Ph–CN as a novel ECL emitter combining catalysis and luminescence in one

Graphitic-phase carbon nitride (CN) has attracted extensive interest in the direction of electrochemiluminescence (ECL) due to its peculiar properties, inexpensive cost and easy synthesis. However, they are often limited by unsatisfactory ECL performance, such as low luminescence efficiency and poor electrical cycling stability, among other characteristics. Here, phenyl-doped carbon nitride (Ph–CN) is prepared by a simple and controllable supramolecular pre-assembly route for high-brightness and high-stability electrochemiluminescence. The variation of phenyl content plays a key role in tailoring the optical behavior, triggering a change in the material energy level and further facilitating the electron transfer between Ph–CN and the co-reacting reagents. Surprisingly, Ph–CN also exhibits high stability of ECL intensity at low concentrations of potassium persulfate (K2S2O8) solution, effectively avoiding oxidative damage to biomolecules caused by high concentrations of co-reactive reagents, and large Stokes shifts have potential applications in bioimaging. To validate the proposed novel luminescent material, Ph–CN is used as a new generation ECL emitter with carcinoembryonic antigen (CEA) as the detection molecule, and the proposed biosensor can analyze tumor markers sensitively and quantitatively. The construction of this work will considerably promote the development of novel ECL materials and have broad application prospects in early diagnosis and biological imaging.