Steadystateandtime-resolvedautofluorescencespectroscopiesareemployedtostudytheautofluorescencecharacteristicsofhumancolonictissuesinvitro.Theexcitationwavelengthvariesfrom260to540nm,andthecorrespondingfluorescenceemissionspectraareacquiredfrom280to800nm.Significantdifferenceinfluorescenceintensityofexcitation-emissionmatrices(EEMs)isobservedbetweennormalandtumorcolonictissues.Comparedwithnormalcolonictissue,lownicotinamideadeninedinucleotide(phosphate)(NAD(P)H)andflavinadeninedinucleotide(FAD),andhighaminoacidsandprotoporphyrinIX(PpIX)fluorescencescharacterizehigh-grademalignanttissue.Moreover,theautofluorescencelifetimesofnormalandcarcinomatouscolonictissuesat635nmunder397-nmexcitationareabout4.32±0.12and18.45±0.05ns,respectively.ThehighaccumulationofendogenousPpIXincoloniccancersisdemonstratedinbothsteadystateandtime-resolvedautofluorescencespectroscopies.更多还原
