fiber biosensors.docx

fiber biosensors.docx

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fiberbiosensors

OpticalBiosensors

InBiomedicalTechnique

Name:

ZhangXiaoliang

StudentNumber:

200800170355

Institute:

ControlScience&Engineering

Major:

BiomedicalEngineering

OpticalbiosensorsinBiomedicalTechnique

Summary:

BiomedicalEngineering（Biomedical-Engineering）isanewinterdisciplinary,whichcombinesengineering,biologicalandmedicaltheoriesandmethods,atalllevelstostudychangesinthestateofthehumansystem,andtheuseofengineeringandtechnicalmeanstocontrolsuchchangesaimedataddressingissuesrelatedtomedicine,toprotecthumanhealthandfordiseaseprevention,diagnosis,treatmentandrehabilitationservices.Opticalbisosorshavemadeanimportantroleinit.

Keywords:

biosensorsfiberapplicationdevelopment

Background

Biomecalhasamainbranchofbiologicalinformationtostudybiologyandchemistry.BiomedicalEngineeringinthe1950stherise,withmedicalengineeringandbiotechnologyhasaverycloserelationship,butalsodevelopingveryrapidly,becomingtheworld'smainareasofcompetitionone.

Manynewhigh-techmaterialshavepromotedthedevelopmentofBiomedicalEngineering.BiomedicalEngineeringinelectronics,microelectronics,moderncomputertechnology,chemistry,polymerchemistry,mechanics,modernphysics,optics,radiationtechnology,precisionmachineryandmodernhigh-techdevelopment,basedonthecombinationwiththemedicalconditionstodevelop.Processanditsdevelopmentiscloselyrelatedtothedevelopmentofhigh-techworld,anditusesalmostallofthehigh-techachievements,suchasspacetechnology,microelectronicstechnology.Amongthesetechniques,opticalsensorshavemadegreatcontributionstoit.

Sensorsarebeingdevelopedtoaddresstheneedforrealtimeanalyticalmeasurementsinthefield,asthephysicalcharacteristicsofconventionalanalyticalinstruments（e.g.size,weight,andfragility）donotfacilitatesuchmeasurements.Thetraditionalprocessofsampling,preparation,andmeasurementcreatesalapsebetweenthetimeananalyticalvalueisrequestedandwhenitisdetermined.Thegoalofsensorresearchistoprovidecontinuousquantitativeand/orqualitativeanalysis,therebyeliminatingthetimelapse,whilepreservingtheprecisionandaccuracyoflaboratoryanalysis.Opticalfiber-basedbiosensorsareoneclassofsensorsthataddressthisgoal.Astheirnameimplies,opticalfiber-basedbiosensorsareasub-classificationofbiosensors,whichIUPACdefinesasadevicethattransformschemicalinformation,rangingfromtheconcentrationofaspecificsamplecomponenttototalcompositionanalysis,intoananalyticallyusefulsignal.isself-contained,allpartsbeingpackagedtogetherinthesameunit,usuallysmall,thebiologicalrecognitionelementbeingindirectspatialcontactwiththetransducingelement."Thus,anopticalfiber-basedbiosensorisabiosensorthatemploysanopticalfiberoropticalfiberbundle,asaplatformforthebiologicalrecognitionelement,andasaconduitforexcitationlightand/ortheresultantsignal.

Opticaltechniqueshaveexperiencedasignificantgrowthoverthelasttwodecades.Thisgrowthstemslargelyfromthedevelopinginfrastructureinthetelecommunicationsandcomputersectors.Intelecommunications,opticalcomponentssuchasnewlightsources,detectors,andopticalfibershavebeendeveloped.Inthecomputerindustry,newlightsourceshavebeendevelopedtoreaddecreasingfeaturesizesinopticalstoragemedia,suchasDVDs.Althoughtheseopticalcomponentsweredevelopedforcompletelydifferentpurposes,theyhavespilloverapplicationsintheopticalsensingarena.Thesecomponentsenablesmaller,low-powered,integrateddevicestobepreparedandusedforavarietyofbiosensingapplicationsinenvironmentsthatwerepreviouslynotpossibleduetothelargesizeorpowerrequirementsofthesecomponent’spredecessors.Therewillcontinuetobefurtherimprovementsandnewcapabilitiesstemmingfromadditionaldevelopmentsinthetelecommunicationsandcomputerindustriesthatwillcontributetoadvancesinopticalsensing.Theintegrationofopticalsensorsintobothtelecommunicationsandcomputersisalogicalnextstepastheirarchitecturesanddeviceoperationsmerge.

Introductionaboutfiberbiosensors

Anopticalfiberisaflexible,transparentfibermadeofverypureGlassnotmuchwiderthanahumanhairthatactsasamaveguide,or"lightpipe",totransmitlightbetweenthetwoendsofthefiber.Fiber-opticbiosensorsofferanumberofadvantages.Theyarewithmanycharacteristicssuchassingle-modefibers,polarizationpre-servingfibersandmultimodefibers.Opticalfibersalsoprovideanumberofconvenientgeometriessuchasasinglecorefiber,adualcorefiber,aY-junctionfiber,andfiberbundles,offeringflexibilitytomakethemcompatibletoaspecificneed.Ontheotherhand,useofalonger-lengthfiberprovidesagainininterationlengthorsurfaceareaformultipleanalytedetection.Opticalfiberscanalsooffercompatibilitieswithcathetersorendoscopesforinvivobisensing.Fiberopticresearchhasbeenexpandingsincefiber-imagingbundleswerefirstputtogetherinthelate1950s.Whiletheirinitialusewassolelyasameanstotransmitlightoveronlyafewtensofcentimeters,fiberopticshaveevolvedtobecomeoneofthemostadvancedmediumsoftransmissionandtranslationavailabletoday.TodaytheyareusedinapplicationsvaryingfromtheInternettomicroscopes.Forthepastdecade,fiberopticbiosensorshavebeentoutedasthemeanstorevolutionizemedicaltechnology,dramaticallyimprovingpatientcareandcuttingoveralloperatingcosts.TheyareimmunetoelectromagneticsignalsandarecurrentlyusedinavarietyofmedicalapplicationssuchasearlycancerandAIDSdetection.Biosensorscanbeclassifiedaccordingtoeitherthenatureofthebioreceptorelementortheprincipleofoperationofthetransducer.Thefiber-opticbiosensorisadevicethatmeasurestheformationofafluorescentcomplexatthesurfaceofanopticalfiber.Antibodies,lectins,andantibioticsprovidethemechanismforrecognizingananalyteofinterestandimmobilizingafluorescentcomplexonthefibersurface.Thebiosensorisfast,sensitive,andpermitsanalysisofhazardousmaterialsremotefromtheinstrumentation.Aportablesensorhasbeenmanufacturedandtestedon-sitefordetectionofexplosivesingroundwater.Antibodiescoatedonthefiberarestableforuptotwoyearsofstoragepriortouse.Thebiosensorhasbeendevelopedtodetectexplosives,pollutants,pathogens,andtoxicmaterials.

OpticalbiosensorsmakeuseofmodificationinopticalpropertiessuchasUV-visabsorption,bioluminescenceandchemiluminescence,reflectanceandfluorescencebroughtbytheinteractionofthebiologicalrecognitionelementwiththetargetanalyte.Opticalsensorsofferadvantagesofcompactness,flexibilityandresistancetoelectricalnoise（Leietal.,2006）.Noneedforareferenceelectrodeandthepossibilitytoconstructverysmallsensors13owingtousingopticalfibersmakeopticaldevicespotentiallysuitableforarangeofmeasurements（LeinerandHartmann,1993;Morganetal.,1996;Mülleretal.,1997）.Affinitybiosensors.Inthesethereceptormoleculebindstheanalyte“irreversibly”andnon-catalytically.Thebindingeventbetweenthetargetmoleculeandthebioreceptor,forinstanceanantibody,anucleicacid,orahormonereceptor,istheoriginofaphysicochemicalchangethatwillbemeasuredbythetransducer.Biosensordevelopmentisdrivenbythecontinuousneedforsimple,rapid,andcontinuousin-situmonitoringtechniquesinabroadrangeofareas,e.g.medical,pharmaceutical,environmental,defense,bioprocessing,orfoodtechnology.Severalreviewsandbookspublishedinrecentyears.Thesedevicescan,becauseoftheirsensitivity,selectivity,versatility,ruggedness,andcapabilityofsimultaneousmultianalytemonitoring,beregardedasaninterestingalternativetoconventionaltechniquesfortheseapplications.

Application&Advantages

Thefieldofopticalbiosensorshasemergedasatopicofgreatinterestbecauseofthegreatneedinmedicaldiagnostics,andmorerecently,theworldwideconcernofthethreatofchemicalandbioterriorism.Theconstanthealthdangerposedbynewstrandsofmicrobialorganismsandspreadofinfectiousdiseasesisanotherconcernrequiringbiosnesingfordetectingandidentifyingthemrapidly.OpticalBiosensortechnologyconcernsthedevelopmentofsensorsthatcanmeasurechangesinlightabsorptionandlightoutput.Thetermisusedintheliteratureinmanyways.Somedefinitionsareasfollows:

a）Adeviceusedtomeasurebiologically-derivedsignals

b）Adevicethat“senses”using“biomimetic”（imitativeoflife）strategies

ex.,“artificialnose”

c）Adevicethatdetectsthepresenceofbiomolecules

Biosensorscanbeuesdinfourmainfields.Thefirstoneisqualityassuranceinagriculture,foodandpharmaceuticalindustries,suchasE.Coli,Salmonella.Theseconduseistomonitorenvironmentalpollutantsandbiologicalwarfareagentsex.,Bacillusanthracis（anthrax）spores.Anditsanotherprimaryapplicationisaboutthemedicaldiagnosticesuchasglucose.AlsoitcanbeusedinbiologicalassaysforDNAmicroarrays.AndthebiosensorswhichcanbeuesdinBiomecalEngineeringfieldisthefiberopticsensors.Itcanluorophoresincorporatedintotipchangeandfluorescenceleveldependingonleveloftargetpresent.Maincomponentsofanopticalbiosensorare（i）alightsource,（ii）anopticaltransmissionmedium（fiber,waveguide,etc）,（iii）immobizedbiologicalrecognitionelement（enzymes,antibodiesormicrobes）,（iv）opticalprobes（suchasafluorescentmarker）fortransduction,and（v）anopticaldetection