Antiviral Properties of Green-Synthesized Silver and Zinc Oxide Nanoparticles Against Coronaviruses: A Review

It is acknowledged that COVID-19 pandemic triggered by SARS-CoV-2 outbreak demands the development of efficient antiviral modalities independent of traditional vaccines and antiviral reagents. Metallic nanoparticles, such as silver nanoparticles (Ag-NPs) and zinc oxide nanoparticles (ZnO-NPs), have attracted considerable attention as promising antiviral agents due to their distinctive physicochemical properties and universal antimicrobial activity. This article examines the progress made between (2021 and 2025) in the green synthesis and the antiviral applications of Ag-NPs and ZnO-NPs against Coronavirus. The environmental friendly synthesis protocols using natural plant juices have been highlighted in this article due to their lower toxicity and greater biocompatibility. Various characterization methods, such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV-Vis spectrophotometry, have been used to examine nanoparticle morphology, stability, and surface characteristics. The findings reveald that Ag-NPs can suppress the viral replication by interacting strongly with S proteins, thereby hindering the cellular entry of the targeted Coronavirus. In contrast, ZnO-NPs showed that they have dual purposes: direct antiviral effects and immunomodulatory effects that involve cytokine regulation. The antiviral properties and the limitations of the individual nanoparticles are significantly modified by hybrid nanocomposites. In closing, the significance of using green-synthesized Ag-NPs and ZnO-NPs as antiviral materials is tremendous and warrants further exploration for antiviral applications. Nonetheless, there are still some unaddressed areas concerning the standardization of synthesis techniques and the validation of prolonged safety. Finally, it has been proven that there is a need for collaboration between nanotechnology and green technology in the development of environmentally benign, and universal antiviral medications against any future coronavirus pandemics.