One-pot synthesis of hollow Au₃Cu₁ spherical-like and biomineral botallackite Cu₂(OH)₃Cl flowerlike architectures exhibiting antimicrobial activity

A new form of Au₃Cu₁ hollow nanostructure was prepared by the reaction of Cu nanoparticles with HAuCl₄. Following a course of aging, the biomineral botallackite Cu₂(OH)₃Cl nanoflowers were developed with the aid of Au₃Cu₁ hollow nanostructures at room temperature. It was proposed that the hollow nanospheres could serve as active centers for heterogeneous nucleation and mediated a mineralization process. Scanning electron microscopy and high-resolution transmission electron microscopy indicated that the nanoflowers are three-dimensional in appearance with a range of 500 nm - to 1 μm in size and made of several nanopetals with about 25 nm in thickness. In addition, we found that the shape separation could be achieved by using cationic cetyltrimethylammonium bromide to filter the different morphology spherical- and flowerlike structures due to the negative charge of hollow nanospheres. Both hollow nanospheres and nanoflowers presented antimicrobial activity toward Streptococcus aureus with MIC₅₀ at 39.6 and 127.2 μg/mL, respectively.