A New Polymer-Based Fluorescent Chemosensor Incorporating Propane-1,3-Dione and 2,5-Diethynylbenzene Moieties for Detection of Copper(II) and Iron(III)

A novel conjugated polymer (PDBDBM) was developed by the polymerization of 1,4-dioctyloxy-2,5-diethynylbenzene with 1,3-bis(4-bromophenyl)propane-1,3-dione based on Pd-catalyzed Sonogashira-coupling reaction. The obtained polymer PDBDBM exhibited bright green photoluminescence under UV irradiation. According to the metal ion titration experiments, PDBDBM showed high sensitivity and selectivity for detection of Cu(2+) and Fe(3+) over other metal ions. The fluorescent detection limits of PDBDBM were calculated to be 5 nM for Cu(2+) and 0.4 μM for Fe(3+) and the Stern–Volmer quenching constant for Cu(2+) and Fe(3+) were found to be 1.28 × 10(8) M(−1) and 2.40 × 10(4) M(−1), respectively. These results indicated that the polymer can be used as a potential probe for Cu(2+) and Fe(3+) detection.