Synthesis of carbazole-based dendritic conjugated polymer: a dual channel optical probe for the detection of I− and Hg2+

A new type of carbazole-based blue-emitting dendritic conjugated polymer, poly[(9,9-dioctyl)-2,7-fluorene-co-4,4’,4”-triphenylamine-co-9-(4-(9H-carbazol-9-yl)butyl)-3,6-carbazole](P), was successfully synthesized by Suzuki coupling reaction. Chemical structures of monomers and polymer were verified by FI-IR and 1HNMR characterizations. We found that polymer showed a special selectivity and high sensitivity for I−. With the addition of I−, the fluorescent polymer solution was obviously quenched. The polymer showed a special detection effect on I−. However, the fluorescent polymer was obviously restored when Hg2+ was added to the P/I− system due to the large complexation between I− and Hg2+. The anti-interference experiments of probe P/I− showed that other background cations have a slight influence on detecting Hg2+, and the calculated detection limit of Hg2+ reached 9.7 × 10−8 M, which could be a potential application for a two-channel cyclic detection of I− and Hg2+. Additionally, it was found that the theoretical values were in agreement with the experimental data.