Detection Of UO22 Research Articles

Amidoxime-grafted fluorinated graphene nanosheets as a trace electrochemical sensing platform of uranyl ion

Current electrode recognition materials have limited the realization of rapid real-time monitoring of trace uranyl ion (UO22+) in real-world waters. Herein, amidoxime-grafted fluorinated graphene (AO-FG) is synthesized via the addition and subsequent amidoximation reactions of FG for the electrochemical determination of trace UO22+. Spectroscopies and microscopies reveal the synthetic and morphological characteristics of AO-FG. Electrochemical measurement indicates a significant improvement in the UO22+ redox activity of FG after amidoximation, which is attributed to the introduction of more UO22+ binding sites on the electrode surface and the restoration of charge transfer of graphene. By optimizing the modifier concentration, pH, temperature, and enrichment time, the linear range of the AO-FG-based electrochemical UO22+ sensor is determined to be 0.015–0.1 ppm (R2 = 0.9945), and the detection limit reaches 9.97 × 10−10 M. Furthermore, it exhibited excellent repeatability, air stability, and reliability in the detection of UO22+ in water samples. This study constitutes a novel pathway of constructing high-efficiency, low-cost, and portable UO22+ sensors via grafting of specific groups on FG substrates.

Luminescent Tb-doped Ca-deficient hydroxyapatite/agar for selective adsorption and detection of UO22+ ion

Uranium is a hazardous radioactive pollutant commonly produced from nuclear energy development and nuclear accidents. It has posed a potentially serious threat to the environment and human health. Thus, it is crucial to develop adsorptive sensors for adsorbing and detecting uranium in the environment. Here, we have synthesized a novel eco-friendly luminescent Tb-doped Ca-deficient hydroxyapatite utilizing agar as a template (denoted as “Tb-DEF-HAP/agar”) to sensitively and selectively adsorb and detect UO22+ ion. Ca2+ vacancy defects within the crystal structure of the Tb-DEF-HAP/agar can be tuned by changing the (Tb+Ca)/P molar ratio of the precursors, which adjusts its luminescence performance. The Tb-DEF-HAP/agar shows fluorescence intensity 3.6 times of the Tb-doped HAP synthesized with stoichiometric (Tb+Ca)/P (denoted as “Tb-HAP/agar”). The Tb-DEF-HAP/agar adsorbs and detects UO22+ ion sensitively with an ultra-low limit of detection of 27.2 nM and shows high selectivity over various other tested metal ions. Moreover, we have investigated the luminescent adsorbing and sensing mechanism of the Tb-DEF-HAP/agar as an adsorptive sensor for UO22+ ion. Our work provides new and valuable insights for the future development of excellent biodegradable rare earth (RE) doped HAP-based luminescent adsorptive sensors by tailoring their chemical composition such as (RE+Ca)/P molar ratios.

Luminescent Tb-Doped Ca-Deficient Hydroxyapatite/Agar for Selective Adsorption and Detection of Uo22+ Ion

Luminescent Tb-Doped Ca-Deficient Hydroxyapatite/Agar for Selective Adsorption and Detection of Uo22+ Ion

Peptide-Mediated Nanopore Detection of Uranyl Ions in Aqueous Media.

Uranium is one of the most common radioactive contaminants in the environment. As a major nuclear material in production, environmental samples (like soil and groundwater) can provide signatures on uranium production activity inside the facility. Thus, developing a new and portable analytical technology for uranium in aqueous media is significant not only for environmental monitoring, but also for nonproliferation. In this work, a label-free method for the detection of uranyl (UO22+) ions is developed by monitoring the translocation of a peptide probe in a nanopore. Based on the difference in the number of peptide events in the absence and presence of uranyl ions, nanomolar concentration of UO22+ ions could be detected in minutes. The method is highly selective; micromolar concentrations of Cd2+, Cu2+, Zn2+, Ni2+, Pb2+, Hg2+, Th4+, Mg2+, and Ca2+ would not interfere with the detection of UO22+ ions. In addition, simulated water samples were successfully analyzed.