Electrochemical detection of melatonin using Gd-doped ZnO nanoparticles modified carbon paste electrode: Original scientific paper. J. Electrochem. Sci. Eng. [Internet]. 2025 Oct. 23 [cited 2026 May 22];16. Available from: https://pub.iapchem.org/ojs/index.php/JESE/article/view/2914