Figure 2.
Illustration of the molecular mechanisms and the bioimaging applications of fluorescent hypoxia probes. (A) Hypoxia-responsive activation utilizing FRET and ACQ for enhanced SNR. (B) Hypoxia-specific accumulation targeting hypoxia-induced enzymes or proteins. Adapted with permission from 106, copyright 2022 Springer Nature. (C) Oxygen-sensing luminescent mechanisms based on oxygen-sensitive metal complexes with long-lived emissions. Adapted with permission from 13, copyright 2022 Wiley. FRET: fluorescence resonance energy transfer; ACQ: aggregation-caused quenching; NTRs: nitroreductases; AzoRs: azoreductases; CAIX: carbonic anhydrase IX; SNR: signal-to-noise ratio; PLN, popliteal lymph node; SLN, sciatic lymph node; ILN, inguinal lymph node; LLN, lumbar lymph node.
