Preparation of nanocomposite-based biosensor for amperometric urea determination in urine

In this study, a nano-composite structure was prepared by combining the electrochemically superior properties of GO, PANI, and Fe3O4, and the amperometric determination of urea was carried out. For this purpose, the prepared nano-composite structure was characterized using SEM and FTIR techniques and used for the modification of the surface of the SPE electrode. Urease enzyme was bound to the electrode surface with glutaraldehyde and the electrode surface was protected with Nafion. Amperometric urea determination was carried out by following the reduction of PANI in response to the retention of the ammonium ion formed by urease cleavage of urea. The prepared urea biosensor has a linear concentration range of 0.01-10.0 mM and a LOD of 0.03 mM. This urea biosensor has good selectivity and reusability. Furthermore, this biosensor was successfully used for the determination of urea in artificial urine samples.