School of Chemistry and Chemical Engineering, Anhui University of Technology, Ma'anshan, 243032, Anhui, China.
Institute of Pharmaceutical Analysis, College of Pharmacy, Jinan University, Guangzhou, 510632, Guangdong, China.
Mikrochim Acta. 2018 Oct 20;185(11):511. doi: 10.1007/s00604-018-3043-8.
A ratiometric probe is described for the fluorometric determination of Cu(II) ions based on their quenching effect on the luminescence of dually-emitting quantum dots (QDs). ZnS QDs were doped with Mn(II) and subsequently modified with mercaptopropionic acid to give the QD probe which consists of a sole fluorophore but has two emission peaks (at 430 and 590 nm under 310 nm excitation, respectively). On addition of Cu(II) ions, the 590 nm band is quenched while the 430 nm band exhibits a little change. The changes in the intensity ratios of the yellow and the purple bands increases linearly in the 0 to 3.0 μM Cu(II) concentration range, and the detection limit reached 14 nM. The QD probe was validated and successfully applied to the determination of Cu(II) in spiked real water samples. Graphical abstract Mn-doped ZnS (ZnS:Mn(II)) quantum dots were synthesized with yellow fluorescence. After the modification of 3-mercaptopropionic acid (MPA), ZnS:Mn(II) was transferred to aqueous phase and became MPA modified Mn-doped ZnS (MPA- ZnS:Mn(II)). The fluorescence was changed to purple upon the addition of copper ions because the yellow band was largely quenched while the purple band only changed a little.
一种比率荧光探针用于荧光法测定 Cu(II)离子，其原理基于 Cu(II)对双发射量子点(QD)荧光的猝灭效应。ZnS QD 掺杂 Mn(II)，随后用巯基丙酸修饰，得到 QD 探针，它由单一荧光体组成，但有两个发射峰(在 310nm 激发下分别为 430nm 和 590nm)。加入 Cu(II)离子后，590nm 带被猝灭，而 430nm 带略有变化。黄带和紫带的强度比值的变化在 0 到 3.0μM Cu(II)浓度范围内呈线性增加，检测限达到 14nM。该 QD 探针得到了验证，并成功应用于加标实际水样中 Cu(II)的测定。
