Biological evaluation of a new highly sensitive and selective fluorescent probe for hypochlorous acid and its imaging application in cell and zebrafish.

Hypochlorous acid is one of the most widely distributed reactive oxygen species in vivo. It is usually used as a signal molecule to participate in various life activities such as immunity and metabolism, and plays a notable role in maintaining homeostasis. When hypochlorous acid level is abnormal in the body, it will lead to a variety of diseases, such as Parkinson's disease, Alzheimer's disease, atherosclerosis and cancer. Therefore, it is necessary to develop a bio-friendly fluorescent probe with fast sensitivity and specific accuracy. In this study, the innovative probe PRS owns good optical properties, sensitivity and selectivity, and the response mechanism that the generation of new bond enhanced the fluorescence intensity is studied. Biocompatibility of probe is systematically and innovatively evaluated by using cells and zebrafish models. Note that the biocompatibility valuation of probe results from cytotoxicity test, zebrafish behavioral test, hepatotoxicity test, cardiotoxicity test, nephrotoxicity test, blood vessel toxicity test, immunotoxicity test and neurotoxicity test, and experimental indicators like swimming duration, swimming distance, swimming speed, pericardial rub, fractional shortening, stroke volume, heart rate, SV-BA, shortening rate of the ventricular short axis, liver area, liver fluorescence intensity, total length of intersegmental vessels, number of vessels, and average vessel length show that the probe has good biocompatibility. Moreover, the detection performance of the probe shows that the probe can target hypochlorous acid in cell and zebrafish models. The probe is proved to be much essential for the monitoring of hypochlorous acid in vivo. Therefore, it has been proven that the meaningful detection of probe PRS for HOCl is promising in the living organism. Moreover, our innovative biocompatibility testing can be used to evaluate the biosafety of fluorescent probe as well.