title: A comparative study of carbon fiber-based microelectrodes for the measurement of nitric oxide in brain tissue.
abstract: The measurement of Nitric oxide (NO) in real-time has been a major concern due to the involvement of this ubiquitous free radical modulator in several physiological and pathological pathways in tissues. Here we performed a study aiming at evaluating different types of carbon fibers, namely Textron, Amoco, Courtaulds and carbon nanotubes (University of Kentucky) covered with Nafion/o-phenylenediamine (o-PD) for NO measurement in terms of sensitivity, LOD, response time and selectivity against major potential interferents in the brain (ascorbate, nitrite and dopamine). The results indicate that, as compared with the other carbon fibers and nanotubes, Textron carbon fiber microelectrodes coated with two layers of Nafion and o-PD exhibited better characteristics for NO measurement as they are highly selective against ascorbate (>30,000:1), nitrite (>2000:1) and dopamine (>80:1). These coated Textron microelectrodes showed an average sensitivity of 341+/-120pA/microM and a detection limit of 16+/-11nM. The better performance of the Textron fibers is likely related to a stronger adhesion or more uniform coating of the Nafion and o-PD polymers to the fiber surface. In addition, the background current of the Textron carbon fibers is low, contributing to the excellent signal-to-noise for detection of NO.
authors.affiliation: Center for Neurosciences and Cell Biology, University of Coimbra, Coimbra, Portugal.
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Santos
authors.forename: Cátia F
authors.initials: CF
authors.lastname: Lourenço
authors.forename: Ana P
authors.initials: AP
authors.lastname: Piedade
authors.forename: Rodney
authors.initials: R
authors.lastname: Andrews
authors.forename: François
authors.initials: F
authors.lastname: Pomerleau
authors.forename: Peter
authors.initials: P
authors.lastname: Huettl
authors.forename: Greg A
authors.initials: GA
authors.lastname: Gerhardt
authors.forename: João
authors.initials: J
authors.lastname: Laranjinha
authors.forename: Rui M
authors.initials: RM
authors.lastname: Barbosa
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001921:Brain / Q000378:metabolism*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008839:Microelectrodes; D036103:Nanotechnology / Q000295:instrumentation* / Q000379:methods; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009569:Nitric Oxide / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D037742:Nanotubes, Carbon; D009569:Nitric Oxide