A New Lysosome-Targetable Turn-On Fluorogenic Probe for Carbon Monoxide Imaging in Living Cells

A lysosome-targetable
fluorogenic probe, LysoFP-NO2,
was designed and synthesized based on a naphthalimide fluorophore
that can detect selectively carbon monoxide (CO) in HEPES buffer (pH
7.4, 37 °C) through the transformation of the nitro group into
an amino-functionalized system in the presence of CO. LysoFP-NO2 triggered a “turn-on” fluorescence response
to CO with a simultaneous increase of fluorescence intensity by more
than 75 times. The response is selective over a variety of relevant
reactive nitrogen, oxygen, and sulfur species. Also, the probe is
an efficient candidate for monitoring changes in intracellular CO
in living cells (MCF7), and the fluorescence signals specifically
localize in the lysosome compartment.