A new phenoxazine-based turn-on fluorescent probe for monitoring hypochlorite in food/urine/water/beverage samples and bioimaging in zebrafish

High level of hypochlorite (ClO−) can lead to oxidative stress responses and cell damage, thus, it is of the utmost importance to monitor ClO− in real-world samples and live systems. In this work, a new phenoxazine-based turn-on fluorescent probe (PB) was reported for detecting ClO− with high specificity and strong anti-interference effect, along with the naked-eye fluorescence color changed from dark to green. Probe PB responded to ClO− with high sensitivity (detection limit: 0.11 µM), broad pH working range (5–9) and fast response (<5 min). The detecting mechanism was verified by the corresponding spectra of 1H NMR/HRMS and DFT calculations. With the favorable sensing performances, the probe PB-coated test strips were fabricated for easy, convenient, fast and colorimetric identification of ClO− with sensitive responses. Meanwhile, probe PB was applied to detect ClO− in urine/food/water/beverage samples, sprouting potatoes and living soybean sprouts, showing its diverse practical applicability. Furthermore, PB probe was also used to monitor exogenous ClO− in zebrafish owing to its good biocompatibility, indicating its great bioimaging potential for micro-level detection of ClO− in vivo. All the investigated results demonstrated that there exist promising possibilities of PB for practical applications in bioimaging system and urine/food/water/beverage monitoring.