Improving the reproducibility of hydrogel-coated glutamate microsensors by using an automated dipcoater

Weite Hendrik Oldenziel*, W. Beukema, B.H.C. Westerink

*Corresponding author for this work

    Research output: Contribution to journalArticleAcademicpeer-review

    31 Citations (Scopus)


    Hydrogel-coated microsensors based oil carbon fiber electrodes (CFEs) are promising tools for in vivo analysis of endogeneous compounds such as glutamate. However. their construction generally depends on manual fabrication. which often results in pool reproducibility. The aim of this study was to improve the reproducibility and performance of glutamate microsensors. CFEs (10 mum diameter. 300-500 mum long) were coated with a cross-linked redox-polymer hydrogel containing L-glutamate oxidase, horseradish peroxidase and ascorbate oxidase. Various parameters that are likely to influence the reproducibility of the glutamate microsensors were studied. It appeared that the most crucial step in determining the microsensor performance is the manual hydrogel-application procedure. To control this procedure an automated dipcoater was constructed, which allowed mechanical application of the hydrogel on the CFE under standardized conditions. Significant improvements in performance were seen when the CFEs were dipcoated for 10 min at 37 degreesC. Further improvements were obtained when the automated hydrogel application was combined with other cross-link methods. such as electrodeposition and electrostatic complexation. A crucial factor in determining the microsensor performance is the hydrogel thickness. Microscopic observations revealed that, despite the use of an automated dipcoater, the layer thickness was not constant. By conbining the automated dipcoat technique with amperometry, the layer thickness could be indirectly monitored and controlled, which resulted ill significant improvements of the reproducibility of the sensors. (C) 2004 Elsevier B.V. All rights reserved.

    Original languageEnglish
    Pages (from-to)117-126
    Number of pages10
    JournalJournal of Neuroscience Methods
    Issue number1-2
    Publication statusPublished - 30-Dec-2004
    Event10th International Conference on In Vivo Methods - , Sweden
    Duration: 24-Jun-200327-Jun-2003


    • CFE
    • hydrogel
    • L-glutamate oxidase
    • microsensor
    • construction
    • L-glutamate
    • IN-VIVO

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