title: Room-temperature phosphorescent discrimination of catechol from resorcinol and hydroquinone based on sodium tripolyphosphate capped Mn-doped ZnS quantum dots.
abstract: A room-temperature phosphorescence (RTP) strategy was developed for direct, additive-free discrimination of catechol from resorcinol and hydroquinone based on sodium tripolyphosphate capped Mn-doped ZnS quantum dots (STPP-Mn-ZnS QDs). The RTP response of STPP-Mn-ZnS QDs to the three isomers was pH-dependent, and the greatest difference in the RTP response to the isomers was observed at pH 8.0: catechol enhanced the RTP intensity of the QDs, while resorcinol and hydroquinone had little effect on the RTP intensity of the QDs. The enhanced RTP intensity of 1 μM catechol was not affected by the coexistence of 30 μM resorcinol and 50 μM hydroquinone at pH 8.0. The detection limit of this RTP method was 53 nM catechol, and the precision was 3.2% (relative standard deviation) for five replicate detections of 1 μM catechol. The discrimination mechanism was ascribed to the weak bonded ligand of STPP-Mn-ZnS QDs and the different interaction between the three isomers and STPP-Mn-ZnS QDs. The strong binding of catechol to Zn resulted in the extraction of Zn from the surface of STPP-Mn-ZnS QDs and the generation of holes that were trapped by Mn(2+) to form Mn(3+). Catechol also promoted the reduction of Mn(3+) into Mn(2+) excited state, thus ultimately inducing the enhanced RTP response of STPP-Mn-ZnS QDs.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology and Research Center for Analytical Sciences, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin 300071, China.
authors.forename: He-Fang
authors.initials: HF
authors.lastname: Wang
authors.forename: Ye-Yu
authors.initials: YY
authors.lastname: Wu
authors.forename: Xiu-Ping
authors.initials: XP
authors.lastname: Yan
mesh_terms: D002396:Catechols / Q000032:analysis*; D006873:Hydroquinones / Q000032:analysis*; D008163:Luminescent Measurements / Q000379:methods*; D008345:Manganese / Q000737:chemistry; D011122:Polyphosphates / Q000737:chemistry*; D045663:Quantum Dots / Q000737:chemistry*; D012118:Resorcinols / Q000032:analysis*; D013440:Sulfides / Q000737:chemistry; D013696:Temperature; D017967:Zinc Compounds / Q000737:chemistry
chemical_list: D002396:Catechols; D006873:Hydroquinones; D011122:Polyphosphates; D012118:Resorcinols; D013440:Sulfides; D017967:Zinc Compounds; D008345:Manganese; C031238:zinc sulfide; C034221:catechol; C005692:triphosphoric acid; C031927:hydroquinone; C031389:resorcinol