title: An electrochemical method for making enzyme microsensors. Application to the detection of dopamine and glutamate.
abstract: A novel method of microbiosensor fabrication is described. It is based on the electrochemical polymerization of an enzyme-amphiphilic pyrroleammonium solution on the surface of a microelectrode in the absence of supporting electrolyte. By trapping glutamate oxidase (GMO) or polyphenol oxidase (PPO) in such polypyrrole films, we made microbiosensors for the amperometric determination of glutamate or dopamine, respectively. The response of the GMO microelectrode to glutamate was based on the amperometric detection of the enzymically generated hydrogen peroxide at 0.6 V vs SCE. The detection limit and sensitivity of this microbiosensor were 1 μM and 32 mA M(-1) cm(-2), respectively. The response of the PPO microelectrode to dopamine was based on the amperometric detection of the enzymically generated quinoid product at -0.2 V. The calibration range for dopamine measurement was 5 × 10(-8)-8 × 10(-5) M and the detection limit and sensitivity were 5 × 10(-8) M and 59 mA M(-1) cm(-2), respectively.
authors.affiliation: Laboratoire d'Electrochimie Organique et de Photochimie Redox, UMR CNRS 5630, Université Joseph Fourier BP 53, 38041 Grenoble Cedex 9, France, and Experimental Ophthalmology Laboratory, Centre Médical Universitaire de Genéve, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: Cosnier
authors.forename: C
authors.initials: C
authors.lastname: Innocent
authors.forename: L
authors.initials: L
authors.lastname: Allien
authors.forename: S
authors.initials: S
authors.lastname: Poitry
authors.forename: M
authors.initials: M
authors.lastname: Tsacopoulos