A BODIPY-Based Far-Red-Absorbing Fluorescent Probe for Hypochlorous Acid Imaging

Hypochlorous acid (HCIO) is produced by white blood cells to defend against injury and bacteria. However, as one of the reactive oxygen species, high intracellular HCIO concentration could lead to chronic diseases that affect the cardiovascular and nervous systems. To monitor HCIO concentrations in biosamples, the fluorescent probe is preferred to have: a) Absorbbability in the far-red window with reduced light toxicity and improved tissue penetration depth; b) Ratiometric features for accurate analysis. In this study, we reported a far-red ratiometric HCIO fluorescence probe based on BODIPY chromophore and aldoxime sensing group. Not only the color change of the probe solution can be detected by the naked eye, but also the emission ratios (I-645/I-670) showed a significant increase upon the introduction of HCIO. More importantly, the feasibility of HCIO monitoring in biosamples was demonstrated in vitro using a confocal microscope.