Electrochemical determination of calcium folinate in the presence of methotrexate and 5-fluorouracil using UiO-66/CdS composite modified screen-printed carbon electrode
Raed Muslim Muhibes, Fatma A. Khazaal, Qasim Mezban Salih, Raad Radi Karabat Raad Radi Karabat
Abstract
Background and purpose: Calcium folinate is frequently co-administered with methotrexate and 5-fluorouracil in chemotherapeutic treatments to enhance therapeutic efficacy and reduce toxicity. Therefore, simple and accurate determination of calcium folinate in the presence of these agents is essential for therapeutic monitoring and pharmaceutical analysis. Experimental approach: The current work is focused on designing and developing a simple and sensitive modified screen-printed carbon electrode (SPCE)-based electrochemical sensor for the determination of calcium folinate in the presence of methotrexate and 5-fluorouracil. For this purpose, a nanostructure of UiO-66/CdS composite was prepared. Then, we used the prepared UiO-66/CdS composite to modify SPCE towards the development of an electrochemical sensing platform (UiO-66/ /CdS/SPCE). Key results: The cyclic voltammetry studies revealed that the UiO-66/CdS/SPCE could significantly improve the detection of calcium folinate with a higher response peak current at a lower overpotential compared to other SPCEs. Also, the UiO-66/CdS/SPCE sensor demonstrated a good ability in the quantitative determination of calcium folinate by the differential pulse voltammetry (DPV) method. Based on DPV measurements, a linearity plot was achieved for the concentration range of 0.1 to 300.0 µM calcium folinate with a limit of detection (LOD) of 0.04 µM and a high sensitivity of 0.0503 µA µM-1. Furthermore, the UiO-66/ /CdS/SPCE sensor showed three well-separated oxidation peaks for the simultaneous determination of calcium folinate, methotrexate, and 5-fluorouracil without interfering with each other. Finally, the UiO-66/CdS/SPCE sensor was used to detect calcium folinate, methotrexate, and 5-fluorouracil in real samples, and the values of recovery and relative standard deviation (RSD) were satisfactory. Conclusion: The results from this study show that the designed sensor can be used as an efficient and promising platform for the determination of these species.