Based on substituents influencing fluorescence of HBT to design enhanced and ratiometric probes for detecting OCl-, applying in strips and Bioimaging

Nitro group with strong electron-withdrawing effect can powerfully influence the fluorescence of fluorophores. In this work, through adjusting the nitro group at HBT fluorophore to construct phenylhydrazone structure, two probes (HBTN and HBTH) were synthesized to detect OCl-. Consequently, HBTN with the nitro group quenched the fluorescence of HBT and HBTH without nitro group make the fluorescence redshift, which result in enhanced and ratiometric fluorescent signal changes during the detection process. Among them, HBTN shows good ability to selectively detect OCl- in the concentration range of 0 – 14 μM with the detection limit of 2.06 nM. Based on HBTN, a portable test strip for detecting OCl- was made to convenient quantification of OCl- concentration with a spectrophotometer, and exogenous and endogenous OCl- were successfully imaged in cells.