Electrochemical determination of furaltadone hydrochloride by hierarchically structured titanium phosphate

Abstract

This work presents the synthesis and investigation of electrochemical properties of microspherical titanium phosphate (TiP) with complex composition and hierarchical structure. The material comprises centrically aggregated micro-sized flakes, employed as a highly efficient electroactive modifier in carbon paste electrodes. The key finding is the superior electrochemical performance of the TiP 1/6 sample (average microsphere size: ~8 μm), which exhibited the lowest charge transfer resistance (Rct = 12 Ω) and highest response current (I = 1.37 mA) among all tested microspheres. This enhancement is attributed to an optimal balance between two critical parameters: (i) surface composition ensuring low charge-transfer resistance, and (ii) hierarchical structure of aggregated micro-scales, facilitating efficient reagent diffusion to active sites. Smaller microspheres (~4 μm, Rct = 41 Ω) demonstrated minimal diffusion barriers, while larger ones (~15 μm, Rct = 15 Ω) displayed favorable surface composition, making TiP 1/6 sample optimized with both characteristics. The TiP 1/6-based sensor has delivered exceptional analytical performance, including a low detection limit of a widespread antibiotic, wide linear working range, and high selectivity. Successful real-sample analysis confirms its practical utility. These results highlight the significant potential of hierarchical TiP 1/6 microspheres for developing highly sensitive and selective electrochemical sensors, suitable for both research and commercial applications.