Carbon-fiber microelectrodes modified with 4-sulfobenzene have increased sensitivity and selectivity for...

Area of Science:

• Electrochemistry
• Materials Science
• Neuroscience

Background:

• Carbon-fiber microelectrodes are crucial tools in neuroscience for detecting neurochemicals.
• Surface modification of electrodes can enhance their sensitivity and selectivity.
• Covalent attachment of specific molecules offers a stable and effective modification strategy.

Purpose of the Study:

• To modify carbon-fiber microelectrodes using 4-sulfobenzenediazonium tetrafluoroborate.
• To evaluate the impact of electrode geometry (elliptical vs. cylindrical) on modification efficiency.
• To assess the performance of modified electrodes for detecting dopamine and other neurochemicals in vitro and in vivo.

Main Methods:

• Electroreduction of 4-sulfobenzenediazonium tetrafluoroborate for covalent attachment.
• Fabrication of elliptical and cylindrical carbon-fiber microelectrodes from Thornel P-55.
• Fast-scan cyclic voltammetry for electrochemical analysis of dopamine and neurochemicals.
• In vivo measurements in mouse brain tissue.

Main Results:

• Elliptical carbon-fiber microelectrodes exhibited the highest degree of 4-sulfobenzene attachment.
• The grafted layer significantly increased sensitivity to dopamine and other positively charged analytes due to enhanced adsorption.
• The modified electrode surface remained permeable to negatively charged compounds.
• Sustained increased sensitivity for dopamine was observed during measurements in mouse brain tissue.

Conclusions:

• Surface modification of carbon-fiber microelectrodes with 4-sulfobenzene enhances dopamine detection sensitivity.
• Elliptical electrode geometry optimizes the covalent attachment and subsequent performance.
• These modified electrodes are suitable for sensitive dopamine measurements in complex biological environments like brain tissue.