Immobilization of urease on nanostructured polymer membrane and preparation of urea amperometric biosensor

The prepared enzyme membrane was used for the construction of amperometric biosensor for urea detection. Its basic amperometric characteristics were investigated. A calibration plot was obtained for urea concentration ranging from 1.6 to 23 mM. A linear interval was detected along the calibration curve from 1.6 to 8.2 mM. The sensitivity of the constructed biosensor was calculated to be 3.1927 μA mM−1 cm−2. The correlation coefficient for this concentration range was 0.998. The detection limit with regard to urea was calculated to be 0.5 mM at a signal-to-noise ratio of 3. The biosensor was employed for 10 days while the maximum response to urea retained 86.8%.