搜索
致谢外文资料原文OLED-PolypropyleneBio-CDSensorSrikanthVengasandra,YuankunCai,DavidGrewell,JosephShinar,andRuthShinarcDepartmentofAgricultural&BiosystemsEngineeringAmesLaboratory-USDOEandDepartmentofPhysics&AstronomyMicroelectronicsResearchCenterandDepartmentofElectricalandComputerEngineeringIowaStateUniversity,Ames,IA50011,U.S.AABSTRACTWiththegoalofdevelopingmicrofluidicplatformsforsensingapplications,flash-freemicropatternswereembossedinpolypropylenesurfaceswithultrasonicheatingforabiosensingapplication.Theembossedfeaturesweredesignedtoactasreservoirs,valves,andreactionchamberstoallow,incombinationwithacompactsensingplatform,themonitoringofanalytelevelsusingastandardPC-CDplayer.Togeneratethecompactsensor,asanexample,wechosethephotoluminescence(PL)-baseddetectionoflactateandglucoseusinganOLED-basedsensingplatform.Onceembossed,thesurfaceenergyoftheplasticsubstratewaschemicallymodifiedtomakeithydrophilic.Reagents,placedinseparatereservoirs,weredirectedthroughburstvalvestowardsareactionchamberviaCDrotation.LactateorglucoseweremonitoredbymeasuringtheeffectoftherelateddissolvedoxygenlevelonthePLdecaytimeofanoxygen-sensitivedye,followinganalyteoxidationcatalyzedbyasuitablespecificoxidaseenzyme.TheresultsdemonstratethepotentialofintegratingOLEDsasexcitationsourcesinPL-basedsensorswithmicrofluidicCD-basedplatforms,includingforsimultaneousmultipleanalyses.Keywords:Organiclight-emittingdiode,OLED,lab-on-a-CD,glucosesensor,lactatesensor1.INTRODUCTIONBiomedicalmicroelectromechanicalsystem(MEMS)-basedsensingplatformsfabricatedonplasticsubstrateshavethepotentialofe.g.,beinglowcost,disposable,cross-contaminationfree,andsensitive.Additionally,suchsensorsshowpromiseforhighthroughputandmultianalytedetection.Theadvantagesofsuchalab-on-CD-basedbiosensingplatformincludeitssimplicityintermsofusageforawiderangeofsolutions,versatilityintermsofmultianalytedetectionfeasibility,andcompactsize.Moreover,valvingiseasilyimplementedinsuchCDs.外文资料原文Thispaperdescribestheuseofultrasonicmicro-embossingtogeneratemicrofluidicchannels,valves,reservoirs,andreactionchambersinapolypropylene(PP)PCcompactdisc(CD).Theultrasonicmicro-embossingwasusedasasourceoflocalizedheat.Theadvantagesofthistechniqueincludeshortcycletimes,easeofde-embossingandlowresidualstresses.Moreover,thisapproachisapplicabletobatchandcontinuousmanufacturing,anditissimplerrelativetothemorecommonfabricationmethods,injectionmoldingandhotembossing.MicrofluidicCDarchitecturesweregeneratedinmaterialssuchaspolycarbonate[1],polystyrene(PS)[2],polydimethylsiloxane(PDMS)[3],andPP[4].Asshowninthiswork,theCDcanbeintegratedwithaphotoluminescence(PL)-basedOLEDsensingplatformtogenerateacompactdeviceformonitoringe.g.,lactateandglucose.TheCDmaterialsaretypicallyofrelativelylowsurfaceenergymakingthemhydrophobic.However,manyofthefunctionsofmicrofluidicdevicesrelyonhydrophilicpropertiessothatthechannelwallscanpromotecapillaryactionandallowproperfluidflow.Thus,toincreasethesurfaceenergychemicaltreatmentandoxidizationbyozoneorplasmaareoftenused.Intheexampleshown,analytessuchasglucoseandlactateweremonitoredbyutilizinganoxygen-sensitivedyeembeddedinathinfilm.Glucoseandlactatewereoxidizedinthepresenceofspecificenzymes,i.e.,glucoseoxidase(GOx)andlactateoxidase(LOx),respectively,andoxygen.Oxygenisconsumedinsuchreactionsandinsolutionunderspecificexperimentalconditionsthefinaldissolvedoxygen(DO)levelisrelatedtotheinitialanalyteconcentration[5].Theenzymescansometimesbeembeddedinathinfilm;alternatively,theycanbedissolvedinsolution.TheconsumptionofDOintheoxidationreactionsresultsinanincreaseinthePLintensityandthePLdecaytimeoftheoxygen-sensitivedye.Inthepreliminarymeasurementsshownbelow,theOLEDpixelarrayandthesensingfilmwerestructurallyintegratedbyattachingtwoglasssubstrates,onwhichtheywereseparatelyfabricated,back-to-back.ThePLwasmonitoredusingaphotomultipliertube(PMT);small-sizeSiphotodiodearrays,compatiblewiththedesignoftheOLEDpixels,arealsousableandwillleadtomorecompact,field-deployablesensors.Amorecompactsensorcanbeobtainedalsobyintegrating,inadditiontotheOLEDexcitationsourceandthesensingfilm,athinfilm-basedphotodetector(PD).SuchPDsbasedonamorphousornanocrystallineSiarecurrentlyunderdevelopment[6,7],however,theircurrentslowspeeddoesnotallowmonitoringoxygeninthetmode.OrganicPDsarealsosuitableforsuchintegrationandpossibly,formeasuringofsuitableluminophores.2.EXPERIMENTALPROCEDURE2.1.Materials外文资料原文FoamedandextrudedsheetsofPPwereobtainedfromTrexelCorporation(MA).ThefoaminglevelspecifiedbyTrexelwasapproximately15%to20%.ThePPsheetshadathicknessofabout5mmandwerecuttothesizeofastandardCDwithcommonshears.ThePP–CDswerethenusedforultrasonicmicro-embossing.Theoxygensensitivedyeused,Ptoctaethyporphyrin(PtOEP),wasobtainedfromH.W.Sands.ItwasembeddedinafilmofPS(molecularweight45000)obtainedfromSigma-Aldrich.GOx(fromAspergillusniger),LOx(frompichiapastoris),glucoseandL-lactatewerepurchasedfromSigma-Aldrich.Allreagentsweredissolvedinaphosphatebufferedsaline(PBS)solution.TheOLEDexcitationsourceusedwasbasedontris(quinolinolate)Al(Alq