A Simple Route of Modifying Copper Electrodes for the Determination of Methanol and Ethylene Glycol

Copper foil electrodes were modified in a stirred NaOH solution at room temperature. Measurements with scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirmed the simultaneous structural transformation and chemical modification of the foil surface. The as-prepared electrodes produced isolated anodic peaks in the cyclic voltammogram of methanol or ethylene glycol in alkaline solution. The highest anodic peak current was achieved at the electrode that was modified for 5 hours. Amperometric study illustrates that the modified electrode can detect lower than 100 mu M methanol with a sensitivity of 15.8 mu A/mM or 10 mu M ethylene glycol with a sensitivity of 193 mu A/mM. Importantly, the method is robust and the prepared electrodes show great reproducibility.