Multifunctional biosensors for electrochemical analysis of brain function
| Project/Area Number |
58870118
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| Research Category |
Grant-in-Aid for Developmental Scientific Research
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| Allocation Type | Single-year Grants |
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| Research Field |
医学一般(含病院管理学・看護学・人類遺伝学・病態検査学・実験動物)
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| Research Institution | Kyushu University |
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Principal Investigator |
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| Project Period (FY) |
1983 – 1985
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| Project Status |
Completed (Fiscal Year 1985)
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| Budget Amount *help |
¥15,000,000 (Direct Cost: ¥15,000,000)
Fiscal Year 1985: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1984: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1983: ¥9,000,000 (Direct Cost: ¥9,000,000)
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| Keywords | multifunctional biosensor / indolamine / dopamine / in vivo voltammetry / carbon fiber electrode / oxygen probe / enzyme membrane / インドールアミン |
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| Research Abstract |
Purpose of this project is to make multifunctional biosensors which can detect local kinetics of endogenous substances influencing neuronal activity in the central nervous system. New type of biogenic amine sensors using voltammetry system and oxygen probe with the enzyme membrane were developed. We examined characteristics of the sensors in vitro and tried to apply in vivo conditions.
As a working electrode of in-vivo voltammetry, carbon fiber electrodes were used. These electrodes were electrochemically activated beforehand by applying a triangular current pulses (0-2V, 70 Hz, 60s) in 0.1 M <H_2> <SO_4> solution. Calibration curves (oxidation current vs concentration) of DOPAC (metabolite of catecholamines) and 5-HIAA (metabolite of indolamines) using these electrodes were confirmed to be linear between 1 <micro> M and 10 <micro> M concentration which was within the physiologically notmal range. The working electrodes were attached to glass micropipette, and the concentration of 5-HT applied iontophoretically with variable amount of current was measured in vivo and in vitro by the voltammetry system. The results clearly showed that the concentration of 5-HT increased in proportion to the rise of current applied. In acute experiment, working electrodes were implanted into the lateral hypothalamic area of anesthetized rats to measure changes in the concentration of 5-HIAA in the LHA after application of 5-HTP and pargyline. In chronic cxperiment, we investigated circadian fluctustion of 5-HIAA concentration in rat LHA.
We made a dopamine sensor assembled by an oxygen probe on which an organic enzyme membrane, dopamine <beta> hydroxylase (an enzyme which oxidizes dopamine under existence of ascorbic acid as coenzyme) was immobilized. The dopamine concentration was measured by this sensor in vitro. However, changes in dopamine voncentration were not detected. We are now trying to complete a new type of biosensor, a FET (field effect transistor) biosensor.
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Report
(1 results)
Research Products
(6 results)
