A dual functional fluorogenic probe for visualization of intracellular pH and formaldehyde with distinct fluorescence signals.

In this study, a single fluorescent probe (DPFP) containing a 1,8-naphthalimide dye and a homoallylamino group for imaging pH and formaldehyde (FA) has been developed that exhibits significant blue fluorescence (λem at 455 nm) under acidic pH conditions (pH < 7.0) and green fluorescence (λem at 555 nm) in the presence of FA, respectively. Furthermore, probe DPFP was successfully applied to image acidic lysosomes and exogenous or endogenous FA in living HeLa cells.