增强微流控芯片化学发光检测灵敏度的研究

Study of Enhancing Detection Sensitivity of Microchip Chemiluminescence System

为增强微流控芯片化学发光检测的灵敏度,扩大该方法的应用领域,利用金属离子催化鲁米诺-过氧化氢反应,通过比较几种结构不同的微流控芯片,对影响检测发光信号灵敏度的因素,如试剂浓度、流速和微通道的尺度等作了详细地讨论。提出了具有双螺旋形结构芯片的微流动注射系统,大大增强了化学发光检测的灵敏度。在最佳实验条件下,铬离子（Cr3＋）浓度在5.0×10-9~2.0×10-6mol/L范围内与其体系的发光信号强度具有一定的线性关系,对浓度为6.0×10-8mol/L的铬连续11次进样,相对标准偏差为1.59%,其检出限为1.50×10-9mol/L。该体系可以成功地用于天然湖水和自来水中金属铬的分析和检测。

To enhance detection sensitivity of microchip chemiluminescence system and expand the application fields of this method,based on the metal ion-catalyzed luminol - peroxide reaction,several different configuration microchip have been compared.Influencing factors of chemiluminescence signals,such as concentration and flow rate of reagents and scale of microchannels have been discussed.A new microflow injection system with double spiral channel configuration was proposed and the sensitivity was greatly enhanced due to more efficient mixing of the analyte and reagent solutions.Under the optimized conditions,a linear calibration curve （R 2 =0.997） over the range 5.0×10 -9 to 2.0×10 -6 mol/Lwas obtained with the detection limit of 1.50×10 9 mol/L for the chromium ion.The relative standard deviation was found to be 1.59% （n=11） for 6.0×10 -8 mol/L.The proposed method has been applied successfully to the analysis of natural lake water and tap water with satisfactory results.