Institute of Nanoscience and Technology

Mohali, India

Institute of Nanoscience and Technology

Mohali, India

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Singh S.,Central Scientific Instruments Organisation | Singh S.,CSIR - Central Electrochemical Research Institute | De Sarkar A.,Institute of NanoScience and Technology | Singh B.,Kurukshetra University | Kaur I.,Central Scientific Instruments Organisation
RSC Advances | Year: 2017

In the present work, density functional theory (DFT) combined with non-equilibrium Green’s function (NEGF) formalism is performed. The electronic properties (band structure and density of states) and transport properties (transmission spectrum and I-V characteristics) of armchair silicene nanoribbons (ASiNRs) doped with various elements, such as Al, Ga, In, Tl, P, As, Sb and Bi, are investigated. The negative differential resistance is observed for each doped ASiNR. The most geometrically stable structure and the maximum peak current to valley current (Ip/Iv) ratio is observed in indium (In) doped ASiNRs. Finally, In doped ASiNRs are proposed for field effect transistor (ASiNR-FET) formation using the high dielectric constant value of lanthanum oxide (La2O3 = 29) at different applied gate voltages (−0.1 to 0.4 V). The In doped ASiNR device shows a negative differential resistance phenomenon, which can be controlled by an applied gate voltage. It is found that doping with In in the electrodes and scattering region provides a higher drain current, and higher Ion/Ioff and Ip/Iv ratios. Our results have great application in digital devices and memory devices, and high frequency applications for future nanoelectronics. © The Royal Society of Chemistry.


Lee J.H.,Gyeongsang National University | Park J.,Gyeongsang National University | Park J.-W.,Gyeongsang National University | Ahn H.-J.,Gyeongsang National University | And 3 more authors.
Nature Communications | Year: 2015

Supramolecular gels comprised of low-molecular-weight gelators are generally regarded as mechanically weak and unable to support formation of free-standing structures, hence, their practical use with applied loads has been limited. Here, we reveal a technique for in situ generation of high tensile strength supramolecular hydrogels derived from low-molecular-weight gelators. By controlling the concentration of hydrochloric acid during hydrazone formation between calix-[4]arene-based gelator precursors, we tune the mechanical and ductile properties of the resulting gel. Organogels formed without hydrochloric acid exhibit impressive tensile strengths, higher than 40 MPa, which is the strongest among self-assembled gels. Hydrogels, prepared by solvent exchange of organogels in water, show 7,000- to 10,000-fold enhanced mechanical properties because of further hydrazone formation. This method of molding also allows the gels to retain shape after processing, and furthermore, we find organogels when prepared as gel electrolytes for lithium battery applications to have good ionic conductivity. © 2015 Macmillan Publishers Limited. All rights reserved.


Sharma P.,Chandigarh Institute of Microbial Technology | Sharma P.,Institute of Nanoscience and Technology | Kukkar M.,Chandigarh Institute of Microbial Technology | Ganguli A.K.,Institute of Nanoscience and Technology | And 2 more authors.
Analyst | Year: 2013

Plasmon enhanced fluorescence immunoassay (PEFI) format has been reported in developing a sensitive heterogeneous fluoroimmunoassay for monitoring the phenylurea herbicide diuron. Computer-assisted molecular modeling was carried out to study the conformational and electrostatic effects of synthesized hapten for producing highly specific egg yolk antibody against a phenyl urea herbicide diuron. The generated antibodies were labeled with fluorescein isothiocyanate at different molar ratios and used as tracer in the developed fluorescence based immunoassay. The sensitivity of the assay format was enhanced by using silver nanoparticles tagged with bovine serum albumin as a new blocking reagent in the developed PEFI format. Enhancer treatment on the developed immunoassay showed a significant improvement of fluorescence signal intensity with approximately 10 fold increase in assay sensitivity. The immunoassay has a detection limit of 0.01 ng mL-1 with good signal precision (∼2%) in the optimum working concentration range between 1 pg mL-1 to 10 μg mL -1 of diuron. These findings facilitate high throughput fluorescence-based processes that could be useful in biology, drug discovery and compound screening applications. © 2013 The Royal Society of Chemistry.


Singh K.P.,Allahabad University | Singh M.K.,Allahabad University | Singh M.,Institute of Nanoscience and Technology
International Journal of Developmental Neuroscience | Year: 2016

A tremendous increase has been documented in the recent past in prescribing second generation atypical antipsychotic drugs (AAPDs) to the pregnant women with psychosis, considering their reproductive and teratogenic safety. Among AAPDs, risperidone (RIS) ranked third after olanzapine (OLZ) and quetiapine (QUE) used during pregnancy, as OLZ is associated to substantial weight gain in adults and offspring. Although teratogenic safety of RIS has been established, its potential role in developmental neurotoxicity and related neurobehavioral impairments in adolescents has not been documented so far. Therefore, present study has been undertaken to elucidate the effect of prenatal exposure to risperidone (RIS) on developmental neurotoxicity and apoptotic neurodegeneration in neocortical region of fetal brain; and related functional sequelae in young rat offspring. The pregnant Wistar rats were exposed to RIS at 0.8, 1.0 and 2.0 mg/kg, at equivalent therapeutic doses, orally from GD 6 to 21. Half of the pregnant rats were sacrificed and their brains were collected, weighed, and processed for neurohistopathological and apoptotic neurodegenerative evaluation. The remaining dams were allowed to deliver naturally, and their offspring were reared up to 10 weeks for neurobehavioral study. Prenatal exposure to RIS induced significant stunting of fetal body and brain weight, substantial reduction in the thickness of neocortical layers and apoptotic neurodegeneration in fetal brains, and delayed postnatal development and growth of the offspring; as well as long- lasting impact on anxiety like impaired behavioral responses on explorative mazes. Therefore, health care providers should be careful in prescribing atypical antipsychotics in general and RIS in particular, to the pregnant psychotic population. © 2016 ISDN.


Cheok H.S.,Hanyang University | Jaworski J.,Hanyang University | Jaworski J.,Institute of Nanoscience and Technology
Biochemical Engineering Journal | Year: 2016

Formylglycine generating enzyme (FGE) is conserved through most organisms for the post-translational formation of aldehyde bearing formylglycine residues, often at sites possessing the general motif XCXPXRX. Using a library of the XCXPXRX repertoire displayed on the p3 protein coat of fd phage, we devised a phage screening strategy for identifying FGE substrates. Our methods of screening phage possessing possible substrates for enzymatic activity made use of the unique aldehyde residues produced on the substrate by reaction with FGE, which facilitated covalent capture of phage onto magnetic beads. This sequence dependent conversion/capture in conjunction with an unexpected sequence dependence of the enzymatic elution step used to liberate the phage for propagation served as the evolutionary selection pressures. The resulting HCTPRRP sequence identified from this phage screening procedure was an effective substrate for FGE, and through the course of the screening process it was selected for its propensity to be cleaved by trypsin. We anticipate this unique methodology for enzyme substrate screening may be applicable to selection of novel enzyme-substrate pairs by virtue of either sequence dependent immobilization or sequence dependent elution. © 2015 Elsevier B.V.


Kim J.Y.,Hanyang University | Jaworski J.,Hanyang University | Jaworski J.,Institute of Nanoscience and Technology
Macromolecular Research | Year: 2015

[Figure not available: see fulltext.] © 2015, The Polymer Society of Korea and Springer Sciene+Business Media Dordrecht.


Kwak E.-A.,Hanyang University | Jaworski J.,Hanyang University | Jaworski J.,Institute of Nanoscience and Technology
Journal of Materials Chemistry B | Year: 2013

A unique method for the controlled attachment of viruses (or other protein based materials) to a range of surfaces is revealed through site-specific linkages engineered at the fd phage p3 protein coat. After genetic encoding of the virus coat position that is to be engineered, enzymatic modification with a formylglycine generating enzyme (FGE) affords the conversion of a single amino acid at a precise location to yield a reactive aldehyde group. By implementing this modification at a specific p3 coat position, we demonstrate the ability to control the directed immobilization of the virus selectively onto amine exposed surfaces including APTES treated glass, polymeric supports, and protein coated magnetic beads. While the immobilized virus remains stable for even a month, we also show by controlled release from the surface that liberated viruses retain their infectivity. The adaptability of this modification strategy for virus engineering is demonstrated showing great potential for bioconjugation with a range of amine functionalized chemical targets. This is expected to greatly enhance the possibilities for future virus based materials and related technologies. © 2013 The Royal Society of Chemistry.


Ghosh K.,Institute of NanoScience and Technology | Ghosh K.,Nanyang Technological University | Verma Y.K.,Institute of NanoScience and Technology | Tan C.S.,Institute of NanoScience and Technology
Materials Today Communications | Year: 2015

Carbon nanotubes (CNT) are being intensely investigated and explored as an alternative to the use of traditional metals in the interconnects for 3D chip-stacking, because of its numerous advantageous properties, in particular high thermal and electrical conductivity that are several times higher than of any comparable metal. In this work, we have successfully implemented growth and realized functional integration of multiwalled-CNT bundles in sub-5μm diameter, high-aspect ratio 'Through-Silicon-Vias' (TSV). Large-area growth of CNT bundles was realized in TSVs on top of metal-lines in a bottom-up approach, at complimentary-metal-oxide-semiconductor processing-compatible temperatures. An innovative approach for minimization of the interfacial-barrier contact resistance between CNT and metal-lines was adopted, by introducing an alloy of Al-rich Al2O3 as catalyst-holding layer, instead of conventional 10nm. Good electrical-contact between metal-lines to CNTs is observed. A repeatable, non-destructive approach was used for electrical characterization studies of CNT-TSVs. The combined electrical resistance of an individual CNT-filled TSV was found to be ~1.2kΩ. Issues related to selective deposition of Fe-catalyst thin-film at the TSV-bottom, and growth of the CNTs from TSV sidewalls were solved by novel approach of wafer-to-wafer bonding. Structural investigations proved that as-grown CNT bundles are anchored robustly in the metal-layers. © 2014 Elsevier Ltd.


Ghosh K.,Nanyang Technological University | Ghosh K.,Institute of NanoScience and Technology | Verma Y.K.,Nanyang Technological University | Tan C.S.,Nanyang Technological University
Journal of Materials Chemistry A | Year: 2015

Having an array of novel functionalities and performance advantages, Multi-Walled Carbon Nanotubes (MWCNT) are one of the most promising nanomaterials to replace metals like copper and aluminum in the low-dimensional interconnects in three-dimensional (3D) integrated circuits (3D-IC) and sensors. Low resistivity, large current density, high thermal conductivity (10 times that of copper), and a low coefficient of thermal expansion (CTE) make MWCNTs a prime choice for integration in next-generation 3D-chip stacks. However, the growth of carbonaceous nanomaterials on top of metals gives rise to issues of high interfacial resistance at the metal/MWCNT interfaces due to large differences in their potential work functions. Although it has become feasible to grow vertically aligned MWCNTs on metal lines, it has not been possible to systematically and precisely determine the interfacial contact resistance values between the as-grown single-, or bundle-MWCNTs and the base metal-lines. Here, we report a novel experimental method for the measurement of metal/carbon interface contact resistance with the aid of nanoprobing setup, thereby eliminating undesirable metal-pad deposition step required in conventional techniques. In the present approach, nanoprobes are placed in contact with individual CNT-bundles making direct electrical contacts. Two-point-probe (2PP) and four-point-probe (4PP) measurements are systematically performed to accurately estimate values of the contact resistance at the metal/CNT interface. The as-measured interfacial contact resistance for a bundle in 2-5 μm diameter oxide-via is found to be ∼730 Ω, while on a per-CNT basis the metal/MWCNT contact resistance is ∼35 kΩ. The reported values of interfacial contact resistance are quite lower than those reported elsewhere in the literature. The characteristic novelty of current experimental approach lies in the total elimination of any steps, involving further chemical, mechanical or physical processing, which cause deformation and/or damage to the intrinsic properties and morphology of as-grown CNT-bundles. Uniquely, no alteration needs to be made to properties or environment of as-grown MWCNTs. The advantages of this approach results in relatively more accurate and error-free determination of the metal/CNT interfacial resistance values than any of earlier techniques. © The Royal Society of Chemistry 2015.


PubMed | Allahabad University and Institute of Nanoscience and Technology
Type: | Journal: International journal of developmental neuroscience : the official journal of the International Society for Developmental Neuroscience | Year: 2016

A tremendous increase has been documented in the recent past in prescribing second generation atypical antipsychotic drugs (AAPDs) to the pregnant women with psychosis, considering their reproductive and teratogenic safety. Among AAPDs, risperidone (RIS) ranked third after olanzapine (OLZ) and quetiapine (QUE) used during pregnancy, as OLZ is associated to substantial weight gain in adults and offspring. Although teratogenic safety of RIS has been established, its potential role in developmental neurotoxicity and related neurobehavioral impairments in adolescents has not been documented so far. Therefore, present study has been undertaken to elucidate the effect of prenatal exposure to risperidone (RIS) on developmental neurotoxicity and apoptotic neurodegeneration in neocortical region of fetal brain; and related functional sequelae in young rat offspring. The pregnant Wistar rats were exposed to RIS at 0.8, 1.0 and 2.0mg/kg, at equivalent therapeutic doses, orally from GD 6 to 21. Half of the pregnant rats were sacrificed and their brains were collected, weighed, and processed for neurohistopathological and apoptotic neurodegenerative evaluation. The remaining dams were allowed to deliver naturally, and their offspring were reared up to 10 weeks for neurobehavioral study. Prenatal exposure to RIS induced significant stunting of fetal body and brain weight, substantial reduction in the thickness of neocortical layers and apoptotic neurodegeneration in fetal brains, and delayed postnatal development and growth of the offspring; as well as long- lasting impact on anxiety like impaired behavioral responses on explorative mazes. Therefore, health care providers should be careful in prescribing atypical antipsychotics in general and RIS in particular, to the pregnant psychotic population.

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