Antibacterial and catalytic activities of biosynthesized silver nanoparticles prepared by using an aqueous extract of green coffee bean as a reducing agent

摘要

Spherical biogenic silver nanoparticles (AgNPs) were synthesized using aqueous green coffee bean extract as a reducing agent. The green coffee bean extract was used for the time to reduce silver ions via a one-step, green, and rapid approach. The prepared AgNPs were characterized via transmission electron microscopy (TEM), atomic force microscopy (AFM), and UV-visible spectroscopy. Dynamic light scattering (DLS) was performed to measure the particle size. These AgNPs exhibit strong antibacterial activity against both Gram-negative and Gram-positive bacteria and the minimum inhibitory concentration (MIC) of AgNPs for Escherichia coli and Staphylococcus aureus are 0.05 μmol L?1 and 0.1 μmol L?1, respectively. Furthermore, AgNPs could serve as an effective catalyst for the reduction of 4-nitrophenol to 4-aminophenol in the presence of NaBH₄.