DNA-based programmed assembly of gold nanoparticles on lithographic patterns with extraordinary specificity

We demonstrate the highly specific and programmed assembly of oligonucleotide-conjugated gold nanoparticles on lithographically defined microscale gold patterns. A key feature of our fabrication technique is the use of poly(ethylene glycol) (PEG) groups to form an inert coating on regions of the chip where no nanoparticle assembly is desired. By assembling multiple layers of DNA-conjugated nanoparticles we illustrate the capability of PEG surface coatings to exquisitely direct the nanoparticles onto the lithographic patterns with almost zero nonspecific reaction per square micron. We further suggest that the use of PEG to eliminate nonspecific reaction may be extended to micro- and nanoscale fabrication systems that make use of a variety of different nanostructures.