Conjugated microporous polymers-based fluorescein for fluorescence detection of 2,4,6-trinitrophenol

Publication date: 1 April 2017
Source:Talanta, Volume 165
Author(s): Tong-Mou Geng, Sai-Nan Ye, Yu Wang, Hai Zhu, Xie Wang, Xue Liu
2,4,6-Trinitrophenol (TNP, also called picric acid, PA) pose a large threat to environmental health, public safety and military security. Conjugated microporous polymers are emerging new fluorescence sensing materials for TNP. In this paper, we report the synthesis of two fluorescein containing conjugated microporous polymers (DTF and TTF) through the palladium catalyzed Sonogashira–Hagihara polycondensation reactions of tetraiodofluorescein sodium salt (TIFA) with 1,4-diethynylbenzene (DEB) or 1,3,5-triethynylbenzene (TEB). DTF and TTF are porous with the BET surface areas of 705 and 712m²g⁻¹ and exhibit high chemical and thermal stabilities. The formation of conjugated polymers with the incorporation of ethynyl groups leads to the fluorescent properties. The fluorescence quenching behaviors of DTF by nitroaromatic analytes in THF suspension are investigated. It is found that the fluorescence of DTF can be effectively quenched by 2,4,6-trinitrophenol over 2-nitrophenol (NP), 4-nitrotoluene (NT), nitrobenzene (NB), phenol (PhOH), p-dichlorobenzene (DClB) and 2,4-dinitrotoluene (DNT) with an SV constant of 2.08×10³Lmol⁻¹ and a detection limit of 7.22×10⁻⁷molL⁻¹ (0.165mgL⁻¹). In short, the DTF may be a new kind of fluorescence sensing material for detecting TNP.

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