Mitochondrial-targeted fluorophore: synthesis, property and cells imaging

Abstract

PEGylated 2-(2-(6-(dimethylamino)benzooxazol-2-yl)vinyl)quinolin-8-ol (BQ-mPEG) was synthesized, which exhibited strong fluorescence at 610 nm (ϕ_f = 0.11) and a large Stoke's shift (Δλ = 202 nm) in the aqueous solution. The fluorophore displayed a two-photon absorption characteristic and a strong red emission (λ_em = 625 nm) was observed with NIR (950 nm) irradiation. The feasibility of using BQ-mPEG as a fluorescent imaging reagent suggested that the fluorophore targets mitochondria, and with 950 nm excitation, bright fluorescence images in HeLa live cells were observed. Furthermore, the fluorophore exhibited some advantages of high photostability and pH stability, as well as low cytotoxicity.