New fluorescent chemosensor for the detection of thiols, fluoride and other important analytes

Fluorescence based sensing systems for chemical and biochemical analyte have received much attention in recent years due to their simplicity, sensitivity, low cost, real-time detection, portability, and potential for in-situ measurement.¹ Various fluorescent sensing methods based on fluorescence quenching process have been designed and developed.^2,3 The most direct way to construct a fluorescent sensor approach is to look for fluorescence sensory molecules instead of absorbing ones. In general, a fluorescent sensory molecule would involve the covalent linking of a receptor domain to a fluorescent fragment. The two components are intramolecularly connected together in such a way that the binding of the target analyte causes significant changes to the photophysical properties of the fluorescent fragment.⁴ However, the design of analyte recognition probe is complicated, because the probe must be specifically sensitive to the analyte and should show good fluorescence properties at the meantime. In the present work, we developed an alternative way of converting the absorption signal of the target analytes such as thiol, fluoride and peroxide/hypochlorite into a fluorescence signal without covalent linking of a chromotropic receptor and a fluorophore. This approach exhibits a feasibility to convert a classic colorimetric protocol into a fluorescence sensing approach, to overcome its inherent shortcomings, e.g., inferior detection sensitivity, poor reiteration, and/or complicated interfering factors.⁵

References

1. Li, Z.; Askim, J.; R. Suslick K. S. Chem. Rev. 2018 DOI: 10.1021/acs.chemrev.8b00226
2. Chen, G.; Song, F.; Xiong, X.; Peng, X. Ind. Eng. Chem. Res. 2013, 52, 11228-11245.
3. Zhang, J.; Cheng, F.; Li, J.; Zhu, J.-J.; Lu Y. Nano Today 2016, 11, 309-329.
4. Jiao, X.; Li, Y.; Niu, J.; Xie, X.; Wang, X.; Tang, B. Anal. Chem. 2018, 90, 533–555
5. Chen, S.; Yu, Y.-L.; Wang, J.-H. Anal. Chim. Acta 2018, 999, 13-26.