This study focuses on the rapid and accurate determination of cesium, a key radioactive contaminant attracting global attention, by creating an ultrasensitive pore-dependent electrochemiluminescence detection system. It has been successfully applied in the determination of various kinds of environmental samples, exhibiting its significance in the fields of environment, ecology, and public health. Abstract There is growing global concern that cesium-137 poses a potential risk to the environment, ecology, and public health. For the first time, an ultrasensitive cesium detection system with a pore-dependent electrochemiluminescence mechanism is developed in this work for the accurate and rapid monitoring in the environment. A cesium-imprinted film is prepared on the electrode to obtain an electrochemiluminescence sensor with cesium-matched pores. Tri- n -propylamine (TPrA) can enter the cesium-matched pores and give an electrochemical oxidation process, while Ru(bpy) 3 2+ cannot. When cesium ions can selectively bind to the ─N═ group to occupy the pores, they block the oxidation process of TPrA in pores to quench the electrochemiluminescence signal of Ru(bpy) 3 2+ with an ultralow limit of detection (50 pg L −1 ). It is successfully employed to the environmental sample (salt water, fresh water, and different animals) determination and the cesium accumulation monitoring in aquatic animals, indicating its application in environmental and ecology research. A chip-type detection system is designed basing on this sensor to realize real-time detection. This work not only aids in environmental monitoring efforts but also contributes to the broader scientific understanding of cesium mobility behavior in aquatic environments, making it important for the fields of environment, ecology, and public health.

Molecular capacitors are modified on carbon nitrides (CN) to dynamically regulate electron capture and accumulation in the defect states under different potentials. As a result, the electrochemiluminescence (ECL) efficiency increases by up to 100 times, owing to a new spatiotemporal coordination mechanism. It enables visual ECL testing of nitrite contaminants with significantly improved sensitivity and linear detection range. Abstract Carbon nitride (CN) enables non-toxicity, low cost, high quantum efficiency, and tunable spectrum. Nevertheless, there co-exists a timescale mismatch among kinetic steps of electrochemiluminescence (ECL) and a spatial competition of electrons between radiative recombination and interfacial redox reactions. Herein, a spatiotemporal coordination strategy is reported to enhance Φ ECL of CN by molecular capacitor functionalization. Mechanism studies show the capacitor, consisting of N-vacancies and −C≡N terminal groups, dynamically regulates electron capture and accumulation. Interestingly, the spatial confinement of accumulated electrons in molecular capacitors effectively enhances the radiative recombination probability. Meanwhile, the accumulated electrons construct a new pathway for fast electron transport, and the relaxation of the accumulated electrons coordinates the electron transfer in bulk CN and redox reactions at the electrode surface on the µs-ms timescale, establishing temporal coordination across multiple time domains. As a result, the Φ ECL of CN increases by up to 100 times, reaching 1480 times that of the standard Ru(bpy) 3 Cl 2 /K 2 S 2 O 8 system. Accordingly, compared to pristine CN, the as-developed ECL sensors using CN with molecular capacitor functionalization demonstrate significantly improved performance in the visual detection of nitrite ions (a typical environmental pollutant), for example, a 3600 fold lower detection limit and a 3-order of magnitude broader detection linear range.