title: Crowned spiropyran fluoroionophores with a carboxyl moiety for the selective detection of lithium ions.
abstract: The absorbance and fluorescence spectra of carboxylated spiropyrans containing methyl-1-aza-12-crown-4, methyl-1-aza-15-crown-5, methyl-1-aza-18-crown-6 moieties are compared. Characteristic changes in spectra after addition of the alkali metal salts of Li(+), Na(+), K(+) and Cs(+) were observed. Chromism induced by the binding of the metal cations was observed as an increase in absorbance and fluorescence. Of these metal cations, the Li(+) ion produced the largest change in all three spiropyran systems. Reversible photoswitching of the spiropyran-metal complexes was observed on irradiation with alternating 352 nm UV and white light. This results in reversible fluorescence based sensing of lithium ions with potential for use in a biological sensor device.
authors.affiliation: ARC Centre of Excellence for Nanoscale BioPhotonics, Institute of Photonics and Advanced Sensing, Department of Chemistry, The University of Adelaide, South Australia, 5005, Australia. andrew.abell@adelaide.edu.au.
authors.forename: D B
authors.initials: DB
authors.lastname: Stubing
authors.affiliation: ARC Centre of Excellence for Nanoscale BioPhotonics, Institute of Photonics and Advanced Sensing, Department of Chemistry, The University of Adelaide, South Australia, 5005, Australia. andrew.abell@adelaide.edu.au.
authors.forename: S
authors.initials: S
authors.lastname: Heng
authors.affiliation: ARC Centre of Excellence for Nanoscale BioPhotonics, Institute of Photonics and Advanced Sensing, Department of Chemistry, The University of Adelaide, South Australia, 5005, Australia. andrew.abell@adelaide.edu.au.
authors.forename: A D
authors.initials: AD
authors.lastname: Abell