Enhanced optical properties, wettability and antibacterial activity of PVP doped Au for optical applications

A casting technique is used to create films of polyvinyl pyrrolidone (PVP) that contained different amounts of gold nanoparticles (Au 0.2, 0.4, 0.6, 0.8, and 1%). Fourier transform infrared (FT-IR) and Ultraviolet/Visible (UV/Vis.) including the optical energy gap (Eg). Using a contact angle system, the sessile drop method is utilized to measure the contact angle and antibacterial activity. It is observed in the UV spectra that a single-bond in the PVP backbone caused an n-π* transition and spectral peak is observed at a wavelength of 531 nm, which is believed to be caused by the surface Plasmon resonance of gold nanoparticles and appear two energy gaps decreased between (2.2-2 ev) and (3.1-2.9 ev) respectively that well-suited for utilization in electrochemical operations, such as polymer electrolytes and optoelectronic devices. The contact angle results showed an increase the contact angle between (43.85º- 55.98º) made this nanocomposite hydrophobic in surface. The antibacterial activity indicated that the inhibition zone measured approximately 12-16 mm and 8-10 mm against Escherichia coli and Staphylococcus aureus, respectively.