Unveiling Electrochemical Frontiers: Enhanced Hydrazine Sensing with Na3[Fe(CN)5(PZT)] Modified Electrodes

This study presents the synthesis, electrochemical characterization, and sensor application of Na3[Fe(CN)5(PZT)], a novel pentacyanidoferrate-based coordination compound incorporating 2-pyrazinylethanethiol (PZT) as a ligand. Unlike conventional Prussian blue analogues, this system exhibits enhanced electrocatalytic properties due to its unique ligand framework, which contributes to increased charge transfer efficiency and stability. The complex was synthesized via a controlled ligand substitution reaction, followed by UV-Vis and IR spectroscopy confirmation of its successful formation. The electrochemical properties of the Na3[Fe(CN)5(PZT)] complex were investigated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), square-wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS). Notably, the modified electrodes exhibited improved charge transfer kinetics and catalytic activity, making them promising candidates for electrochemical sensing applications. The Na3[Fe(CN)5(PZT)]-modified electrode demonstrated outstanding electrocatalytic performance towards hydrazine oxidation, exhibiting a low detection limit of 7.38 × 10−6 M, a wide linear response range from 5 to 64 µmol L−1, and high sensitivity. The proposed system enables precise quantification of hydrazine with high selectivity, positioning Na3[Fe(CN)5(PZT)] as an effective electrochemical mediator for advanced sensing platforms. These findings provide new insights into the design of next-generation Prussian blue analogue-based sensors with superior analytical performance.