Selective Determination of Dopamine on a Boron‐Doped Diamond Electrode Modified with Gold Nanoparticle/Polyelectrolyte‐coated Polystyrene Colloids |
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Authors: | Min Wei Li‐Guo Sun Zhuo‐Ying Xie Jin‐Fang Zhii Akira Fujishima Yasuaki Einaga De‐Gang Fu Xue‐Mei Wang Zhong‐Ze Gu |
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Affiliation: | 1. State Key Laboratory of Bioelectronics Southeast University Nanjing 210096 (P.R. China);2. Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100080 (P.R. China);3. Kanagawa Academy of Science and Tedchnology KSP, 3‐2‐1 Sakado, Kawasaki 213‐0012 (Japan);4. Department of Chemistry Faculty of Science and Technology Keio University, 3‐14‐1 Hiyoshi Yokohama 223‐8522 (Japan) |
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Abstract: | Negatively charged gold nanoparticles (AuNPs) and a polyelectrolyte (PE) have been assembled alternately on a polystyrene (PS) colloid by a layer‐by‐layer (LBL) self‐assembly technique to form three‐dimensional (Au/PAH)4/(PSS/PAH)4 multilayer‐coated PS spheres (Au/PE/PS multilayer spheres). The Au/PE/PS multilayer spheres have been used to modify a boron‐doped diamond (BDD) electrode. Cyclic voltammetry is utilized to investigate the properties of the modified electrode in a 1.0 M KCl solution that contains 5.0 × 10?3 M K3Fe(CN)6, and the result shows a dramatically decreased redox activity compared with the bare BDD electrode. The electrochemical behaviors of dopamine (DA) and ascorbic acid (AA) on the bare and modified BDD electrode are studied. The cyclic voltammetric studies indicate that the negatively charged, three‐dimensional Au/PE/PS multilayer sphere‐modified electrodes show high electrocatalytic activity and promote the oxidation of DA, whereas they inhibit the electrochemical reaction of AA, and can effectively be used to determine DA in the presence of AA with good selectivity. The detection limit of DA is 0.8 × 10?6 M in a linear range from 5 × 10?6 to 100 × 10?6 M in the presence of 1 × 10?3 M AA. |
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Keywords: | electrodes layer‐by‐layer assembly multilayer architectures polyelectrolytes sensors |
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