Green tea induced gold nanostar synthesis mediated by Ag(I) ions
  We report a synthesis of tea components conjugated gold nanostars (AuNSs) with strong near infrared absorption by reducing an aqueous solution of chloroauric acid trihydrate via green tea in association with Ag(I) ions. Green tea acts as a reducing agent by providing electrons for the gold (III) reduction as well as a stabilizing agent by conjugating some of its components on the surfaces of AuNSs. Moreover, the Ag(I) ions play an important role in mediating the branched growth of the resultant AuNSs by inducing anisotropic growth on the surfaces of initially formed spherical gold nanoparticles. 
Qiang Chen, Toshiro Kaneko, Rikizo Hatakeyama
cond-mat.mtrl-sci