Synthesis and Microstructure Influenced Antimicrobial Properties of Dispersed Nanoporous Gold Rods.

Highly dispersed nanoporous Au rods have been prepared from arc melted Ag₇₀Au₃₀ alloy using site-selective electrochemical potential controlled dealloying method followed by Au anodizing process. The microstructure studies using scanning electron microscope and atomic force microscope indicate that selective removal of Ag from the Ag₇₀Au₃₀, precursor results in the formation of bi-continuous three-dimensional network structures with uniform pores and Au ligaments diameter of 6 nm. The noticeable features present in the optical studies of highly dispersed nanoporous Au rods using UV—Vis spectroscopy are two absorption bands peaking at 477 and 546 nm with overlapping of these bands at 520 nm. The antimicrobial testing by Agar well diffusion method reveals that the dispersed porous Au rods have greater inhibitory effect against both Gram-positive and Gram-negative bacterial strains. The results obtained provide opportunities to design and manipulate nanoporous Au rods at atomic level to achieve antimicrobial efficacy for biomedical applications. [ABSTRACT FROM AUTHOR]