Carbon-fiber microelectrodes modified with 4-sulfobenzene have increased sensitivity and selectivity for catecholamines.
Elliptical and cylindrical geometries of carbon-fiber microelectrodes were modified by covalent attachment of 4-sulfobenzenediazonium tetrafluoroborate following its electroreduction. Elliptical electrodes fabricated from Thornel P-55 carbon fibers show the highest amount of 4-sulfobenzene attached to the electrode. Fast-scan cyclic voltammetry was used to compare the response to dopamine and other neurochemicals at these modified carbon-fiber microelectrodes. The grafted layer causes an increased sensitivity to dopamine and other positively charged analytes that is due to increased adsorption of analyte in the grafted layer. However, this layer remains permeable to negatively charged compounds. Modified electrodes retain the increased sensitivity for dopamine during measurements in mouse brain tissue.
Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3290, USA.
Andre
A
Hermans
Andrew T
AT
Seipel
Charles E
CE
Miller
R Mark
RM
Wightman
D000327:Adsorption; D000818:Animals; D001557:Benzenesulfonates; D001923:Brain Chemistry; D002244:Carbon; D002395:Catecholamines / Q000032:analysis*; D003979:Diazonium Compounds; D004298:Dopamine / Q000032:analysis; D004563:Electrochemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008839:Microelectrodes
D001557:Benzenesulfonates; D002395:Catecholamines; D003979:Diazonium Compounds; D002244:Carbon; D004298:Dopamine