Highly Sensitive Trimetazidine Determination Using Composite Yttria-Stabilized Zirconia Doped with Titanium...

A novel composite voltammetric biosensor has been developed for the first time, utilizing a glassy carbon electrode modified with yttria-stabilized zirconia doped with titanium dioxide and carbon black (YSZTiO₂-CB/GCE), specifically designed for the detection of trimetazidine (TMZ). The measurement conditions, including both the supporting electrolyte and instrumental settings, were optimized to enhance performance. In the concentration range of 0.5 to 7 µM, it is not necessary to use preconcentration time for the determination of TMZ. The limit of detection (for 60 s of preconcentration time) was equal to 5.5 nM (1.87 ng mL^-1), outperforming other voltammetric methods in terms of sensitivity. The reproducibility of the trimetazidine signal (with a concentration of 0.05 µM) exhibited a relative standard deviation (RSD) of 3.3% over 10 measurements. Additionally, our biosensor is characterized by excellent stability, ease of use, and straightforward preparation. The proposed biosensor and method have proven effective in analyzing TMZ in a variety of matrices, including urine, blood plasma, pharmaceutical formulations, as well as gastric and intestinal fluids, yielding recovery rates ranging from 97.7 to 102.3%.