北京大學電分析電分析化學新技術elec6課件

NovelTechniquesinElectroanalyticalChemistry

電分析化學新技術

YuanhuaShao（邵元華，教授Ph.D.） CollegeofChemistryandMolecularEngineering PekingUniversityOutline:

1.Ultramicroelectrode(microelectrode) (超微電極或微電極） 2.Electroanalyticalchemistryat liquid/liquidinterfaces (液/液界面電分析化學) 3.Scanningprobemicroscopy (掃描探針顯微術） 4.Spectroscopictechniques (光譜或波譜技術） 5.Nano-electrochemistry (納米電化學）

GeneralBooks:1*A.J.BardandL.R.Faulkner,Electrochemicalmethods,fundamentalsandapplications,Wiley,NewYork,1980(2ndEdition,2001)2*C.M.A.BrettandA.M.O.Brett,Electrochemistry,Principles,Methods,andApplications,Oxford,19933*SouthamptonElectrochemistryGroup,NewInstrumentalMethodsinElectrochemistry,EllisHorwood,Chichester,19854A.M.Bond,ModernpolarographicmethodsinAnalyticalChemistry,Dekker,NewYork,19805J.Koryta,PrinciplesofElectrochemistry,Wiley,19876P.Delahay,NewInstrumentalmethodsinElectrochemistry,19547R.N.Adams,Electrochemistryatsolidelectrodes,19698*J.O'M.BockrisandA.N.Reddy,ModernElectrochemistry,Plenum,NewYork,19709電化學基礎，張祖訓，汪爾康，200010生命科學中的電分析化學，彭圖治，楊麗菊編著,199911*電極過程動力學導論，查全性，1976(19872ndEdition)12電化學研究方法，田昭武，198413*電化學測定方法，騰島昭等著，陳震等譯，199514電分析化學，蒲國剛，袁倬斌，吳守國編著，199315超微電極電化學，張祖訓，1998Reviews:AccountsofChemicalResearchAnalyticalChemistryAnnualReviewsofPhysicalChemistryChemicalReviewsWebsites:PartOne(第一部分)1.Ultramicroelectrodes(UMEs)(microelectrodes) (超微電極或微電極）

1.1 Introduction1.2 Definition1.3 BriefHistory1.4 Theoryandapplications1.1 Introduction(導言) 電分析化學在60年代末期基本上停止不前，極譜學的研究已經(jīng)達到其最高峰。隨著其它分析化學技術的發(fā)展，極譜學越來越不重要。光譜電化學及微電極的出現(xiàn)重新使電化學及電分析化學獲得新生！M.Fleischmann,A.Bewicketal:1970sto1980s,insitu光譜、波譜電化學M.Fleischmann,M.Wightmanetal:ultramicroelectrodes1970s-1980s1.2 DefinitionCommongeometriesincludespherical,hemispherical,disc,ring,andline.1.2 DefinitionCommongeometriesincludespherical,hemispherical,disk,ring,andline.MostcommonisthediskUME,whichcanbefabricatedbysealingafinewireinaninsulator,suchasglassoraplasticresin,andthenexposingandPolishingacross-sectionofthewire.SphericalUMEscanbemadeforgold,butaredifficulttorealizeforothermaterials.HemisphericalUMEscanbeachievedbyplatingmercuryontoamicroelectrodedisk.QuitedifferentisthebandUME,whichhasasitscriticaldimensionawidth,w,intherangebelow25m.Thelength,L,canbemuchlarger,eveninthecentimeterrange.CylindricalUMEetc.1.3 BriefhistoryInthelate1970s,M.Fleischmannetal.atSouthamptonUniversityofU.K,andM.Wightmanetal.atIndianaUniversityofUSAstartedtoworkwithverysmallelectrodes.

ThediffusionequationforspeciesOiswrittenasfollowsforthisgeometryWhererdescribesradialpositionnormaltotheaxisofsymmetryatr=0,andzdescribeslineardisplacementnormaltotheplaneoftheelectrodeatz=0.Fiveboundaryconditionsareneededforasolution.Threecomefromtheinitialconditionandtwosemi-infiniteconditionsSummaryofBehavioratUltramicroelectrodesAlthoughtherearesomeimportantdifferencesinthebehaviorofUMEswithdifferentshapes,itisusefulheretorecollectsomecommonfeaturesintheresponsestoalarge-amplitudepotentialStep: First,atshorttime,wherethediffusion-layerthicknessissmallcomparedtothecriticaldimension,thecurrentatanyUMEfollowstheCottrellequation,andsemi-infinitelineardiffusionapplies. Second,atlongtimes,wherethediffusion-layerthicknessislargecomparedtothecriticaldimension,thecurrentatanyUMEapproachesasteadystateoraquasi-steadystate.Onecanwritethecurrentinthislimitasfollowing:UMEshaveextendedelectrochemicalmethodologyintobroadnewdomainsofspace,time,chemicalmedium,andmethodologyApplications最常用的采用穩(wěn)態(tài)伏安法獲取動力學數(shù)據(jù)的方法MethodofMirkinandBard2.CurvefittingsizeBiologicalSystemORGANISMTISSUESCELLSAMINOACIDSH2O,CO2

PROTEINSPOLYPEPIDE

MEMBRANEENZYMETheSEMdiagramsofNano-andMicropipettesMicropipettesNanopipettes我們group可以制備內(nèi)徑從幾個nm到十幾個m的玻璃納、微米管AqueousPhaseOrganicPhaseAqueousPhaseOr