(188cc) NiO2, Pt, and Cu Surface Modifications of a Glassy Carbon Electrode for Electrocatalysis of Amino Acids

Changes in clinically relevant amino acid concentration, such as valine, arginine, serine, and alanine, have been implicated as biomarkers for various diseases, such as obesity and major depressive disorder. Typically, liquid chromatography-mass spectrometry (LCMS) and nuclear magnetic resonance spectroscopy are used for detection. Some caveats to these methods are long acquisition times, complicated analysis, and low throughput. Electrochemical detection methods, on the other hand, provide a much more simplistic approach that also provides high sensitivity, portability, low cost, and rapid response time. One of the challenges of using electrochemical sensors for detection is that amino acids are not typically electrochemically active. However, in the presence of metal catalysts immobilized on the electrode surface, such as platinum or nickel compounds, electrocatalytic reactions of biomolecules occur.

Discussed herein are the surface modifications of a glassy carbon electrode with platinum, platinum-copper hexacyanoferrate hybrid, and nickel(IV) oxide surfaces through electrodeposition and passivation. The sensors were tested through detection of arginine, alanine, serine, and valine at physiological pH by cyclic voltammetry in a flow cell. We will report on the found sensitivity towards arginine, alanine, serine, and valine. In addition, the stability of the surfaces was also investigated. The sensitivity and stability of both sensor modification, towards amino acid detection, will be compared.