Exogenous Coreactant-Free Electrocatalytic Reactive Oxygen Species-Driven Dual-Signal Molecularly Imprinted Electrochemiluminescence Sensor for the Detection of Trenbolone

Conventional dual-signal electrochemiluminescence (ECL) sensors feature high sensitivity and reliability, but the involvement of coreactants inevitably results in a complex configuration and shows reproducibility risk. Here, we propose an exogenous coreactant-free dual-signal platform, comprising luminol (anodic luminophore), CdSe quantum dots (cathodic luminophore), and Co₃O₄/Ti₃C₂ electrocatalyst (coreaction promoter). At different redox potentials, Co₃O₄/Ti₃C₂ induces water oxidation and oxygen reduction to produce ^•OH and O₂^•- radicals, which subsequently drive cathodic and anodic ECL emission, respectively. The dual-signal ECL pathways are confirmed by reactive oxygen species (ROS) scavenging, and the effect of dissolved oxygen is excluded. By integrating with molecular imprinting technology, this dual-signal ECL sensor is employed for the quantitative detection of trenbolone. It exhibits high sensitivity, broad linear range (1.0 × 10¹ to 1.0 × 10⁸ fg mL^-1), low detection limit, and detection capability of real samples. This work presents a new endogenous ROS-driven dual-signal ECL sensor that excludes the use of exogenous coreactants and offers new insights into ROS generation in a coreactant-free sensor design.