Biosensing Properties of TitanateNanotube Films: Selective Detection of Dopamine in the Presence of Ascorbate and Uric Acid

Authors

  • A. Liu,

    1. Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan
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  • M. D. Wei,

    1. Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan
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  • I. Honma,

    1. Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan
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  • H. Zhou

    1. Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Umezono 1-1-1, Tsukuba 305-8568, Japan
    2. PRESTO, Japan Science and Technology Agency (JST), Kawauchi, Saitama 332-0012, Japan
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  • Dr. A. Liu gratefully acknowledges the Japan Society for the Promotion of Science (JSPS) for the financial support of this work.

Abstract

A novel strategy based on titanate nanotubes (TNTs) for developing an electrochemical biosensor is proposed. Stable TNT films are fabricated on glassy carbon (GC) electrodes by a casting technique. Cyclic voltammetry, electrochemical impedance spectrometry, and linear-sweep voltammetry are used to characterize the TNT membrane-covered GC electrodes (TNT/GCs). The TNT film is shown to demonstrate selectivity by charge exclusion. The TNT film is also shown to be capable of improving the mass transport to the electrode surface and electron transfer between dopamine (DA) and the electrode. Therefore, DA exhibits a quasireversible electrochemical reaction at the TNT/GC electrode. The voltammetric signal of DA is well resolved from those of ascorbate (AA) and uric acid (UA) at the TNT/GC electrode; therefore, DA can be selectively detected in the presence of a large excess of AA and UA at physiological pH. The linear calibration curve for DA is obtained over the concentration range 0.1–30 μM in a physiological solution that contains 0.1 mM AA and 0.3 mM UA.

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