Evaluation of Metal Oxide Surface Catalysts for the Electrochemical Activation of Amino Acids

• Published in: Sensors (Basel, Switzerland) Vol. 18; no. 9; p. 3144
• Main Authors: Tooley, Christian A, Gasperoni, Charles H, Marnoto, Sabrina, Halpern, Jeffrey Mark
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.09.2018; MDPI
• Subjects: Alanine; Amino acids; Amino Acids - analysis; Amino Acids - chemistry; Carbon; Carbon - chemistry; Catalysis; Catalysts; Caustic soda; Corrosion tests; cyclic voltammetry; electrocatalysis; Electrochemical activation; Electrochemical analysis; Electrochemical Techniques; Electrode polarization; Electrodes; Energy dispersive X ray spectroscopy; Glassy carbon; Imines; Metal Nanoparticles - chemistry; Metal oxides; Nanocomposites; Nanoparticles; Nickel - chemistry; Nickel oxides; NMR; Nuclear magnetic resonance; Oxidation; Peptides; Platinum - chemistry; Scanning electron microscopy; Schiff Bases - chemistry; sensor; Sodium hydroxide; Valine; Voltammetry; X ray spectra; United States > US; cyclic voltammetry; electrocatalysis; sensor
• ISSN: 1424-8220; 1424-8220
• DOI: 10.3390/s18093144

Electrochemical detection of amino acids is important due to their correlation with certain diseases; however, most amino acids require a catalyst to electrochemically activate. One common catalyst for electrochemical detection of amino acids are metal oxides. Metal oxide nanoparticles were electrodeposited onto glassy carbon and platinum working electrodes. Cyclic voltammetry (CV) experiments in a flow cell were performed to evaluate the sensors' ability to detect arginine, alanine, serine, and valine at micromolar and nanomolar concentrations as high as 4 mM. Solutions were prepared in phosphate buffer saline (PBS) and then 100 mM NaOH. Specifically, NiO surfaces were responsive to amino acids but variable, especially when exposed to arginine. Polarization resistance experiments and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) data indicated that arginine accelerated the corrosion of the NiO catalyst through the formation of a Schiff base complex.