Microwave-assisted green synthesis of gold nanoparticles using amino acids and their antibacterial and catalytic activities

We synthesized gold nanoparticles (AuNPs) using a green and environmentally friendly method that involves microwave irradiation and amino acids with carbonyl groups as reducing and stabilizing agents. The resulting AuNPs had a small average size of 5.25 nm, a large surface area, and an absorption peak at 546 nm. They also exhibited a face-centered cubic (FCC) crystal structure. We tested the antibacterial activity of the AuNPs against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and found that they were highly effective in killing both types of bacteria. Moreover, we evaluated the catalytic performance of the AuNPs in the reduction of 4-nitrophenol (4-NP) and found that they had a high reaction rate constant of 0.22 s-1. We also demonstrated that the AuNPs could be recycled and reused for multiple cycles without significant loss of activity. Therefore, we concluded that our microwave-assisted synthesis of green AuNPs is a simple, fast, and versatile method that can produce multifunctional nanocatalysts with potential applications in environmental remediation and biomedicine.