Current Issue : July - September Volume : 2013 Issue Number : 3 Articles : 6 Articles
Biosensors are enormously used for diagnosing applications owing to its compact size and simplicity. Biosensors task is to identify presence of targeted molecule and provide result into a measurable signal. Cantilever is one of the most reliable methods of designing biosensor. Cantilever biosensor is preferable because analyte required is very less as compared to conventional method. In order to detect presence of specific bio-molecule, it is necessary to immobilized particular receptors for that bio-molecule. If sample contain bio-molecule of the interest then cantilever show deflection otherwise it will remain in its original position. Same deflection can be obtain by applying force(equivalent to bio-agent mass) to cantilever .This paper relates acting mass of bio-particle with external applied force in order to get same deformation of cantilever. Coventorware software is used for simulation. For simulation results shows mechanical properties of device after application of load....
In this paper, the analysis of charge injection\r\nfrommetaltoacontactedgraphenenanoribbon(GNR)is\r\ndevelopedbymeansofascatteringmatrixapproach.The\r\ncharge transport, described by the SchrÃ?¶dinger equation\r\nin the 2D domain of theGNRs, is solved, together with\r\nthe 3D Poisson equation for the potential distribution.\r\nVarying theworkfunction of the metal contacted to the\r\nGNR,altersthesocalledââ?¬Å?metaldopingââ?¬Â,i.e.,theamount\r\nof charge in the GNR. As easily expected, this in turn\r\naffectstheIVcharacteristicofaGNRchannelacrosstwo\r\nelectrodes. Interesting effects appear as the contribution\r\nofGNRsubbandisconsideredandincludedintheself\r\nconsistentcalculation....
Inthischapter,wewillfocusonaspecificXray\r\nbased technique among those employed in surface\r\nscience andwhich is especially suitable for the study of\r\nselfassemblednanocrystals:GrazingIncidenceSmallAngle\r\nXray Scattering (GISAXS). We will first introduce the\r\nmainfield of investigation considered herein, with basic\r\nnotions of Xray scattering from surfaces, and then\r\naddress basic concepts about GISAXS. Finally, we will\r\ndescribe a few relevant examples of studies, of\r\nnanostructured architectures, through ex situ and in situ\r\nexperiments of grazing incidence Xray scattering. This\r\nmanuscript is focused on the former, showing that they\r\ncanbeperformedbyusinglaboratoryinstruments.Insitu\r\ninvestigationsstillneedsynchrotronradiationsourcesin\r\nmostcases;therefore,onlyafewexamplesselectedfrom\r\nthe literature are reported here, for the sake of\r\ncompleteness. The experiments described are mainly\r\nperformed in the small angle range, providing\r\ninformation on the size and shape of nanocrystals,\r\ntogetherwiththeirspatialarrangement.Both2Dand3D\r\narchitectures are considered. In particular, GISAXS\r\nmeasurements of 2D superlattices of nanooctapods,\r\nperformed both at a third generation synchrotron\r\nbeamlineand with a tabletop setup, arecompared;the\r\nemployed tabletop setup is described in a dedicated\r\nparagraph.Furtherexamplesofgrazingincidencestudies\r\nas performed by the authors with a tabletop setup are\r\nreported: a GISAXS study of 3D iron oxide nanocrystal\r\nsuperlattices, showing the importance of modelling in\r\norder to obtain structural information from data; a\r\ncombined small/wide angle scattering(GISAXS/GIWAXS)\r\nstudyof3DPbSnanocrystalsuperlattices;andaGIWAXS\r\nstudy of P3HT nanofibres, showing how the ordering at\r\nthemolecularandatomiclengthscalescanbeobtainedby\r\nexploring different angular ranges in the same grazing\r\nincidence geometry. Finally, selected examples of in situ\r\nGISAXS studies, performed with synchrotron radiation\r\nsources,aredescribed....
In this paper, we report on multiphysics full\r\nwave techniques in the frequency (energy)domain and\r\nthe timedomain, aimed at the investigation of the\r\ncombinedelectromagneticcoherenttransportproblemin\r\ncarbon based on nanostructured materials and devices,\r\ne.g.,graphenenanoribbons.\r\n\r\nThefrequencydomainapproachisintroducedinorderto\r\ndescribe a Poisson/Schr�¶dinger system in a quasi static\r\nframework.Anexampleoftheselfconsistentsolutionof\r\nlaterallycoupledgraphenenanoribbonsisshown.\r\n\r\nThetimedomainapproachdealswiththesolutionofthe\r\ncombinedMaxwell/Schr�¶dingersystemofequations.The\r\npropagationofachargewavepacketisreported,showing\r\nthe effectof the selfgenerated electromagnetic field that\r\naffectsthedynamicsofthechargewavepacket....
The nanoscale semiconductor mercuric\r\nsulphide (HgS) has promising applications in electronic\r\nand optical fields. Continued development of synthesis\r\nmethods is needed to expand approaches that produce\r\nuniform particles, while avoiding reagents of high\r\ntoxicityandecologicalimpact.Asolventbasedapproach\r\nwas developed using mercuric chloride and elemental\r\nsulphur as the mercury and chalcogenide sources.\r\nEthanolwasusedasthesolventandsodiumhydroxideas\r\nthehydrolysisreagent.Useofmildsonicationresultedin\r\nsmaller particles (average 11nm diameter) than without\r\nsonication treatment (average 17nm diameter) and\r\ncontinuousnitrogenpurgingreducedthesurfaceoxygen\r\ncontent of the particles from approximately 25% to 6%.\r\nParticle characterization methods included TEM, XRD,\r\nXPS,UVvisible absorbance spectroscopy and DLS. The\r\nnanoparticles were typically spheres of 1015nm in\r\ndiameter. Aggregates formed in aqueous solutions\r\ntendedtobeintherangeof100nmormore.Theoverall\r\nprocess can be performed simply at room temperature\r\nandiscomparativelyfreeoftoxicchemicalhazards.The\r\nprocess does not include surfactants or other stabilizers\r\nthat could potentially contaminate the nanocrystals. In\r\nprinciple, the method could be applied to synthesis of\r\nothermetalchalcogenidenanoparticles....
Wide bandgap semiconductor ZnO, GaN and\r\nInNnanowireshavedisplayedtheabilitytodetectmany\r\ntypes of gases and biological and chemical species of\r\ninterest.Inthisreview,wegivesomerecentexamplesof\r\nusing these nanowires for applications in pH sensing,\r\nglucosedetectionandhydrogendetectionatppmlevels.\r\nThewidebandgapmaterialsofferadvantagesintermsof\r\nsensing because of their tolerance to high temperatures,\r\nenvironmentalstabilityandthefactthattheyareusually\r\npiezoelectric. They are also readily integrated with\r\nwirelesscommunicationcircuitryfordatatransmission....
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