Selective detection of transition metal ions by an array of functionalized fluorescent conjugated polymer chemosensors

摘要

We have designed a series of luminescent polymeric chemosensors consisting of an emissive conjugated polymeric backbone functionalized with receptor moieties. These polymers are based on the highly luminescent polyphenylene ethynylene thienyl ethynylene polymer backbone (PPETE) to which Lewis base receptor moieties such as tolylterpyridine and bipyridine have been added as pendant functional groups at the thienyl units. Emission quenching studies on these polymers in the presence of transition metal ions led to the observation of positive deviations from Stern-Volmer behavior. Each pendant polymer deviates from linear Stern-Volmer quenching differently depending on which transition metal ion is present in solution. Further, the relative loading of transition metal ions onto these polymers determines the onset of positive deviation from linear quenching. These two factors can be utilized to generate an array of polymers differentiated in concentration on one axis and pendant- functionality on the other to determine the identity and relative concentration of transition metal analytes in solution. We have demonstrated this approach through UV-Vis absorption, emission spectroscopy, and Stern-Volmer quenching analyses.