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A DNA-gold nanoparticle-based colorimetric competition assay for the detection of cysteine

Lee, Jae-Seung and Ulmann, Pirmin A. and Han, Min Su and Mirkin, Chad A. (2008) A DNA-gold nanoparticle-based colorimetric competition assay for the detection of cysteine. NANO LETTERS, 8 (2). pp. 529-533.

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Official URL: http://pubs.acs.org/doi/abs/10.1021/nl0727563

Abstract

We report the development of a highly sensitive and selective colorimetric detection method for cysteine based upon oligonucleotide-functionalized gold nanoparticle probes that contain strategically placed thymidine-thymidine (T-T) mismatches complexed with Hg2+. This assay relies upon the distance-dependent optical properties of gold nanoparticles, the sharp melting transition of oligonucleotide-linked nanoparticle aggregates, and the very selective coordination of Hg2+ with cysteine. The concentration of cysteine can be determined by monitoring with the naked eye or a UV-vis spectrometer the temperature at which the purple-to-red color change associated with aggregate dissociation takes place. This assay does not utilize organic cosolvents, enzymatic reactions, light-sensitive dye molecules, lengthy protocols, or sophisticated instrumentation thereby overcoming some of the limitations of more conventional methods.

Item Type:Article
Subjects:Biomedical Science > Nanobiotechnology
Biomedical Science > Nanomedicine
ID Code:3536
Deposited By:Farnush Anwar
Deposited On:16 Jan 2009 16:47
Last Modified:29 Jan 2009 11:41

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