A novel, low power biosensor for real time monitoring of creatinine and urea in peritoneal dialysis

Novel biosensors, based on immobilized creatininase, creatinase and urease are developed, using ISFETs with weak inversion at pH 6–8 and 37.0 °C. The ISFETs with circuitry, demonstrate a linear relationship of urea and creatinine at the range of 0–200 and 0–20 mM, respectively. Preliminary results show that biosensors operating in weak inversion mode can eliminate many of the disadvantages of ISFETs operating in the strong inversion region, providing a wide dynamic range output in nanoAmp. Such characteristics fit the analytical requirements for improving real-time monitoring in peritoneal dialysis (PD). Further work covers stability of ISFET sensors biased with CMOS circuits in the weak inversion mode working in the room temperature of 15–40 °C.