Micromachines (Jun 2021)

Dual-Emission Fluorescence Probe Based on CdTe Quantum Dots and Rhodamine B for Visual Detection of Mercury and Its Logic Gate Behavior

  • Yuefeng Gao,
  • Sai Xu,
  • Zhijian Liu,
  • Kezhen Yu,
  • Xinxiang Pan

DOI
https://doi.org/10.3390/mi12060713
Journal volume & issue
Vol. 12, no. 6
p. 713

Abstract

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It is urgent that a convenient and sensitive technique of detecting Hg2+ be developed because of its toxicity. Conventional fluorescence analysis works with a single fluorescence probe, and it often suffers from signal fluctuations which are influenced by external factors. In this research, a novel dual-emission probe assembled through utilizing CdTe quantum dots (QDs) and rhodamine B was designed to detect Hg2+ visually. Only the emission of CdTe QDs was quenched after adding Hg2+ in the dual-emission probe, which caused an intensity ratio change of the two different emission wavelengths and hence facilitated the visual detection of Hg2+. Compared to single emission QDs-based probe, a better linear relationship was shown between the variation of fluorescence intensity and the concentration of Hg2+, and the limit of detection (LOD) was found to be11.4 nM in the range of 0–2.6 μM. Interestingly, the intensity of the probe containing Hg2+ could be recovered in presence of glutathione (GSH) due to the stronger binding affinity of Hg2+ towards GSH than that towards CdTe QDs. Based on this phenomenon, an IMPLICATION logic gate using Hg2+/GSH as inputs and the fluorescence signal of QDs as an output was constructed.

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