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

Abstract

An actinyl peroxide cage cluster, Li48+m K12 (OH)m [UO2 (O2 )(OH)]60 (H2 O)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.

Beyond Charge Balance: Counter‐Cations in Polyoxometalate Chemistry

“…Since their initial discovery, Blackberry formation is now accepted as a common phenomenon for inorganic POMs and for amphiphilic POMs that are functionalized by hydrophobic organic “tails” . Also noteworthy, the uranyl peroxide polyoxometalates of several distinct geometries and compositions, as well as the noble metal POMs, also assemble into blackberry structures, indicating the universality of the underlying structure formation processes. Beyond the scope of this Review, blackberry structures have also assembled from cationic coordination compound nanocages …”

Jenseits von Ladungsausgleich: Gegenkationen in der Polyoxometallat‐Chemie

“…Aufsätze gen [52,[96][97][98] sowie durch Edelmetall-POMs. [99,100] Dies lässt auf eine generelle Zugänglichkeit von POM-basierten Blackberrys schließen.…”

Smart polymer-based calcium-ion self-regulated nanochannels by mimicking the biological Ca2+-induced Ca2+ release process

“…Natural ion channels, with high fidelity to specific ions, act as a pivotal part in supporting the metabolism of living cells (Scheme 1), and their dysfunction can lead to various diseases 1,2 ; 40% of clinical drugs are designed to target ion channel proteins. Among ion channels, Ca 2+ channels are prerequisites for an extensive range of life processes 3,4 , such as functions of nervous systems, cell proliferation, genetic transcription, and muscular contraction 5,6 . In particular, ryanodine receptors (RyRs) on sarcoplasmic reticulum (SR) membranes, which are in charge of the release of intracellular Ca 2+ stores, are sensitive to the concentration of Ca 2+ (Scheme 1, the lower part).…”

“…Time dependency of frequency a dissipation and b variations during MgCl 2 , CaCl 2 , FeCl 3 , ZnCl 2 , AlCl 3 , or KCl (10 μM in pure water) adsorbed on the copolymer-modified quartz crystal resonator surface at 20°C. c Nyquist plots of EIS obtained at the copolymer-modified electrode surface in 0.1 M KCl solution containing 5 mM Fe (CN)6 3−/4− upon additions of CaCl 2 from 10 −10 to 10 −4 M. Inset, equivalent circuit of the electrochemical sensor to study the impedance spectra.d CaCl 2 concentration dependence of the impedance change ratio (R ct ) of the copolymer-modified gold electrodes in 5 mM [Fe(CN) 6 ] 3−/4− . Inset: the Ca 2+ -triggered transition of the copolymer chains promoted the mass transport of [Fe(CN) 6 ] 3−/4− through the copolymer brush.…”