A highly selective "Turn On" fluorescent probe based on FRET mechanism for hydrogen sulfide detection in living cells.

• A novel fluorescent "OFF-ON" probe based on a FRET approach was successfully developed. • A dabsylfluorescein probe demonstrated a superb selectivity and great specificity towards H 2 S. • A dabsylfluorescein probe can potentially be applied for the visualization of H 2 S in living cells. A novel class of fluorescent "turn on" probe based on the fluorescence resonance energy transfer (FRET) approach was designed, and successfully synthesized for the detection of hydrogen sulfide (H 2 S) both in vitro and in vivo. This new H 2 S responsive fluorescent probe was developed based on the basis of the dabsyl and fluorescein FRET system. In the presence of H 2 S, a fluorescence enhancement was markedly observed mainly due to the inhibition of the FRET process. This probe could quantitatively measure the level of H 2 S with the detection limit of 0.02 μM. Cell imaging results demonstrated the potential applicability of a dabsylfluorescein probe for H 2 S detection in living cells. [ABSTRACT FROM AUTHOR]