Glutaraldehyde cross-linked glutamate oxidase coated microelectrode arrays: Selectivity and resting levels of glutamate in the CNS

Jason J. Burmeister, Verda A. Davis, Jorge E. Quintero, Francois Pomerleau, Peter Huettl, Greg A. Gerhardt

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


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.

Original languageEnglish
Pages (from-to)721-728
Number of pages8
JournalACS Chemical Neuroscience
Issue number5
StatePublished - May 15 2013


  • Glutamate
  • amino acid
  • brain
  • electrode
  • glutaraldehyde
  • microelectrode
  • neurotransmitter
  • selectivity

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Cognitive Neuroscience
  • Cell Biology


Dive into the research topics of 'Glutaraldehyde cross-linked glutamate oxidase coated microelectrode arrays: Selectivity and resting levels of glutamate in the CNS'. Together they form a unique fingerprint.

Cite this