The Electroanalytical Performance of Sonogel Carbon Titanium (IV) Oxide Electrodes versus Conducting Polymer Electrodes in the Electrochemical Detection of Biological Molecules

by Stinson, Jelynn A.

Stinson, Jelynn Anneula. M.S., Department of Chemistry, Wright State University, 2007. The Electroanalytical Performance of Sonogel Carbon Titanium (IV) Oxide Electrodes versus Conducting Polymer Electrodes in the Electrochemical Detection of Biological Molecules. The electrochemical performance of a newly developed sonogel carbon titanium (IV) oxide (SGC/TiO2 ) electrode against poly(3-methylthiophene) (P3MT) and poly(2,2’-bithiophene) (PBTP) modified electrodes in the electrochemical detection of biological molecules is reported. The stability of the Titanium (IV) Oxide coating on the sonogel carbon electrode was shown to be greater than the P3MT coating on the conventional size glassy carbon electrode. After 10 consecutive scans, there was a 21% loss of the initial signal at the P3MT modified electrode and a 5% loss of the initial signal at the SGC/TiO2 electrode. The influence of NAD+ on NADH response was tested. The PBTP modified electrode and bare electrode demonstrated the inability to stabilize the interference due to NAD+. The SGC/TiO2 electrode was able to detour the susceptibility to interfering NAD+. The response potential was improved by 141 mV. Response time for 5mM catechol (CAT) and 5mM ascorbic acid (AA) in 0.01M sulfuric acid was determined. Specificity for CAT detection was measured using a 5mM CAT + 5mM AA mixture in 0.01M sulfuric acid. The SGC/TiO2 electrode permits a shorter response time and improved selectivity for CAT. NADH was irreversible in all electrolytes. Highest anodic peak potential, at the PBTP modified electrode, was measured in sodium nitrate. Highest anodic peak potential at the SGC/TiO2 electrode was recorded in sulfuric acid.