Chemistry in Pictures: Let there be light

In the beginning, there was darkness: a nonfluorescent solution of cesium bromide, lead(II) bromide, and a metal-organic framework dispersed in dimethyl sulfoxide. But all it takes is the addition of some hexanes as an “antisolvent” to get the metal ions to assemble themselves into bright green fluorescent perovskite quantum dots inside the MOF’s nanosized pores.

Nima Tabatabaei Rezaei, a PhD student in mechanical engineering at the University of Calgary, captured the luminous transformation on video as part of his research on ways to stabilize quantum dots for biological imaging applications. The goal is to prevent the perovskites from shedding toxic lead ions inside cells. Tucked inside the MOF framework, the nanoparticles are shielded from degradation by moisture and oxygen for months, compared to mere hours for quantum dots made by traditional ligand-assisted methods. Tabatabaei Rezaei envisions that stable quantum dot–carrying MOFs could also be loaded with drugs for targeted delivery.

Submitted by Nima Tabatabaei Rezaei

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