Measuring the Affinities of RNA and DNA Aptamers with DNA Origami-Based Chiral Plasmonic Probes.

Reliable characterization of binding affinities is crucial for selected aptamers. However, the limited repertoire of universal approaches to obtain the dissociation constant () values often hinders the further development of aptamer-based applications. Herein, we present a competitive hybridization-based strategy to characterize aptamers using DNA origami-based chiral plasmonic assemblies as optical reporters.

Advancing the Utility of DNA Origami Technique through Enhanced Stability of DNA-Origami-Based Assemblies.

Since its discovery in 2006, the DNA origami technique has revolutionized bottom-up nanofabrication. This technique is simple yet versatile and enables the fabrication of nanostructures of almost arbitrary shapes. Furthermore, due to their intrinsic addressability, DNA origami structures can serve as templates for the arrangement of various nanoscale components (small molecules, proteins, nanoparticles, etc.

Characterizing Aptamers with Reconfigurable Chiral Plasmonic Assemblies.

Aptamers have emerged as versatile affinity ligands and as promising alternatives to protein antibodies. However, the inconsistency in the reported affinities and specificities of aptamers has greatly hindered the development of aptamer-based applications. Herein, we present a strategy to characterize aptamers by using DNA origami-based chiral plasmonic assemblies as reporters and establishing a competitive hybridization reaction-based thermodynamic model.

Light-Responsive Dynamic DNA-Origami-Based Plasmonic Assemblies.

DNA nanotechnology offers a versatile toolbox for precise spatial and temporal manipulation of matter on the nanoscale. However, rendering DNA-based systems responsive to light has remained challenging. Herein, we describe the remote manipulation of native (non-photoresponsive) chiral plasmonic molecules (CPMs) using light.

Reconfigurable Chiral Plasmonics beyond Single Chiral Centers.

Understanding how the geometrical property of chirality is transferred into the physical properties of chiral materials is becoming increasingly important in various research fields, including plasmonics. Advances in DNA nanotechnology, especially DNA origami techniques, have enabled routine fabrication of complex chiral plasmonic assemblies. However, most of the work undertaken to date has involved plasmonic enantiomers.

Assembly of Gold Nanorods into Chiral Plasmonic Metamolecules Using DNA Origami Templates.

The inherent addressability of DNA origami structures makes them ideal templates for the arrangement of metal nanoparticles into complex plasmonic nanostructures. The high spatial precision of a DNA origami-templated assembly allows controlling the coupling between plasmonic resonances of individual particles and enables tailoring optical properties of the constructed nanostructures. Recently, chiral plasmonic systems attracted a lot of attention due to the strong correlation between the spatial configuration of plasmonic assemblies and their optical responses (e.

A DNA Origami-Based Chiral Plasmonic Sensing Device.

Accurate and reliable biosensing is crucial for environmental monitoring, food safety, and diagnostics. Spatially reconfigurable DNA origami nanostructures are excellent candidates for the generation of custom sensing probes. Here we present a nanoscale biosensing device that combines the accuracy and precision of the DNA origami nanofabrication technique, unique optical responses of chiral plasmonic assemblies, and high affinity and selectivity of aptamers.

A Plasmonic Coupling Substrate Based on Sandwich Structure of Ultrathin Silica-Coated Silver Nanocubes and Flower-Like Alumina-Coated Etched Aluminum for Sensitive Detection of Biomarkers in Urine.

Interactions between substrate and plasmonic nanostructures can give rise to unique optical properties and influence performance in plasmonic biosensing applications. In this study, a substrate with low refractive index and roughness based on flower-like alumina-coated etched aluminum foil (f-Al O /e-Al) has been fabricated. Silver@silica (Ag@SiO ) nanocubes (NCs) assemble in an edge-edge configuration when deposited on this substrate.

Highly sensitive and stable Ag@SiO nanocubes for label-free SERS-photoluminescence detection of biomolecules.

Surface-enhanced Raman scattering (SERS) and fluorescence microscopy are a widely used biological and chemical characterization techniques. However, the peak overlapping in multiplexed experiments and rapid photobleaching of fluorescent organic dyes is still the limitations. When compared to Ag nanocubes (NCs), higher SERS sensitivities can be obtained with thin shelled silica Ag@SiO NCs, in contrast metal-enhanced photoluminescence (MEPL) is only found with NCs that have thicker silica shells.