Tombach B, Schneider J, Matzkies F, Schaefer R M, Chemnitius G C
Department of Internal Medicine, Westfalian Wilhelms-University of Münster, Albert-Schweitzer-Str. 33, 48129, Münster, Germany.
Clin Chim Acta. 2001 Oct;312(1-2):129-34. doi: 10.1016/s0009-8981(01)00610-6.
Creatinine is an important clinical laboratory parameter for the evaluation of kidney function. It is essential to determine its concentration in serum of patients suffering from renal insufficiency. During hemodialysis treatment, the measurement of creatinine in the effluent dialysate or ultrafiltrate may give additional information on the efficiency of the extracorporal procedure. Therefore, enzyme sensors with co-immobilized creatinine amidohydrolase, creatine amidinohydrolase and sarcosine oxidase have been used to determine creatinine.
Enzymatically generated hydrogen peroxide has amperometrically been detected at a platinum-working electrode. To exclude electroactive compounds of the sample matrix, which might interfere with the electrochemical measurement, the sensors have additionally been modified by a Nafion membrane.
Such sensors showed a linear detection range of 0.06-1.7 mg/dl for creatinine. Diluting the sample with measuring buffer, it has also been possible to measure pathological creatinine concentrations up to 11 mg/dl. A good correlation between creatinine concentrations in serum, dialysate and ultrafiltrate determined by the presented enzyme sensors and those obtained by both, conventional colorimetric Jaffé and enzymatic measurements have been achieved.
Further developments will aim at the integration of this measuring principle into the concept to low-cost disposable planar sensors.
肌酐是评估肾功能的一项重要临床实验室参数。对于肾功能不全患者，测定其血清中的肌酐浓度至关重要。在血液透析治疗过程中，测定流出的透析液或超滤液中的肌酐含量，可能会提供有关体外治疗效率的额外信息。因此，已使用共固定肌酐酰胺水解酶、肌酸脒基水解酶和肌氨酸氧化酶的酶传感器来测定肌酐。
在铂工作电极上通过安培法检测酶促产生的过氧化氢。为排除可能干扰电化学测量的样品基质中的电活性化合物，传感器还通过Nafion膜进行了修饰。
此类传感器对肌酐的线性检测范围为0.06 - 1.7mg/dl。用测量缓冲液稀释样品后，也能够测量高达11mg/dl的病理性肌酐浓度。通过所展示的酶传感器测定的血清、透析液和超滤液中的肌酐浓度，与通过传统比色法Jaffé和酶法测量获得的浓度之间具有良好的相关性。
进一步的发展将致力于把这种测量原理整合到低成本一次性平面传感器的概念中。
