Exploring the sensing properties of pH-sensitive carbazole-based AIE emitters and their applications in paper strip sensing.

A novel carbazole-coupled phenanthridine molecule with an intense blue emissive fluorescence was produced through a two-step synthesis of 5-(4-(9-carbazol-9-yl)phenyl)-7,8,13,14-tetrahydrodibenzo[,]phenanthridine (DSPH). This blue probe shows a good thermal and electrochemical stability. It has been used for sensing trifluoracetic acid (TFA) with a limit of detection (LoD) value of 198 pM. The probe tends to show aggregation induced emission (AIE) characteristics. Additionally, the experimental data were supported by DFT analysis.