Abstract
Nanocomposite sensors consisting of carbon fiber microelectrodes modified with Nafion® and carbon nanotubes, and ceramic-based microelectrode biosensor arrays were used to measure ascorbate and glutamate in the brain with high spatial, temporal and chemical resolution. Nanocomposite sensors displayed electrocatalytic properties towards ascorbate oxidation, translated into a negative shift from +0.20 V to −0.05 V vs. Ag/AgCl, as well as a significant increase (10-fold) of electroactive surface area. The estimated average basal concentration of ascorbate in vivo in the CA1, CA3 and dentate gyrus (DG) sub regions of the hippocampus were 276 ± 60 μM (n = 10), 183 ± 30 μM (n = 10) and 133 ± 42 μM (n = 10), respectively. The glutamate microbiosensor arrays showed a high sensitivity of 5.3 ± 0.8 pA μM−1 (n = 18), and LOD of 204 ± 32 nM (n = 10), and t50% response time of 0.9 ± 0.02 s (n = 6) and high selectivity against major interferents. The simultaneous and real-time measurements of glutamate and ascorbate in the hippocampus of anesthetized rats following local stimulus with KCl or glutamate revealed a dynamic interaction between the two neurochemicals.
Original language | English |
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Pages (from-to) | 142-150 |
Number of pages | 9 |
Journal | Bioelectrochemistry |
Volume | 121 |
DOIs | |
State | Published - Jun 2018 |
Bibliographical note
Funding Information:This work was funded by the European Regional Development Fund (ERDF), through the Centro 2020 Regional Operational Program: project CENTRO-01-0145-FEDER-000012-HealthyAging2020 , the COMPETE 2020 - Operational Program for Competitiveness and Internationalization, and the Portuguese national funds via FCT – Fundação para a Ciência e a Tecnologia , I.P.: project POCI-01-0145-FEDER-007440 .
Keywords
- Ascorbate
- Carbon nanotubes
- Glutamate
- In vivo monitoring
- Microelectrode arrays
ASJC Scopus subject areas
- Biophysics
- Physical and Theoretical Chemistry
- Electrochemistry