Optimization of the byosynthesis of gold nanoparticles using Hypericum perforatum and evaluation of their antimicrobial activity

The functionality of metal nanoparticles is reported mainly in the pharmaceutical and biomedical areas. Gold nanoparticles (AuNPs) have shown numerous activities among these the microbicidal capacity, as transporters of therapeutic drugs and in the treatment of genetic diseases. The AuNPs are synthesized by physical, chemical and biological methods; the green synthesis is a eco-friendly method based on biological principles that have functional groups serving as reducing agents and stabilizers in the reaction. The objective of this work was the optimization in the conditions for AuNPs synthesis using Hypericum perforatum and assess the antimicrobial activity of optimal treatments obtained. The AuNPs were synthesized by the combination of biological and physical methods, characterized by FTIR, spectrophotometry, TEM and DLS; and the antimicrobial effect of the optimized AuNPs was evaluated. The smallest particle size obtained was 20 nm, however not all AuNPs showed antimicrobial activity, the minimum inhibitory and minimum bactericidal concentrations were 0.42 and 0.84 μg AuNPs/mL, respectively. The information obtained presents a method of AuNPs synthesis in a fast and free of pollutants for the environment, providing an alternative to obtain antimicrobial compounds with no microbial resistance

Keywords: gold nanoparticles, Hypericum perforatum, antimicrobial activity, optimized treatments.