1. Colorimetric assay for mercury (II) based on mercury-specific deoxyribonucleic acid-functionalized gold nanoparticles
- Author
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Yuzhi Fang, Lanying Li, Pingang He, Jikui Wu, Dan Zhu, and Guifang Cheng
- Subjects
Detection limit ,Metal ions in aqueous solution ,Magnesium Chloride ,Analytical chemistry ,Metal Nanoparticles ,chemistry.chemical_element ,Nanoprobe ,Nanoparticle ,DNA ,Mercury ,Biochemistry ,Colorimetry (chemical method) ,Analytical Chemistry ,Mercury (element) ,Metal ,chemistry ,Colloidal gold ,visual_art ,visual_art.visual_art_medium ,Environmental Chemistry ,Colorimetry ,Gold ,Thymine ,Spectroscopy ,Nuclear chemistry - Abstract
A colorimetric nanoprobe-mercury-specific DNA-functionalized gold nanoparticles (Au-MSD) was developed for sensing Hg(2+). The new mercury-sensing concept relies on measuring changes in the inhibition of "non-crosslinking" aggregation of Au-MSD-induced by the folding of mercury-specific DNA strand through the thymine-Hg(2+)-thymine (T-Hg(2+)-T) coordination. In the absence of Hg(2+), a high concentration of MgCl(2) (50 mM) results in a rapid aggregation of Au-MSD because of the removal of charge repulsion. When Hg(2+) is present, the particles remain stable due to the folding of MSD functionalized on the particle surface. The assay enables the colorimetric detection of Hg(2+) in the concentration range of 0.1-10 μM Hg(2+) ions with a detection limit of 60 nM, and allows for the selective discrimination of Hg(2+) ions from the other competitive metal ions. Toward the goal for practical applications, the sensor was further evaluated by monitoring Hg(2+) in fish tissue samples.
- Published
- 2011
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