Scalable green synthesis of Ag/Cu bimetallic nanoparticles via electron beam irradiation for synergistic antimicrobial protection against plant pathogens

The development of scalable and eco-friendly synthesis of antimicrobial nanomaterials is pivotal for sustainable plant disease control. In this study, chitosan-stabilized silver/copper bimetallic nanoparticles (Ag/Cu BNPs) were fabricated in a continuous large-batch process using electron beam (EB) irradiation, approaching the limitations of conventional lab-scale methods. The EB-induced reduction enabled the mass production of pseudo-spherical Ag/Cu BNPs with an average diameter of approximately 15 nm and minimal copper oxide impurities, ensuring consistent achievement of dose uniformity across 10-liter batches. In vitro antimicrobial assays revealed that the Ag/Cu BNPs exhibited significantly enhanced antibacterial and antifungal activity against Pseudomonas solanacearum and Neoscytalidium dimidiatum , achieving ∼30% higher efficacy than monometallic Ag or Cu nanoparticles at equivalent concentrations. This superior performance is attributed to a synergistic bimetallic effect, involving the simultaneous release of Ag + and Cu 2+ ions, accelerated reactive oxygen species (ROS) generation, and intensified microbial membrane disruption. The obtained results establish that EB irradiation is a green, scalable, and efficient procedure for producing high-performance Ag/Cu bimetallic nanomaterials, highlighting their potential as next-generation antimicrobial agents for sustainable agricultural applications. • Eco-friendly large-batch Ag/Cu BNPs synthesis via electron beam irradiation. • Custom containers ensure optimal dose uniformity for scalable Ag/Cu BNPs production. • Pseudo-spherical Ag/Cu BNPs (∼15 nm) show high purity and alloyed structure. • Ag/Cu BNPs is 30% higher synergistic efficacy than monoforms against phytopathogens. • Ag/Cu BNPs outperform individual nanoforms for sustainable plant protection.