Dopamine Detection using Mercaptopropionic Acid and Cysteamine for Electrodes Surface Modification

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Gold electrodes suffer from passivation during dopamine detection due to non-conducting polymer layer formation.
• This passivation increases electrode resistance, hindering accurate electrochemical measurements.
• Developing robust electrode surfaces is crucial for reliable dopamine sensing.

Purpose of the Study:

• To investigate surface modifications for enhanced dopamine detection on gold electrodes.
• To compare cysteamine and mercaptopropionic acid modifications in microfluidic chips.
• To evaluate the impact of fabrication techniques on electrode performance for dopamine sensing.

Main Methods:

• Comparative study using electrochemical impedance spectroscopy and cyclic voltammetry.
• Surface modification of gold electrodes with cysteamine and mercaptopropionic acid.
• Fabrication of microfluidic chips using thermal bonding and ultrasonic welding.

Main Results:

• Modified electrodes showed improved dopamine detection compared to unmodified surfaces.
• Optimized tubing, bonding, and cleaning methods (KOH) significantly enhanced device performance.
• Successful determination of unknown dopamine concentrations using flow injection analysis.

Conclusions:

• Cysteamine and mercaptopropionic acid modifications effectively mitigate gold electrode passivation in dopamine detection.
• Microfluidic chip fabrication and optimization are critical for sensitive and stable electrochemical sensing.
• The presented methods offer a promising approach for reliable dopamine monitoring.