Design,Synthesis And Application Of Novel Fluorescent Probe For The Detection Of Hypochlorite

Hypochlorite(ClO~-),as a kind of ROS,is produced in cells by the reaction of hydrogen peroxide with chloride mediated by myeloperoxidase.If generated under regulation,it helps to maintain normal physiological activities and plays a pivotal role in the innate immune defence against pathogens.However,abnormal production of hypochlorite leads to the oxidation of biomolecules which results in tissue damage and contributes to the progression of numerous human diseases.The basal ClO~-level in cells is quite low.Besides,ClO~-is rather reactive by nature and tends to be short-lived in cells.These all pose challenges to the detection of ClO~-in vivo.Currently,the understanding of the role of ClO~-in the occurance of cancers is still less clear than that of other ROS.Great progress has been made to design various probes for hypochlorite,however,problems still exist,such as slow response time and low quantum yield.Therefore,the design of fast responsive,highly selective and sensitive probe is still highly desired.Herein,a BODIPY-based ultrafast responsive fluorescent probe for the detection of endogenous hypochlorite in live cells was designed and synthesized,the details are as follows:With BODIPY as the fluorophore,a turn-on fluorescent probe was designed based on the C=N isomerisation mechanism as well as the property of ClO~-to specifically oxidize C=N.The characterizations proved that the product is of the designed structure.Then,in vitro analytical test of the probe was conducted.The results showed that the probe responded ultrafast to ClO~-with a response time of about 0.2 s.After the detection,the absorption peak blue shifted and the color of the system changed from pink to green,which was easily detected by the naked eye.Meanwhile,the fluorescence of the system increased significantly.Within 0-15?M,the fluorescence intensity was in good linear relationship with the amount of ClO~-added and the detection limit was calculated to be4.27 nM.The probe showed a wide range(4-13)pH compatability and can be used under physiological conditions.Selectivity and competition test showed that the probe is of good selectivity and could easily discriminate against other potential interfering analytes.The characterizations of the reaction product of B-Ts with ClO~-showed that the product is BODIPY with an aldehyde group,which means that ClO~-oxidizes the C=N moiety into aldehyde group to trigger the fluorescence.Considering the excellent analytical performance of the probe,it is applied to the detection of ClO~-in live cells.MTT experiments showed that the probe is of neglectable cytotoxicity and could be used in live cells.Finally,the probe was successfully utilized in the detection of endogenous and exogenous ClO~-in live cells.