A smart cubebinol-CuO nanocomposite for dual electrochemical sensing and visible-light-driven photodegradation of tetracycline: Box-Behnken optimization, mechanistic insight and kinetics.

Globally, tetracycline is a widely used antibiotic, and its extensive usage has posed serious environmental concerns. This study introduces a novel approach integrating cubebinol, a natural compound extracted from Piper cubeba seeds using eco-friendly reflux-assisted soxhlet extraction, and biogenic copper oxide (CuO) nanoparticles. The cubebinol-CuO nanocomposite, prepared via the solvent-driven phase separation method, demonstrates exceptional potential in electrode-driven sensing and light-induced pollutant breakdown of tetracycline from contaminated water. The characterization by SEM, UV-Visible, FTIR, and Raman spectroscopy revealed its structural and morphological properties. The electrochemical studies showed excellent sensing performance, with a sensitivity of 1.036 µA µM⁻1 cm⁻2 in the linear range of 10-100 µM, and a low limit of detection (LOD) of 12.95 µM. For photocatalytic degradation, Box-Behnken design optimized parameters, achieving 89.09% degradation under visible light at pH 12, with 14.56 mg/L of nanocomposite in 145 min. Unlike conventional methods that rely on harsh chemicals, synthetic reagents, or high energy inputs, this study leverages plant-derived materials and visible light for a cost-effective, eco-friendly, and energy-efficient process. Phytotoxicity assays on seeds confirmed reduced toxicity in treated water, ensuring its environmental safety. This work addresses limitations in current tetracycline removal technologies by combining sustainable synthesis with multifunctional performance for both electrochemical sensing and photocatalytic degradation. The findings validate cubebinol's potential in advancing green technologies for water purification and offer a significant improvement over existing methods in terms of sustainability, efficiency, and environmental impact.