Formation of the diimine and its
Figure 4. Fast scan cyclic voltammograms of 10 μM 2,8-dihydroxyadenine at different carbon microfiber electrodes, in 31 mM phosphate buffer, CHIR-99021 7.4, 500 V s−1, 250 cycles, results after background subtraction.Figure optionsDownload full-size imageDownload as PowerPoint slide
Peaks observed at ca. 0.98 V in ADO voltammograms and at ca. 0.8 V were measured to obtain ADO and 2,8-DHA calibration curves, respectively (Abou El-Nour and Brajter-Toth, 2000 and Kathiwala et al., 2010).
Current traces between 0 and 0.1 V and ca. 1.2 V (Figure 3 and Figure 4) are likely due to products resulting from the incomplete background subtraction.
Reduction of diimine is likely responsible for the reduction peaks between ca. −0.27 V and −0.36 V Figure 3 and Figure 4. The reduction of diimine followed by reoxidation process is quite fast as shown by the near reversibility of the oxidation/reduction peaks in the voltammograms of ADO and 2,8-DHA.