Visible light initiated release of calcium ions through photochemical electron transfer reactions

Abstract

Photolysis of anthraquinone or flavin photosensitizers in the presence of calcium EDTA complexes results in decomposition of the EDTA complex, releasing free Ca²⁺. In the case of the flavin sensitizers, it is shown that millimolar concentrations of Ca²⁺ can be released using visible light (>440 nm) and with quantum yields as high as 0.31. The utility of this system is further demonstrated by in situ photogelation of an alginate solution.