Golgi-targetable fluorescent probe for ratiometric imaging of CO in cells and zebrafish

Carbon monoxide (CO) plays a vital role in living organisms. The detection of CO at the subcellular level is of great significance to clarify its biological functions. Increasing evidence shows that CO is important in Golgi apparatus, but so far, no probe has been reported to detect CO in Golgi. In this paper, an effective fluorescence probe Gol-CO was reported for CO imaging in Golgi apparatus. Gol-CO uses a Golgi-targetable aminoquinoline derivative as the fluorophore and importantly, it shows significant ratiometric fluorescence signal changes at 520/425 nm in aqueous solutions with high selectivity and sensitivity (about 41 nM of detection limit) for CO. Imaging experiments showed that Gol-CO has excellent targeting ability to Golgi apparatus and excellent ratiometric fluorescence imaging ability for CO in cells and zebrafish. Gol-CO also succeeded in visualizing the level increase of CO in living cells under oxidative stress.