Soutenance de thèse de Wenbo Liu

Green synthesis of multifunctional silver nanoparticle composites endowed with antibacterial properties

Antimicrobial resistance (AMR) has become a critical threat to public health, while traditional antibiotics are increasingly ineffective against multidrug-resistant bacteria. Nanotechnology, particularly silver nanoparticles (AgNPs), offers powerful antimicrobial strategies through multiple mechanisms, reducing the likelihood of bacterial resistance. However, conventional synthesis of AgNPs raises biosafety concerns due to toxic byproducts. Green synthesis methods are emerging to improve biosafety, thereby enhancing the clinical potential of AgNPs.Aqueous radiation-induced synthesis provides a clean, precise, and scalable way for producing biomedical AgNPs via hydrated electrons, eliminating the need for toxic reductants and yielding high-purity, biosafe AgNPs with tunable properties and inherent sterilization. Here, radiosynthesis using Ag₂SO₄ as a precursor generated three different AgNPs with uniform, smaller, compared to the preferred water-soluble AgNO₃. Moreover, green room-temperature synthesis with natural reductants like ascorbic acid (H₂Asc) enables controlled, impurity-free AgNPs production. Here, we report an eco-friendly route for H₂Asc-mediated AgNPs (Asc-AgNPs). All of these AgNPs demonstrated broad-spectrum antimicrobial activity against pathogenic bacteria. In a nutshell, these studies pave the way towards engineering the green synthesis of facile and scalable silver nanomaterials for antimicrobial applications.