“…In recent years, metal nanoparticles such as gold, silver, platinum, and copper have attracted the attention and interest of engineers and scientists for specific physical and chemical properties such as their size-dependent surface-plasmon response. , Gold nanoparticles [actually, nanoclusters of gold nanoparticles (hereafter referred to as AuNPs)] and nanorods have promising applications particularly in fields such as biology, biomedicine, − and catalysis . Diverse physical techniques such as thermolysis and irradiation with ultrasound, microwaves, γ-rays, or electron beams − are often used to synthesize AuNPs, but they can also be produced chemically through the reduction of cationic Au(III) by a reducing agent such as sodium citrate, ascorbic acid, or sodium boron hydride. − During these processes, undesirable aggregation of AuNPs is prevented by additives such as thiolate surfactants for dispersion in liquid and metal oxides as solid supports. − Since such chemicals may contaminate the finished AuNPs through infiltration and/or capping and are often toxic to organisms including humans, the use of toxic chemicals to produce AuNPs greatly limits applications in biomedical fields, especially for clinical purposes. ,, …”