Light upconverting soft particles: triplet-triplet annihilation in the phospholipid bilayer of self-assembled vesicles

Large unilamellar vesicles (100 nm) were functionalised to obtain supramolecular particles capable of light upconversion in pure aqueous media. Triplet-triplet annihilation of diphenylanthracene ( DPA ) leading to delayed fluorescence at 420 nm was used to up-convert the light absorbed by embedded metal complex sensitisers. The lipid type and the chromophore position in the membrane affect the TTA intensity, which remains constant over a large concentration range. Large unilamellar vesicles (100 nm) were functionalised to obtain supramolecular particles capable of light upconversion in pure aqueous media.