Identification of ischemic stroke during hyperacute phase is crucial for subsequent treatment decisions and patient prognosis. However, existing diagnostic techniques, such as magnetic resonance imaging (MRI), still face limitations, including a relatively delayed detection window and high examination costs, making it difficult to fully meet the clinical demand for rapid identification during the hyperacute phase. Optical molecular imaging based on abnormal changes in stroke-related endogenous metabolites provides a new approach for earlier lesion identification. Hydrogen polysulfides (H2Sn) and formaldehyde (FA) are two key metabolites that are synergistically elevated during the process of ischemic stroke, serving as potential dual targets for molecular imaging in the hyperacute phase. In this work, we obtained an H2Sn/FA cascade-responsive two-photon fluorescent probe, H2Sn-FA, which can sequentially recognize H2Sn and FA to trigger a cascade “turn-on” signal amplification, thereby improving the recognition specificity and imaging sensitivity in complex biological environments. Experimental results demonstrate that H2Sn-FA exhibits excellent selectivity and sensitivity toward the target molecules, along with low cytotoxicity. In a mouse model of ischemic stroke, H2Sn-FA enabled in vivo fluorescence imaging within 15 min, while MRI required up to 30 min to obtain an identifiable signal, saving 15 min for treatment decision. Furthermore, the probe allowed for the dynamic monitoring of secondary injury in the contralateral cerebral hemisphere induced by ischemia-reperfusion. This study establishes a H2Sn/FA cascade response strategy for hyperacute imaging of ischemic stroke; providing a potential tool for rapid molecular identification of stroke and laying a foundation for future clinical translation.
