Carbon dots in electrochemiluminescence: Mechanisms, interface engineering, and bioanalytical applications

Carbon dots (CDs) have emerged as versatile electrochemiluminescent nanomaterials because of their tunable electronic structures, rich surface chemistry, favorable biocompatibility, and multifunctional interfacial roles. Compared with classical molecular luminophores, and complementary to semiconductor quantum dots whose core/shell structures and surface ligands are also highly engineerable, CDs possess heterogeneous carbon core–surface architectures that enable ECL modulation through synthesis, doping, surface‐state regulation, and interface design. This review provides a mechanism‐aware and interface‐oriented framework for understanding how carbon‐dot structure, interfacial processes, and signal architecture jointly determine ECL performance. We discuss the classification, synthesis, physicochemical properties, and redox behavior of CDs, then analyze their mechanistic roles as luminophores, co‐reactants, and participants in interfacial electron‐ and energy‐transfer processes. We further review engineering strategies for improving CD‐ECL performance, including band‐structure modulation, surface functionalization, composite construction, interface engineering, and spectral/signal programming. Finally, we highlight bioanalytical applications, current challenges, and future opportunities in predictive design, intelligent analysis, and practical translation.