Bimetallic Nanocomposite of Gold/Silver Scattered in Chitosan via Laser Ablation for Electrical and Antibacterial Utilization.

Chitosan is embedded by different ratios of Au/Ag NPs. Au/Ag NPs have been synthesised by laser ablation. The electrical conductivity and antibacterial behaviour of the synthesized films were obtained. In x-ray diffraction (XRD), a new pattern appeared at 2θ = 38.3° and 44.0° which correspond to face-centered cubic Ag, and a new pattern appeared at 38.5°, 45.0°, and 66.1° which corresponds to face-centered cubic Au. Fourier transform infrared (FTIR) data confirmed the interaction and miscibility between chitosan chains and Ag/Au NPs. Chitosan embedded with a 2/3 ratio of Au/Ag NPs reacted properly. Ultraviolet-visible (UV-Vis) spectroscopy results show a peak at 410 nm, corresponding to Ag NPs, and a very weak peak at 528 nm, corresponding to Au NPs, which shows evidence of the complexation between chitosan and Au/Ag NPs. The values of the ε' and loss ε̎ were increased after being embedded by pure Ag NPs until they reached a high value for sample S3 (2/3) (Au/Ag), then began to decrease by increasing the content of Au NPs and decreasing the ratio of Ag NPs. By decreasing the concentration of Ag NPs from S1 (0/5) to S6 (5/0) in the ration of Au/Ag NPs, there are decreases in the inhibition zone for both of the gram-negative bacterial strains tested, and the two gram-positive strains, using the zone of inhibition. The obtained results suggest that chitosan embedded with 2/3 Au/Ag possesses possible antibacterial action against the given bacteria. The given results suggest that the 2/3 Au/Ag-doped chitosan is the proper ratio used for both electrical and biomedical applications. [ABSTRACT FROM AUTHOR]