The voltammetric sensor for sensitive determination of 8-hydroxyquinoline based on MWNTs/Nafion/GCE

A multiwall carbon nanotube/Nafion composite modified glassy carbon electrode (MWNT/Nafion/GCE) was prepared and characterized by Atomic Force Microscopy (AFM) and Transmission Electron Microscope(TEM). This voltammetric sensor exhibited strong catalytic effect toward the oxidation of 8- hydroxyquinoline(8-HQ) in HAc-NaAc buffer solution (0.2M, pH 3.6). A new analytical method for determining 8-HQ was established. Under the optimized condition, the anodic peak current was linear with the concentration of 8-HQ in the range of 2x10(-8)similar to 1.0x10(-5)M with a detection limit of 9x10(-9) M. The practical application of MWNT/Nafion/GCE was carried out for determining 8-HQ in cosmetic sample with satisfactory results. The number of electron and proton taking part in the reaction was calculated, and then the electrode reaction mechanism was confirmed by UV-vis spectra.