Influence of morphology and topography on potentiometric response of magnesium and calcium sensitive PEDOT films doped with adenosine triphosphate (ATP)

Poly(3,4-ethylenedioxythiophene) (PEDOT) films doped with adenosine triphosphate (ATP) are used to study the biologically relevant competitive magnesium and calcium ion-exchange at ATP membrane sites. It is shown, by atomic force microscopy (AFM) and scanning electron microscopy (SEM), that the surface topography and morphology of the PEDOT–ATP films determines the quality of their potentiometric response. More smooth and less rough films result in better potentiometric characteristics, particularly in a faster response. The topography/morphology of the PEDOT–ATP films is influenced by conditions during electrodeposition (electrochemical method of deposition, pH, concentration of electrolytes) and post-deposition soaking (including net-time of soaking), as evidenced by X-ray photoelectron spectroscopy (XPS) and energy dispersive analysis of X-rays (EDAX).