酶催化荧光猝灭法测定痕量葡萄糖

摘要

In phosphate buffer solution(pH 7.0),glucose oxidase(GOx)can catalyze the reaction of glu-cose with oxygen generate hydrogen peroxide,then hydrogen peroxide reaction with excess I- in dilute sulfuric acid solution to form I-3.The I-3combines with Rhodamine 6G(Rh6G) to form Rh6G-I3associat-ed particles which result in fluorescence quenching at 553 nm.Based on the significant quenching effect of glucose on the fluorescence of Rh6G,a new method with high sensitivity and good selectivity for the determination of glucose was established.Under the optimal conditions,the concentration of glucose in the range of 2.0 ×10 -7~1.4 ×10 -5mol/L is linear with their fluorescence quenching at 553 nm,with detection limits of 6.77×10 -8mol/L glucose.This assay was applied to the determination of glucose in the serum samples with satisfactory results,the recoveries obtained were 85.0% ~102.5%.%在pH 7.0的磷酸盐缓冲液中,葡萄糖氧化酶(GOx)催化葡萄糖与氧反应生成H2O2,在H2SO4介质中H2O2与I-发生氧化还原反应生成I2,过量的I-与I2生成I-3,I-3使阳离子荧光剂罗丹明6G位于553 nm波长处的荧光发生猝灭,猝灭程度与葡萄糖浓度相关,据此建立检测葡萄糖的新方法.方法线性范围为2.0×10-7~1.4×10-5mol/L,检出限为6.77 ×10-8mol/L.将该方法用于血糖样品测定,加标回收率为85.0% ~102.5%,操作简便、结果准确可靠.