High Redox Activity and Water Solubility Empower Viologens for Superior Electrochemiluminescence Performance

Abstract High-performance luminescent materials are indispensable for advancing the development of electrochemiluminescence (ECL). In this work, a series of organic small-molecule ECL materials viologens were rationally designed and synthesized, which possess favorable redox activity, superior water solubility, and outstanding luminous efficiency. All prepared samples generate intense annihilation and coreactant-promoted ECL signals. Experimental and theoretical investigations demonstrate that side-substituted groups can greatly modulate the ECL properties. Among them, viologen Nap-Py-2PF6 with a large conjugated framework delivers the highest luminous efficiency, up to 74.36%. Relying on the facile complexation between the probe and uric acid, the established sensing strategy realized ultrasensitive detection of uric acid in real samples. This study pioneers the application of viologen derivatives in ECL sensing and explores their favorable luminescence properties, offering an effective new route for uric acid quantitative analysis.