N-Acetyl-L-cysteine(NAC)andL-cysteine(Cys)cappedMndopedZnSquantumdots(NAC-Mn/ZnSQDs
and Cys-Mn/ZnSQDs)are firstly preparedbyhydrothermalmethods.TheseQDsdisplaystrong
phosphorescence emissionpeaksat583and580nmuponexcitationat315and306nm,respectively.
Since theirroom-temperaturephosphorescenceisefficiently quenchedbyL-ascorbicacid(AA),theyhave
been employedasphosphorescenceprobesfordetectingAA.Thelinearworkingrangesare2.5–37.5and
2.5–47.5 mM andthelimitsofdetectionare0.72and1.38 mM forNAC-Mn/ZnSQDsandCys-Mn/ZnSQDs,
respectively.Thepossiblequenchingmechanismshavebeendiscussedindetail.TheQDsprobesare
highly selectivetoAAoverothercommonions,aminoacids,glucoseandbovineserumalbum.Finally,
they havebeenappliedsuccessfullyfordetectionofAAinhumanurinesampleswithsatisfactoryresults.
The recoveriesare98–104%.Ourworkprovidesasimpleandconvenientphosphorescencemethodto
determine AAinrealsamples.