Preparation of UiO-67 metal-organic framework carbon paste electrode as a sensor for electroanalytical determination of Ofloxacin in human plasma

The study presents an innovative UiO-67 modified carbon paste electrode (UiO-67/CPE) for electrochemical sensing of ofloxacin (OFX), demonstrating exceptional sensitivity and selectivity. The UiO-67 MOF nanostructure was synthesized via solvothermal methods and characterized by XRD, FT-IR, BET, FESEM, TEM, and EDX analyses, confirming its high crystallinity, and porosity. The electrochemical performance of the fabricated UiO-67/CPE was investigated through CV, LSV, and SWV techniques. From EIS analysis, the lower charge transfer resistance was detected in the UiO-67/CPE compared to bare CPE is mainly attributed to the high surface area and porous framework of UiO-67. The modified electrode demonstrated enhanced electrocatalytic activity, and amplified active surface area compared to the unmodified CPE. Optimization of analytical parameters using response surface methodology (RSM) yielded optimal detection conditions at pH 3.0, 0.03 g of UiO-67, and a scan rate ( υ ) of 0.06 V s −1 . Under these circumstances, the sensor exhibited a wide linear dynamic range (0.167–242.42 μM), a low detection limit (0.05 μM), and excellent reproducibility, stability, and anti-interference capability. The sensor was effectively applied to quantify OFX in human plasma samples with high recovery rates (98–103 %). These results highlight the potential of UiO-67/CPE as a rapid, low-cost, and reliable platform for electroanalytical applications in clinical and pharmaceutical analysis. • Synthesis and characterization of UiO-67 MOF. • Quantification of ofloxacin by UiO-67/CPE sensor. • Obtaining maximum current densities based on response surface methodology. • Advantages of stability, repeatability and reproducibility of the UiO-67/CPE. • Good capability of UiO-67/CPE for determination of ofloxacin in the human plasma.