Development of a Creatinine ELISA and an Amperometric Antibody-Based Creatinine Sensor with a Detection Limit in the Nanomolar Range
作者:Alexander Benkert、Frieder Scheller、Werner Schössler、Christian Hentschel、Burkhard Micheel、Olaf Behrsing、Gudrun Scharte、Walter Stöcklein、Axel Warsinke
DOI:10.1021/ac9909047
日期:2000.3.1
Creatinine-specific antibodies have been generated and used for highly sensitive and specific immunochemical creatinine determinations. Creatinine was derivatized at N3 and coupled to KLH carrier protein. On the basis of this immunogen, monoclonal antibodies were developed by hybridoma technology. Antibodies from various clones have been characterized with BIAcore 2000 with respect to the dissociation constant and specificity. Antibodies of clone B90-AH5 exhibited the lowest dissociation constant (0.74 μM) and the highest specificity for creatinine and were chosen for the development of a competitive ELISA and an amperometric creatinine sensor. The creatinine sensor was constructed by fixing a creatinine-modified membrane on the top of a platinum working electrode which was then incorporated into a stirred electrochemical measuring cell. For creatinine determination the creatinine-containing sample was incubated with B90-AH5 and anti-IgG(mouse)−glucose oxidase conjugate and applied to the measuring cell. After a washing step glucose was added and the produced hydrogen peroxide was registrated at Eappl = +600 mV vs Ag/AgCl. The measuring range was 0.01−10 μg/mL. The highest sensitivity for creatinine was achieved at 330 ng/mL (3 μM) and the lower detection limit at 4.5 ng/mL (40 nM). This is far below the relevant clinical range, which is 5−17 μg/mL (44−150 μM) and allows a reliable determination of very low creatinine concentrations in serum, where standard methods cannot be applied. After each measurement the sensor was regenerated with 10 mM HCl without any loss in binding activity.
生成了肌酐特异性抗体,并将其用于高灵敏度和特异性免疫化学肌酐测定。肌酐在 N3 处被衍生化,并与 KLH 载体蛋白偶联。在此免疫原的基础上,通过杂交瘤技术开发出了单克隆抗体。用 BIAcore 2000 对来自不同克隆的抗体的解离常数和特异性进行了鉴定。克隆 B90-AH5 的抗体表现出最低的解离常数(0.74 μM)和对肌酐最高的特异性,因此被选为竞争性 ELISA 和安培肌酐传感器的开发对象。肌酐传感器的制作方法是在铂工作电极的顶部固定一层肌酐修饰膜,然后将其放入搅拌式电化学测量池中。在测定肌酐时,将含肌酐的样品与 B90-AH5 和抗 IgG(小鼠)-葡萄糖氧化酶结合物孵育,然后将其置于测量池中。经过洗涤步骤后加入葡萄糖,产生的过氧化氢在 Eappl = +600 mV 对 Ag/AgCl 时被记录下来。测量范围为 0.01-10 μg/mL。肌酐的最高灵敏度为 330 纳克/毫升(3 μM),检测下限为 4.5 纳克/毫升(40 nM)。这远远低于 5-17 μg/mL (44-150 μM)的相关临床范围,因此可以可靠地测定血清中浓度极低的肌酐,而标准方法则无法应用。每次测量后,用 10 mM HCl 对传感器进行再生,其结合活性没有任何下降。