HighlightsDOI:10.1002/anie.200805651FluorescentProbesforH2O2LightingupH2O2:TheMoleculethatIsa“NecessaryEvil”intheCellWeiZhao*fluorescentprobes·hydrogenperoxide·imaging·livingcells·mitochondria2008wasanexcitingyearforscientistsinthefluorescencenanotubes.[7]Thetraditionalfluorescentprobeshavebeenimagingcommunity,whowitnessedtheawardoftheNobleusedwidelyforthefluorometricdetectionofH2O2,buttheyPrizeinChemistrytothreescientistsforthediscoveryandarenotspecificforH2O2andtendtoreactwithvariousotherdevelopmentofafluorescentproteinforliving-cellvisual-ROStogiveafluorescenceresponse.Recently,afewnewization.ArecentreportonanewfluorescentprobetoimagefluorescentprobescapableofselectivelydetectingH2O2havemitochondrialhydrogenperoxide(H2O2)inlivingcellsbybeensynthesized.TheseincludepentafluorobenzenesulfonylChangetal.[1]hasbroughtmoreexcitementtothecommun-fluoresceins,Peroxyfluor-1,aminocoumarinmaskedbytheity.butanediolesterofap-dihydroxyborylbenzyloxycarbonyl[2]H2O2hasbeencalleda“necessaryevil”becauseofitsderivative,7-hydroxy-2-oxo-N-(2-(diphenylphosphino)eth-dualcharacterofadverseand,morerecentlydiscovered,yl)-2H-chromene-3-carboxamide,andaEu3+tetracyclinebeneficialactivities.[1–5]Asamajorreactiveoxygenspeciescomplex.[6]Someoftheseprobeshavebeenusedtomonitor[6](ROS)inlivingorganisms,itsoverproductionincellularintracellularH2O2levels.mitochondriaisimplicatedinthedevelopmentofmanyThefluorescentprobeslistedabovearespecifictoH2O2;severediseasessuchascancerandneurodegenerativePar-however,noneofthemselectivelytargetscellularmitochon-kinsonsandAlzheimersdiseases.[1,3]Amorerecentstudydria.Inrecentyears,ChangsgrouphassynthesizedafamilysuggeststhatH2O2isresponsiblefortheanticanceractivityofofboronate-basedprobes,red-fluorescentPeroxyresorufin-1,[5]vitaminC.Asasecondmessenger,H2O2determineslife-green-fluorescentPeroxyfluor-1,andblue-fluorescent[4][6]spanandplaysanimportantroleinintracellularsignalingPeroxyxanthone-1.TheselectivityoftheseprobestoH2O2