Synthesis of Biscarbazole-Based Donor-Acceptor Architectures with Diverse Acceptors Enabling Ultrasensitive Dopamine...

Herein, employing biscarbazole as the electron donor and aromatic rings with varied electronic effects as acceptors, four homologous donor-acceptor architectures (CzDAa ∼ d) were synthesized and characterized. Their steady-state spectroscopy and transient spectroscopy were then investigated. Interestingly, all displayed intense fluorescence emission in the visible region, and their intramolecular charge transfer character was then disclosed by solvent-dependent fluorescence spectra. As a result, with the enhancement of the electron-accepting capability of the acceptor, the corresponding structure exhibited a significantly red-shifted emission. Subsequently, strong and stable electrochemiluminescence emission was observed for all target structures. Surprisingly, CzDAb with a thienyl group as the acceptor displayed the strongest electrochemiluminescence emission, which was selected as an electrode material to construct a highly efficient sensor for dopamine detection, validating the practical potential of those D-A structures. This study provides insights into the regulation of the photoelectric properties of D-A architectures and extends their application in the field of sensors.