Disposablepaper-basedelectrochemicalsensor

utilizinginkjet-printedPolyanilinemodified

screen-printedcarbonelectrodeforAscorbicaciddetectionJournalofElectroanalyticalChemistry685(2012)72–78AbstractInthiswork,anewpaper-basedelectrochemicalsensorisdevelopedasalow-costanddisposablepointof-caredeviceforpre-screeningpurpose.Electrodesofthisnewsensorarefabricatedusingtwoprintingtechniques,i.e.screen-printingforbasematerialandinkjet-printingformodifyingfunctionalmaterial,andtheperformanceoffabricatedsensorsforAscorbicaciddetectionisdemonstrated.Thepaper-baseddeviceconsistsofthreeelectrodesincludingPolyaniline(PANI)modifiedScreen-PrintedCarbonElectrode(SPCE)asworkingelectrodeandtwobareSPCEsasreferenceandcounterelectrodes.ThreeSPCEsareinitiallyscreen-printedonafilterpaper,andPANIisconsecutivelyinkjet-printedonthedesignatedworkingSPCE.ItselectrochemicalperformancesaresystematicallyinvestigatedtowardsAscorbicacidusingCyclicVoltammetry(CV)withdifferentAcetatebufferpHsandnumbersofprinted-PANIlayers.TheCVresultsshowthattheoptimalbufferpHandnumberofPANIlayersare4.0–5.0and5,respectively.Consequently,real-timedetectionofAscorbicacidconcentrationisperformedusingChronoamperometrytechniqueundertheoptimalconditionsfrompreviousCVstudies.Fromtheresults,thesensorexhibitsagoodsensitivityof17.7μA/mMandamoderatelylowlimit-of-detectionof30±3μMinaconcentrationrange

of30–270μM.Accordingtocostversusperformance,theutilizationofpaper-basedsensorwithinkjet-printedPANImodifiedSCPEisanalternativechoiceforlow-costanddisposablepoint-of-careapplications.printingtechniquesinkjet-printingscreen-printingawell-knowncontactprintingmethodlowcost,suitableforlarge-scaleproductionpoordetectionsensitivityandselectivitylowmaterialconsumptionhighpatternresolutiongoodthicknesscontrolhighuniformitylowtemperatureprocessinglow-costinstrumentationDimatixMaterialsPrinterDMP-2800basematerialmodifyingfunctionalmaterialPolyaniline(PANI)聚苯胺，高分子化合物的一種，具有特殊的電學(xué)、光學(xué)性質(zhì)，經(jīng)摻雜后可具有導(dǎo)電性。聚苯胺分子鏈中的P電子共軛結(jié)構(gòu)。摻雜的質(zhì)子酸分解產(chǎn)生H+和對陰離子（如Cl-等）進(jìn)入主鏈，與胺和亞胺基團(tuán)中N原子結(jié)合形成極子（polaron）和雙極子離域到整個分子鏈的P鍵中，從而使聚苯胺呈現(xiàn)較高的導(dǎo)電性。不同氧化程度聚苯胺摻雜方式Polyaniline(PANI)聚苯胺，高分子化合物的一種，具有特殊的電學(xué)、光學(xué)性質(zhì)，經(jīng)摻雜后可具有導(dǎo)電性。LeucoemeraldinebasePernigranilinebaseEmeraldineEmeraldinesalt王耀文.聚苯胺與石墨烯在防腐涂料中的應(yīng)用[D].哈爾濱工程大學(xué)，2012不同氧化態(tài)聚苯胺之間的可逆反應(yīng)PANIsynthesis0.19MLABSALABSA-LinearAlkylBenzeneSulphonicAcid,APS-AmmoniumPeroxydisulfate40mldistilledwater+LABSAsolutionheated,5min0.08MAPS0.16MAniline20mlLABSAsolution+APS–LABSAmixture+Aniline–LABSAmixtureStirred,2.5hPANIdispersedsolutioncentrifugesupernatantDialysismembranePANIinkππ*πpolaronπ*polaronUV–VisspectrumofanaqueousdispersionofPANIinkPrintingofelectrodesdesigneddevicefabricateddevicecarbongraphitepastescreen-printingWhatmanGradeNo.1filterpaperthreeSPCEsheated

workingelectrodesreferenceelectrodescounterelectrodessynthesizedPANIinkinkjet-printingheatedmodifiedworkingelectrode

modifiedworkingelectrode0.3%Parafilmwaxdesiredworkingelectrodecarbongraphitepaste--GwentElectronicMaterialLtd.submergedExperimentsonPANImodifiedelectrodePerformanceofPANImodifiedelectrodeWorkingpHofAcetatebufferNumberofprintedPANIlayersScanrateDemonstrationforAscorbicaciddetectionPANImodifiedelectrodeexaminationat2mMofAscorbicacidinAcetatebufferatpHof5.0andscanrateof50mV/stendeviceswithbareSPCEsrepeatabilitylowerthan2%ofpeakcurrentdeviationaverygoodreproducibilityofSPCEsbackgroundsignalTest1,inAcetatebuffersolutionTest2,inAscorbicacidwithAcetatebuffersolutioneffectiveelectricalsignalthree-cycleaveragedsignalsSEMimagesofvariousfabricationconditionsBareSPCEone-layer-polyanilineprintedonSPCEfive-layer-polyanilineonSPCEafterheattreatmentsmallerthan2μmPANIfilmPerformanceofPANImodifiedelectrodeat2mMAscorbicacidinAcetatebufferatpHof5.0atscanrateof50mV/s.bareSPCEfive-layerprinted-PANImodifiedSPCEtentimeslargerIpoverbareSPCEhighelectrochemicalredox

catalyticproperties

ofPANItowardsAscorbicacidWorkingpHofAcetatebufferat2mMAscorbicacidinAcetatebufferatscanrateof50mV/s.pH2.0–3.5twocurrentpeaks0.35and0.45VLuecoemeraldinetoEmeraldineSalt(ES)EStoPernigranilineSalt(PS)pH4.0–5.0identicallysteeperasthetwopeaksoverlapintoonepeakLuecoemeraldinetoPSpH5.0–6.0thecurrentamplitudebecomesmuchlowerpH5.0NumberofprintedPANIlayersat1mMAscorbicacidinAcetatebufferatpHof5.0atscanrateof50mV/sfive-PANI-layermodifiedelectrode1layerto5layersbesharperwithhighercurrentamplitudebeyond5layersbecomesunclearandverybroadScanrateat2mMAscorbicacidinAcetatebufferatpHof5.0electrochemicalreactiondiffusionprocesselectrontransferprocess

theredoxreactionAscorbicacidelectrodese-relativelyslowAAelectrodesDemonstrationforAscorbicaciddetectiontherange,30–270μM.thesensitivity,17.7μA/mM.maximumstandarddeviationaround0.6μAat200μMAALOD,30±3μM.DemonstrationforAscorbicaciddetection100μMAscorbicaciddetectioninAcetatebufferatpHof5.0at0.4Vwithdifferentinterferences0–500μMdoesnotaffect0–140μMdoesnotaffectDemonstrationforAscorbicaciddetectionarelativelylowconcentrationrange,moderatelylowLODandgoodsensitivity