1 research outputs found
Room-Temperature Phosphorescent Discrimination of Catechol from Resorcinol and Hydroquinone Based on Sodium Tripolyphosphate Capped Mn-Doped ZnS Quantum Dots
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<sup>2+</sup> to form Mn<sup>3+</sup>. Catechol also promoted
the reduction of Mn<sup>3+</sup> into Mn<sup>2+</sup> excited state,
thus ultimately inducing the enhanced RTP response of STPP-Mn-ZnS
QDs