Surface-Enhanced Raman Scattering Plasmonic Enhancement Using DNA Origami-Based Complex Metallic Nanostructures

Abstract

DNA origami is a novel self-assembly technique allowing one to form various 2Dshapes and position matter with nanometer accuracy. We use DNA origami templates to engineer Surface Enhanced Raman Scattering (SERS) substrates. Specifically, gold nanoparticles were selectively placed on the corners of rectangular origami and subsequently enlarged via solution-based metal deposition. The resulting assemblies exhibit "hot spots" of enhanced electromagnetic field between the nanoparticles. We observed a significant Raman signal enhancement from molecules covalently attached to the assemblies, as compared to control nanoparticle samples which lack inter-particle hot spots. Furthermore, Raman molecules are used to map out the hot spots' distribution, as they are burned when experiencing a threshold electric field. Our method opens up the prospects of using DNA origami to rationally engineer and assemble plasmonic structures for molecular spectroscopy.

Recent advances in plasmonic nanostructures for sensing: a review

“…By generating such ordered arrays, the potential for reproducible and sensitive quantitative SERS analyses exists. In addition to the development of patterned arrays (already described), there has also been a great deal of recent research into the development of isolated SERS active nanoparticle dimers 68,[88][89][90][91] and target-triggered, ordered nanoparticle aggregates. 69,[92][93][94][95] Such isolated dimers and ordered aggregates offer the potential of significantly enhanced SERS signals over individual particles or larger ordered arrays, with good reproducibility.…”

“…5(h)]. 91 Unlike the previous dimer fabrication methods, the oligonucleotide-specific interactions associated with DNA and RNA allow for much more diverse and complicated structures to be formed. However, the complexity of forming such elegant and well-defined nanostructures is limited by the melting and binding conditions required for each different interaction.…”

“…To provide plasmonic nanostructures, the oligonucleotides are functionalized with colloidal metal nanoparticles at specific locations, providing a means of coordinating the nanoparticles with precision limited only by the flexibility of the specific oligonucleotide sequences employed. 91 An alternative approach to controlled aggregation of SERS nanoparticles that have recently seen growth for SERS sensing applications has been analyte-induced or analyte-triggered nanoparticle aggregation-based systems [see Fig. 5(i)].…”

Characterization of Emergence of the Coulomb Blockade in a Pearl-Like DNA-AuNP Assembly

“…Also direct metallization of origami to form nanoscale wires and other metallic shapes has been investigated widely [20], but this approach does not provide an easy way to produce functional electronic devices. Many groups have demonstrated optical devices based on organizing metallic NPs exhibiting localized surface plasmon resonance [21][22][23][24], but despite the promises only few DNA based electrical devices or studies have been realized [19,[25][26][27].…”

Nanoplasmonic biosensors: current perspectives

“…7 Researchers have also studied the formation of hot spots, ie, small regions of highly enhanced EM field, to obtain high SERS intensity. 8,9 Nanostructures either exist in solution phase or are confined on a substrate in the form of a nanofilm or a periodic array. Historically, a large number of studies exist on nanoplasmonic biosensors based on solution phase nanoparticles, where aggregation of nanoparticles is used for the determination of biomolecular interactions.…”