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About OMICS Group

About OMICS Group.

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About OMICS Group

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  1. About OMICS Group OMICS Group International is an amalgamation of Open Access publications and worldwide international science conferences and events. Established in the year 2007 with the sole aim of making the information on Sciences and technology ‘Open Access’, OMICS Group publishes 400 online open access scholarly journals in all aspects of Science, Engineering, Management and Technology journals. OMICS Group has been instrumental in taking the knowledge on Science & technology to the doorsteps of ordinary men and women. Research Scholars, Students, Libraries, Educational Institutions, Research centers and the industry are main stakeholders that benefitted greatly from this knowledge dissemination. OMICS Group also organizes 300 International conferences annually across the globe, where knowledge transfer takes place through debates, round table discussions, poster presentations, workshops, symposia and exhibitions.

  2. About OMICS Group Conferences OMICS Group International is a pioneer and leading science event organizer, which publishes around 400 open access journals and conducts over 300 Medical, Clinical, Engineering, Life Sciences, Pharma scientific conferences all over the globe annually with the support of more than 1000 scientific associations and 30,000 editorial board members and 3.5 million followers to its credit. OMICS Group has organized 500 conferences, workshops and national symposiums across the major cities including San Francisco, Las Vegas, San Antonio, Omaha, Orlando, Raleigh, Santa Clara, Chicago, Philadelphia, Baltimore, United Kingdom, Valencia, Dubai, Beijing, Hyderabad, Bengaluru and Mumbai.

  3. Keynote:MolecularSensingBasedonOpticalWhispering-GalleryModeMicrosensorsKeynote:MolecularSensingBasedonOpticalWhispering-GalleryModeMicrosensors Zhixiong“James”Guo 3rdInternationalConferenceandExhibitiononBiosensors&BioelectronicsAugust11-13,2014,SanAntonio,Taxes,USA

  4. RutgersJerseyRoots,GlobalReach • Withmorethan65,000studentsoncampusesinCamden,Newark,andNewBrunswick,Rutgersisoneofthenation’smajorpublic institutionsofhighereducation. • Charteredin1766,Rutgershasauniquehistoryasacolonialcollege,aland-grantinstitution,andastateuniversity.In1864,RutgersprevailedoveranothermajorcollegeinNJtobecomethestate’sland-grantcollege. TheBirthplaceofCollegeFootball

  5. MajorCampus–NewBrunswick/Piscataway Land:2,688acres Students:>50,000 <40milestoTimesSquare,NYC

  6. PresentationOutline • Introduction Whatiswhispering-gallerymode? LabfabricationofopticalWGMdevicesMolecularsensingbasedonopticalWGM    • PhysicalandMathematicalDescription WGMsensorinamicro-opto-electro-fluidicsystem(MOEFS)Governingequations ----Chargeandfluidtransport ----Dynamicsofadsorptionanddesorption ----Maxwell’sequations   • ResultsandDiscussion ValidationwithexperimentalmeasurementInfluenceofappliedelectricalpotentialDynamicsofadsorption InfluenceofresonancemodesSensorcurves      • Concludingremarks

  7. WhisperingGallery Imagesfrom Wikipedia • Whisperinggalleryat St.Paul’sCathedral Simulationof the whisperinggallery atSt.Paul’sCathedral • Thestudy of acousticwhisperinggallerybeganin St. Paul’sCathedral, • London • LordRayleighwasthefirsttodescribehowsoundwaveswerereflectedaroundthewallsofthegalleryduetoitscircularshapein1878 • Theterm'whisperinggallery'hasbeenborrowedinthephysicalsciencestodescribeotherformsofwhispering-gallerywavessuchaslight

  8. OpticalWhisperingGalleries • Soundwaveshaveawavelengthonorderofmeters.Light,ontheotherhand,hasawavelengthontheorderofmicronsorless • Opticalwhispering-gallerymode(WGM)occursinsmalldielectriccircularshapessuchasspheres,rings,orcylinders,withdiametersonthemicrometerscale • OpticalWGMresonatorsarecharacterizedashavingextremelyhighQualityfactors(Q-factors)andverysmallmodevolumes • Suchfeaturesthemidealformicro/nanophotonicdevices,suchaslasers,filters,sensors,andquantumsystems • DistinctresearchersincludeStephenArnoldatNYU-Poly,KerryVahalaatCaltech,RussianscientistV.S.Ilchenko,FrenchscientistSergeHaroche(NobelLaureateinPhysics,2012),etc. Imagesfrom Vahala 2003,Nature424 Whisperinggallerymode resonators

  9. FabricationofMicrobeads&Tapers Imagesfrom Ma, Rossmann& Guo, 2008, J.Phys. D

  10. GenerationofOpticalWGM WGMoccurs whenlight,confinedbytotal internalreflections,orbitsnearthesurfaceof adielectricmediumofcirculargeometry andreturnsinphaseaftereachrevolution.Theelectromagneticfieldcancloseonitself,givingriseto resonance. SensingPrinciple: f/fr/rn/n Typicalresonancespectrum

  11. Example:SensingofASingleNano-Entity SingleNanoParticle 1.0 400nm Cavityof2µmindiameter Incontact 0.5 0 -0.5 -1.0 Waveguide H.Quan&Z.Guo,Nanotechnology,2007;orHaiyongQuang,Ph.D.Dissertation,RutgersUniversity,2006.

  12. EarlierLiteratureonSingleMoleculeDetection • • Science10August2007:Vol.317no.5839pp.783-787 • Receivedforpublication11May2007 • Label-Free,Single-MoleculeDetectionwithOpticalMicrocavities • (Dr.ZhixiongGuoproposedsuchasimilaridealbackinearly2005,Seebelow) • NSFProposalNumber:CTS-0541585.StartingDate:August15,2005 • PrincipalInvestigator:Guo,Zhixiong • ProposalTitle:SGER:SingleMolecule-RadiationInteractioninWhisperingGallery • ModeEvanescentField • • Nanotechnology18(2007)375702(5pp) • Received9May2007.Published22August2007 • Simulationofsingletransparentmoleculeinteractionwithanopticalmicrocavity. • HaiyongQuanandZhixiongGuo • Resultsfrom • HaiyongQuan,Ph.D.Dissertation,RutgersUniversity,May2006 • CharacterizationofOpticalWhisperingGalleryModeResonanceandApplications • • NatureMethods-5,591-596(2008) • Whispering-gallery-modebiosensing:label-freedetectiondowntosinglemolecules.FrankVollmer&StephenArnold

  13. EarlierLiteratureonLayeredDetection • • Appl.Phys.Lett.80,4057(2002) • Proteindetectionbyopticalshiftofaresonantmicrocavity. • F.Vollmer,D.Braun,A.Libchaber,M.Khoshsima,I.Teraoka,S.Arnold. • OpticsLetters,Vol.28,Issue4,pp.272-274(2003) • Shiftofwhispering-gallerymodesinmicrospheresbyproteinadsorption. • S.Arnold,M.Khoshsima,I.Teraoka,S.Holler,andF.Vollmer • SelectedTopicsinQuantumElectronics,IEEEJ,vol.12(1),2006 • Polymermicroringresonatorsforbiochemicalsensingapplications • C.Y.Chao,W.Fung,L.J.Guo • AdvancedFunctionalMaterials,vol.15(11),pp.1851-1859,2005 • MacroporousSiliconMicrocavitiesforMacromoleculeDetection • H.Ouyang,M.Christophersen,R.Viard,B. L.MillerandP. M.Fauchet • • JQSRT,vol.93(1-3),pp.231–243,2005 • Simulationofwhispering-gallery-moderesonanceshiftsforopticalminiaturebiosensors • H.QuanandZ.Guo • andmanyothers

  14. ProposedMOEFSwithaWGMSensor Ground/Anode Anode/Gound Analyteinlet port Bufferinlet port Outlet port Channel Enlarged simulationregion WGM sensor Chargedanalyte flow direction Totalinternalreflection d Channel h ө Gap w Optical waveguide Incident light l

  15. AdsorptionandSensingofSmallMolecules Molecules/Analytes Molecularmonolayer Method I:SurfaceattachmentofanalytesLeiandGuo2011,Biomicrofluidics Method II:Filtrationandtrappingofanalytesinporouslayer LeiandGuo2012, Nanotech.

  16. GoverningEquations • Charge transportationequations forthe chargedanalyte, hydroxideionand hydrogenion. C D2C i1,2,3 KVC(zwFC)K i i,c i i i i i,di i t • Poisson equationfor electricalpotential EF(cizi) i 2  f E • Navier-Stokesequation with porousmediummodel P2 V VVV   E  t   • Langmuirmodelfor adsorption C C s K (C)KC 1 ads    s des s t

  17. GoverningEquations(cont.) • Time-dependentMaxwell’sequations 1  E;EH 2E2E0 c   t   12H2H0 H0;HJE c   where t j 2c ci cr0   • j=1,2indicatethe electricalconductivityof bulk solutionandmicro resonator,respectively. • In-planeTEwaves • E(x,y,t)E(x,y)eeit • z z • H(x,y,t)[H(x,y)eH(x,y)e]eit • x x y y

  18. ValidationwithExperiment Sample analyte: BovineSerumAlbumin(BSA)proteins thatcarry negativecharges at neutralpH • Ona hydrophilic surface, the electrostaticattractionbetween oppositelychargedmaterialis often the major drivingforce for adsorptionof biomolecules. In a Si3N4/H2O solution, 0.8 Relativecoverage(Cs/) UnaffectExperimentSimulation 0.6 the SiNH+species remains thecharged 3 one. 20pM 0.4 • Langmuirapproachis adoptedto describethe protein adsorption process. Thekeyassumptions are:(a) only a monolayerformsbyadsorption;(b) the adsorbingsurface is composedof discrete,identical,andnon-interacting sites;(c) the adsorptionprocess for eachmolecule isindependent;and(d) there is nomolecule-molecule interactionssince the concentrationis verylow. 0.2 500pM 0 0200 400600 Time(s) AdsorptionofBSAat twodifferent concentrationsontoasilica microresonator at pH6.6intheabsenceofexternalelectricalfield(experimentalresultsbyYeunget al. 2009,Colloids andsurfacesB:Biointerfaces)

  19. Results:DetectionofBSAProteins 16.7V/cm50pM 80 Theresonancefrequencyshifts versus thebulk BSAconcentrationfor differentappliedvoltagegradientsatsteadystate Frequencydownshift(MHz) 60 23.3V/cm10pM 400 350 23.3V/cm 16.7V/cm 6.67V/cm 40 Frequencydownshift(MHz) 300 20 Langmuirfitting 250 200 5000 1000015000 Time(s) 150 Timetraceof optical resonancefrequency down shifts inducedby BSAadsorption, showing theLangmuiradsorptionpattern 100 50 0 0 204060 Concentration(pM) 80

  20. Results:AminoglycosideAdsorptioninPorousLayer Samplemolecules:Neomycin,an aminoglycosideantibiotic,thatcarriespositive charges at neutralpH • Contourofanalyteconcentrationintheporousresonatorandtheequipotentiallinesoftheelectricalpotentialfieldforthecasewith10pMfeedand17.7V/cm • Agroundingelectrodeisplacedinsidetheresonatortoattractthepositively-chargedneomycin molecules. Theporousvicinitysurroundingtheelectrodeisthemostconcentratedregion,which justifiesthefactthat,theappliedelectricalpotentialisapredominantdrivenmechanismoverthe convectionanddiffusionforthechargedanalyte transport. • Molecularconcentrationneartheresonatorcanbeenhancedbyamagnitudeoforder,thatis veryusefulforextremelylow-concentration moleculedetection.

  21. InfluenceofElectricalPotentialonAdsorption Averagedsurfacedensity(pg/cm2) 250 10pM 50pM 200 150 100 50 0 510152025 Electricalpotentialgradient(V/cm) Theaminoglycosideconcentration profilesalong the resonatorradial direction with a feed concentrationof 10pM forvariousappliedvoltage gradients. Influence of electricalpotentialon the surfacedensity insidethe porous resonator

  22. TimeTraceofAdsorptionandInducedWGMShifts Thetimetrace of the adsorbed aminoglycosides on the resonator surfaceforthree differentoperation cases. Theresonancefrequencydownshiftswith Langmuirfittingfortwo differentfeeding and applied voltageconditions underthe first-order andsecond-ordermodes, respectively.

  23. ModeProfileandSensorCurves 13 3.5 4 4.5 5 5.5 90 0.8 80 Concentration(pM) Normalizedenergy 70 0.6 1stordermode2ndordermodeConcentration 60 0.4 50 0.2 40 30 03 3.544.555.5 Distancefromtheresonatorcenter(m) Energydistributionsinthe resonatorradial direction forthe first-andsecond-order modes andthe amino concentrationprofile in andoutsidethe resonatorforthe caseof 17.7V/cm applied voltagegradient and10 pMfeedconcentration. Theopticalsensorcurvesat steady-state aminoglycoside deposition.

  24. Conclusions • Aporousringmicroresonatorintegratedinamicroelectrofluidicsystemcanfunctionasbothafilterandanopticalwhispering-gallerymodesensor. • Themicroelectrofluidicforcesaugmentsubstantiallythefiltrationcapabilityofthesystem,whichseparatesthetargetmoleculesfromitssolutionandenrichestheanalytedepositioninsidetheporousresonator. • ThisalterstheopticalpropertiesoftheresonatorandshiftstheopticalWGMresonancefrequency,leadingtolabel-freeultrasensitivedetectionofsmallmoleculesatpicomolarconcentrationlevelsandbelow. • Thesecond-orderwhispering-gallerymodesignalisfoundtogivegreaterresonancefrequencyshiftthanthecommonlyadoptedfirst-ordermodeofothertypesofWGMsensors. • Forlargemoleculessuchasproteins,theyaredetectableviadirectsurfaceattachmentduetosurfacemodificationorelectrostaticforce.

  25. Acknowledgment ThankYou! • Thismaterialisbased upon work supportedby NSFgrants CBET-1067141 andCTS-0541585, andby the US DepartmentofAgricultureundergrant number2008-01336. • Former graduate studentswho made great contributions: Dr. Haiyong Quan • Dr. LeiHuang • Dr. QiulinMa • Useful discussion withDr.Guoying Chen,ResearchChemist, at EasternRegional ResearchCenter,USDAAgricultural ResearchService,isappreciated.

  26. Let Us Meet Again We welcome you all to our future conferences of OMICS Group International Please Visit:www.omicsgroup.com www.conferenceseries.com www.pharmaceuticalconferences.com

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