and colony forming units (CFU) counts. Changes in cellular morphology as investigated by atomic force microscopy and scanning electron microscopy, show destruction and even rupture of cell wall at higher ZnO concentration. This study pertains to any alterations brought about at the cellular level, which may be extended to other nanomaterials in the environment and the effect on human cells as well.

Double imprinting in a single molecularly imprinted polymer format for the determination of ascorbic acid and dopamine

Mahavir Prasad Tiwari; Rashmi Madhuri; Deepak Kumar; Darshika Jauhari; Bhim Bali Prasad

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 276-280
DOI: 10.5185/amlett.indias.202

A new molecularly imprinted polymer – carbon composite fiber is constructed using reversible addition-fragmentation chain transfer polymerization technique. The fiber was evaluated as a sensor for the simultaneous determination of ascorbic acid and dopamine at ultratrace level, in aqueous samples, without any cross-reactivity. The binding characteristics of ascorbic acid and dopamine were also evaluated by differential pulse cathodic stripping voltammetry.

Structural properties of Fe doped TiO2 films on LaAlO3 and Si substrates

Komal Bapna; R.J. Choudhary; D.M. Phase

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 281-284
DOI: 10.5185/amlett.indias.205

We have prepared 4 at.% Fe doped TiO2 thin films on LAO (001) and Si (111) substrates by pulsed laser deposition. X-ray diffraction (XRD) studies suggest different structural properties of the films on the different substrates. Raman measurements corroborate the XRD findings. The thicknesses of the films are also different on the two substrates, suggesting different nucleation process on the two substrates. Interestingly on both the substrates, Fe is not in metal clusters, suggesting their possible incorporation in TiO2 matrix.

VUV excited photoluminescence of Eu3+ doped Y2O3 nanoparticles

Prashant K. Sharma; Ranu K. Dutta; Avinash C. Pandey

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 285-289
DOI: 10.5185/amlett.indias.195

Spherical nanoparticles of Y2O3:Eu 3+ with cubic phase has been synthesized by solution combustion method using glycine as chelating agent and urea as fuel. The 1200 °C annealed sample yield intense red luminescence at 610 nm corresponding to 5 D0→ 7 F2 transition of Eu 3+ ion under vacuum ultraviolet (VUV)/ultraviolet (UV) excitation. Furthermore, the luminescence decay time of the 5 D0→ 7 F2 transition at 610 nm was also calculated against the 147 nm VUV excitation and found to be ~ 4 ms. These highly luminescent spherical nanopartcles of Y2O3:Eu 3+ seems to be one of the promising candidates for modern age display devices.

First principle study of bandgap modification of doped transparent conducting oxide CdO

Pankaj Srivastava; Yamini Sharma

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 290-293
DOI: 10.5185/amlett.indias.206

Transparent conducting oxide CdO has a wide range of applications in optoelectronics. We present the results of electronic and optical properties of pure and transition metal ions Sc, Y and Ti-doped CdO. The electronic structure is calculated within the full-potential linearized augmented plane wave (LAPW) + local orbitals (lo). The calculated band gap for pure CdO is 0.51 eV and changes significantly with doping. The calculated bandgap for Sc-doped CdO (CSO) is 2.67 eV, for Y-doped CdO (CYO) is 2.93 eV, and for Ti-doped CdO (CTO) is 2.53 eV. The effect of doping is clearly seen in the optical absorption profiles as well as in the enhanced electrical conductivities. Due to the widened optical transparency window, doped TCO has nearly 75-80% transmittance in the optical region. There is possibility of greater multiple direct and indirect interband transitions due to availability of more states compared to pure CdO.

Molecularly imprinted polymer-modified electrochemical sensor for simultaneous determination of copper and zinc

Deepak Kumar; Rashmi Madhuri; Mahavir Prasad Tiwari; Pankhuri Sinha; Bhim Bali Prasad

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 294-297
DOI: 10.5185/amlett.indias.207

A procedure for the simultaneous determination of copper and zinc using molecularly imprinted polymer-modified sensor is developed. The linear range of copper and zinc was observed in the concentration window 0.098-23.80 µg L -1 , with detection limits (S/N=3) as low as 0.0275 µg L -1 (zinc) and 0.0159 µg L -1 (copper).

Photoluminescence and ultraviolet photoresponse in ZnO nanophorsphors prepared by thermal decomposition of zinc acetate

Sheo K. Mishra; Smriti Srivastava; Rajneesh K. Srivastava; A.C. Panday; S.G. Prakash

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 298-302
DOI: 10.5185/amlett.indias.210

In the present work, simple, low-cost, and direct route is used for the UV- photodetection and photoluminescent zinc-oxide nanoparticles (NPs) by decomposing zinc acetate in air at 400 0 C for 12 hrs. The X-ray diffraction (XRD) result indicates that the synthesized ZnO NPs is pure and single crystalline structure with wurtzite type. The crystallite size of the ZnO nanoparticles is in the range of 20–50 nm and average crystallite size of synthesized nanoparticles is found to be ~33 nm. The synthesized ZnO NPs exhibits several photoluminescence peaks centered at 396 nm, 418 nm, 441 nm, 481 nm and 522 nm. The time-resolved rise and decay of photocurrent spectrum shows initial significant increase in photocurrent and, subsequently falls gradually under UV-illumination. The photocurrent abruptly falls when illumination is turned off. The variation of photo and dark-current with applied field is found to follow power-law i.e I α V. At low voltage the behavior is sub-linear which becomes super-linear at high voltages. The ZnO NPs is found to have double traps of 0.59 eV and 0.67 eV.

Electronic transport properties of liquid lanthanides

P.B. Thakor; Y.A. Sonvane; P.N. Gajjar; A.R. Jani

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 303-308
DOI: 10.5185/amlett.indias.200

The electronic transport properties like electrical resistivity (ρ), thermoelectric power (Q) and thermal conductivity (σ) of liquid lanthanides are calculated through Ziman’s formulism. To describe electron-ion interaction we have used our newly constructed parameter free model potential alongwith Percus Yevick hard sphere (PYHS) reference system. To see the influence of exchange and correlation effect on the electronic transport properties, we have used five different local field correction functions like Hartree (H), Sarkar et al. (S), Taylor (T), Ichimaru Utsumi (IU) and Farid et al. (F). The obtained results have found good in agreement with available experimental data as well as other theoretical data. Lastly, we conclude that our newly constructed model potential is capable to explain the electronic transport properties of liquid lanthanides.

Adsorption of cobalt(II) from aqueous solution onto hydroxyapatite/zeolite composite

Neha Gupta; Atul K. Kushwaha;M.C. Chattopadhyaya

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 309-312
DOI: 10.5185/amlett.indias.201

The Hydroxyapatite/Zeolite (HApZ) composite were synthesized by precipitation method and used as an adsorbent for the removal of cobalt ions from the aqueous solution. The materials were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. It has been observed that there was slight enhancement in the % removal of cobalt ions from aqueous solution by HApZ (63%) than HAp (58%) and zeolite (47%). Batch experiments were performed to observe the effect of pH, adsorbent dose, contact time and initial cobalt (II) concentration. Kinetic study shows that the adsorption process follow pseudo-second order kinetic model. Equilibrium data were well fitted to Langmuir and Freundlich isotherm model.

Biological approach of zinc oxide nanoparticles formation and its characterization

Ravindra P. Singh; Vineet K. Shukla; Raghvendra S. Yadav; Prashant K. Sharma; Prashant K. Singh; Avinash C. Pandey

Advanced Materials Letters, 2011, Volume 2, Issue 4, Pages 313-317
DOI: 10.5185/amlett.indias.204

Herein, we are reporting a novel biological approach for the formation of zinc oxide (ZnO) nanoparticles using Maddar (Calotropis procera) latex at room temperature. X-Ray diffraction (XRD) pattern reveals the formation of ZnO nanoparticles, which shows crystallinity. Transmission electron microscopy (TEM) suggested particles size and shape in the range of 5-40 nm. Scanning electron microscopy (SEM) image reveals that the particles are of spherical and granular nature. UV-Vis absorption shows characteristic absorption peak of ZnO nanoparticles. Photoluminescence (PL) studies were performed to emphasize its emission properties. This simple and cost-effective biological approach for the formation of ZnO NPs has a promising application in biosensing, electronics and photonics.