Dual-Enhancement Electrochemiluminescence Device for Ultratrace Uranium Visualized Monitoring in Fish, Hair, and Nail Samples

Uranium is a nuclear fuel but also a hazardous contaminant due to its radioactivity and chemical toxicity. To prevent and mitigate its potential threat, the accurate monitoring of ultratrace uranium (orders of magnitude of pg g^-1) in practical environmental samples has become an important scientific problem. To meet this challenge, we developed an efficient electrochemiluminescence (ECL) UO₂²⁺ detection device by a novel dual-enhancement mechanism. In detail, poly[(9,9-dioctylfuor-enyl-2,7-diyl)-alt-co-(1,4-benzo-{2,1,3}-thiadiazole)] polymer dots (Pdots) are modified by the UO₂²⁺ DNA aptamer, and rhodamine B (RhB) is combined with dsDNA to quench the ECL signal via a resonance energy transfer (RET) process. UO₂²⁺ can cut off the DNA aptamer to release RhB, which generates an ECL enhancement process, and then, UO₂²⁺ continuously combines with the DNA chain, inducing another ECL enhancement by the RET process from UO₂²⁺ to Pdots. This device achieves an ultralow detection limit (12 pg L^-1) and a wide linear range (113 pg L^-1−11.3 mg L^-1), which can successfully give accurate determination results to the ultratrace uranium in biosamples (<1 pg g^-1) to monitor the uranium simulation of fish. This work presents an efficient strategy for ultratrace uranium determination in the environment, highlighting its significance in public health and environmental fields.