title: Vertically aligned carbon nanotube-sheathed carbon fibers as pristine microelectrodes for selective monitoring of ascorbate in vivo.
abstract: Using as-synthesized vertically aligned carbon nanotube-sheathed carbon fibers (VACNT-CFs) as microelectrodes without any postsynthesis functionalization, we have developed in this study a new method for in vivo monitoring of ascorbate with high selectivity and reproducibility. The VACNT-CFs are formed via pyrolysis of iron phthalocyanine (FePc) on the carbon fiber support. After electrochemical pretreatment in 1.0 M NaOH solution, the pristine VACNT-CF microelectrodes exhibit typical microelectrode behavior with fast electron transfer kinetics for electrochemical oxidation of ascorbate and are useful for selective ascorbate monitoring even with other electroactive species (e.g., dopamine, uric acid, and 5-hydroxytryptamine) coexisting in rat brain. Pristine VACNT-CFs are further demonstrated to be a reliable and stable microelectrode for in vivo recording of the dynamic increase of ascorbate evoked by intracerebral infusion of glutamate. Use of a pristine VACNT-CF microelectrode can effectively avoid any manual electrode modification and is free from person-to-person and/or electrode-to-electrode deviations intrinsically associated with conventional CF electrode fabrication, which often involves electrode surface modification with randomly distributed CNTs or other pretreatments, and hence allows easy fabrication of highly selective, reproducible, and stable microelectrodes even by nonelectrochemists. Thus, this study offers a new and reliable platform for in vivo monitoring of neurochemicals (e.g., ascorbate) to largely facilitate future studies on the neurochemical processes involved in various physiological events.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Xiang
authors.forename: Ping
authors.initials: P
authors.lastname: Yu
authors.forename: Jie
authors.initials: J
authors.lastname: Hao
authors.forename: Meining
authors.initials: M
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.forename: Liming
authors.initials: L
authors.lastname: Dai
authors.forename: Lanqun
authors.initials: L
authors.lastname: Mao
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000032:analysis*; D001923:Brain Chemistry / Q000187:drug effects; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D004563:Electrochemistry; D018698:Glutamic Acid / Q000494:pharmacology; D008297:Male; D008839:Microelectrodes; D008855:Microscopy, Electron, Scanning; D037742:Nanotubes, Carbon / Q000737:chemistry*; D017072:Neostriatum / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results
chemical_list: D000077482:Carbon Fiber; D037742:Nanotubes, Carbon; D018698:Glutamic Acid; D002244:Carbon; D001205:Ascorbic Acid