ENHANCEMENT OF SENSITIVITY, DETECTION RANGE, AND DETECTION LIMIT USING GA METHOD POTENTIOMETRIC BIOSENSOR WITH UREASE ENZYME IMMOBILIZATION TECHNIQUE ON PVA

This study aims to increase the sensitivity range of the width of the UV-Vis absorbance peak with Glutaraldehyde (GA) crosslinking and useful to determine the level of urea in the urine. The potentiometer cell consists of an indicator electrode and a reference electrode. The indicator electrode is denoted PVA-Enzyme/GA/PVC-KTpCIPB, meaning PVA-Enzim as the first layer, GA as the second layer and PVC-KTpCIPB as the third layer. Biosensor with urease enzyme immobilization technique analyzed variations of urea 10-7-10-1 M. The potentiometric method of the biosensor detects signal and voltage (potentiometer cell). The signals that were analyzed for signal variables were symmetrical up and down signals of 2000 signals/second. Voltage was carried out by linear curve analysis, the results of linear curve analysis were the range of detection from a concentration of 10-4-10-2 M with cross-linked GA which increased the absorbance, the detection limit was 10-4 M, the sensitivity was 46.67 mV/ war reversibly and R squared (R2) which is 0.9839 is close to linear.