Microfabricated On-Line Sensor for Continuous Monitoring of L-Glutamate

Osamu Niwa, Tsutomu Horiuchi, Ryoji Kurita, Hisao Tabei, Keiichi Torimitsu

Research output: Contribution to journalArticlepeer-review

23 Citations (Scopus)


An on-line sensor was developed by using a micro-machining technique for the continuous measurement of extracellular glutamate. The sensor was made by bonding two glass plates together. One of the plates has a rectangular flow channel which is connected to both a sampling and an outlet capillary. The other has a carbon film-based electrochemical cell, which consists of an enzyme-modified electrode surrounded by polymer film to form a thin-layer-channel flow cell. The sensor has a high analyte conversion efficiency due to the cell structure. As a result, we obtained a low detection limit of 44 nM (S/N=3). The cathodic current started to increase about 10 s after sample introduction at a flow rale of 2 μl/min due to its small inner volume. Using the sensor, we can monitor the extracellular L-glutamate increase caused by stimulating it with KCl and γ-aminobutyric acid (GABA) by locating the sampling capillary very close to the cell.

Original languageEnglish
Pages (from-to)947-953
Number of pages7
Journalanalytical sciences
Issue number5
Publication statusPublished - 1998
Externally publishedYes


  • Enzyme-modified electrode
  • L-glutamate
  • Micro-machining
  • Nerve cell
  • Neurotransmitter
  • On-line sensor

ASJC Scopus subject areas

  • Analytical Chemistry


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