Potentiometric ion-selective silicon sensors for the online monitoring of blood electrolytes

A non-invasive on-line monitoring system for blood electrolytes has been developed on the basis of potentiometric ion-selective silicon sensors. The microsensors were fabricated in the patented containment technology owned by ICB. Additionally, multianalyte sensors with two and three containment sensor elements integrated on chip were realized. The new polysiloxane membrane functionalized with trifluoropropyl groups with improved adhesion on the silicon oxide surface were used as matrix membrane for all prepared solid state microsensors. The following containment sensors have been developed: potassium, calcium, sodium, and pH. They were characterized in physiological test solutions. The excellent reliability of the potassium sensors has been demonstrated successfully in clinical trials with real circulating whole blood samples and on extracorporal animal blood circulation. First simultaneous measurements of potassium, sodium and pH have also been performed in vitro using human blood samples.