A xanthene-based fluorescent probe for detection of peroxynitrite in living cells and zebrafish

Peroxynitrite (ONOO⁻) is one of quite critical reactive oxygen species that acts critical roles in a number of diverse biological functions and pathological events. Notably, excessive ONOO⁻ will lead to sorts of diseases. Thus, monitoring of endogenous ONOO⁻ levels will be conducive to exploring the physiological activities and functions of ONOO⁻. Here, a simple turn-on fluorescent probe named DMX is reported using C[dbnd]N bond as the ONOO⁻ recognition site and xanthene as the fluorophore. DMX possessed a good linear dependence with ONOO⁻ concentration (0–9 μM), highly sensitive detection (DL = 37 nM), and excellent selectivity towards ONOO⁻. What is more, the biological experiments reveal that DMX is able to be utilized to track exogenous/endogenous ONOO⁻ employing confocal laser scanning microscopy. Visualization of ONOO⁻ in zebrafish was also successfully conducted, suggesting that DMX might be used to study ONOO⁻ roles in vivo. We believe that DMX will have potential for exploring the pivotal role of ONOO⁻ during all sorts of physiological and pathological activities.