Thenoyltrifluoroacetone (TTA)-Carbon Dot/Aerogel Fluorescent Sensor for Lanthanide and Actinide Ions

Contamination of groundwater with radioactive substances comprising actinides and lanthanides is a significant environmental hazard, and thus development of selective, sensitive, and easy-to-apply sensors for water-soluble actinide and lanthanide ions is highly sought. We present a new selective fluorescent sensor for lanthanide and actinide metal ion e.g., UO22+, Sm3+, and Eu3+ based on carbon dot (C-dot)-aerogel hybrid prepared through in-situ carbonization of 2-thenoyltrifluoroacetone (TTA), a high-affinity heavy metal chelator. The TTA-C-dot-aerogel enabled detection of UO22+ ions which induced a significant red fluorescence shift, while Eu3+ and particularly Sm3+ ions gave rise to pronounced fluorescence quenching. Importantly, the lanthanide/actinide ion-selective TTA-C-dots could be synthesized only in situ inside the aerogel pores, pointing to the crucial role of the aerogel host matrix both in enabling formation of the C-dots, as well as promoting adsorption and interactions of the lanthanide and actinide metal ions with the embedded C-dots. The TTA-C-dot-aerogel construct is resilient, easy to produce in large quantities, and could be effectively used as a platform for detection and speciation of lanthanide and actinide metal ions.