Synergistic Nanoarchitectonics of Carbon Aerogel/TiO2-NiO@PANi Modified Electrode for Highly Sensitive Voltammetric Detection of Diazinon Pesticide Endocrine Disruptor

Abstract: This study reports the development of a highly sensitive and cost-effective voltammetric sensor based on a carbon aerogel/TiO2-NiO@PANi modified electrode for the detection of diazinon, an endocrine-disrupting organophosphate pesticide. Carbon aerogel (CA) was synthesized from palm shell waste and served as a high-surface-area conductive scaffold, while TiO2-NiO nanoparticles acted as the electroactive catalytic sites, and polyaniline (PANi) provided additional electron conduction pathways. The resulting composite was characterized by XRD, SEM, and EDX analyses, confirming homogeneous dispersion of TiO2-NiO nanoparticles and the successful incorporation of PANi. Cyclic voltammetry (CV) studies revealed that CA/TiO2-NiO@PANi exhibited enhanced redox peak currents and reduced peak-to-peak separation (ΔEp), indicating improved electron transfer kinetics compared to unmodified CA and CA/TiO2-NiO electrodes. The developed sensor demonstrated a linear electrochemical response to diazinon concentrations in the range of 0.1-1.0 ppm, with a regression equation of Ipa = 164.66DZN - 34.937 (R2 = 0.997) and a limit of detection (LOD) of 0.0182 ppm. These findings suggest that the CA/TiO2-NiO@PANi electrode offers a promising platform for rapid, reproducible, and highly sensitive non-enzymatic detection of diazinon, providing an environmentally friendly approach for monitoring pesticide contamination in agricultural and environmental samples.