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1、CarbonNanotubesasBiosensorsME695YangYang11/30/2004OutlinesIntroductionAmperometricbiosensorsCarbonnanotube-modifiedamperometricbiosensorsConclusionReferencesIntroductionMaterialsforBiosensors1.inertmetals(Pt.Gold)2.carbonaceousmaterials(graphite,carbonfibers,glassycarbonandcarbonnanotube
2、s)IntroductionCarbonNanotubesFabrication-catalyticchemicalvapordeposition(CVD)methodIntroductionTypesofCarbonNanotubesArmchair(n,n)-allmetallicZig-zag(n,0)-1/3metallic(n=3k);2/3semi-conducting(remainder)Chiral(n,m)-1/3metallic(n-m=3k);2/3semi-conducting(remainder)Single-walled:dia.0.4nm-
3、2.0nmMulti-walled:dia.4.0nm-50.0nmAmperometricbiosensorsBiosensors:1.convertsabiologicalresponseintoanelectricalsignal;2.fordeterminetheconcentrationofsubstancesandotherbiologicalparameters.Amperometricbiosensorsa:biocatalystb:transducer—calorimetric,potentiometric,amperometric,pizeo-ele
4、ctricc:amplifierd:integratedcircuite:displayAmperometricbiosensorCarbonnanotube-modifiedamperometricbiosensorsPreparationofcarbon-nanotubeelectrodewithPtnanoparticles1.GrowCNTdirectlyfromgraphitesubstratetoformCNTelectrode;2.PurifyCNTelectrode;3.PtnanoparticlesaredispersedonCNTelectrodeb
5、ypotentialstepdepositiontoobtainPt/CNTelectrode;4.ImmobilizeGODontoPt/CNTelectrodetoobtainGOD/Pt/CNTelectrodebybathingPt/CNTinenzymaticsolutionfor12hr;5.GOD/Pt/CNTelectrodeimmersedinNafionsolutiontopreventfallingoff;Carbonnanotube-modifiedamperometricbiosensorsCurrentresponsetosuccessive
6、injectionof0.1mMhydrogenperoxide1-5:CNTelectrodes;6:GraphiteelectrodesCNTelectrodesmoreelectrocatalyticactivethanGraphiteelectrodesCarbonnanotube-modifiedamperometricbiosensorsCurrentresponsetosuccessiveinjectionof0.1mMhydrogenperoxide2(0.2V)-3(0.6):Pt/CNTelectrodes;1(0.6V):Pt/Graphiteel
7、ectrodesResponsebehaviorofPt/CNTat0.6VMuchbetterthanPt/GraphiteComparingcurve3in(b)andcurve1in(a),Ptnanoparticlesgreatlyimprovestheelectrocatalyticactivity.Carbonnanotube-modifiedamperometricbiosensorsCurrentresponsetosuccessiveinjectionof0.1mMglucoseCurve1:Nafion/GOD/CNT