Synthesis and antimicrobial activity of gold/silver-tellurium nanostructures.

Gold–tellurium nanostructures (Au–Te NSs), silver–tellurium nanostructures (Ag–Te NSs), and gold/silver–tellurium nanostructures (Au/Ag–Te NSs) have been prepared through galvanic reactions of tellurium nanotubes (Te NTs) with Au3+, Ag+, and both ions, respectively. Unlike the use of less environmentally friendly hydrazine, fructose as a reducing agent has been used to prepare Te NTs from TeO2 powders under alkaline conditions. The Au/Ag–Te NSs have highly catlaytic activity to convert nonfluorescent Amplex Red to form fluorescent product, revealing their great strength of generating reactive oxygen species (ROS). Au/Ag–Te NSs relative to the other two NSs exhibit greater antimicrobial activity toward the growth of E. coli, S. enteritidis, and S. aureus; the minimal inhibitory concentration (MIC) values of Au/Ag–Te NSs were much lower (>10-fold) than that of Ag–Te NSs and Au–Te NSs. The antibacterial activity of Au/Ag–Te NSs is mainly due to the release of Ag+ ions and Te-related ions and also may be due ...