Thermal Responsive Ion Selectivity of Uranyl Peroxide Nanocages: An Inorganic Mimic of K+ Ion Channels.

An actinyl peroxide cage cluster, Li48+ mK12(OH) m[UO2(O2)(OH)]60 (H2O) n ( m≈20 and n≈310; U60), discriminates precisely between Na+ and K+ ions when heated to certain temperatures, a most essential feature for K+ selective filters. The U60 clusters demonstrate several other features in common with K+ ion channels, including passive transport of K+ ions, a high flux rate, and the dehydration of U60 and K+ ions. These qualities make U60 (a pure inorganic cluster) a promising ion channel mimic in an aqueous environment. Laser light scattering (LLS) and isothermal titration calorimetry (ITC) studies revealed that the tailorable ion selectivity of U60 clusters is a result of the thermal responsiveness of the U60 hydration shells. [ABSTRACT FROM AUTHOR]