Electrode modification using iron metallophthalocyanine through click chemistry and axial ligation with pyridine

Electrochemical grafting of 4-azidobenzenediazonium salt and click chemistry with ethynylpyridine was used to modify a glassy carbon electrode surface, and iron phthalocyanine was subsequently attached through axial ligation to the surface pyridine groups. The strong axial bond formed by the interaction between the central metal and the lone pair of the nitrogen in the pyridine group resulted in stable modified electrodes. The electrocatalytic ability of this sensor was shown using hydrazine as a test analyte, with a linear range from 1.0 × 10−5 to 3.4 × 10−4 M and a limit of detection of 10.0 ± 1.3 μM.