Barley-Derived Green Synthesis of Gold and Silver Nanoparticles: Transforming Agricultural Resources into Sustainable Nanomaterials

This study presents a novel approach utilizing barley grains for the green synthesis of gold (Barley-AuNPs) and silver nanoparticles (Barley-AgNPs). The study emphasizes the sustainable nature of barley-mediated synthesis, positioning it as an environmentally friendly alternative for nanoparticle production. The rapid synthesis of Barley-AuNPs within 20 minutes and Barley-AgNPs within 30 minutes at 90°C underscores the efficiency of barley as a green precursor. Characterization through advanced techniques, including SEM, TEM, EDX, AFM, DLS, FTIR, MALDI-TOF and sp-ICPMS, reveals the 20–30 nm size for Barley-AuNPs, while Barley-AgNPs demonstrate 2–10 nm size with monodispersity. A notable contribution lies in the stability of these nanoparticles over extended periods, attributed to a thick biological corona layer. This corona layer, which enhances stability, also influences the antimicrobial activity of Barley-AgNPs, presenting an intriguing trade-off. Moreover, the antimicrobial investigations highlight the significant potential of Barley-AgNPs, with distinct minimum bactericidal concentrations (MIC) against P. aeruginosa and E. coli at 8 µg/ml. Overall, this research not only pioneers the use of barley in nanoparticle synthesis but also unveils the unique characteristics and potential applications of these nanoparticles, contributing to the evolving landscape of sustainable nanotechnology.