Nanometer light source: Interaction between high-affinity binding sites on lipid-coated nanocrystals (NCs) and different proteins enables the controlled formation of supramolecular nanostructures on micropatterned surfaces (see picture; FRET = fluorescence resonant energy transfer, NTA = nitrilotriacetic acid, His₆ = hexahistidine). The NCs serve as local light sources emitting light over distances from 1 to more than 10 nm.