Tsuchida T, Yoda K
Clin Chem. 1983 Jan;29(1):51-5.
An enzyme electrode system for the determination of creatinine and creatine was developed by utilizing three enzymes: creatinine amidohydrolase (CA), creatine amidinohydrolase (Cl), and sarcosine oxidase (SO). These enzymes were co-immobilized onto the porous side of a cellulose acetate membrane with asymmetric structure, which has selective permeability to hydrogen peroxide. Two kinds of multi-enzyme electrodes were constructed by combining a polarographic electrode for sensing hydrogen peroxide and an immobilized CA/Cl/SO membrane or Cl/SO membrane for creatinine plus creatine or creatine, respectively. The multi-enzyme electrodes responded linearly up to 100 mg of creatinine and creatine per liter in human serum. Response time was 20 s in the rate method and the detection limit was 1 mg/L. Only 25 microL of serum sample is required. Analytical recoveries, precisions, and correlations with the Jaffé method were excellent, and the multi-enzyme electrodes were sufficiently stable to perform more than 500 assays. No loss of activity of immobilized enzymes was observed after nine months of storage at 4 degrees C in air.
肌酸酐酰胺水解酶（CA）、肌酸脒基水解酶（Cl）和肌氨酸氧化酶（SO），开发了一种用于测定肌酐和肌酸的酶电极系统。这些酶被共固定在具有不对称结构的醋酸纤维素膜的多孔侧，该膜对过氧化氢具有选择性渗透性。通过将用于检测过氧化氢的极谱电极与分别用于肌酐加肌酸或肌酸的固定化CA/Cl/SO膜或Cl/SO膜相结合，构建了两种多酶电极。多酶电极对人血清中每升高达100毫克的肌酐和肌酸呈线性响应。速率法中的响应时间为20秒，检测限为1毫克/升。仅需要25微升血清样本。分析回收率、精密度以及与Jaffé法的相关性都非常好，并且多酶电极足够稳定，能够进行超过500次测定。在4摄氏度空气中储存九个月后，未观察到固定化酶的活性损失。
