Unconventional active biosensor made of piezoelectric BaTiO₃ nanoparticles for biomolecule detection

Selvarajan, Sophia,Alluri, Nagamalleswara Rao,Chandrasekhar, Arunkumar,Kim, Sang-Jae Elsevier 2017 Sensors and actuators. B Chemical Vol.253 No.-

<P><B>Abstract</B></P> <P>A smart biosensor based on piezoelectric and semiconducting properties of Barium titanate nanoparticles (BT NPs) by means of a piezoelectric nanogenerator (PNG) is reported for the first time. An Al/BT/ITO NG (Aluminum (Al)/Barium titanate (BT)/Indium Tin Oxide (ITO) nanogenerator) was devised as a self-powered biosensor for actively detecting glucose. The piezoelectric output generated from this NG has dual functions, as both an energy source and a biosensing signal. The biomolecule alters device conductance (charge-carrier density), providing a gate potential, and can vary the local work function and band alignment due to its adsorption on the surface of BT NPs (interfacial contact effect). Here, we tailored the piezoelectric and semiconducting properties of BT NPs using glucose molecules. The glucose molecules (lewis base) on the surface of BT NPs film (lewis acid) act as a gate potential, and the field effect eventually influence the charge carrier density (electrons) of BT NPs film, which varies the screening effect of free-carriers on the piezoelectric output. The novel self-powered glucose biosensor has good selectivity (∼6-fold increase in response <I>vs</I>. interferents) and the approach demonstrated here can serve as a prototype for the development of next-generation smart/self-powered nanosystems for theranostic applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report on BaTiO<SUB>3</SUB> NPs film based nanogenerator as one-stop active glucose sensor. </LI> <LI> Multifunctional and biocompatible BaTiO<SUB>3</SUB> NPs with piezoelectric and semiconducting properties. </LI> <LI> Device with dual functions, as both an energy source and a biosensing signal. </LI> <LI> Proposed sensor has good selectivity and detection limits down to 10μM. </LI> <LI> Prototype for smart/intelligent implantable nanosystems for theranostic applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Direct detection of cysteine using functionalized BaTiO₃ nanoparticles film based self-powered biosensor

Selvarajan, Sophia,Alluri, Nagamalleswara Rao,Chandrasekhar, Arunkumar,Kim, Sang-Jae Elsevier 2017 Biosensors & Bioelectronics Vol.91 No.-

<P><B>Abstract</B></P> <P>Simple, novel, and direct detection of clinically important biomolecules have continuous demand among scientific community as well as in market. Here, we report the first direct detection and facile fabrication of a cysteine-responsive, film-based, self-powered device. NH<SUB>2</SUB> functionalized BaTiO<SUB>3</SUB> nanoparticles (BT-NH<SUB>2</SUB> NPs) suspended in a three-dimensional matrix of an agarose (Ag) film, were used for cysteine detection. BaTiO<SUB>3</SUB> nanoparticles (BT NPs) semiconducting as well as piezoelectric properties were harnessed in this study. The changes in surface charge properties of the film with respect to cysteine concentrations were determined using a current–voltage (<I>I-V</I>) technique. The current response increased with cysteine concentration (linear concentration range=10µM–1mM). Based on the properties of the composite (BT/Ag), we created a self-powered cysteine sensor in which the output voltage from a piezoelectric nanogenerator was used to drive the sensor. The potential drop across the sensor was measured as a function of cysteine concentrations. Real-time analysis of sensor performance was carried out on urine samples by non-invasive method. This novel sensor demonstrated good selectivity, linear concentration range and detection limit of 10µM; acceptable for routine analysis.</P> <P><B>Highlights</B></P> <P> <UL> <LI> First report on facile and direct detection of cysteine through I-V technique. </LI> <LI> Functionalized BaTiO<SUB>3</SUB> NPs for self-powered cysteine biosensing system. </LI> <LI> Biocompatible BaTiO<SUB>3</SUB> NPs and agarose biopolymer paves way for green chemistry. </LI> <LI> Proposed sensor has good selectivity and detection limits down to 10 µM (3 s/m). </LI> <LI> The findings may further lead to novel piezoelectric-biosensing devices. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Modelling and experimental investigation of process parameters in EDM of Si3N4 -TiN composites using GRA-RSM

Selvarajan L,M. Manohar,A. Udhaya kumar,P. Dhinakaran 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.1

Electric discharge machining (EDM) is a highly promising machining process of ceramics. This research is an out of the paradigm investigation of EDM on Si 3 N 4 -TiN with Copper electrode. Ceramics are used for extrusion dies and bearing balls and they are more efficient, effective and even have longer life than conventional metal alloys. Owing to high hardness of ceramic composites, they are almost impossible to be machined by conventional machining as it entirely depends on relative hardness of tool with work piece. Whereas EDM offers easy machinability combined with exceptional surface finish. Input parameters of paramount significance such as current (I), pulse on (P on ) and off time (P off ), Dielectric pressure (DP) and gap voltage (SV) are studied using L 25 orthogonal array. With help of mean effective plots the relationship of output parameters like Material removal rate (MRR), Tool wear rate (TWR), Surface roughness (Ra), Radial overcut (ROC), Taper angle (α), Circularity (CIR), Cylindricity (CYL) and Perpendicularity (PER) with the considered input parameters and their individual influence were investigated. The significant machining parameters were obtained by Analysis of variance (ANOVA) based on Grey relational analysis (GRA) and value of regression coefficient was determined for each model. The results were further evaluated by using confirmatory experiment which illustrated that spark eroding process could effectively be improved.

Fabrication of mesoporous BaTiO3/SnO2 nanorods with highly enhanced photocatalytic degradation of organic pollutants

S. Selvarajan,P. Malathy,A. Suganthi,M. Rajarajan 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.53 No.-

Novel UV–vis-light-driven BaTiO3/SnO2 nanocomposites with three different molar ratios (1%, 3%, 5%) were synthesized by hydrothermal and precipitation deposition methods. The successfully characterized by UV-visible diffuse reflectance spectroscopy (DRS), FT-IR spectroscopy, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), photoluminescence spectroscopy (PL), and Brunauer–Emmett–Teller surface area analysis (BET) techniques. The lmax of the prepared nanocomposite was highly red shifted from 220 nm to 410 nm compared to the bare metal oxides. The degradation of organic pollutants such as o-Chloroaniline (o-CLA) and methylene blue (MB) were studied using the prepared nanocomposite. The nanocomposite with molar ratio of 3% BaTiO3/SnO2 photocatalyst possesses excellent photocatalytic activity than the nanocomposite with molar ratio 1% BaTiO3/SnO2, 5% BaTiO3/SnO2, and the individual components BaTiO3, SnO2. The band edges of materials have been theoretically calculated on the basis of Mullikan electronegativity of atoms. The effect of operational parameters such as; pollutant concentration, pH, catalyst loading, OH radical trapping and COD (carbon oxygen demand) have been investigated in details. The kinetics of the photodegradation reactions were correlated with the pseudofirst- order model. The stability of nanocomposite was examined by recycling experiments.

Anti-Inflammatory and Antioxidant Activities of the Nonlipid (Aqueous) Components of Sesame Oil: Potential Use in Atherosclerosis

Krithika Selvarajan,Chandrakala Aluganti Narasimhulu,Reena Bapputty,Sampath Parthasarathy 한국식품영양과학회 2015 Journal of medicinal food Vol.18 No.4

Dietary intervention to prevent inflammation and atherosclerosis has been a major focus in recent years. We previously reported that sesame oil (SO) was effective in inhibiting atherosclerosis in low-density lipoprotein-receptor negative mice. We also noted that the levels of many proinflammatory markers were lower in the SO-treated animals. In this study we tested whether the non-lipid, aqueous components associated with SO would have anti-inflammatory and antioxidant effects. Polymerase chain reaction array data indicated that sesame oil aqueous extract (SOAE) was effective in reducing lipopolysaccharide (LPS)-induced inflammation in RAW 264.7 macrophage cells. Expression of inflammatory cytokines such as interleukin (IL)-1α, IL-6, and tumor necrosis factor α (TNF-α) was also analyzed independently in cells pretreated with SOAE followed by inflammatory assault. Effect of SOAE on TNF-α-induced MCP-1 and VCAM1 expression was also tested in human umbilical vein endothelial cells. We observed that SOAE significantly reduced inflammatory markers in both macrophages and endothelial cells in a concentration-dependent manner. SOAE was also effective in inhibiting LPS-induced TNF-α and IL-6 levels in vivo at different concentrations. We also noted that in the presence of SOAE, transcription and translocation of NF-κB was suppressed. SOAE was also effective in inhibiting oxidation of lipoproteins in vitro. These results suggest the presence of potent anti-inflammatory and antioxidant compounds in SOAE. Furthermore, SOAE differentially regulated expression of scavenger receptors and increased ATP-binding cassette A1 (ABCA1) mRNA expression by activating liver X receptors (LXRs), suggesting additional effects on lipid metabolism. Thus, SOAE appears multipotent and may serve as a valuable nonpharmacological agent in atherosclerosis and other inflammatory diseases.

Financial Integration and Economic Growth: Should Asia Emulate Europe?

Sonia Kumari Selvarajan,Rossazana Ab-Rahim 세종대학교 경제통합연구소 2020 Journal of Economic Integration Vol.35 No.1

The Asian financial crisis of 1997~1998 was the catalyst for the movement toward regional cooperation between Asian countries, having triggered the common interests and vulnerabilities among the affected nations. As a result, policymakers have resorted to financial integration to unleash their potentials. Nevertheless, this approach is still in its infancy, largely underpinned by the heterogeneity in institutional and structural characteristics of the financial systems between countries. The authorities are cautious, as there is a trade-off between liquidity of capital markets and financial/economic stability. Considering these scenarios, the present study attempts to examine the dynamic relationship between financial integration and growth in Asian regions. Specifically, this study aims to investigate the financial-growth nexus pre-crisis (1980~1995) and post-crisis (1998~2015) as well as throughout the study period (1980~2015). The results of this study show a significant financial-growth relationship pre-crisis, but the impact wanes in the post-crisis and overall time periods. The results indicate to policymakers the heterogeneous characteristics of each country and to what extent financial integration should be emulated from their European counterparts.

Worm structure piezoelectric energy harvester using ionotropic gelation of barium titanate-calcium alginate composite

Alluri, Nagamalleswara Rao,Selvarajan, Sophia,Chandrasekhar, Arunkumar,Saravanakumar, Balasubramaniam,Lee, Gae Myoung,Jeong, Ji Hyun,Kim, Sang-Jae Elsevier 2017 ENERGY Vol.118 No.-

<P><B>Abstract</B></P> <P>A laterally aligned flexible composite linear worm-based piezoelectric energy harvester made up of piezoelectric barium titanate nanoparticles and a three dimensional gel network of calcium alginate biopolymer was aimed to harness the low frequency mechanical energy. It is highly desirable to fabricate innovative micro/nanostructures for high performance energy harvesting beyond the conventional thin films, and small scale fabrication of nanowires (or rods). The open circuit voltage of a single composite worm-based energy harvester (diameter ≈ 550 μm, length ≈ 2.5 cm) increases up to 5 times by increasing the frequency of mechanical load (11 N) from 3 to 20 Hz. Similarly, 1.5 times voltage increment was observed by increasing the length of the composite worm from 1.5 to 3.5 cm upon the bio-mechanical hand force. The energy harvester can function as an efficient portable/wearable self-powered device due to its good flexibility, and multiple lengths of composite linear worms can be utilized to drive low-power electronic devices. In this work, the composite worms were prepared by an ionotropic gelation approach, which is eco-friendly, non-toxic, having low processing temperature/time, and potential for cost-effective, large-scale fabrication, making it suitable for low frequency based self-powered devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Portable energy harvester was developed using composite linear worm structure. </LI> <LI> Real time power generating shoe insole was demonstrated by two energy harvesters. </LI> <LI> Energy harvested from the applied mechanical load, air and human body motions. </LI> <LI> The relation between composite worm length and generated energy was identified. </LI> <LI> Eco-friendly, Mass production of worms developed by ionotropic gelation method. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

In-flight particle behaviour and its effect on co-spraying of alumina?titania

G. Shanmugavelayutham,V. Selvarajan,T.K. Thiyagarajan,P.V.A. Padmanabhan,K.P. Sreekumar,R.U. Satpute Y. Zhai 한국물리학회 2006 Current Applied Physics Vol.6 No.1

The present paper investigate and illustrate the importance of plasmaparticle interaction in controlling the plasma spray processwhile spraying aluminatitania powder blend. Plasma sprayed coatings of aluminatitania (6040l m) have been prepared at dier-chemical composition of aluminatitania coatings, prepared at low input power, is signicantly dierent from that of the feed stockpowder. Coating composition progressively approaches that of the feedstock powder at higher power inputs. Experimental resultsare explained in terms of the in-ight behaviour of alumina and titania particles in the plasma jet using a one-dimensional model topredict the thermal state of the particles. In particular, the eect of particle size and input power are considered in this study.

Investigation on surface properties of TiO2 films modified by DC glow discharge plasma

K. Navaneetha Pandiyaraj,V. Selvarajan,Matteo Pavese,Polycarpos Falaras,Dimitrios Tsoukleris 한국물리학회 2009 Current Applied Physics Vol.9 No.5

In the present work, TiO2 films deposited on polyethylene terephthalate substrates by dip coating technique were subsequently treated by DC glow discharge plasma as a function of discharge potential. Hydrophilicity of these TiO2 film surfaces was analyzed by contact angle measurements. Atomic force microscopy (AFM) revealed changes in surface morphology of the plasma treated TiO2 films. Modifications in structural and chemical composition of the TiO2 films were detected by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The blood compatibility of TiO2 films was studied by in vitro investigation which includes thrombus formation and whole blood clotting time analysis (WBCT). It was found that the plasma treatment results in blood compatibility enhancement attributed to the structural, chemical and morphological properties of the modified film surfaces.

Effect of powder loading on the excitation temperature of a plasma jet in DC thermal plasma spray torch

G. Shanmugavelayutham,V. Selvarajan,P.V.A. Padmanabhan,K.P. Sreekumar,N.K. Joshi 한국물리학회 2007 Current Applied Physics Vol.7 No.2

A DC non-transferred mode plasma spray torch was fabricated for plasma spheroidization. The eect of powder-carrier gas and pow-der loading on the temperature of the plasma jet generated by the torch has been studied. The experiment was done at dierent inputparticles in the size range from 40 to 100l m were processed. The temperature of the jet was estimated after owing powder-carrier gasonly into the plasma jet and with powder-carrier gas feeding powder into the ame. On introduction of powder-carrier gas and powderloading the temperature of the jet was found to decrease appreciably down to 11%. The temperature of the plasma jet was estimatedusing the Atomic Boltzmann plot method.