Copper–Silver Nanoparticle/Lipase Nanobiohybrids for Enhanced Activity Against Viral Pathogens

The development of sustainable, low-toxicity materials that are effective against a wide range of microorganisms is crucial in addressing emerging infectious diseases. The recent spread of monkeypox virus (MPXV), respiratory pathogens such as rhinoviruses or seasonal coronaviruses, and animal pathogens such as porcine reproductive and respiratory syndrome virus (PRRSV) highlights the urgent need for innovative solutions in both human and animal health. In this study, we designed a bimetallic nanobiohybrid material, NanoCuAg, composed of a lipase and in situ-synthesized copper and silver nanoparticles, with a low silver-to-copper ratio, through a simple and sustainable synthetic process. The nanobiomaterial, featuring a supramolecular flower structure containing ∼4 nm average diameter nanoparticles, contains 32% copper and 3% silver, mainly in the Cu(II) and Ag(I) oxidation states. Despite its low silver content, the nanobiomaterial showed a strong catalytic efficacy in different model reactions. Then, its virucidal activity was evaluated under different conditions. At 200 ppm, in combination with hydrogen peroxide, it inactivated 99% of human rhinovirus B14 and 99.99% of human coronavirus 229E. At 1000 ppm, it achieved 90% efficacy against MPXV and a 4.8 log₁₀ (≈99.999%) reduction in PRRSV. These results demonstrate the potential of NanoCuAg as a highly effective virucidal material, capable of inactivating both enveloped and nonenveloped viruses at low concentrations, making it a promising candidate for broad-spectrum virucidal applications.