Original Papers
A Glass Capillary Microelectrode Based on Capillarity and Its Application to the Detection of L-Glutamate Release from Mouse Brain Slices
2003 年 19 巻 1 号 p. 55-60
詳細
2003 年 19 巻 1 号 p. 55-60
A new glass capillary microelectrode for L-glutamate is described using pulled glass capillaries (tip size, ∼12.5 μm) with a very small volume (∼2 μl) of inner solution containing glutamate oxidase (GluOx) and ascorbate oxidase. The operation of the electrode is based on capillary action that samples L-glutamate into the inner solution. The enzyme reaction by GluOx generates hydrogen peroxide that is detected at an Os-gel-HRP polymer modified Pt electrode in a three-electrode configuration. The amperometric response behavior of the electrode was characterized in terms of the capillarity, response time, sensitivity and selectivity for measurements of L-glutamate. The currents at 0 V vs. Ag/AgCl increased linearly with the L-glutamate concentration from 10 to 150 μM for in vitro and in situ calibrations. The reponse was highly selective to L-glutamate over ascorbate, depamine, serotonin and other amino acids. The detection of L-glutamate in the extracellular fluids of different regions of mouse hippocampal slices under stimulation of KCl was demonstrated.
