ABSTRACT
To monitor delicate changes of biological HOCl in vivo, a new probe (OH-substituted coumarin-hemicyanine, probe 2) was synthesized for NIR and ratiometric HOCl detection. Selectivity studies indicated that the electron-donating group (OH) substituted on the indolium moiety enhanced the selectivity to detect HOCl. With HOCl, the probe showed a ratiometric fluorescence (I500/I650) with a low detection limit (49.1 nM) and a rapid response (within 2 min). In addition, probe 2 was successfully applied to visualize exogenous and endogenous HOCl in living cells and animals and exhibited a perfect mitochondria target ability. This probe has been further studied as a potential and powerful tool to probe HOCl in arthritis models.
Subject(s)
Coumarins/chemistry , Fluorescent Dyes/chemistry , Hypochlorous Acid/analysis , Indoles/chemistry , Animals , Arthritis/chemically induced , Arthritis/diagnosis , Carrageenan , Coumarins/chemical synthesis , Coumarins/toxicity , Fluorescent Dyes/chemical synthesis , Fluorescent Dyes/toxicity , Hep G2 Cells , Humans , Indoles/chemical synthesis , Indoles/toxicity , Limit of Detection , Mice , Microscopy, Confocal/methods , Microscopy, Fluorescence/methods , Mitochondria/metabolism , RAW 264.7 Cells , Spectrometry, Fluorescence/methods , ZebrafishABSTRACT
Based upon the intramolecular charge transfer (ICT) mechanism, a novel ratiometric fluorescent probe EB was developed to detect SO32-/HSO3-. The probe displayed both colorimetric and ratiometric responses toward SO32-/HSO3-. It displayed a quick response (within 60 s), good selectivity and high sensitivity (a detection limit of 28 nM) towards SO32-/HSO3-. The SO32-/HSO3- sensing mechanism was confirmed as the Michael addition reaction by ESI-MS. Moreover, the probe could be applied to measure the level of sulfite in real samples, like sugar and chrysanthemum, and it could also be used to detect SO32-/HSO3- in HepG2 cells through confocal fluorescence microscopy, which proved its practical application in clinical diagnosis.
