A new red fluorescent probe based on the rosamine-phenothiazine for highly selective and rapid detection of hypochlorite and its bioimaging in live cells
In this study, a new water-soluble rosamine-based fluorescent probe (RClO) was designed and prepared to detect for ClO− with rapid response and high selectivity, which utilized the oxidation of S atom in phenothiazine by ClO− to form the sulfoxide-type structure. The fluorescence intensity of the probe was enhanced by 120-fold, after reacting with HOCl, with a fast response time (~20 s). The limit of detection (LOD) for ClO− was obtained as 17.8 nM from the fluorescence titration experiment. The recognizing mechanism was based on the donor-excited photo-induced electron transfer (d-PeT) which rationalized by the theoretical calculations and successfully consistent by the Mass spectral analysis. Due to the rapid response and excellent water solubility of the probe, it had been successfully applied to image HOCl in living cells.