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

Ofra Paz Tal, Department of Chemistry, Nuclear Research Center-Negev, Beer-Sheva 84190, Israel (ofrapt@gmail.com)
Susmita Dolai, Department of Chemistry, Ben Gurion University Of The Negev, Beer Sheva 84105, Israel
Susanta Kumar Bhunia, Department of Chemistry, Ben Gurion University Of The Negev, Beer Sheva 84105, Israel
Leila Zeiri, Ilse Katz Institute For Nanotechnology, Ben Gurion University Of The Negev, Beer Sheva 84105, Israel
Raz Jelinek, Ilse Katz Institute For Nanotechnology, Ben Gurion University Of The Negev, Beer Sheva 84105, Israel

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.