Biosynthesis and characterization of mono and bimetallic nanoparticles by green Coffea arabica beans extract
Jarvy Francisco Cruz-Hernández, Maricela Villanueva-Ibáñez, Blanca Estela Jaramillo-Loranca
Universidad Politécnica de Pachuca
A topic of great interest in green chemistry is the biosynthesis of silver (AgNPs), gold (AuNPs) and silver-gold bimetallic nanoparticles (Ag/AuNPs) due to their physicochemical properties. The union of two different monometallics results in a material that differs from its components and whose applications are promising in biomedical devices, medicine, and catalysis. In this work, mono and bimetallic nanoparticles were biosynthesized using the aqueous extract of the green bean from Coffea arabica as a reducing agent. AuNPs and AgNPs were obtained with their respective methodologies, and the Au/Ag composite material used a combined method that allowed to obtain hollow hexagonal nanoparticles. UV-vis showed the absorption bands of the surface plasmon of the nanoparticles located at 430nm for AgNPs, 525nm for AuNPs, and 556nm for Ag/AuNPs. FT-IR analysis revealed the functional groups C=O, CH3, CH2, NH2 and OH of biomolecules such as chlorogenic acids and extract proteins, which interact with metal ions for nanoparticle biosynthesis. The DLS results showed particle sizes of 18 nm, 2 nm, and 55 nm for AgNP, AuNP, and Ag/AuNP, respectively. Biosynthesis studies can provide an understanding of how parameters affect nanoparticle formation.