Novel conductive polycarbazolic polymer embedded with palladium nanoparticles as a highly sensitive electrochemical sensor for hydrazine detection

To meet the demand for sensitive, trace-level hydrazine detection, we present a novel, high-sensitivity electrochemical sensor. We synthesized a novel carbazole-based conducting polymer (CRCP) as a distinctive host matrix, demonstrating exceptional stability, high redox potential, and excellent electrochemical properties. Subsequently, we developed an innovative electrochemical sensor by controllably embedding Pd nanoparticles (Pd) into this as-synthesized CRCP matrix using a simple cyclic voltammetry (CV) method to create a highly efficient Pd/PCz@GCE system for sensitive detection of hydrazine in alkaline media. The modified electrode exhibited significant electrocatalytic activity towards hydrazine oxidation. Notably, the FE-SEM analysis revealed an even distribution of spherical Pd nanoparticles (measuring 62-98 nm) across the polymer surface, a key factor that enhances electrocatalytic performance. It has a low detection limit of 0.084 μM, high sensitivity (56.64 μA Μm^-1 cm^-2), and excellent selectivity and is comparable or superior to previously reported sensors. The sensor offers a broad linear detection range (0.3-100 μM), and its performance is reproducible, repeatable, and stable. Kinetic studies revealed a diffusion-controlled process at the electrode surface. The effectiveness of the Pd/PCz@GCE was evaluated in real samples. These results indicate that the Pd/PCz@GCE sensor could serve as a reliable and practical platform for sensitive hydrazine detection in environmental analysis.