Glutamate detection at the cellular level by means of polymer/enzyme multilayer modified carbon nanoelectrodes

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Vol. 8; no. 16; pp. 3631 - 3639
• Main Authors: Marquitan, Miriam, Mark, Melanie D, Ernst, Andrzej, Muhs, Anna, Herlitze, Stefan, Ruff, Adrian, Schuhmann, Wolfgang
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 29.04.2020
• Subjects: Amino Acid Oxidoreductases - chemistry; Amino Acid Oxidoreductases - metabolism; Animals; Astrocytes; Astrocytes - chemistry; Biosensing Techniques; Carbon; Carbon - chemistry; Carbon - metabolism; Cells, Cultured; Electrochemical Techniques; Electrodes; Enzymes; Enzymes, Immobilized - chemistry; Enzymes, Immobilized - metabolism; Glutamates - analysis; Glutamates - metabolism; Horseradish peroxidase; Hydrogen peroxide; Mice; Mice, Inbred C57BL; Molecular Structure; Multilayers; Nanoparticles - chemistry; Nanoparticles - metabolism; Particle Size; Peroxidase; Polymers; Polymers - chemistry; Polymers - metabolism; Streptomyces - enzymology; Surface Properties
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/c9tb02461a

Carbon nanoelectrodes in the sub-micron range were modified with an enzyme cascade immobilized in a spatially separated polymer double layer system for the detection of glutamate at the cellular level. The enzyme cascade consists of glutamate oxidase (GlutOx) that was immobilized in a hydrophilic redox silent polymer on top of a horseradish peroxidase (HRP)/redox polymer layer. In the presence of O 2 , glutamate was oxidized under concomitant reduction of O 2 to H 2 O 2 at GlutOx. H 2 O 2 is further reduced to water by means of HRP and electrons are shuttled via the redox polymer matrix that wires the HRP to the electrode surface, hence delivering a current response proportional to the glutamate concentration. The nanometer-sized sensors could be successfully used to measure glutamate release from primary mouse astrocytes in 10 mM HEPES buffer. Carbon nanoelectrodes in the sub-micron range were modified with an enzyme cascade immobilized in a spatially separated polymer double layer system for the detection of glutamate at the cellular level.