Synthesis of Carbazole-Based Electron Donor–Acceptor Architectures Enabling Ultrasensitive Epinephrine Detection

In this work, using carbazole as the electron donor and pyridinyl as the acceptor, we synthesized three novel donor–acceptor (D–A) architectures ( CzP s). Notably, all exhibited significant solvent-dependent fluorescence emission in the visible-light region. Interestingly, the antiaromatic diazocine core interrupted the electron transfer from the donor to the acceptor, resulting in decreased fluorescence. Moreover, all exhibited strong and stable electrochemiluminescence (ECL) emissions. Finally, CzPc was used to construct an epinephrine sensor. This work broadens the application of D–A structures in biological analysis.