title: A portable lab-on-a-chip system for gold-nanoparticle-based colorimetric detection of metal ions in water.
abstract: Heavy metal ions released into various water systems have a severe impact on the environment and human beings, and excess exposure to toxic metal ions through drinking water poses high risks to human health and causes life-threatening diseases. Thus, there is high demand for the development of a rapid, low-cost, and sensitive method for detection of metal ions in water. We present a portable analytical system for colorimetric detection of lead (Pb(2+)) and aluminum (Al(3+)) ions in water based on gold nanoparticle probes and lab-on-a-chip instrumentation. The colorimetric detection of metal ions is conducted via single-step assays with low limits of detection (LODs) and high selectivity. We design a custom-made microwell plate and a handheld colorimetric reader for implementing the assays and quantifying the signal readout. The calibration experiments 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. It promises an effective platform for metal ion analysis in a more economical and convenient way, which is particularly useful for water quality monitoring in field and resource-poor settings.
authors.affiliation: Department of Mechanical Engineering, McGill University , 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
authors.forename: Chen
authors.initials: C
authors.lastname: Zhao
authors.affiliation: Department of Civil Engineering and Applied Mechanics, McGill University , 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
authors.forename: Guowei
authors.initials: G
authors.lastname: Zhong
authors.affiliation: Department of Mechanical Engineering, McGill University , 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
authors.forename: Da-Eun
authors.initials: DE
authors.lastname: Kim
authors.affiliation: Department of Civil Engineering and Applied Mechanics, McGill University , 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
authors.forename: Jinxia
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Mechanical Engineering, McGill University , 817 Sherbrooke Street West, Montreal, Quebec H3A 0C3, Canada.
authors.forename: Xinyu
authors.initials: X
authors.lastname: Liu