Andri Hardiansyah, Rifqi Fajar Maulana, Ni Luh Wulan Septiani, Chen-Ying Su, Hsu-Wei Fang, Angga Hermawan, Akhmad Sabarudin, Yu-Wei Cheng, Chih-Yu Kuo, Tetsuya Kida, Ting-Yu Liu
Chitosan (CS) is a cationic linear polysaccharide rich in functional groups (–OH and –NH2) that enable diverse biochemical interactions, making it a promising candidate for the electrochemical detection of dopamine (DA), uric acid (UA), and ascorbic acid (AA). However, its poor electrical conductivity and limited thermal stability restrict its standalone performance, thus requiring the formation of composites with other materials. In this study, we report the synthesis of a chitosan/Fe3O4/graphene nanoplatelet (CS@Fe3O4/GNP) nanocomposite for the highly sensitive and selective electrochemical detection of DA, UA, and AA. The nanocomposite integrates the superior conductivity and high surface area of GNP, the electrocatalytic activity of Fe3O4 nanoparticles, and the biocompatibility and adhesive nature of chitosan. The CS@Fe3O4/GNP composite with various CS concentration (0.0625, 0.125, and 0.25%) was synthesized via a facile in-situ co-precipitation method. Electrochemical studies demonstrated that the 0.25% CS@Fe3O4/GNP-modified glassy carbon electrode (GCE) exhibited excellent detection performance toward DA, UA, and AA, with limits of detection (LOD) of 28.37 nM (range 30–488 nM), 566.27 nM (range 0.98–15.6 μM), and 26.54 μM (range 31.25–500 μM), respectively. The sensor also achieved recovery rates of 87.83–92.68% (DA), 82.41–91.61% (UA), and 88.83–95.04% (AA) in human blood serum samples. © 2026 Elsevier Ltd.
Research Center for Nanotechnology Systems, National Research and Innovation Agency (BRIN), Tangerang Selatan, Banten, 15314, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Brawijaya University, East Java, Malang, 65145, Indonesia; Research Center for Electronics, National Research and Innovation Agency (BRIN), West Java, Bandung, 40135, Indonesia; High-Value Biomaterials Research and Commercialization Center, National Taipei University of Technology, Taipei, 106, Taiwan; Department of Chemical Engineering, Ming Chi University of Technology, New Taipei City, 24301, Taiwan; Department of Chemical Engineering & Biotechnology, National Taipei University of Technology, Taiwan; Division of Materials Science, Faculty of Advanced Science and Technology (Department of Applied Chemistry & Biochemistry), Kumamoto University, Kumamoto, 860-8555, Japan; Department of Materials Engineering, Ming Chi University of Technology, New Taipei City, 243303, Taiwan; R&D Center of Biochemical Engineering Technology, Ming Chi University of Technology, New Taipei City, 243303, Taiwan; Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan City, 32003, Taiwan; College of Chemical Engineering and Center for Sustainability and Energy Technologies, Chang Gung University, Taoyuan, 33302, Taiwan
