Licorice-Based Biosynthesis of Gold Nanoparticles and Evaluation of Some Pathogenic Bacteria’s Resistance to Antibacterial Agents

Abstract

This research aims to prepare gold nanoparticles by the biological method, using the licorice as a reduced agent, and to investigate the potential of gold nanoparticles as antibacterial agents. Nanoparticles of the distinctive gold peak have been observed at a wavelength of 515–518[Formula: see text]nm before and after adding the plant extract; this is known as plasmonic surface resonance, where the particles were synthesized and tested using several techniques such as using ultraviolet–visible radiation, zeta potentials, FT-IR, TEM, XRD FTIR measurement detection that shows peaks Absorption at 1388[Formula: see text]cm[Formula: see text] C–O extension of a carboxylic acid. TEM measurements show particles with a size of 39[Formula: see text]nm under ideal conditions, the crystallization phase of the XRD patterns of the produced Au NPs was (38.41, 44.6, 64.72, 77.618), correspond to (111), (200), (220), and (311) plane of metallic Au, confirming the crystal structure of Au. The generated AuNPs are relatively stable, due to the coating process, licorice extract is critical to maintaining the stability of the nanoparticles and preventing them from agglomerating. Compared to the uncoated gold nanoparticles, the coated licorice extract shows a larger zeta capacity (15.8 mV). For two pathogenic bacteria of Streptococcus mutans, Mirabilis proteome was (6–22) and (6–25)[Formula: see text]mm. The results show that licorice extract can be used for more environmentally friendly production of AuNPs with homogeneous particle sizes.