%0 Journal Article
%T The Unexpected Selectivity Switching from Mitochondria to Lysosome in a D-π-A Cyanine Dye.
%A Abeywickrama CS
%A Baumann HJ
%A Bertman KA
%A Corbin B
%A Pang Y
%A Abeywickrama CS
%A Baumann HJ
%A Bertman KA
%A Corbin B
%A Pang Y
%A Abeywickrama CS
%A Baumann HJ
%A Bertman KA
%A Corbin B
%A Pang Y
%J Biosensors (Basel)
%V 12
%N 7
%D Jul 2022 10
%M 35884307
%F 5.743
%R 10.3390/bios12070504
%X Two interesting benzothizolium-based D-π-A type hemicyanine dyes (3a-3b) with a diphenylamine (-NPh2) donor group were evaluated for fluorescence confocal microscopy imaging ability in live cells (MO3.13, NHLF). In sharp contrast to previously reported D-π-A dyes with alkyl amine donor (-NR2) groups (1), 3a and 3b exhibited significantly different photophysical properties and organelle selectivity. Probes 3a and 3b were nearly non-fluorescent in many polar and non-polar solvents but exhibited a bright red fluorescence (λem ≈ 630-640 nm) in stained MO3.13 and NHLF with very low probe concentrations (i.e., 200 nM). Fluorescence confocal microscopy-based co-localization studies revealed excellent lysosome selectivity from the probes 3a-3b, which is in sharp contrast to previously reported D-π-A type benzothiazolium dyes (1) with an alkyl amine donor group (-NR2) (exhibiting selectivity towards cellular mitochondria). The photostability of probe 3 was found to be dependent on the substituent (R') attached to the quaternary nitrogen atom in the cyanine dye structure. The observed donor-dependent selectivity switching phenomenon can be highly useful in designing novel organelle-targeted fluorescent probes for live-cell imaging applications.