Fluorescence turn-on probes for intracellular DNA/RNA distribution based on asymmetric bis(styryl) dyes

[Display omitted] •Bis(styryl) dyes possessing two different chromophores linked to each other by an aliphatic or triazole linker were synthesized.•The fluorescence enhancement effects on interaction with DNA are 151 times for dye with aliphatic linker and 118 times for dye with triazole linker.•The fluorescence enhancement effects when binding with RNA are 23 times for dye with aliphatic linker and 36 times for dye with triazole linker.•For dye with aliphatic linker the efficient intracellular fluorescence quenching was observed in the DNase digest test. Two bis(styryl) dyes, varying in type of spacer between two mono(styryl) units, were tested for interactions with ct-DNA or cl-RNA. Both compounds showed strong affinity toward ds-DNA/ss-RNA, the binding mode of the interaction is shifting between DNA groove binding to RNA intercalation. Consequently, interaction with DNA shows a stronger flare-up of fluorescence (151 times for dye 1 and 118 times for dye 2) than when binding with RNA (23 times and 36 times correspondingly). The presence of energy transfer in the bis(styryl) system increases the Stokes shift of the dye, so when irradiating the system in the region of 370–380 nm, fluorescence is detected at 610–620 nm. The biological experiments showed that the efficient intracellular fluorescence quench was observed in the DNase digest test suggested that dyes can be applied by recognition of DNA in the presence of RNA molecules.