No abstract

Abstract. Utilizing the mechanism of HOCl-mediated cyclization of rhodamine 101 thiosemicarbazide (non-fluorescent) to rhodamine 101 oxadiazoles (fluorescent), we successfully developed a novel off-on far-red fluorescent probe ( 1 ) toward HOCl with high selectivity, great functionality at physiological pH and good cell-membrane permeability. Probe 1 was linearly proportional to the concentration of HOCl in the range of 1-10 M and the detection limit is 0.3 M. Moreover, the proposed probe (1) was successfully used for the detection of hypochlorous acid in HepG2 cells by fluorescent imaging.