Three Recent <i>para</i> ‐Nitrobenzyl‐Based Hypoxia Probes: Promising Directions for Sensitivity, Reversibility, or Near‐IR Emission

Hypoxia bioimaging attracts tremendous attention due to its profound implications in diagnosis of a range of pathological conditions. Nitroaromatics-based fluorescent probes are the most popular approach to tackle this problem. Despite intensive efforts of the field over the past 15 years and the development of a range of such probes, three challenges are still not addressed, i.e., highly sensitive probes necessitating a one-electron reduction, real-time monitoring probes with reversible sensing capability, and near-infrared probes with in vivo imaging potentials. Three groups have recently reported notable progresses regarding these challenges, which may spur another wave of development along this line of research and meet the need of real-world applications from researchers and doctors.