title: Laser Treated Carbon Nanotube Yarn Microelectrodes for Rapid and Sensitive Detection of Dopaminein Vivo.
abstract: Carbon nanotube yarn microelectrodes (CNTYMEs) exhibit rapid and selective detection of dopamine with fast-scan cyclic voltammetry (FSCV); however, the sensitivity limits their applicationin vivo. In this study, we introduce laser treatment as a simple, reliable, and efficient approach to improve the sensitivity of CNTYMEs by three fold while maintaining high temporal resolution. The effect of laser treatment on the microelectrode surface was characterized by scanning electron microscopy, Raman spectroscopy, energy dispersion spectroscopy, and laser confocal microscopy. Laser treatment increases the surface area and oxygen containing functional groups on the surface, which provides more adsorption sites for dopamine than at unmodified CNTYMEs. Moreover, similar to unmodified CNTYMEs, the dopamine signal at laser treated CNTYMEs is not dependent on scan repetition frequency, unlike the current at carbon fiber microelectrodes (CFMEs) which decreases with increasing scan repetition frequency. This frequency independence is caused by the significantly larger surface roughness which would trap dopamine-o-quinone and amplify the dopamine signal. CNTYMEs were applied as anin vivosensor with FSCV for the first time and laser treated CNTYMEs maintained high dopamine sensitivity compared to CFMEs with an increased scan repetition frequency of 50 Hz, which is five-fold faster than the conventional frequency. CNTYMEs with laser treatment are advantageous because of their easy fabrication, high reproducibility, fast electron transfer kinetics, high sensitivity, and rapidin vivomeasurement of dopamine and could be a potential alternative to CFMEs in the future.
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22904.
authors.forename: Cheng
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22904.
authors.forename: Elefterios
authors.initials: E
authors.lastname: Trikantzopoulos
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22904.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Nguyen
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Jacobs
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22904.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States.
authors.forename: Masoud
authors.initials: M
authors.lastname: Mahjouri-Samani
authors.affiliation: Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, United States.
authors.forename: Ilia N
authors.initials: IN
authors.lastname: Ivanov
authors.affiliation: Department of Chemistry, University of Virginia, Charlottesville, VA 22904.
authors.forename: B Jill
authors.initials: BJ
authors.lastname: Venton
keywords: Ascorbic acid; CNT yarn; Dopamine; Fast-scan Cyclic Voltammetry; In vivo; Laser treatment