Localized visualization of chemical cross-talk in microsensor arrays by using scanning electrochemical microscopy

An investigation of an array of four Pt microband electrodes 25 mu m wide and spaced 25 mu m apart was performed with the scanning electrochemical microscope (SECM). Where possible the SECM measurements were confirmed with conventional electrochemical measurements. It is shown how the sensitivity of the SECM recycling current to the activity of the underlying surface can be used to probe the homogeneity of enzyme-modified microelectrodes. The diffusion of H2O2 between these micro enzyme-electrodes and unmodified electrodes was investigated and it was demonstrated how the SECM can be a powerful tool in the elucidation of the properties of these electrodes.