A Viable Route for Lithium ion detection

Quartz substrates were first functionalized with 4-ClCH2-C6H4SiCl3 and then allowed to react with 5-(4-pyridylazo)-25,26,27-tris(ethoxycarbonylmethoxy)-28-hydroxycalix[4]-arene in a covalent fashion to yield a hybrid material with animmobilized monolayer of a chromogenic sensing agent. Thestructural characterization of this ionophore monolayer onsilica surfaces was performed by X-ray photoelectron spectroscopy.This technique was also used together with UV/Vis spectroscopy to investigate the ionophoric properties of themonolayer, which was found to reversibly recognize andbind lithium ions at ppm levels even in the presence (in acomparable concentration) of highly competitive cationssuch as Na+. Overall, our procedure shows that a single-molecule property can be successfully transferred to a solidstatedevice

Invited for the cover of this issue is the Gulino group at the University of Catania, Italy, with collaborators atthe University of Messina. The cover image shows the mechanism of the reversible lithium-sensing monolayersystem.