A study of the electrochemical behavior of an oxadiazole derivative electrodeposited on multi-wall carbon nanotube-modified electrode and its application as a hydrazine sensor

In this study, an oxadiazole multi-wall carbon nanotube-modified glassy carbon electrode (OMWCNT-GCE) was used as a highly sensitive electrochemical sensor for hydrazine determination. The surface charge transfer rate constant, k (s), and the charge transfer coefficient, alpha, for electron transfer between GCE and electrodeposited oxadiazole were calculated as 19.4 +/- 0.5 s(-1) and 0.51, respectively at pH = 7.0. The obtained results indicate that hydrazine peak potential at OMWCNT-GCE shifted for 14, 109, and 136 mV to negative values as compared with oxadiazole-modified GCE, MWCNT-GCE, and activated GCE surface, respectively. The electron transfer coefficient, alpha, and the heterogeneous rate constant, k', for the oxidation of hydrazine at OMWCNT-GCE were also determined by cyclic voltammetry measurements. Two linear dynamic ranges of 0.6 to 10.0 mu M and 10.0 to 400.0 mu M and detection limit of 0.17 mu M for hydrazine determination were evaluated using differential pulse voltammetry. In addition, OMWCNT-GCE was shown to be successfully applied to determine hydrazine in various water samples.