Synthesis and spectroscopic properties of a FRET pair based on PPO and DBD dyes

• A new FRET pair consisting of PPO as donor and DBD as acceptor has been developed.
• Synthesis and spectroscopic properties are presented.
• The system exhibits a Förster distance of 2.9 nm and an FRET efficiency of 0.88.
• The pseudo Stokes shift of amounts to 190 nm.

A new pair of Förster resonance energy transfer (FRET) performing fluorophores is introduced: An amine functionalized 2,5-diphenyloxazole (PPO) donor tethered via a flexible linker to a carboxylic acid functionalised ester-[1,3]-dioxolo[4.5-f][1,3]benzodioxole (ester DBD) acceptor. Synthesis and spectroscopic properties of this proof-of-concept molecule in acetonitrile are presented and compared to those of its independent chromophores. The system exhibits a Förster distance of 2.9 nm, high FRET efficiency of 0.88 and a pseudo Stokes shift of 190 nm.