Chemistry in Pictures: Cascade of chemiluminescence

Qun Song, Mingming Ma, and their team at the University of Science and Technology of China created this rainbow of colors starting with just one common luminescent molecule, luminol. By adding different reagents and other fluorescent molecules, they produced a range of colors through what’s called a cascade energy transfer, in which, starting with luminol, molecules in the vials emit and absorb different energies of light to produce desired colors. First in the cascade, luminol releases blue light when it gets oxidized by hydrogen peroxide and a cobalt catalyst. To get the next colors, the team added a second molecule—a fluorescent dye—to each vial to capture luminol’s blue light and then re-emit another color. In some of these vials, the researchers included a fluorescent third molecule that captures the second molecule’s emitted light and then produces another color.

Credit: Qun Song. Find out how the team pulled this off in their ACS Nano paper (2020, DOI: 10.1021/acsnano.0c00847).

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