Freeze-Driven Adsorption of Poly-A DNA on Gold Nanoparticles: From a Stable Biointerface to Plasmonic Dimers.

ABSTRACT: Increasing attention is paid to poly-adenine (poly-A) DNA-functionalized gold nanoparticles due to the high cost of thiols. Freezing is an effective approach for immobilizing poly-A DNA on gold nanoparticles, but its mechanism remains elusive. To cope with this issue, in this paper, some experimental insights are provided. It is shown that (1) the DNA loading density is independent of the length of poly-A. (2) DNA is densely packed on gold nanoparticles, and the biointerface is peculiarly stable, which is not in line with the existing "wrapping" model. (3) Using a DNA-staining dye, thiazole orange, it is shown that poly-A duplex structures are formed on the surface of gold nanoparticles, with evidence given by fluorescence and Raman measurements. An alternative model involving stable poly-

SUBMITTER: Ye Y 

PROVIDER: S-EPMC9022424 | biostudies-literature | 2022 Apr

REPOSITORIES: biostudies-literature