Excellent Electrochemiluminescence Performance of Carbazolyl Benzene via Substituent Optimization: A Structure–Performance Relationship Study

Carbazole derivatives have great potential in the field of electrochemiluminescence (ECL) due to their excellent photoelectric properties. The ECL properties of carbazole derivatives have been studied by modifying different substituents on carbazolyl benzene. Among them, DPA-BFCz shows obvious aggregated enhanced luminescence (AEE) and excellent ECL performance. Notably, scanning photoelectrochemical microscopy (SPECM) and intensity-modulated photocurrent spectroscopy (IMPS) are used to analyze the charge transfer kinetics of the emitters. In addition, a sensor of Cyt c with an ECL-resonance energy transfer (RET) mechanism is developed by taking advantage of the superior ECL performance of DPA-BFCz, with a concentration range of 1.0 to 500 nM and a detection limit of 0.20 nM. This work presents a novel strategy for rapid and sensitive detection of Cyt c.