Development of a Flow-Thru System Containing a p-Well Type Ion Sensitive Field Effect Transistor Array for Determination of Electrolytes and Urea in Dialysate

In this paper, technology of p-well type ISFETs sensor array, its local chemical and enzymatic modifications resulting in sensors sensitive to different analytes are presented. The developed flow-thru system consisted of a monolithic six-sensor array of p-well type ISFETs fabricated in a CMOS technology. The sensor array is prevented to cross-talk between sensors. Application of the sensor array led to significant simplification of construction of the multi-parameter analytical system. The performances of a model ISFET array with sensors sensitive to: potassium, hydrogen and ammonium ions, as well as urea are described.