Sustainable development of ZnO nanoparticles and nanocellulose-modified CPE for electrochemical sensing of tinidazole

The detection of tinidazole (TIZ) in environmental and pharmaceutical samples remains constrained by conventional electrochemical sensors, which often rely on energy-intensive synthesis routes and toxic modifiers, undermining their sustainability. To bridge this gap, this study introduces a green synthesis approach for sensor fabrication, leveraging the concept of waste-to-value by converting banana peel into nanocellulose (PNC) and using it as a sustainable scaffold for zinc oxide nanoparticles (ZnO NPs). The enhanced performance of the PNC-ZnO/CPE sensor originates from a synergistic interplay between the high surface area and conductivity of ZnO NPs and the dispersive and stabilizing properties of PNC, which collectively facilitate the electron transfer kinetics for TIZ reduction. The prepared samples were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDX). The sensor demonstrated a linear response to TIZ concentrations ranging from 9.0 ×10^-9 M to 25.0 ×10^-6 M, with a detection limit of 2.1 nM under optimized conditions. Furthermore, selectivity was quantitatively demonstrated, with the sensor maintaining a stable signal (<5% deviation) in the presence of common interferents. The combination of performance metrics derived from agricultural waste not only validates the sensor's efficacy but also provides a cost-effective and environmentally benign alternative, advancing the principles of green chemistry in electroanalysis. This work establishes a platform for the future development of sustainable, waste-derived nanocomposites for a broader range of electrochemical sensing applications.