Amphiphilic di-cationic cyanostilbene derivatives with aggregation induced emission (AIE) features formed luminescent supramolecular polymers in aqueous media. They bind bio-polyanion heparin, a known anticoagulant, in a multivalent fashion through the formation of co-assemblies with highly enhanced greenish-yellow emission. Heparin detection in nanomolar concentrations in buffer and in medically relevant concentrations in human serum and plasma was achieved.