An activatable near-infrared probe for in situ monitoring of hydrogen peroxide in plant tissues

Biotic and abiotic stresses can disrupt plant metabolic processes. This leads to the excessive accumulation of hydrogen peroxide (H 2 O 2 ) in plants, which in turn induces oxidative stress. Therefore, detection of H 2 O 2 is critical to understanding plant growth. In this study, we developed a naphthalene-based fluorescein near-infrared fluorescent probe (NAPF-AC) for the sensitive and selective detection of H 2 O 2 . Upon exposure to H 2 O 2 , the probe undergoes disruption of its push-pull electronic structure, triggering an intramolecular charge transfer process that allows for fluorescence-based detection. NAPF-AC exhibited excellent linearity (R 2  = 0.998) over a wide concentration range of H 2 O 2 (0.1 to 100 μM), with a limit of detection (LOD) as low as 0.05 μM. In addition, NAPF-AC was successfully used for the in-situ detection of H 2 O 2 in plant tissues. This study provides a powerful tool for studying H 2 O 2 dynamics in plants and offers new insights into the mechanisms regulating plant growth and stress responses.