Sustainable green synthesis of cerium and copper nanoparticles from agro-industrial biowaste of hazelnut (Corylus avellana L.) husk: comprehensive characterization, sustainability index-based assessment, and multi-target bioactivity evaluation

Abstract

In this study, cerium oxide (CeO2) and copper oxide (CuO) nanoparticles were synthesized from the shell of Corylus avellana L. (hazelnut), an agro-industrial waste belonging to the Betulaceae family, using a rapid green synthesis approach. The structural and morphological properties of the synthesized nanoparticles were characterized using UV-Visible spectroscopy, optical microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and atomic force microscopy (AFM). The results confirmed that the nanoparticles were highly pure, exhibited crystalline geometry, and had particle sizes ranging from 10 to 20 nm. The total phenolic content of the dry hazelnut shell extract was 86.18 +/- 8.03 mg GAE/g. Anticancer activity studies revealed that CuO nanoparticles significantly reduced cell viability in HCT-116 cells at concentrations of 1.695-3.39 mu g/mL and in SW480 cells at 0.8475-3.39 mu g/mL. In contrast, CeO2 nanoparticles showed no significant cytotoxic effect within the tested range (0.211-3.39 mu g/mL). Regarding antimicrobial activity, CuO nanoparticles exhibited strong antibacterial effects, particularly against Gram-positive bacteria, whereas CeO2 nanoparticles showed no activity. Additionally, CuO nanoparticles demonstrated a higher biofilm inhibition rate (60.09 %) compared to CeO2 nanoparticles (46.99 %), while no anti-quorum sensing activity was observed. Overall, these findings highlight the potential of synthesized CuO nanoparticles for pharmacological applications.