Oligonucleotide nanoparticle conjugate: A versatile probe in biodetection

ANYL 306

Chad A. Mirkin, chadnano@northwestern.edu, Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208
Over the last ten years, DNA-modified gold nanoparticles have been used extensively for the detection of nucleic acids. Their unique and intense optical properties and cooperative binding properties have led to several detection systems with high sensitivity and selectivity. Recently, we have extended the use of these materials to the detection of non-nucleic acid targets. In particular, we have developed methods based on the optical properties of DNA-modified gold nanoparticles. These methods are directed at identifying target molecules which perturb the DNA that interconnects the gold nanoparticle networks. When target molecules interact with the DNA interconnects, they affect the stability of the system thereby inducing a colorimetric change. This is a compelling detection method because the DNA interconnects can be designed with different configurations which target a variety of small molecules. We will present detection methods which screen for duplex and triplex DNA binders and demonstrate how sequence specificity can also be obtained. We will also show how simply changing the DNA interconnects can lead to the detection of metal ions such as mercury.