Phenothiazine-based porous organic polymers with high sensitivity and selective fluorescence response to mercury ions

A new Porous Organic Polymer (POP), termed CTF-PTZ, was synthesized through polymerization of 10-methyl-10H-phenothiazine-3,7-dicarbonitrile in the presence of trifluoromethanesulfonic acid catalyst. Owing to the richness of heteroatoms such as N and S atoms in its molecular structure, the fluorescence response of CTF-PTZ to metal ions was studied, and it was found that CTF-PTZ had a specific fluorescence response to Hg2+. Thus, high selectivity in fluorescence responsiveness to Hg2+ of CTF-PTZ was revealed and the detection limit of it was up to be 2.09 ​× ​10−7 moL·L−1, which was found by fluorescence spectroscopy titration and fluorescence competition experiments. We successfully demonstrated that the fluorescence responsive POP material provides the promising potential for Hg2+ detection.