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).