Construction of a Miniaturized Electrochemical Sensor for Voltammetric Detection of 17β-Estradiol using a g-C3N4-Decorated Gold Nanoparticles Electrode

Background: 17β-estradiol (E2) is a steroid hormone that has the potential to disrupt the endocrine system, leading to adverse effects on both humans and ecosystems, even when present in low concentrations. The quantitative determination of E2 is of great practical significance. Hypothesis: Electrochemical methods offer several advantages, including low cost, ease of operation, and potential for miniaturization, which makes them suitable for on-field detection applications. Methods: This research developed a miniaturized electrochemical sensor utilizing graphitic carbon nitride (g-C3N4) assembled on an AuNPs/ITO film electrode for sensitive voltammetric detection of a steroid hormone, E2. Results: Compared with AuNPs/ITO electrodes, the g-C3N4/AuNPs/ITO exhibits higher sensitivity for voltammetric detection of E2. Under optimal conditions, the differential pulse voltammetric response on the g-C3N4/AuNPs/ITO electrode was proportional to E2 concentration in the 25 ~ 600 µmol/L range, with a detection limit of 6.5 µmol/L. Conclusion: The proposed g-C3N4/AuNPs/ITO electrode exhibited a wide linear range, good selectivity, and practical applicability for determining E2 in environmental water samples with acceptable recovery.