Gold nanoparticles (AuNPs) were synthesized with the bifunctional N,N′-bis(acryloyl)-(L)-cystine (CiBA) playing the dual role of reducing and stabilizing agent. Their physico-chemical properties were compared to those of AuNPs synthesized according to the well-known Turkevich method using trisodium citrate (TSC). The CiBA–AuNPs have highly similar optical properties to TSC–AuNPs. Furthermore, CiBA endows the AuNPs with a reactive acryloyl functionality that may enable subsequent ligand chemistry, making CiBA–AuNPs more useful than TSC–AuNPs.