A PORTABLE ANALYTICAL SYSTEM FOR COLORIMETRIC DETECTION OF METAL IONS IN WATER

摘要

Heavy metal ions released into various water environments have severe impact on both human beings and aqueous environments, and excess amount of lead and aluminum ions pose high risks to human health and could cause life-threatened diseases. The existence of metal ions in drinking water contributes most to the daily intake by humans, and thus it urges to develop a rapid, low-cost and sensitive method for detection of heavy metal ions. In this research, we develop a portable analytical system for metal ion detection in water by combining a powerful gold nanoparticle (AuNP) based colorimetric method with lab-on-a-chip technology. We utilize single-step assays involving surface functionalized AuNPs for colorimetric detection of lead (Pb~(2+)) and aluminum (Al~(3+)) ions in water with low limit of detection (LOD) and high sensitivity. We demonstrate that this portable system provides LODs of 30 ppb for Pb~(2+) and 89 ppb for Al~(3+), both comparable to bench-top analytical spectrometers. The system permits metal ion detections in a more economical and convenient fashion, and is particularly useful for water quality monitoring in remote and/or resource-poor settings.