Harnessing the Sustainable Approach for Copper Nanoparticle Biosynthesis: Investigation of Antiviral and Antioxidant Efficacy and an In Silico Study

Abstract

The emergence of SARS-CoV-2 and other virus threats has renewed interest in nanoparticles as potential antivirals. Green synthesis of nanoparticles using biological methods offers an eco-friendly, cost-effective alternative to conventional approaches. In this study, copper nanoparticles (Cu-NPs) were biosynthesized using Artemisia sieberi (A.s) florets extract, which acts as a reducing, capping, and stabilizing agent. The synthesized Cu-NPs/A.s were characterized using transmission electron microscopy (TEM), UV-Visible spectroscopy, energy-dispersive X-ray spectroscopy (EDX), and dynamic light scattering (DLS). The antiviral and antioxidant activities of Cu-NPs/A.s were evaluated, and molecular docking was performed to explore possible interactions between Cu-NPs/A.s with SARS-CoV-2 main protease and influenza A virus RNA polymerase as a hypothesis-generating approach. Structural and morphological characterisations confirmed successful nanoparticle formation, and Cu nanoparticles exhibited smaller particle dimensions (particle size of 63.7 ± 19.5). The Cu-NPs/A.s demonstrated notable antioxidant activity (55% scavenging in phosphomolybdate assay) compared to ascorbic acid and a strong inhibitory effect against influenza A virus (IAV) (70.67%). Docking studies indicated favorable binding energy interactions between chlorogenic acid - copper nanoparticles (CGA-Cu NPs /A.s) and SARS-CoV-2 are -8.22 kcal/mol; similarly, the influenza A virus (IAV) gives the binding energy -9.22 kcal/mol, which may inform future experimental investigations. The DFT parameters indicate that the Cu-complex possesses favourable electronic properties, a substantial charge transfer capability, and elevated reactivity. To assess organ-specific toxicity, bioavailability and metabolic interactions, a full computational toxicological evaluation using ProTox-3.0 is performed based on a chemical model for a combination hearing aid.