agent. The different factor affecting silver reduction was investigated. The optimum con-
ditions were silver nitrate (1.75 mM), BPE (20.4 mg dry weight), pH (4.5) and incubation time
(72 h). BPE can reduces silver ions into silver nanoparticles within 5 min after heating the
reaction mixture (40e100 C) as indicated by the developed reddish brown color.