A planar conductimetric sensor for continuous monitoring of haemodialysis

An easy-to-use, urea-specific conductimetric enzyme sensor for monitoring haemodialysis is described. Although the principle of conductimetry is applicable to a variety of enzyme-based systems, it is not often used in enzyme sensor technology. The main problem, particularly in a dialysate circuit, is the presence of a high background conductivity. It is shown that the use of a differential measurement setup can avoid this problem. The proposed method can lead to a sensor the performance of which is almost completely controlled by geometric design parameters, reducing calibration to an electronic-gain adjustment