title: A microelectrode biosensor for real time monitoring of L-glutamate release.
abstract: We have developed an amperometric microbiosensor for real time monitoring L-glutamate release in neural tissue, based on enzymatic oxidation catalyzed by the L-glutamate oxidase. By means of a sol-gel coating method, L-glutamate oxidase was entrapped in a biocompatible gel layer that provided a benign environment and retained enzyme activity on the surface of Pt microelectrode. Prior to gel layer formation, a modification on the surface of Pt microelectrode with poly(phenylene diamine) enabled the microbiosensor screen majority of common potential interfering substances existing in physiological samples. The miniaturized biosensor achieved a steady state response to l-glutamate within 10 s and exhibited a linear dependence on the concentration of L-glutamate from 0.5 to 100 micromol L(-1) with a high sensitivity of 279.4 +/- 2.0 microA (mmol L(-1))(-1) cm(-2) (n = 4, R.S.D. = 2.8%). The microbiosensor also exhibited excellent long-term stability in dry storage. We have successfully used the microbiosensor for real time measuring of L-glutamate in vivo.
authors.affiliation: Warwick Biosensors Group, Department of Biological Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, United Kingdom. f.tian@warwick.ac.uk
authors.forename: Faming
authors.initials: F
authors.lastname: Tian
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Gourine
authors.forename: Robert T R
authors.initials: RT
authors.lastname: Huckstepp
authors.forename: Nicholas
authors.initials: N
authors.lastname: Dale
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000378:metabolism*; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D004800:Enzymes, Immobilized / Q000378:metabolism; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D008297:Male; D008839:Microelectrodes; D044367:Phase Transition; D051381:Rats; D017207:Rats, Sprague-Dawley; D012680:Sensitivity and Specificity; D017552:Solitary Nucleus / Q000737:chemistry; D013302:Streptomyces / Q000201:enzymology*
chemical_list: D004800:Enzymes, Immobilized; D018698:Glutamic Acid; D000594:Amino Acid Oxidoreductases; C023061:L-glutamate oxidase