聚结晶紫薄膜修饰电极对多巴胺与尿酸的电催化作用

聚结晶紫薄膜修饰电极对多巴胺与尿酸的电催化作用 聚结晶紫薄膜修饰电极对多巴胺与尿酸的 电催化作用 第19卷第3期 2007年9月 湖南文理学院(自然科学版) JournalofHunanUniversityofArtsandScience(NaturalScienceEdition) V_01.19No.3 Sep.2007 文章编号:1672.6146(2007)03.0024—05 TheElectr0catalyticActionsofPoly(CrystalViolet) FilmModifiedElectrodesonUricAcidandDopamine SUNYuan—xi,HUXia,ZHOUGu—zhen (ChemistryDepartmentofTheHunanUniversityofArtsandScience,ChangdeHunan415000) Abstract:Thepoly(crystalviolet)filmmodifiedelectrodes (PCVE)werepreparedbycyclicvoltammetry,electrocatalytic actionofPCVEonUricAcid(UA)andDopamine(DA)had beenstudiedinparticular.Theresultshaveshownthatthe PCVEhasastrongelectrocatalyticactionforUAandDA,and astrongpowerofresistinginterfereofAA.UricAcidand Dopaminecanbemeasuredinexistenceof1000timesAA. CombiningPCVEwithdifferencepulsevoltammetry(DPV), thelinearityrangeofdeterm!ningDAis4.0xl0,mol/L, 2.5x105mol/L,thedeterminationlimitsreachuDto3.5x10- moI]L;thelinearityrangeofdeterminingUAis5.0X10-mol/L 5.0xl0..mol/L,thedeterminationlimitsare5.0xl0一mol/L. TheDAandUAcanbemeasuredatthesametime.Theresults aresimilarbyUsingthesamemethodwithUAofUrine samples. Keywords:Poly(CrystalViolet);Electrocatalyse;Modified Electrodes;.Dopamine;UricAcid CLCnamber:O657.1DocumentCode:A Applicationofchemicalmodifiedelectrodesin biologyandchemistryhasbeenpaidmoreandmore attentionrecently.Especially,theappearanceof modifiedelectrodeswithbiologicaldyeshasforced thestudyoftheelectrochemistryofbiological substancessuchasproteinsandenzymeslJ1.Peopleare mostjnterestedinpolymerfilmmodifiedelectrodes. suchasA.A.Karyakin,ShaojunDong引,Hongyuan Chen『4l,ZhuobinYuan[引,HuangxianJu[刚.Thevhad polymerfilmmodifiedelectrodessuchasmethylene blue,AzureA,methyleneviolet,isonicotinicacid,nile bluebydifferentmethods.Thesemethodscanform functiongroupsofhighconcentrationonthesurface ofanelectrodeandatthesametimecanincreasethe stabilityoffixfunctiongroupsandselectivityof reactions.Therefore,thepolymerfilmmodified electrodeshavefoundbroadlystudiedandapplied. Inthestudyofthepoly(neutralred)film modifiedelectrode【7,8】.authordiscoveredthatcrystal violet,akindofbiologicdyemolecule,canforma filminthesurfaceofglasscarbonbyelectrochemistry polymerizationmethod.Thispaperemphasizesthe preparationofPCVEbycirclevoltanunetryand specialtyofelectroanalyticalchemistry.Results indicatedthatPCVEhadagoodelectrocatalytic reactionforDopamine(DA)anduricacid(UA),the catalyticpeakcurrenthadwelllinearrelationshipwith itsconcentrationinwidestrange.DAandUAin biosamplescanbecontinuouslymeasured. 1Experimentparts 1.1Instrumentsandreagents CHI660AElectrochemistryworkstation(Shang haichenhuainstrumentcompany),Usingthree electrodessysteminexperimentation:Theworking electrodeisglasscarbonelectrodeorpolymerfilm modifiedelectrode(mm),thereferenceelectrodeis saturationcalomelelectrodeandtheauxiliary electrodeisplatinumpieceorsilkelectrode;P.1 polishingmachine;CQ一50Ultrasoniccleanouteretc. Crystalviolet(biochemicalreagent,forshortC madeinYuxireagentcompanyinCongming,China.), itwasmade0.1%watersolutions;Dopamine(USA. Sigma.co.),preparedinto0.0010mol/Lstandardsolu— tion;Uricacid(China,Shanghai,AR),itpreparedinto O.010mol/LstandardrepertorysolutionbyO.01mol/L Na2CO3solution,testingsolutionwaspreparedby dilutionbeforeusing;Phosphatebuffersolution (pH=6.0,6.85);Aceticacidbuffersolution(pH=4.5, 第3期 SUNYuan—xi,HUXia.ZHOUGu—zhenTheElectrocatalyticActionsofPolylCrystalViolet)……25 C=0.2mol/L),1mol/LKNO3solution,Physiological buffersolution(forshortPBS),0.1mol/LNa2C03 solution,etc.theywerepreparedsolutionsusing analyzepurereagent.Thewaterusedinexperimentsis distillingwaterbyquadraticquartzdistillatory,not havegonitrogengastodeoxidizeinexperiment process. 1.2Experimentmethods 1.2.1ThePreparationofPCVE Glasscarbonelectrodewasbeenburnishedin metallographysandpaperorpolishingmachineand polishingintomirrorsurfaceusingA1203,andthenput itinto1:1HNO3,1:1ethanolandpurewater,Going onultrasoniccleanoutforabout15minwere necessary.Glasscarbonelectrodesafterpolishingand ultrasoniccleaningwereputinto0.5mol/LH2504 solution,thenitwaspolarizationdealwithcyclic voltammetryscanning,untilareproducible voltammogramwasobtained(about10rain).The electrodepretreatedwasputinpurewaterforstandby. Puttingtheelectrodepretreatedintosystem:O.05 mol/LKH2PO4一Na/HPO4(pH=6.81+0.2mol/L KNO3+2.0xl0-mol/LCV,connectingthreeelectrodes systemandconnectedwithelectrochemistrysystem, controlthescanrate:50mV/sandscanningpotential range:一1.2,1.8V,theblue—purplepolymerfilm wasobtainedbycyclicscanning20times(the continuouscyclicvoltammogramsofpolymerization process:Fig1).CapabilitiesofPCVEpreparedinthis conditionswasverysteady,thepropertiesofPCVE hasnotevidentlychangesafterputtinginphosphate buffer(pH=6.0)afterfourweeks. 1.2.2Experimentalmethods ForPCVEtoworkingelectrode,controllingscan potentialrange:0~0.6V.theelectroanalysischemistry behaviorsofPCVEwasstudiedbycyclicvoltammetry anddifferencepulsevoltammetryjn0.1mol/L CH3COOH—CH3COONa(pH=4.5)systemofcontain— ingUA,itwassameusedtoanalysiscontentofUAin uricsample. 2Resultsanddiscussions 2.1ThecyclicvoltammetryofUAinPCVE Fig2showedthatthePCVEhaselectrocatalytic actionforoxidationOf.UA.theoxidationactionisno reversibleprocess.Oxidationpeakpotentialis0.465V andpeakcurrentcorrelateswithscanrate,atalow scanrate(v<100mV/s),oxidationpeakcurrentand scanratehasagoodlinearrelationship,linear equationandlinearcorrelationcoefficientare/p(A): 0.079+0.05lv(mV).T=0.9991.Whenscanratereach— es100~1000mV/s,peakcurrentandthesquareroot ofscanratehavealinearrelationship,linearequation andlinearcorrelationcoefficientare:lp(A)=6.34+ O.717v”(mV),Y=0.9995.Peakpotentialcorrelation withscanrate,asscanrateincreased,itmovesslowly positivepotentialway(peakpotentialandlogarithmof scanratehasalinearrelationship). 《 寸 芒 j U 一 2.4 一 1.8 一 1.2 一 O.6 O O.6 1.2 1.2—0.8—0.400.40.81.21.62.0 PotentiaJ,V Fig1Cyclicvoitammogramsofelectropolymerization System:0.05mol/Lphosphatebuffers+0.2mol/LKNO3 +2.OxlO’mol/LCV. Scanpotentialrange:一1.2-1.8V Scanrate:50mV,s 00.100.200.300.400.500.600.700.80 Potential,V Fig2ThecyclicvoitammogramsofPCVE System:0.1mol/LCH3COOH—CH3COONa(pH=4.4, +1.0~10’5mol/LUA Scanpotentialrange:0-0.8V Scanrate(frominnertoout):10,25,50,75,100mV/s. O8642O2468O2 0OOOOOOLL 《IIJnU 湖南文理学院(自然科学版)2007年 Thepeakcurrentincreasedlinearlywithconcen— trationofUAinlargerange.itwasusedtoanalysis UAofrealsampleintherangeof1.0xl06,2. 0xlO4 mol/L. 2.2ThecyclicvoltammetrybehavesofDAandUA inPCVE 1[11ePCVEhasagoodelectrocatalyticactionfor redoxofDAalso.IncyclicvoltammetryCHINes(see fig3),oxidationandreductionpeal(potentialsale-. Epa=0.320Epc=0.270Differencebetweenoxida— tionpeakpotentialofDAandUAis?l25mV. 1[11eydonotinterfaceeachother. Potential,V Fig3TheCVcurveinmixingDAandUAsolutionofPCVE System:0.1mol/LCH3COOH-CH3COONa(pH=4.51+ 4.0xl0一mol/LDA+5.0xl0-6mol/LUA Scanrate:100mV/s; ScanPotentialrange:0~0.8V 2.3ThedifferencepulsevoltammetryofUAandDAin PCVE 2.3.1TheDPVbehavesofUAatdifferentsystems Duetothedifferencepulsevoltammetry(forshortDPV) hashigherdelicacyandgoodselectivity,SOitwasbeenused broadly.CombiningPCVEandDPV,thedelicacyof determiningUAhadgotmoreincrease.Indifferencesystems, theDPVgramsaredifferent.Fig4wasshowedthatDPV behavesofUAinPCVEatdifferencesystems.Fig4,showsthe determiningsystemhasveryinfluenceonpeakpotentialand peakcurrent.Allappearance.thedeterminingUAisappropriate in0.1mol/LCH3COOH-CHaCOONa. In0.1mol/LCH3COOH-CH3COONa(pH=4.51buffer solution,theDPVoxidationpeakcurrentandconcentrationof UAhasagoodlinearrelationshipindefiniterange(seefig5). Linearequationandlinearcorrelationcoefficientale: Ip(1aA)=4.76+15.06x106CoA(mOl/L),丫=0.9993.UsingPCVE workingelectrodeandDPV,thelimitofdeterminedUACan reach5.0x10..mol/L(oxidationpeakofUACanbeobserved exactiyinDPVcurve).Byusingthismethods,wecandirectly analyzecontentofUAinurinesampleandplasma’sample. 善 ‘忘 凸 Potennal,V Fig4TheDPVcalvesofUAindirentsystems System1.OxlOmol/LUArfromlefttoright): 1:0.025mol/LPBS(pH=7)+0.1mol/LKNO3 2:0.1mol/LCH3COOH—CH3COONa(pH=4.51 3:0.1mol/LH2504 P0tential,V Fig5TheDPVdifferentialcoefficientcuofUAinPCVE System:0.1mol/LCH3COOH-CH3COONa(pH=4.51+COA CuA:5.0x10.7;1. 25x10.;2.50x10.;5.00~10.;8.00xl0-6mol/L (frominnertoout) Scanpotentialrange:0~1.0V Potenti Fig6TheDPVcurveofPCVEinmixingDAandUAsolution System:0.1mol/LCH3COOH—CH3COONa(pH--4.51 +4.0x106mol/LDA+1.0xl0.mol/LUA ,《-a_【/. Q OOOOOOOOOOO m吨02468m 《6_【,莓-基U OOOOOOOOOOOOOOOO 54321123456789O ,《-a_【/.焉 第3期 SUNYuan-xi,HUXia,ZHOUGu—zhenTheElectrocatalyticActionsofPoly(CrystalViolet)……27 2.3.2TheDPvbehavesofDAandUAinPC? Fig6showedthat.DPVcurvewasgetinmixed solutionofDAandUAonPCVE.Peakspotentialof DAandUAareseparately:Ep(DA)----0.25EpfUA)=0.40 VTheoxidationcurrentsandconcentrationshada goodlinearrelationshiprseefig7andfig8).W_ecan determinesynchronouslythecontentofDAandUAin realsample.,1entogetherDAwimUA,thelinear equationandlinearcorrelationcoefficientare separately: DA(4.0xl0,,8.0xl0一mol/L),IpfOA)=一l1.12+ 30.82x10.CDA(mOI/L),.9995. UA(5.0xl0,,1.0xl0一mol/L)./P(UA)=2.26+ 6.74x10~CDA(mOI/L),.9993. Usingthismethod,wecancarryoutsimultaneity determiningofDAandUAinrealsamples. ConcentrationofDA(e.6)/mo1.L- F妒ThecurveofDAconcentrationandpeakcurrent ConcentrationofUA(e.6)/too1.L Fig8ThecurveofUAconcentrationandpeakcurrent 2.4Sampleanalyzing 2.4.1ThereclaimingtestofDAandUAin mixingsolution ngstandardsolutionsofDAandUA, differentconcentrationmixturesolutionsareprepared, andthentakingappropriatevolumeofthismix solutiongotodetermineofDAandUAbyabovetest method.theresultsarrangedintable1. TablelTheanalyzingresultsofDAandUAmixingsolutions 2.4.2ThedeterminationofUAinurinesamples Preparationofsamplesolutions:takingfresh urinesolution2.00mL,putitinquantitativebottle, added2.0mL0.1mol/LNa2COsolutiontobottle. 砀enitwasdilutedto50mLbypurewater,thisis analysissolution. Putaboveanalysissolutions0.5mLin10mL electrolysiscell,5.0mL0.2mol/LCH3COOH. CH3COONa(pH--4.5)buffersolutionwasaddedinit, addpurewaterto10.0mL,determinationresultsgot beforetestmethodwerearrangedintable2. 2.4.3Recoveryexperimentofsample Preparationofsamplerecoverysolution:taking freshurine2.00mL.putitinquantitativebottleof50 mL,add1.00mL0.010mol/LUAstandardsolutionto bottle,put2.0mL0.1mol/LNa2CO3solutioninbottle. Thenitwasdilutedto50mLbypurewater.Taking thissolution0.25mLin10mLelectrolysiscell, determinationresultsgotabovetestmethodwere simultaneityarrangedintable2. Table2Thedeterminationresultsofsampleandrecovery Averagevalueof5timesdeterminationresults r,(6冒lllJIlu《,【.苦ju 洲南迎J:tI院报(h然科学版)2007 3Epilogue Preparationofpoly(crystalviolet)filmmodified electrodeissimple,andusinglifeislong,ithasstrong electrocatalyticactions.CombiningPCVE.andDPV, sensitivityandselectivityofPCVEfordetermining DAandUAgetholdofmoreincrease.Usingthis methodintodetectionofUAinurinesample,anydeal withprocessareneedless,analyticresultsare satisfactory.ThisiSasimpleandsensitivitymethod fordeterminingDAandUAfororganismsamples. References: 【1】ChenTing,DongShaojun,XieYuanwuElectrochemical ReactionofRedoxProteinsSpeededupbytheDye ModifiedElectrodes[J]Electrochemistry,1995(2):125. 【2】KaryakinAA,StrakhovaAK,KaryakinaEE.The electrochemicalpolymerizationofmethyleneblueand bioelectrochemicalactivityoftheresultingfilm[J]. BioelectrochemistryandBioenergetics,1993,32:35-43. 【3】DongShaojun,ChuQinghui.StudyoftheElectrodeProcess ofHemoglobinataPolymerizedAzureAFilmElectrode[J]. Electroanalysis,1993,5:135—140 【4】WangYun,ZhouDongmei,ChenGuang,eta1.The electrochemicalpolymerizationofMethylenevioletand electrocatalyticalreductionofNitrite[J].ChemicalJournal ofChineseUniversities,1997,6:864—868. 【5】ZhaoHong,ZhangYuzhong,YuanZhuobin.Poly (isonicotinicacid)modifiedglassycarbonelectrodefor electrochemicaldetectionofnorepinephrine[J].Analytica ChimicaActa,2002,454(1):75—81. f6】JuHuangxian,ShenChunze.ElectrocatalyticReductionand DeterminationofDissolvedOxygenataPoly(nileblue) ModifiedElectrode[J]Electroanalysis,2001,13(8-9): 789.793. 【7】SunYuanxi,YeBaoxian,ZhouXingyao.Simultaneous determinationofDopamineeandascorbicacidatpoly(NR) modifiedelectrodes[J].AnalyticaChimicaActa,l998,363: 75.80. 【8】SunYuanxi,YeBaoxian,ZhouXingyaoStudyonthe DeterminationofNeurotransmittersUsingPoly(NR) CoatedCarbonFiberMicroelectrodes[J].Microcherni}cal Journal,1998.58:182.191 聚结晶紫薄膜修饰电极对多巴胺与尿酸的 电催化作用 孙元喜,胡霞,周谷珍 (湖南丈理学院化学化工系,湖南常德415000) 摘要:利用循环伏安法制备了聚结晶紫薄膜修饰电极 (PCVE),详细研究了该修饰电极对生物分子多巴胺(DA)和 尿酸(uA)的电催化作用.结果表明,PCVE对DA和UA具 有较强的电催化作用,并且对抗坏血酸(AA)具有较强的抗={ 扰作用,允许高达1000倍以上AA存在而不干扰痕量DA 的测定.将PCVE结合差分脉冲伏安(DPV)技术,对DA的 检测线性范围为4.0x10’.mol/L,2.5x10一mol/L,检测限町 达35x10一mol/L;对uA的检测线性范围为5.OxlO,mol/L, 5.0×10,mol/L,检测限达5.0×10一mol/L.利用该法可以埘 DA和uA进行同时测定,将该法用于尿液中尿酸的测定, 取得满意结果. 关键词:聚结晶紫:电催化:修饰电极;多巴胺;尿酸 收稿日期:2007.04.03 作者简介:孙元喜(1954.),男,教授,研究方向为电化学与 电分析化学. tit任鳊校:刘刚我)