In Situ Piezoelectric Infrared Spectroelectrochemistry for Study of Electrochemical Oxidation of o-Tolidine

In situ piezoelectric infrared spectroelectrochemistry was used to study the electrochemical behavior of o-tolidine (OTD) on gold electrode. The piezoelectric and electrochemistry results showed that the oxidation of OTD in BR buffer solution was greatly affected by the potential. In the range of 0–0.4 V, the intermediate compound was formed and dissolved during the potential scanning, while the potential scanned up to 0.6 V, the intermediate compound was formed and dissolved, and some of it was deposited on the electrode surface at the same time. If the potential expanded to 0–0.75 V, the intermediate compound formed, dissolved, and deposited and the polymerization of OTD was found. In situ piezoelectric infrared spectroelectrochemistry showed that the intermediate compound was formed between the first oxidation products of OTD. The effect of large-sized anion such as heparin was also investigated.