DNA-mediated electrostatic assembly of gold nanoparticles into linear arrays by a simple drop-coating procedure

The assembly of nanoparticles in topologically predefined superstructures i s an important problem in the area of nanoscale architecture. In this lette r, we demonstrate the electrostatic assembly of lysine-capped colloidal gol d particles on drop-coated DNA films. Electrostatic interaction between the positive charges on the gold nanoparticles and the negative charges on the phosphate groups of the DNA template molecules leads to the assembly of th e gold nanoparticles in linear superstructures. The use of DNA as templates for the assembly of nanoparticles shows promise for extension to more comp lex geometries through rational design of the DNA base sequences as well as in the realization of nanowires by stringing together metal nanoparticles. (C) 2001 American Institute of Physics.