Spirulina platensis gold nanoparticles (AuNPs) and its activity against cancer cell lines and as antioxidant agents

Gold nanoparticles (AuNPs) attracted great attention due to their unusual and fascinating properties, and applications in many fields. The synthesis of AuNPs was mediated by Spirulina platensis which observed by the color change from yellow to red and detected using UV-visible spectra that showed a strong absorption peak at 400 nm indicating the presence of AuNPs. Characterization was performed through different techniques such as Fourier transform infrared spectroscopy (FTIR) which the spectral analysis of Spirulina platensis AuNPs shows an array of absorbance bands at 3459.8906, 1643.0157, 1383.9352, 1107.1169, and 674.4665 cm−1. The application of gold nanoparticles as antimicrobial agent was examined which AuNPs possessed antimicrobial activity against all tested pathogens. The most pronounced effect was against Enterococcus faecalis recording an inhibition zone of 2.6 mm.