Pre-treated pencil graphite modified electrode sensor for melatonin: Original scientific paper. Journal of Electrochemical Science and Engineering, [S. l.], v. 15, n. 5, 2025. DOI: 10.5599/jese.2594. Disponível em: https://pub.iapchem.org/ojs/index.php/JESE/article/view/2594. Acesso em: 27 apr. 2026.