Gold Nanoparticles Modified with Double-stranded DNA for Analytical Applications

Abstract

Gold naoparticles densely functionalized with a DNA duplex undergo rapid and spontaneous aggregation in a medium of relatively high ionic strength. This non-crosslinking aggregation occurs irrespective of the particle size and the DNA length, while it exhibits both greater temperature- and salt concentration-dependence than that of DNA duplex formation. Interestingly, no aggregation takes place under the same conditions when the DNA duplex has a single-base mismatch at the distal end, which is located at the outermost surface of the particle. In this review, we describe applications of the DNA-carrying gold nanoparticles to gene diagnosis and chemical sensing, with emphasis placed on some attempts to improve the sensitivity.