Electrochemical Bacillus licheniformis Whole-Cell-Based Sensor and its Potential Application in Detecting Urea Concentration in Urine
D. Ariyanti, D. Iswantini, Purwantiningsih, N. Nurhidayat, and H. Effendi
Electrochemical biosensor based on Bacillus licheniformis whole cell can detect urea level in a synthetic urine. We employed a synthetic urine solution as the urea source, and the level was indirectly monitored through the ammonia oxidation reaction using B. licheniformis microorganism on an electrode surface. The working electrode was a screen-printed carbon electrode (SPCE). B. licheniformis pellet was placed on the operated electrode carbon and was added with various urea concentrations in the synthetic urine, then kept for 30 minutes and tested using a cyclic voltammetry technique. The biosensor system results in a limit of detection of 0.01 M urea, 1.278 µA/M sensitivity, and linearity in the range of 0.01?0.2 M urea concentration with R 2 0.990. We conclude that the developed system performs better limit detection as compared to the previous work, and the range of linearity concentration range is within the urea level in the urine. Therefore, this biosensor system can be applied for urea level determination that is an indicator of the kidney health problems.