Graphene Oxide Based Fluorometric Detection of Hydrogen Peroxide in Milk

Nanda, Sitansu Sekhar,Yi, Dong Kee,Kim, Kwangmeyung American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.1

<P>We report a highly rapid, visual, precise, selective and sensitive analytical method for the determination of hydrogen peroxide (H2O2) in milk using Graphene oxide (GO) with 2',7'-dichlorfluorescein diacetate (DCFH-DA). A 1000 mu L aliquots of 10-fold diluted samples (high and low-fat milk) directly onto the 100 mu L of GO and 100 mu L of 100 mu M DCFH-DA produced green colour under Ultraviolet light at 365 nm. The analytical feature of our proposed method includes low detection limit (10 mmol mL(-1)) and satisfactory recovery values for samples. The presence of H2O2 in milk is a major concern because it constitutes a public health hazard. Many milk indursties are using H2O2 as a preservative, but if the concentration increases then it causes so many health problems such as neurodegenerative disorders, cancer and diabetes. Present methods show an easy way for detecting H2O2 generally require considerable time and laboratory facilities. The chemical tests have sufficient sensitivity to detect wide linear range of H2O2 concentration.</P>

Financial Innovation and Investor Wealth: A Study of the Poison Put in Convertible Bonds

Nanda, Vikram,Yun, Young-Keol Korean Financial Management Association 1996 財務管理論叢 Vol.3 No.1

The takeover boom of the 1980s was accompanied by a series of innovations in debt contracts, including the poison put that allows bonds to be redeemed in the event of a corporate control change. The poison put was included in a large majority of convertible debt offerings, shortly after the first issues with such provisions. We attempt to understand the factors that contributed to the widespread adoption of this innovation in convertible bonds and the consequences for shareholder wealth. Our, findings suggest that by reducing the potential for bondholder-shareholder conflicts and by conveying positive information about future takeover prospect'5, poison puts result in significant benefits to issuing firm shareholders, particularly if the firm is under takeover speculation. There are, however, no benefits when a firm has adopted anti-takeover measures prior to the offering. There is weaker evidence that existing bondholders do worse when poison puts are present.

Study on structural damping of aluminium using multi-layered and jointed construction

Nanda, B.K.,Behera, A.K. Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.20 No.6

In this work, the mechanism of damping and its theoretical evaluation for layered aluminium cantilever structures jointed with a number of equispaced connecting bolts under an equal tightening torque have been considered. Extensive experiments have been conducted on a number of specimens for comparison with numerical results. Intensity of interface pressure, its distribution pattern, dynamic slip ratio and kinematic coefficient of friction at the interfaces, relative spacing of the connecting bolts, frequency and amplitude of excitation are found to play a major role on the damping capacity of such structures. It is established that the damping capacity of structures jointed with connecting bolts can be improved largely with an increase in number of layers maintaining uniform intensity of pressure distribution at the interfaces. Thus the above principle can be utilized in practice for construction of aircraft and aerospace structures effectively in order to improve their damping capacity which is one of the prime considerations for their design.

Synthesis of polyurethane nanocomposites of functionalized carbon nanotubes by in-situ polymerization methods

Nanda Sahoo,Jae Whan Cho,Hyang Hwa So,정용채 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.I

Carboxylic functionalized multi-walled carbon nanotubes (MWNTs) have been incorporated to segmented polyurethane block copolymer (PU) to demonstrate the effect of the chemical functionalization of MWNTs on the thermal, morphological and mechanical properties of MWNT-reinforced nanocomposites. Polyurethane was synthesized in a two-step process from a reaction of 4,4$^\prime$-methylene bis(phenylisocyanate), poly($\varepsilon$-caprolactone)diol, and 1,1,1-tris(hydroxymethyl)propane as a chain extender. The nature of the interaction between chemical groups on the PU and the MWNT surface was probed by measuring the extent of the shift in absorbing wavelength of key groups in the polymer and on the MWNT after mixing of these components. Mechanical properties of the PU-MWNT nanocomposites were assessed as a function of MWNT concentration and dispersion of MWNT in PU matrix. Scanning electron microscopy observation indicated that homogeneous dispersion of functionalized MWNTs throughout PU matrix and strong interfacial adhesion between functionalized MWNTs and the matrix were achieved in PU nanocomposites, which brought an enhancement in the mechanical properties. MWNTs improved the thermal stability of the nanocomposites, as evidenced by thermogravimetric analysis.

Development of SCAR Marker for the Detection of QTL for Resistance to Dollar Spot in Creeping Bentgrass (Agrostis stolonifera L.)

Nanda Chakraborty,심성철,Michael Casler,정근화 한국원예학회 2014 Horticulture, Environment, and Biotechnology Vol.55 No.4

Dollar spot (caused by Sclerotinia homoeocarpa F. T. Bennett) is the most economically important fungalturf disease on golf courses in North America. This disease is mainly controlled by using multiple fungicides. However,the causal fungus has developed resistance to seveal classes of fungicides and host resistance is an alternative controlstrategy. A creeping bentgrass (Agrostis stolonifera L.) cultivar improved with dollar spot resistance would greatly reducethe costs and environmental impacts of fungicide applications. Our previous QTL analysis in the creeping bentgrass‘549 × 372’ population detected one QTL with a large effect for dollar spot resistance and several QTLs with smallereffects. One RAPD primer, AW10, amplified an 650-bp band in the parent ‘372’, was named 3.AW10.650. This RAPDmarker was located on linkage group 7.1 and was significantly (p < 0.0001) associated with the QTL for dollar spotresistance based on 697 progeny of the ‘549 × 372’ population. In this study, we converted the RAPD marker 3.AW10.650into a sequence characterized amplified region (SCAR) marker, named CreepDSp.650. The SCAR marker showed asignificant association (p = 0.006) with dollar spot resistance in an additional segregating population developed at theUniversity of Illinois. We report here the first PCR-based SCAR marker associated with a major-effect QTL for dollarspot resistance in creeping bentgrass. This SCAR marker will facilitate evaluating relatively large numbers of breedingprogeny for marker-assisted selection (MAS) in bentgrasses.

Recent advances in biocompatible semiconductor nanocrystals for immunobiological applications

Nanda, Sitansu Sekhar,Kim, Min Jik,Kim, Kwangmeyung,Papaefthymiou, Georgia C.,Selvan, Subramanian Tamil,Yi, Dong Kee Elsevier 2017 Colloids and Surfaces B Vol.159 No.-

<P><B>Abstract</B></P> <P>Quantum confinement in inorganic semiconductor nanocrystals produces brightly luminescent nanoparticles endowed with unique photo-physical properties, such as tunable optical properties. These have found widespread applications in nanotechnology. The ability to render such nanostructures biocompatible, while maintaining their tunable radiation in the visible range of the electromagnetic spectrum, renders them appropriate for bio-applications. Promising <I>in vitro</I> and <I>in vivo</I> diagnostic applications have been demonstrated, such as fluorescence-based detection of biological interactions, single molecule tracking, multiplexing and immunoassaying. In particular, these fluorescent inorganic semiconductor nanocrystals, generally known as quantum dots, have the potential of remarkable immunobiological applications. This review focuses on the current status of biocompatible quantum dots and their applications in immunobiology − immunosensing, immunofluorescent imaging and immunotherapy.</P> <P><B>Highlights</B></P> <P> <UL> <LI> QDs enabled for promising in vivo diagnostics applications. </LI> <LI> QDs have emerged as a versatile tool in immunosensing applications. </LI> <LI> QDs showed remarkable immunobiological applications. </LI> <LI> QD-antibody conjugates to study the specific binding events. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Measurement of creatinine in human plasma using a functional porous polymer structure sensing motif

Nanda, Sitansu Sekhar,An, Seong Soo A,Yi, Dong Kee Dove Medical Press 2015 INTERNATIONAL JOURNAL OF NANOMEDICINE Vol.10 No.specal

<P>In this study, a new method for detecting creatinine was developed. This novel sensor comprised of two ionic liquids, poly-lactic-<I>co</I>-glycolic acid (PLGA) and 1-butyl-3-methylimidazolium (BMIM) chloride, in the presence of 2′,7′-dichlorofluorescein diacetate (DCFH-DA). PLGA and BMIM chloride formed a functional porous polymer structure (FPPS)-like structure. Creatinine within the FPPS rapidly hydrolyzed and released OH<SUP>−</SUP>, which in turn converted DCFH-DA to DCFH, developing an intense green color or green fluorescence. The conversion of DCFH to DCF<SUP>+</SUP> resulted in swelling of FPPS and increased solubility. This DCF<SUP>+</SUP>-based sensor could detect creatinine levels with detection limit of 5 µM and also measure the creatinine in blood. This novel method could be used in diagnostic applications for monitoring individuals with renal dysfunction.</P>

Nitrophenyl Functionalization of Carbon Nanotubes and Its Effect on Properties of MWCNT/LCP Composites

Nanda Gopal Sahoo,Henry Kuo Feng Cheng,Hongqian Bao,Siew Hwa Chan,Lin Li,Jianhong Zhao 한국고분자학회 2011 Macromolecular Research Vol.19 No.7

Multiwalled carbon nanotubes (MWCNTs) were functionalized on their sidewalls with p-nitrophenyl (C_6H_4NO_2) to make MWCNTs compatible with liquid crystalline polymer (LCP) through a specific interaction with LCP. This study examined the rheological, morphological, mechanical, dynamic mechanical, and thermal properties of LCP in detail with a variation of the nitrophenyl-functionalized MWCNTs in the LCP matrix. A higher complex viscosity, storage, and loss modulus were observed in the nitrophenyl-functionalized MWCNTs/LCP composites than the composites with the same loading of raw MWCNTs. The nitrophenyl groups attached to the MWCNTs improved their dispersion and interfacial adhesion with the LCP matrix, which was confirmed by field emission scanning electron microscopy (FESEM). As a result, the incorporation of the nitrophenyl-functionalized MWCNTs effectively enhanced the mechanical and thermal stability of the LCP.

Damage assessment from curvature mode shape using unified particle swarm optimization

Nanda, Bharadwaj,Maity, Damodar,Maiti, Dipak Kumar Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.52 No.2

A two-step procedure to detect and quantify damages in structures from changes in curvature mode shapes is presented here. In the first step the maximum difference in curvature mode shapes of the undamaged and damaged structure are used for visual identification of the damaged internal-substructure. In the next step, the identified substructures are searched using unified particle swarm optimization technique for exact identification of damage location and amount. Efficiency of the developed procedure is demonstrated using beam like structures. This methodology may be extended for identifying damages in general frame structures.

Raman spectrum of graphene with its versatile future perspectives

Nanda, S.S.,Kim, M.J.,Yeom, K.S.,An, S.S.A.,Ju, H.,Yi, D.K. Elsevier Scientific Pub. Co 2016 Trends in analytical chemistry Vol.80 No.-

<P>Raman spectroscopy is performing as a powerful analytical technique for qualitative and quantitative analysis of graphene and graphene-related compounds. Graphene and graphene-related compounds exhibit intense Raman vibrations. Raman spectroscopic techniques for determination of several graphene layers, and the quality and type of edges, disorders, and functional groups in graphene and graphene-related compounds are of increasing importance. Herein, we review the developments and discuss the future direction and various questions relevant to Raman spectroscopic analysis of graphene and graphenerelated compounds. An update of the basic concepts underlying the Raman spectroscopy of graphene is presented and conclusions regarding this matter are provided. The biomedical and physical applications of Raman spectroscopy of graphene are evaluated. The chemical enhancement of the Raman signals and studies of these enhancements are known as Surface enhanced Raman spectroscopy (SERS) and Tip enhanced Raman spectroscopy (TERS). Different mechanisms of achieving chemical enhancement of the Raman signal of the graphene surface and study of these enhancements through Raman spectroscopy are discussed in this critical review illustrating the growth in the use of Raman spectroscopy in graphene research. (C) 2016 Elsevier B.V. All rights reserved.</P>