Preparation and properties of a micro enzyme sensor for creatine

Abstract A micro enzyme sensor using creatine amidinohydrolase (EC 3. 5. 3. 3) and sarcosine oxidase (EC 1. 5. 3. 1) was developed for measuring creatine. The sensor consisted of platinum and silver wires fixed in a glass tubing with epoxy resin adhesive, and creatine amidinohydrolase and sarcosine oxidase immobilized on their tip by cross-linking method. The calibration curve for measurement of creatine, the effects of pH, temperature, the amount of flavin adenine dinucleotide and compounds on the sensitivity, and the life-time of the sensor were examined. Under optimal conditions, the response of the sensor was linear in the concontration range of 10 μ M ∼ 0.65 mM creatine.