Measuring the distribution of glutathione (GSH) in living cells is useful for investigations of disease-related cell metabolism. However, conventional methods for imaging GSH distributions only work in isolated organelles or fixed cells.

Bin Liu, National University of Singapore, Jianping Lei, Nanjing University, China, and colleagues have developed a quencher-delocalized emission strategy for the in situ profiling of GSH in living cells. The team designed a non-emissive metal-organic framework nanoprobe (Cu-tpMOF), which consists of fluorogens with aggregation‐induced emission characteristics (AIEgens) as the linker and Cu(II) as both central node and quencher.

The AIEgen in Cu-tpMOF can be “lit up” in living cells through binding between GSH and Cu(II) to give green and yellow emissions under neutral and acidic conditions, respectively (pictured). Using a two-channel imaging analysis, the researchers can extract GSH signals from different locations within the cell. Cu-tpMOF could, for exmaple, be used to monitor the effects of drugs on the GSH distribution in cells.

• Quencher-Delocalized Emission Strategy of AIEgen-Based Metal-Organic Framework for Profiling of Subcellular Glutathione,
  Longyi Zhu, Bernardino J. Córdova Wong, Yang Li, Hao Xin, Bin Liu, Jianping Lei,
  Chem. Eur. J. 2019, 25, 4665–4669.
  https://doi.org/10.1002/chem.201900151