title: A robust, state-of-the-art amperometric microbiosensor for glutamate detection.
abstract: Scientific knowledge of glutamate (GLU) neurobiology is severely hampered by the inadequacy of the available in vivo brain sampling techniques. Due to the crucial role of GLU in central nervous system function and pathology, the development of a reliable sampling device is mandatory. GLU biosensor holds potential to address many of the known issues of in vivo GLU measurement. We report here on the development and test of a labor- and cost-effective microbiosensor, suitable to be applied for measuring brain GLU. A glycerol-based cryopreservation method was also tested. Needle type Pt biosensors were coated with a permselective Nafion-Poly(o-phenylenediamine) layer and cross-linked to l-glutamate oxidase with poly(ethylene glycol) diglycidyl ether. Tested in vitro, the device shows high sensitivity and specificity for GLU, while being poorly influenced by common interfering substances such as ascorbate, dopamine and dihydroxyphenylacetic acid. Further, the cryopreservation procedure kept sensitivity unaltered for 30 days and possibly longer. We conclude that a highly efficient GLU biosensor of minimal dimensions can be consistently and affordably constructed with relative ease. Together with the possibility of cryopreservation this shall foster diffusion and exploitation of GLU biosensors technology.
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
authors.forename: Donatella
authors.initials: D
authors.lastname: Sirca
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Vardeu
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
authors.forename: Milo
authors.initials: M
authors.lastname: Pinna
authors.affiliation: "G. Minardi" Laboratory of Cognitive Neuroscience, Department of Chemistry and Pharmacy, University of Sassari, Sassari, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Diana
authors.affiliation: Department of Biomedical Sciences, University of Sassari, Sassari, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Enrico
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D015374:Biosensing Techniques / Q000295:instrumentation*; D015925:Cryopreservation; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004800:Enzymes, Immobilized / Q000737:chemistry / Q000378:metabolism; D004867:Equipment Design; D005465:Fluorocarbon Polymers / Q000737:chemistry; D018698:Glutamic Acid / Q000032:analysis* / Q000378:metabolism; D057230:Limit of Detection; D010655:Phenylenediamines / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D013302:Streptomyces / Q000201:enzymology
chemical_list: D004800:Enzymes, Immobilized; D005465:Fluorocarbon Polymers; D010655:Phenylenediamines; C530487:poly(o-phenylenediamine); C040402:perfluorosulfonic acid; D018698:Glutamic Acid; D010984:Platinum; D000594:Amino Acid Oxidoreductases; C023061:L-glutamate oxidase
keywords: Amperometry; Cryopreservation; Glutamate biosensor; Permselective membrane; Platinum