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