Electrochemical characterization and development of an enzymatic creatinine thick film biosensor

The objective of this research was to develop a miniature creatinine biosensor to aid in the initial detection of kidney disease. The biosensor prototypes were microfabricated using thick film printing. To provide a fundamental platform for the sensor development, the multi-enzyme creatinine reaction sequence was electrochemically assessed using cyclic voltammetry and chronoamperometry. In the reaction sequence, creatinine was converted to hydrogen peroxide, and its amount was used to quantify the creatinine initially present. The performances of a laboratory electrode system and the thick film sensor were evaluated and compared. The sensitivity of the biosensor to hydrogen peroxide was approximately 10 times larger than that of the standard system. Chronoamperometry was the more promising electrochemical technique and was used to characterize the creatinine reaction sequence. A linear relationship between the sensor output and the initial creatinine concentration existed over the physiological creatinine concentration range of 50 to 150 μM.