均相时间分辨荧光免疫分析综述

LanthanideLuminescenceforBiomedicalAnalysesandImagingJean-ClaudeG.Bu¨nzli*LaboratoryofLanthanideSupramolecularChemistry,E´colePolytechniqueFe´de´raledeLausanne(EPFL),BCH1402,CH-1015Lausanne,Switzerland,andDepartmentofAdvancedMaterialsChemistry,WCUCenterforNextGenerationPhotovoltaicSystems,KoreaUniversity,SejongCampus,208Seochang,Jochiwon,ChungNam339-700,RepublicofKoreaReceivedNovember5,2009Contents1.Introduction27292.LanthanideLuminescence27302.1.BasicFacts27302.2.SensitizationbyOrganicLigands27322.3.InformationGainedfromLanthanideLuminescentProbes27322.3.1.HydrationNumbers27322.3.2.EnergyTransferandFRETExperiments27332.3.3.Collisional(Stern-Volmer)Quenching27342.4.DesigningEfficientLanthanideLuminescentBioprobes(LLBs)27353.LanthanideBioconjugates27364.BioanalyseswithLanthanideLuminescentProbes27374.1.HeterogeneousImmunoassays27374.2.HomogeneousImmunoassays27384.3.Up-ConvertingPhosphorsand/orNanoparticles27404.4.DeterminationofEnzymeActivity27404.1.1.pHProbes27414.1.2.OxygenandSingletOxygenProbes27414.2.3.HydrogenPeroxideProbes27424.2.4.PhosphateProbes27424.2.5.EnzymeKinetics27434.5.DNAAnalysis27434.6.DetectionandQuantificationofSimpleAnalytes27465.CellandTissueImaging27475.1.MicroscopeDesignandInitialExperiments27475.2.FurtherDevelopments27485.3.Cyclen-BasedChelatesasLLBs27485.4.BinuclearHelicatesasLLBs27495.5.OvercomingExcitationWavelengthLimitationbyMultiphotonExcitation27505.6.ImprovingSensitivitywithNanoparticles27506.Perspectives27517.Acknowledgments27518.References27511.IntroductionGaininggreaterunderstandingofthestructuralandfunctionalpropertiesoflivingsystemsisakeychallengeinbiologyandmedicine.Onamorepracticalside,thediagnosisandtreatmentofcancerisrequiringindividualizedap-proaches1which,inturn,necessitatesbetterandfasterpathologicalanalysesaswellashighlycontrasted,real-timebioimages.Noninvasivemethodologiesarerequiredinordertoperturbtheinvestigatedsystemsandorgansaslittleaspossible,andopticalemissiveprobesareemergingasstrongcandidatesforthispurpose.Indeed,whenappropriatewavelengthsareused,penetrationdepthmaybesubstantialandlightcanreachregionsofcomplexmolecularedificeswhicharenotaccessibletoothermolecularprobes.2Inaddition,theemittedphotonsareeasilydetectedbyhighlysensitivedevicesandtechniques,includingsingle-photondetection.Whenthelifetimeoftheexcitedemittinglevelislongenough,time-resolveddetection(TRD)considerablyenhancesthesignal-to-noiseratio.Organicluminophoresarecommonlyfluorescentandthereforehighlyemissivebecausethetransitionisparityallowed,buttheyaresubjecttophotobleachingandTRDnecessitatessophisticatedmeth-odologiesinviewoftheverylargeemissionrates:107-109s-1,correspondingtoexcitedstatelifetimesbetween100and1ns.Semiconductorquantumdots(CdSenanocrystalswith2-10nmdiameter)andtheirbioconjugatesarepotentialsubstitutes,beinghighlyluminescent,tunableintheentirevisiblerange,anddisplayingasuperiorphotostabilitycomparedtoorganicluminophores.Theyhavebeenusedforbothinvitroanalysesandinvivoimaging,buttheirintroductionintobiologyandmedicineisslowbecausethey*Towhomcorrespondenceshouldbeaddressed.E-mail:jean-claude.bunzli@epfl.ch.Jean-ClaudeBu¨nzliisanactiveresearcherinthefieldofco-ordination,supramolecular,andbiologicalchemistryofthelanthanideions.Heearnedadegreeinchemicalengineeringin1968andaPh.D.in1971fromtheE´colePolytechniqueFe´de´raledeLausanne(EPFL).HespenttwoyearsattheUniversityofBritishColumbia(Canada)andoneyearattheSwissFederalInstituteofTechnologyinZu¨richbeforebeingappointedattheUniversityofLausannein1974andatEPFLin2001asafullprofessorofinorganicchemistry.SinceSeptember2009,healsoholdsaWCUprofessorshipatKoreaUniversity,SejongCampus,Jochiwon,SouthKorea.Hisresearchfocusesonthedesignand/orself-assemblyofbuildingblocksforphotoluminescentmaterialsandlanthanideluminescentbioprobes,withparticularemphasisontheimagingofcancerouscellsandtissues.Chem.Rev.2010,110,2729–2755272910.1021/cr900362e2010AmericanChemicalSocietyPublishedonWeb02/12/2010sufferfromflawswhicharetrickytoremedysuchasthedifficultyingettingnear-infrared(NIR)emissionfordeepertissuepenetration,thehightoxicityofcadmiumandsele-nium,andtheirshortcirculationhalf-timepreventinglong-termimagingorcell-trackingstudies.3Trivalentlanthanideions,LnIII,presentanotheralternativetoorganicluminescentstainsinviewoftheirsingularproperties,enablingeasyspectralandtimediscriminationoftheiremissionbandswhichspanboththevisibleandNIRranges.Thefirststainingofbiologicalcellswithlanthanidesdatesbackto1969whenbacterialsmears(Escherichiacolicellwalls)weretreatedwithaqueousethanolicsolutionsofeuropiumthenoyltrifluoroacetonate,henceforthappearingasbrightredspotsundermercurylampillumination,4butfurtherexperimentshadtowaitalongtime.Infact,attentiononluminescentlanthanidebioprobesstartedinthemid-1970swhenFinnishresearchersinTurkuproposedEuIII,SmIII,TbIII,andDyIIIpolyaminocarboxylatesand
-diketonatesaslu-minescentsensorsintime-resolvedluminescent(TRL)immunoassays.5,6ThisnewtechnologygeneratedabroadinterestandsubsequentdevelopmentssuchashomogeneousTRLassays,7optimizationofbioconju