Electroanalytical determination of melatonin in natural waters using pencil graphite electrodes

• Grant number: 25/14458-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2025
• End date: October 31, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Lucia Codognoto de Oliveira
• Grantee: Ana Vitoria de Faria Billa
• Host Institution: Instituto de Ciências Ambientais, Químicas e Farmacêuticas (ICAQF). Universidade Federal de São Paulo (UNIFESP). Campus Diadema. Diadema , SP, Brazil

Abstract

The increasing water pollution caused by emerging pollutants poses a global environmental threat, as conventional water and wastewater treatments are unable to eliminate these substances. Among them, melatonin, a hormone with potential ecotoxicological impacts, especially on the reproduction and development of aquatic species, requires more efficient and accessible detection methods. This project aims to develop an innovative electroanalytical methodology for the determination of melatonin in natural waters, using pencil graphite electrodes (PGE) modified by in situ electrogeneration of graphite oxide (GrO-PGE). These electrodes offer significant advantages, such as high sensitivity, low cost, ease of disposal, shorter analysis time, and reduced sample handling. Samples will be collected from the Billings Reservoir in Diadema, São Paulo, contributing to a realistic assessment of the hormone's presence in the environment. In addition to providing an efficient analytical tool, the study also aims to deepen the understanding of melatonin oxidation and reduction processes, enabling the identification of potential environmental metabolites. Thus, it is expected not only to promote technological advances in the detection of emerging pollutants, but also to offer important subsidies for the assessment of environmental risks and the formulation of more effective mitigation strategies.