REVIEWColorful“Stars”intheDarkChaoJinga,Yi-TaoLongb,c,*aShanghaiInstituteofAppliedPhysics,ChineseAcademyofSciences,Shanghai,201800,PRChinabStateKeyLaboratoryofAnalyticalChemistryforLifeScience;SchoolofChemistryandChemicalEngineering,NanjingUniversity,Nanjing,210023,PRChinacMolecularSensingandImagingCenter,NanjingUniversity,Nanjing,210023,PRChinaAbstractPlasmonicnanoparticlessuchasAuandAgwithlocalizedsurfaceplasmonresonance(LSPR)propertyexhibituniquescatteringandabsorptionfeatures.Theplasmonicscatteringandabsorptionbandsaremainlylocatedatvisiblelightregionwhichcanbeeasilyappliedinvisualdetections.Bymodulatingthesize,shapeandcompositionofgoldandsilvercolloidsolutions,plentyofcolorimetricmethodshavebeendesignedforthedetectionofmetalions,biomoleculesandenvironmentalcontaminants.Formanyyears,theLSPR-basedmeasurementsareimplementedinreagenttubes.Since2000,theplasmonresonancescattering(PRS)lightofmetalnanoparticlescapturedbydark-fieldmicroscopyenablestheinvestigationatthenanoscaledimension.Mono-dispersednanoparticlesunderadark-fieldmicroscopeshoweddistinctscatteringlightspots,likecolorfulstarsinthedarksky.ThePRSlightofasinglenanoparticleopensanewwayforultra-sensitivesensingwhicheliminatestheaverageeffectsinbulkandprovidesmoreaccuratereactioninformation.Thus,individualnanoparticleswithspecificscatteringcolorsareexcellentnanoprobesintheapplicationsofbiology,physics,andchemistry.Inthisreview,theplasmonicsbasedcolorimetricnanosensorsarepresented.Particularly,theapplicationofin-situPRSinthedynamicallymonitoringofelectrocatalyticreactionsishighlighted.Wefirstlyintroduceashorthistoryofthediscoveryanddevelopmentofplasmonicnano-particlesfromtheancientartworktothemoderncharacterizationtechniques.Somefactorsincludingmorphology,anddielectricconstantsthatarecorrelatedtotheLSPRbandsandscatteringlightcolorsarelisted.Secondly,wedemonstratetheuseofsingleplasmonicnanoparticlesasvisualizedcolor-codednanoprobes.AsthemorphologyofparticleshasstrongeffectonthePRSlight,elegantsensorshavebeen...
