A novel mitochondrial-targeted two-photon fluorescent probe for ultrafast monitoring of SO2 derivatives and its applications.

SO2 derivatives maintain a certain balance and play an important role in many metabolic processes. However, excessive ingestion of them can lead to serious complications of various diseases. Therefore, a rapid and precision detection of SO2 derivatives with high selectivity and sensitivity would be an advance for their bio-analytic studies. Accordingly, a novel deep red and two-photon fluorescent SO2 derivatives probe (DRQ) was developed here for the first time. The probe showed fast ratio response rate (within 5 s), excellent sensitivity (the detection limit is 103 nM for red channel and 17 nM for green channel), and outstanding selectivity toward SO2 derivatives in 10 mM PBS buffer. Moreover, the ratiometric probe DRQ displays a 99 nm blue-shift in emission upon addition of SO2 derivatives. Intriguingly, the probe can be made into test papers for real-time monitoring of SO2 derivatives. Moreover, it can be also applied for visual ratio imaging of SO2 derivatives in cellular mitochondria and zebrafish under two-photon absorption (green channel) and one-photon absorption (red channel).