Both nitroreductase and the folate receptor are highly expressed in hypoxic tumors. The is a potential target for tumors, can selectively turn on fluorescence of probes by reducing nitro group to an amino group. Karan et al. (Karana, S., Cho, M., Lee, H., Park, Sundararajan, Sessler, J., Hong, K. Near-infrared fluorescent probe activated vitro vivo tumor detection. J. Med. Chem. 2021) developed...