Light-Assisted Activation Probes for Time-Controllable Monitoring of O ₂ ^•– in Cerebral Ischemia-Reperfusion Injury

Light-activated fluorescence probes are powerful tools for monitoring the subcellular structure. However, their applications in biological tissues remain limited due to long reaction times and poor specificity. Herein, we have developed a novel class of light-assisted activation fluorescent probes based on a sulfonic acid ester trigger, which produces fluorescence signals only upon simultaneous exposure to ultraviolet (UV) light and superoxide anions (O 2 •– ). This dual-recognition mechanism ensures precise controllability of fluorescence signals while maintaining high specificity and the fastest reaction kinetics (<30 s). Based on this design, a mitochondria-targeting and blood–brain barrier (BBB)-penetrating probe ( SWJT-30 ) was constructed for time-controllable detection of O 2 •– in cerebral ischemia-reperfusion injury (CIRI). Through this study, we not only elucidated the role of cuproptosis in CIRI but also demonstrated the broad potential of light-assisted activation probes for spatiotemporally controlled imaging in diverse pathological and physiological contexts.