表面等離子體共振及其在探測(cè)金表面大分子方面的應(yīng)用

^論文塩表￡窓表面等離子體共振及其在探測(cè)金表面大分子方面的應(yīng)用【摘要】：表面等離子體共振(surfaceplasmonresonance)可以存在于金屬和電介質(zhì)的交界面上，它的局域電場(chǎng)放大效應(yīng)使得它對(duì)表面的特性非常敏感。在本論文中表面等離子體共振技術(shù)被用來研究金表面的大分子自組裝效應(yīng)。我們首先進(jìn)行了一些實(shí)驗(yàn)和理論的工作來提高表面等離子體共振探測(cè)器的性能。通過對(duì)表面等離子體共振系統(tǒng)用多層膜模型來模擬，并且用菲涅耳理論來處理它的反射,我們研究了實(shí)驗(yàn)結(jié)果和理論模擬之間差別的來源。我們發(fā)現(xiàn)這種差別主要并不是由金表面的粗糙引起的，而是由金膜的緊密度引起的。我們改進(jìn)了金膜的制備方法來減小實(shí)驗(yàn)結(jié)果與理論計(jì)算之間的差別。通過高沉積速度制備的金膜具有更高的緊密性,并且它的表面更平整，因此更適合制備高性能的SPR探測(cè)器。自組裝單層膜(self-assembedmonolayers)被制備在金表面上用來幫助吸附DNA等大分子。我們成功的制備了幾種不同的自組裝單層膜，并且通過電化學(xué)阻抗譜(electrochemicalimpedancespectroscopy)測(cè)試了它們的特性。此外，我們還通過表面等離子體共振技術(shù)實(shí)時(shí)監(jiān)測(cè)了自組裝單層膜形成的動(dòng)力學(xué)過程。我們證明了通過巰丙基三甲氧基硅烷((3-Mercaptopropyl)trimethoxysilane)和3-氨丙基三乙氧基硅烷(3-Aminopropyl-triethoxysilan)構(gòu)造的雙層自組裝單層膜來吸附DNA分子是可行的，但是它的效率不高。我們通過電化學(xué)阻抗譜和表面等離子體共振詳細(xì)研究了巰基十一烷醇(11-Mercaptoundecanol)和11-氨^論文塩表F家基-1-十一烷硫醇(ll-Amino-1-undecanethiol)分子構(gòu)成的混合自組裝單層膜。因?yàn)樵诰彌_液中巰基十一烷醇分子是不帶電的，但是11-氨基-1-十一烷硫醇分子可以帶有正電荷，具有自組裝單層膜的表面的電荷可以通過改變這兩種分子的比例以及緩沖液的特性來調(diào)節(jié)。我們研究了他們與溶液離子力以及酸堿度的關(guān)系。這種巰基十一烷醇/11-氨基-1-十一烷硫醇的自組裝單層膜具有很好的電流阻斷特性。此外，我們還研究了它們對(duì)施加電壓的反應(yīng),這些自組裝單層膜在一個(gè)很小的電壓范圍內(nèi)喪失這種好的電流阻斷特性，這個(gè)范圍相對(duì)于銀/氯化銀標(biāo)準(zhǔn)參考電極一般為［-100mV,0mV］。為了制備基于表面等離子體共振的DNA芯片，我們致力于研究DNA在這些巰基^一烷醇/11-氨基-1-十一烷硫醇的混合自組裝單層膜表面的吸附。我們通過表面等離子體共振測(cè)量了DNA吸附在這些混合自組裝單層膜上的動(dòng)力學(xué)過程。研究的DNA有兩種，一種為3000對(duì)基的環(huán)形質(zhì)粒DNA，另外一種為200對(duì)基的直DNA。我們分別研究了DNA吸附對(duì)于溶液中DNA的濃度、表面電荷、溶液離子力的關(guān)系。吸附在金表面的DNA的拓?fù)鋱D也用原子力顯微鏡進(jìn)行了觀察。通過這兩種方法的結(jié)合，我們可以提取DNA吸附的很多信息。為了從DNA芯片上提取基因信息，我們提出利用表面等離子體共振的電場(chǎng)增強(qiáng)效應(yīng)構(gòu)建一種新的靈敏的表面二次諧波顯微鏡。數(shù)值模擬的結(jié)果表明這種表面等離子體共振增強(qiáng)二次諧波顯微鏡能夠探測(cè)更多的表面二階非線性極化系數(shù)。它還具有高分辨率表面成像和探測(cè)表面分子取向的潛力。【關(guān)鍵詞】DNA芯片表面等離子體共振有效介質(zhì)理論自組裝單層膜電化學(xué)阻抗譜原子力顯^論文塩表F家微鏡表面二次諧波產(chǎn)生【學(xué)位授予單位】華東師范大學(xué)【學(xué)位級(jí)別】博士【學(xué)位授予年份】2008【分類號(hào)】O53【目錄】：摘要6-8Abstract8-10RGsumG10-12Acknowledgementsl2-19Preamblel9-23Preparationofhighperformancegoldlayersandtheircharacterizationl9-20PreparationofSAMsandtheircharacterization20-21AdsorptionofDNAsonSAMsandtheircharacterization21-22DevelopingaSPRenhancedsecondharmonicgenerationmicroscopy22Conclusion22-231IntroductiontoSurfacePlasmonResonance23-511.1FundamentalsofSPs23-291.1.1DefinitionsofSPs23-241.1.2HistoryandapplicationsofSPtechniques24-Ultra-sensitivedetectors24-Plasmonics251.1.3DispersionrelationofSPR25-271.1.4Opticalcouplingmethods271.1.5VariousopticalconfigurationstoexciteSPR27-291.2DescriptionofourSPRexperiment29-321.2.1OpticalsystemstogenerateSPR29-301.2.2Micro-fluidsystems30-311.2.3Preparationofmetalfilms31-321.3Computationofreflectedandtransmittedfields32-451.3.1Reflectionandtransmissionofopticalwavesinisotropiclayeredmedia32-3Sn^論文塩表F家ell'slaw32-3Fresnel'sfOrmulae33-3Totalinternalreflectionandcriticalangle3Evanescentwaveandattenuatedtotalreflection35-361.3.2Matrixformulationforisotropiclayeredmedia36-4Transmissionandpropagationmatrices36-3Matrixformulationforamultilayersystem37-3ApplicationofmatrixformulationonthemodelingofSPR3Thedistributionofthetransmittedandreflectedfields39-4InfluenceofvariationofrefractiveindicesonSPReffect42-4InfluenceofexcitationwavelengthonSPReffect43-4InfluenceofthethicknessofgoldlayeronSPReffect44-451.4Finesizeeffects45-491.4.1Focalizationofthebeam45-471.4.2Parallelismoftheexcitingbeam47-491.5Conclusion49-512EffectofinhomogeneityofgoldonSPRreflectivitycurves51-892.1Methodsofgoldthermalvaporization51-522.1.1Slowthermaldeposition522.1.2Fastthermaldeposition522.2Set(A)ofslowandfastgoldvaporization52-672.2.1Experimentalconfigurationforpolarization52-542.2.2Slowgoldvaporization54-5AFMcharacterization54-5SPRcharacterization56-572.2.3Reproducibilityoftheslowdeposition57-60AFMcharacterization57-5SPRcharacterization59-602.2.4Fastgoldvaporization60-6AFMcharacterization60-6SPRcharacterization62-632.2.5Agingofthegoldlayers63-6AFMcharacterization64-6SPRcharacterization672.3Set(B)ofslowandfastgoldvaporization67-752.3.1Experimentalconfigurationforpolarization67-682.3.2Slowgoldvaporization68-702.3.2.lAFMcharacterization68-6SPRcharacterization69-702.3.3Fastgol^論女塩表F家dvaporization70-7AFMcharacterization70-7SPRcharacterization72-732.3.4Reproducibilityoftheseries(B)732.3.5Preliminaryconclusions73-752.4Effectivemediummodelforgoldvaporizedlayers75-872.4.1Maxwell-GarnetandBruggemanmodel75-772.4.2Roughnessofgoldsurfacesmodellingwithaneffectivelayer77-80Slowdepositionmode78-7Fastdepositionmode79-802.4.3Fittingslowandfastgolddepositionwithmodifiedgoldindexvalues80-8Slowdepositionmode81-8Fastdepositionmode82-852.4.4ScanningSurfacePlasmonMicroscopyImages85-862.4.5AFMimagesoffastand”chopped”depositiongoldsurf72dfe86Conclusion87-893Self-AssembedMonolayers89-1233.1IntroductiontoSAMs89-993.1.1Methodsofpreparingultrathinlayers89-9Spincoating89-90Langmuir-Blodgetttechnique90-9Selfassembledmonolayer(SAM)91-923.1.2SAMsofalkanethiolmoleculesonAu92-9ThereasonofchoosingongoldtoprepareSAMs9MethodofpreparingSAMs9StructureofalkanethiolSAMsonAu92-9Otherresults943.1.3MethodsofcharacterizationofSAMs94-9AFMtechnique95-9EIStechnique96-993.2PreparationofSAMs99-1033.2.1PreparationofdoubleSAMsofMPTSandAPTES99-1003.2.2PreparationofmixedSAMsofMUOandAUTinethanoll00-1013.2.3PreparationofmixedSAMsofMUOandAUTinbuffersl01-1033.3Resultsl03-1233.3.1AFMimagesofSAMsurfacel03-10AFMimagesofDoubleSAMsofMPTSandAPTES103-10AFMimagesofofmixedSAMsofMUOandAUT1043.3.2Formati^論文塩表F家onofSAMsstudiedbySPR104-10Descriptionofexperimentsl05-10Experimentalresultsl06-1083.3.3CharacterizationofSAMsbyEISl08-1DescriptionofEISexperimentsl08-1Modellingtheinterracialimpedancell0-1TypicalcurvesrecordedduringanEISexperimentsll2-1ModulationofthegoldpotentialduringanEISexperimentll3-1PotentialresponseofanunchargedMUOSAM114-1PotentialresponseofachargedAUTSAM117-1PotentialresponseofmixedSAMsl20-1ConclusionoftheEISstudyofSAMsongoldl21-1234CharacterizationofDNAadsorptionbySPR123-1394.1ThepurposeofstudyingtheadsorptionofDNA123-1284.1.1IntroductiontothestructureofDNA123-1ChemicalcompositesofDNA123-1PhysicalstructuresofDNA124-1254.1.2DNAchipsl25-1264.1.3DynamicsofDNAl26-12SpontaneousbendingofDNA12LongrangecorrelationinDNA126-1284.2AdsorptionoflongchainDNA128-1344.2.1InfluenceofDNAconcentrationonDNAadsorptionl28-1304.2.2InfluenceofsurfacechargesonDNAadsorptionl30-1324.2.3InfluenceofthesolutionionicstrengthonDNAadsorptionl32-1344.3AdsorptionofshortDNAchainl34-1394.3.1InfluenceofMUO/AUTproportiononDNAadsorptionl34-1374.3.2ComparisonoftheadsorptionoflongandshortDNAsl37-1395SPRenhancedsurfacesecondharmonicgenerationl39-1655.1IntroductiontoSSHG139-1425.2SPRenhancedSSHG142-1475.2.1Dependenceoffieldenhancementongoldlayerthicknessl42-1445.2.2Descriptionofexperimentandprimaryresultsl44-1475.3S^

論文塩表F家PRenhancedSHGmicroscopyl47-1655.3.1ExcitationofSPRenhancedSSHGbyobjectivelensl48-1505.3.2Electromagneticfieldnearfocusl50-15Scalardiffractiontheoryl50-15Vectorialfielddistributioninastratifiedfocalregionl51-15Transformationmatricesl53-15Expressionofelectricfieldnearfocusl56-1575.3.3Numer