Brighten up

Abstract

Using a strategy that is applicable to many fluorescent dyes, chemists have created the brightest-ever fluorescent materials. The approach combines commonly available cationic dyes and a colorless macrocycle that sequesters anions. The resulting fluorescent materials could be used in medical diagnostics and lasers. Most dyes that fluoresce brightly in solution discolor, fade, or lose their fluorescence altogether when incorporated into solids. In the solid state, the dye molecules pack together and quench one another so that they no longer emit photons. The solution to this problem is to move the fluorophores further apart, according to Indiana University chemistry professor Amar H. Flood. To distance the dyes, chemists add bulky groups to them. This bespoke process works via trial and error, so there’s no guarantee that the bulked-up molecule will fluoresce in the solid state. Now, a team led by Flood and the University of Copenhagen’s Bo W. Laursen has come