Rifqi Fajar Maulana, Andri Hardiansyah, Angga Hermawan, Ni Luh Wulan Septiani, Akhmad Sabarudin, Yu-Wei Cheng, Chih-Yu Kuo, Tetsuya Kida, Ting-Yu Liu
Dopamine (DA) is a crucial neurotransmitter involved in metabolism, the immune system, and hormonal regulation. However, its accurate detection is challenging due to interference from compounds such as uric acid (UA) and ascorbic acid (AA). Here, we developed a polypyrrole/iron oxide/graphene nanoplatelet (PPy/Fe3O4/GNP)-modified glassy carbon electrode (GCE) for the selective detection of DA. FESEM analysis revealed a spherical bead-like morphology with a surface sheet of PPy, Fe3O4, and GNP. Electrochemical performance evaluation demonstrated that the PPy/Fe3O4/GNP-modified GCE possessed a high electroactive surface area (ECSA), that is, 0.099 cm2, facilitating enhanced electron transfer. The sensor exhibited a linear detection range of 5.25–1000 μM and a limit of detection (LOD) of 5.25 μM for DA. Upon the addition of UA and AA, their oxidation peaks remained well-separated from the DA oxidation peak, confirming the selectivity of the PPy/Fe3O4/GNP-modified GCE. Furthermore, the sensor demonstrated excellent stability for 5 days with a Relative Standard Deviation (RSD) value of 28%, repeatability up to 50 cycles with an RSD value of 24.21%, and reproducibility on three different electrodes, giving the same response pattern with an RSD value of 5.55%. The real sample analysis using human serum yielded a recovery percentage of 82.17%–120.91%, indicating the sensor's reliability in biological sample detection. In conclusion, the PPy/Fe3O4/GNP-modified GCE is a highly sensitive and selective electrochemical sensor for DA detection, effectively minimizing interference from UA and AA. These findings highlight its potential for reliable neurotransmitter-sensing applications. © 2025 The Chemical Society Located in Taipei & Wiley-VCH GmbH.
Department of Chemistry, Faculty of Mathematics and Natural Sciences, Brawijaya University, Malang, Indonesia; Research Center for Nanotechnology Systems, National Research and Innovation Agency (BRIN), Tangerang Selatan, Indonesia; Research Center for Electronics, National Research and Innovation Agency (BRIN), Bandung, Indonesia; Department of Chemical Engineering, Ming Chi University of Technology, New Taipei, Taiwan; Department of Chemical Engineering & Biotechnology, National Taipei University of Technology, Taipei, Taiwan; Division of Materials Science, Faculty of Advanced Science and Technology (Department of Applied Chemistry & Biochemistry), Kumamoto University, Kumamoto, Japan; Department of Materials Engineering, Ming Chi University of Technology, New Taipei, Taiwan; College of Engineering and Center for Sustainability and Energy Technologies, Chang Gung University, Taoyuan, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, Taiwan; Center for Plasma and Thin Film Technologies & Research Center for Intelligent Medical Devices, Ming Chi University of Technology, New Taipei, Taiwan
