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 (UO) 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 UO ions could be detected in minutes. The method is highly selective; micromolar concentrations of Cd, Cu, Zn, Ni, Pb, Hg, Th, Mg, and Ca would not interfere with the detection of UO ions. In addition, simulated water samples were successfully analyzed.