Imaging the lipid bilayer of giant unilamellar vesicles using red-to-blue light upconversion.

Red-to-blue triplet-triplet annihilation upconversion was obtained in giant unilamellar vesicles. The upconverted light was homogeneously distributed across the membrane and could be utilized for the imaging of individual giant vesicles in three dimensions. These results show the great potential of TTA-UC for imaging applications under anoxic conditions.