Eco-sustainable fabrication of copper oxide nanoparticles from Barleria longiflora: Implications for water treatment and cancer therapeutics

The development of multifunctional nanomaterials with improved antitumor efficacy and precise targeted drug delivery has garnered increasing interest recently. This study presents an eco-friendly synthesis of copper oxide nanoparticles (CuO-NPs) using Barleria longiflora leaf extract and evaluates their biological applications. The synthesized CuO-NPs were characterized using UV–Vis spectroscopy, Fourier transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), High Resolution-Scanning Electron Microscopy (HR-SEM), High resolution-Transmission electron microscopy (HR-TEM), and photoluminescence analysis, confirming a monoclinic structure, rod-like morphology, with an average size of 32.28 nm. FTIR indicated the presence of functional groups aiding nanoparticle stabilization. HR-SEM and Enery Dispersive Xray Spectrocopy (EDX) revealed micro-flower structures and a Cu:O ratio of 18:68. The CuO-NPs exhibited significant antibacterial activity against both Gram-positive and Gram-negative bacteria, with maximum inhibition (16 mm) against E. coli. Anticancer evaluation against (MCF-7) breast cancer cells demonstrated dose-dependent cytotoxicity with an IC₅₀ value of 40.83 µg/mL, inducing apoptotic cell death confirmed by Acridine orange/ Ethidium bromide (AO/EB) staining. The nanoparticles showed excellent photocatalytic activity, degrading 80% of methylene blue dye within 2.5 min following pseudo-first-order kinetics. The photocatalyst maintained structural stability through four consecutive cycles, demonstrating potential reusability for wastewater remediation. The photocatalytic effectiveness of CuO-NPs in degrading methylene blue was examined under UV light, focusing on catalytic stability. FTIR examination confirmed that CuO's structural stability remained maintained, revealing its stable nature for treating wastewater and there was no noticeable copper ion leaching. This study highlights the multifunctional applications of bio-mediated CuO-NPs as effective antimicrobial agents, anticancer therapeutics, and environmental photocatalysts, offering a sustainable approach to addressing healthcare and environmental challenges.