Potential generating interactions of electrolytes on CF-polymer surfaces in aqueous solutions

The usability of chemical sensors based on ion sensitive field effect transistor structures (ISFETs) depends on an electrolyte hence gate contact, which promotes a chemically independent reference potential over the variety of the electrolytes to be analysed. This paper is based on research to generate a reference FET (REFET) following the ion blocking membranes approach. Besides a successful reduction of selective hydrogen ion sensitivities, dependencies from the cationic electrolyte concentration have been found. A model is suggested that assumes cation adsorption on the polymeric gate insulator as a potential generating interaction. The model describes measurement values obtained from EIS-CV-measurements and polymeric gate REFETs in a qualitative and quantitative way.