北京大学电分析电分析化学新技术elec6课件

NovelTechniquesinElectroanalyticalChemistry

电分析化学新技术

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

1.Ultramicroelectrode(microelectrode) (超微电极或微电极） 2.Electroanalyticalchemistryat liquid/liquidinterfaces (液/液界面电分析化学) 3.Scanningprobemicroscopy (扫描探针显微术） 4.Spectroscopictechniques (光谱或波谱技术） 5.Nano-electrochemistry (纳米电化学）

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电化学基础，张祖训，汪尔康，200010生命科学中的电分析化学，彭图治，杨丽菊编著,199911*电极过程动力学导论，查全性，1976(19872ndEdition)12电化学研究方法，田昭武，198413*电化学测定方法，腾岛昭等著，陈震等译，199514电分析化学，蒲国刚，袁倬斌，吴守国编著，199315超微电极电化学，张祖训，1998Reviews:AccountsofChemicalResearchAnalyticalChemistryAnnualReviewsofPhysicalChemistryChemicalReviewsWebsites:PartOne(第一部分)1.Ultramicroelectrodes(UMEs)(microelectrodes) (超微电极或微电极）

1.1 Introduction1.2 Definition1.3 BriefHistory1.4 Theoryandapplications1.1 Introduction(导言) 电分析化学在60年代末期基本上停止不前，极谱学的研究已经达到其最高峰。随着其它分析化学技术的发展，极谱学越来越不重要。光谱电化学及微电极的出现重新使电化学及电分析化学获得新生！M.Fleischmann,A.Bewicketal:1970sto1980s,insitu光谱、波谱电化学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最常用的采用稳态伏安法获取动力学数据的方法MethodofMirkinandBard2.CurvefittingsizeBiologicalSystemORGANISMTISSUESCELLSAMINOACIDSH2O,CO2

PROTEINSPOLYPEPIDE

MEMBRANEENZYMETheSEMdiagramsofNano-andMicropipettesMicropipettesNanopipettes我们group可以制备内径从几个nm到十几个m的玻璃纳、微米管AqueousPhaseOrganicPhaseAqueousPhaseOr