ECsens, Department of Analytical Chemistry, Campus Fuentenueva, Faculty of Sciences, University of Granada, E-18071 Granada, Spain.
Anal Chim Acta. 2013 Apr 3;770:153-60. doi: 10.1016/j.aca.2013.01.045. Epub 2013 Feb 1.
A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)-uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy)3(2+)) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric acid biosensing is based on the ECL quenching produced by uric acid over the cathodic ECL caused by immobilized Ru(bpy)3(2+) in the presence of uricase. The use of a -1.1 V pulse for 1s with a dwelling time of 10s makes it possible to estimate the initial enzymatic rate, which is used as the analytical signal. The Stern-Volmer type calibration function shows a dynamic range from 1.0×10(-5) to 1.0×10(-3)M with a limit of detection of 3.1×10(-6)M and an accuracy of 13.6% (1.0×10(-4)M, n=5) as relative standard deviation. Satisfactory results were obtained for urine samples, creating an affordable alternative for uric acid determination.
基于三（2,2-联吡啶）钌（II）-尿酸酶体系的阴极电化学发光（ECL）猝灭的尿酸（UA）测定新方法。该生物传感器基于双层设计，第一层是电化学固定在石墨丝网印刷细胞上的三（2,2-联吡啶）钌（II）（Ru（bpy）3（2+）），第二层是壳聚糖中的尿酸酶。尿酸生物传感是基于尿酸酶存在下固定的 Ru（bpy）3（2+）在阴极 ECL 上产生的 ECL 猝灭。使用 1s 的-1.1V 脉冲，驻留时间为 10s，可估计初始酶速率，用作分析信号。Stern-Volmer 型校准函数显示出从 1.0×10（-5）到 1.0×10（-3）M 的动态范围，检测限为 3.1×10（-6）M，准确度为 13.6%（1.0×10（-4）M，n=5）作为相对标准偏差。对尿液样本进行了满意的测试，为尿酸测定提供了一种经济实惠的替代方法。
