Enhanced photocurrent generation by förster resonance energy transfer between phospholipid-assembled conjugated oligoelectrolytes and nile red

We show that Förster resonance energy transfer (FRET) between a conjugated oligoelectrolyte based on distyrylstilbene (DSSN+) and Nile red can enhance photocurrent generation when the photoagents are assembled vertically on gold electrodes. DSSN+ and Nile red intercalated into phospholipid membranes of unilamellar vesicles were found to form a useful FRET system because of the solvatochromic properties of DSSN+, and the accompanying photophysical properties were suitable for FRET with Nile red. As a result, a FRET efficiency of 93-94% was achieved, as shown by steady-state and time-resolved spectra in vesicle solutions. When Nile red was tethered in a self-assembled monolayer of 11-mercaptoundecanoic acid (MUA) on gold electrodes and phospholipid-assembled DSSN+ was sequentially organized on the MUA layer, the anodic photocurrent increased notably, reaching about 815 nA/cm² by virtue of FRET between the vertically aligned dyes.