Amphiphilic cyanostilbenes with donor–acceptor functionalities formed luminescent supramolecular nanofibers in aqueous media. They demonstrated multivalent binding of heparin leading to a modulation of luminescence behaviour in their co-assemblies. Notably, in the presence of heparin, the derivative with a smaller ethyl chain displayed a red-shifted emission whereas the derivative with a longer n-dodecyl chain exhibited a blue shift in its emission maximum. In both cases, significant enhancements in their emission intensities were observed. The co-assemblies were further explored as artificial light-harvesting systems showing excellent energy transfer efficiencies and antenna effects.