Flow injection analysis of glucose based on its inhibition of electrochemiluminescence in a Ru(bpy) 32+–tripropylamine system

Abstract

Based on the linear relationship between concentration of H 2O 2 and the decrease of electrochemiluminescence (ECL) intensity in a Ru(bpy) 3 2+–tripropylamine (TPA) system, procedures for the indirect determination of glucose with a flow injection analysis system were developed. By passing solutions of glucose through a glucose oxidase (GOx)-immobilized sol–gel column and an ECL system of Ru(bpy) 3 2+ and TPA, glucose can be determined optimally with a detection limit of 1.0 μM in a linear dynamic range of 1.0–200 μM. A repetitive injection of glucose (100 μM) and human serum solutions gave satisfactory reproducibility with R.S.D. of 1.3 ( n=31) and 3.9% ( n=42), respectively. Interference as a result of the presence of ascorbic acid, uric acid or other reducible agents in solution can be corrected by passing sample solutions through another sol–gel column which contained no GOx. From the agreement between the contents of glucose in human serum and soft drink analyzed by the developed method and those obtained by the spectroscopy method-based glucose assay kit and satisfactory recovery of glucose from interferent containing solutions, the feasibility of the developed method for real sample analysis was confirmed.