| Year | 2013 |
|---|---|
| Journal Info. | Lab on a Chip, 13, 260-266 (2013). |
| Author | Eunsu Chung, Rongke Gao, Juhui Ko, Namhyun Choi, Dong Woo Lim, Eun Kyu Lee, Soo-Ik Chang and Jaebum Choo* |
| etc. |
Abstract
We report the rapid and highly sensitive trace analysis of mercury (II) ions in water using a surface-enhanced Raman scattering (SERS)-based microdroplet sensor. Aptamer-modified Au/Ag core-shell nanoparticles have been fabricated and utilized as highly functional sensing probes. All detection processes for the reaction between mercury (II) ions and aptamer-modified nanoparticles were performed in a specially designed microdroplet channel. Small water droplets that included sample reagents were separated from each other by an oil phase that continuously flowed along the channel. This two-phase liquid/liquid segmented flow system prevented adsorption of aggregated colloid to the channel walls due to localized reagents within encapsulated droplets. The result was reduced residence time distributions. The limit of detection (LOD) of mercury (II) ions in water was determined by SERS-based microdroplet sensor to be below 10 pM, which is three orders below the EPA-defined maximum contaminant level. This combination of SERS-based microfluidic sensor with aptamer-based functional nanoprobes can be used for in-the-field sensing platforms due to its size and simplicity.
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