Optical activity invertible chiral WSe2 quantum dots as intracellular redox state indicator and regulator

Indicating and regulating intracellular redox states is crucial in interrogating their dynamic biological processes in healthy and disease states. However, this goal is subjected to dynamic changes in cellular redox. Herein, an optical invertible chiral WSe 2 QDs (L-Cys-WSe 2 QDs) for indicating and regulating the dynamic changes of intracellular redox state was developed based on ligand exchange. The L-Cys-WSe 2 QDs could respond specifically to cellular GSH with excellent anti-interference capability and high stability. This chiral probe was also applied to discriminate normal and cancerous cells on the basal of their different GSH levels. The universal application in indicating the different redox states within cells was demonstrated as well. Moreover, the as-prepared chiral WSe 2 QDs displayed good glutathione peroxidase (GPx)-like activity to regulate intracellular redox state by catalytically reducing toxic H 2 O 2 in vitro and in vivo . We anticipate that the chiroptical invertible probe should have broad applications in the dynamic analysis of the redox-based process in vivo .