The present study concerns methodological issues of electrochemical recordings using Nafion-coated 30 μm diameter single carbon fiber microelectrodes for high-speed chronoamperometric measurements of biogenic amines. First, the single carbon fiber microelectrodes were coated with Nafion and dried at 85 vs. 200 °C and their recording properties were determined. Second, the effects of shifts in solution pH, ionic strength, changes in recording solution levels of Ca2+ or Mg2+ and temperature on the recording characteristics and sensitivity of Nafion-coated high temperature dried (200 °C) single carbon fiber microelectrodes for measures of dopamine were studied. These studies showed that the high temperature drying of the Nafion produced a microelectrode with better recording properties: higher selectivity for cations versus anions, increased differences between the reduction and oxidation current ratios for the identification of dopamine versus serotonin, and more rapid response times. In addition, these studies demonstrated that the chronoamperometric recordings were insensitive to small changes in pH and divalent cations such as Ca2+ or Mg2+. However, increases in ionic strength decreased the sensitivity of the microelectrodes, while increases in temperature produced increases in the sensitivity of the microelectrodes for biogenic amines. These data support that Nafion-coated high temperature (200 °C) dried microelectrodes have enhanced recording properties as compared to microelectrodes, which are coated with Nafion and dried at 85 °C. In addition, high-speed chronoamperometric recordings of biogenic amines are not affected by solution changes in divalent cations (Ca2+ or Mg2+).
|Number of pages||9|
|Journal||Journal of Neuroscience Methods|
|State||Published - Aug 15 2001|
Bibliographical noteFunding Information:
This work was supported by USPHS grants AG06434, NS39787 and a Level II Research Scientist Development Award MH 01245 (G.A.G.). We would like to thank Mr Scott Robinson and Dr Jason Burmeister for help with some of the recordings presented in this manuscript.
- Nafion-coated microelectrodes
ASJC Scopus subject areas
- Neuroscience (all)