Glutaraldehyde cross-linked glutamate oxidase coated microelectrode arrays: selectivity and resting levels of glutamate in the CNS.
ACS Chem Neurosci
; 4(5): 721-8, 2013 May 15.
Article
em En
| MEDLINE
| ID: mdl-23650904
ABSTRACT
Glutaraldehyde is widely used as a cross-linking agent for enzyme immobilization onto microelectrodes. Recent studies and prior reports indicate changes in enzyme activity and selectivity with certain glutaraldehyde cross-linking procedures that may jeopardize the performance of microelectrode recordings and lead to falsely elevated responses in biological systems. In this study, the sensitivity of glutaraldehyde cross-linked glutamate oxidase-based microelectrode arrays to 22 amino acids was tested and compared to glutamate. As expected, responses to electroactive amino acids (Cys, Tyr, Trp) were detected at both nonenzyme-coated and enzyme-coated microelectrodes sites, while the remaining amino acids yielded no detectable responses. Electroactive amino acids were effectively blocked with a m-phenylene diamine (mPD) layer and, subsequently, no responses were detected. Preliminary results on the use of poly(ethylene glycol) diglycidyl ether (PEGDE) as a potentially more reliable cross-linking agent for the immobilization of glutamate oxidase onto ceramic-based microelectrode arrays are reported and show no significant advantages over glutaraldehyde as we observe comparable selectivities and responses. These results support that glutaraldehyde-cross-linked glutamate oxidase retains sufficient enzyme specificity for accurate in vivo brain measures of tonic and phasic glutamate levels when immobilized using specific "wet" coating procedures.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Glutaral
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Ácido Glutâmico
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Reagentes de Ligações Cruzadas
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Enzimas Imobilizadas
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Aminoácido Oxirredutases
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article