Highly selective turn-on fluorescent probe for hypochlorite and viscosity detection

•Water-soluble fluorescent probes PTZ-TPP and PTZ-MP based on phenothiazine moiety were developed.•The sensing mechanism of probe with HOCl was elucidated.•The detection limit (LOD) of probe PTZ-TPP and PTZ-MP was evaluated to be 14.7 and 19.4 nM respectively.•The probe PTZ-MP was further used for the detection of viscosity. Due to the important role of hypochlorous acid (HOCl) in immune prevention of bacteria towards living organisms and its variations may be related to the change of intracellular viscosity, it is significant to design fluorescent probe to accurately analyze changes for detecting HOCl and viscosity simultaneously. In this paper, water-soluble, very fast-responsive fluorescent probes PTZ-TPP and PTZ-MP based on phenothiazine moiety were developed. The sensing mechanism of the probe with HOCl was elucidated by emission spectra at long and short excited wavelength 480 and 380 nm, and the oxidation structure OPTZ-TPP, sulfur peroxide structure O3PTZ-TPP as well as carbon-carbon double bond cleavage structure OCy-TPP were confirmed by ESI-MS analysis. The detection limit (LOD) of probe PTZ-TPP and PTZ-MP was evaluated to be 14.7 and 19.4 nM respectively. Moreover, the probe PTZ-MP was further used for the detection of viscosity. Furthermore, cell imaging of PTZ-TPP towards HOCl was conducted. And it is expected to be used in simultaneous determination of HOCl and viscosity in intracellular. A novel water-soluble, very fast-responsive fluorescent probes PTZ-TPP and PTZ-MP based on phenothiazine moiety were developed. The sensing mechanism of probe with HOCl was elucidated by emission spectra at different excited wavelength, and the oxidation structure OPTZ-TPP, sulfur peroxide structure O3PTZ-TPP as well as carbon-carbon double bond cleavage structure OCy-TPP were confirmed by ESI-MS analysis. The detection limit (LOD) of probe PTZ-TPP and PTZ-MP was evaluated to be 14.7 and 19.4 nM respectively. Moreover, probe PTZ-MP was further used for the detection of viscosity, and PTZ-TPP can be employed for specific detection of NaClO in living INS-1 cells. [Display omitted]