Probing the sensitive and selective luminescent detection of peroxynitrite using thiol-capped CdTe and CdTe@ZnS quantum dots

Oluwasesan Adegoke, Tebello Nyokong (Lead / Corresponding author)

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CdTe and CdTe@ZnS quantum dots (QDs) capped with 3-mercaptopropionic acid (MPA), thioglycolic acid (TGA), or glutathione (GSH) have been employed for the first time as luminescent probes for the sensitive and selective detection of peroxynitrite (ONOO−) in aqueous solution. The sensitivity of the proposed probe followed the order: MPA–TGA–CdTe@ZnS>GSH–TGA–CdTe@ZnS>MPA–CdTe QDs. The varying degree of quenching is elucidated based on the QD–thiolate bond of CdTe@ZnS being more sensitive to oxidation from ONOO− than CdTe. The selectivity of the probe in the presence of co-existing species followed the order: GSH–TGA–CdTe@ZnS>MPA–TGA–CdTe@ZnS>MPA–CdTe QDs. QDs capped with MPA showed less selectivity for ONOO− than GSH. The best limit of detection (LOD) of 12.6 nM was obtained for MPA–TGA–CdTe@ZnS QDs. Time-resolved fluorescence measurements indicated that the interaction between ONOO− and the QDs is static in nature.
Original languageEnglish
Pages (from-to)448-455
Number of pages8
JournalJournal of Luminescence
Early online date23 Aug 2012
Publication statusPublished - Feb 2013


  • Fluorescence quenching
  • Quantum dots
  • Peroxynitrite
  • Glutathione
  • Mercaptopropionic acid

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