Porous organic polymer nanotubes as luminescent probe for highly selective and sensitive detection of Fe3+

Two porous organic polymer nanotubes (PNT-2 and PNT-3) were synthesized via Ni-catalyzed Yamamoto reaction, using 2,4,6-tris-(4-bromo-phenyl)-[1,3,5]-triazine (TBT) as one monomer, and 2,7-dibromopyrene (DBP) or 1,3,6,8-tetrabromopyrene (TBP) as another monomer. The scanning electron microscope (SEM) images show that both PNT-2 and PNT-3 possess clear hollow tube structures. Luminescent measurements indicate that both PNT-2 and PNT-3 can serve as luminescent probe for highly selective and sensitive detection of Fe3+ by luminescent quenching effect. Absorption competition quenching (ACQ) mechanism is also proposed to explain luminescent quenching behavior, i.e., the overlap of the UV-spectra between Fe3+ and PNTs causes the energy competition, and therefore leads to luminescent quenching. Moreover, both PNT-2 and PNT-3 still show high selectivity and sensitivity for sensing Fe3+ in 10% ethanol aqueous solution, which means that the two porous PNTs are promising candidates as luminescent probes for detecting Fe3+ in practical applications.