DNA-mediated control of Au shell nanostructure and controlled intra-nanogap for a highly sensitive and broad plasmonic response range

Abstract

We report DNA-mediated simple synthetic methods to obtain anisotropic plasmonic nanostructures with a tailorable intra-nanogap distance ranging from 0.9 to 4.0 nm. Anisotropic half-shell structures with sub-1.0 nm intra-nanogaps showed a wavelength-independent surface-enhanced Raman scattering (SERS) intensity and a highly sensitive SERS response to NIR light. We found that the reaction conditions such as pH and NaCl concentration are responsible for the resulting shell structures and intra-nanogap distances. Three noticeable plasmonic nanostructures [i.e., half-shell with sub-1.0 nm nanogaps, closedshell with a wide nanogap (2.1 nm) and star-shaped with an irregular nanogap (1.5-4.0 nm)] were synthesized, and solution-based and single particle-based Raman measurements showed a strong relationship between the plasmonic structures and the SERS intensity. An understanding of DNA-mediated control for nanogap-engineered plasmonic nanostructures and studies of SERS-activity relationships using single particle-correlated measurements can provide new insights into the design of new plasmonic nanostructures and SERS-based biosensing applications.

Simultaneous Surface-Enhanced Raman Spectroscopy Detection of Multiplexed MicroRNA Biomarkers

“…Recently, novel nanoprobes called “SERS tags”, consisting of silver or gold nanostructures and specific Raman reporter molecules, have been synthesized to develop SERS-based biological analyses. − Despite the ultrasensitive, multiplex, and biocompatible properties of SERS tags, challenges are often encountered in the complex and delicate synthetic steps, as well as practical use . More recent research has led to the synthesis of well-defined gold nanobridged nanogap particles (Au-NNPs) for stable, highly quantitative, and controllable SERS enhancement. − The existence of interior nanogaps in nanostructures holds great promise for developing universal SERS nanotags and multiplex nanoprobes. However, several critical techniques still remain challenging, including simple and controllable synthesis of Au-NNPs, modification of the interior nanogap of nanotags with Raman reporters to produce intense and stable multiplex SERS signals, and functionalization of the nanotags as SERS nanoprobes to recognize different bioactive molecules.…”

PEGylated crushed gold shell-radiolabeled core nanoballs for in vivo tumor imaging with dual positron emission tomography and Cerenkov luminescent imaging

“…Perrault et al [ 44 ] reported that rod-shaped nanomaterials have much higher blood circulation half-lives than spherical nanomaterials. Moreover, Lee et al [ 45 ] reported the successful control of gold shell nanostructures such as a star-shaped shell with irregular nanogap and intra-nanogap distances by pH and NaCl concentrations. Accordingly, we attempted to modulate the shape of gold shell nanostructures through modulations of pH to protect the release of radioiodine from gold core nanoparticles by various biological factors in living subjects and effectively enhance passive tumor targeting efficiency.…”

Applications of DNA Nanotechnology in Synthesis and Assembly of Inorganic Nanomaterials

“…The EM field inside Au-NNP generated by the complete Au shell is stronger and more uniform than that generated by the incomplete one ( Figure 4C3). Similarly, Lee and his co-workers [66] found the reaction parameters such as pH and NaCl concentration, have great influence on the DNA conformation, and thereby they obtained three anisotropic plasmonic nanostructures with different shell structures and adjustable intra-nanogap distance on a nanoscale. It is worth expecting that other materials such as Ag and Pt-NNPs can be synthesized, and then be applied to more scientific and engineering fields.…”