Formation of gold nanoparticle dimers on silicon by sacrificial DNA origami technique

Abstract

To create a nanogap-based device for single-molecule label-free detection using surface-enhanced Raman spectroscopy (SERS), a new approach utilising DNA origami (DO) as a sacrificial nanostructure is proposed. In this approach, 15-nm diameter gold nanoparticles (AuNPs) are precisely self-assembled to form a dimer structure on opposite faces of a rectangular DO structure. The AuNPs are then fixed on a silicon chip supporting an amino-terminated monolayer and the DO is selectively removed by vacuum ultraviolet (VUV) treatment followed by ultrapure water cleaning. X-ray photoelectron spectroscopy measurements confirmed the successful removal of the DNA nanostructures and the VUV treatment had little effect on the diameter of the AuNPs. Quantitative evaluations showed that the original gap distance of about 3.8 nm was reduced to <2 nm after the DO structures were removed by the VUV treatment and ultrapure water rinse. The proposed technique can therefore be considered a simple and low-cost alternative to EB lithography approaches.

Coupling effects in QD dimers at sub-nanometer interparticle distance

“…Recognition mechanisms of biological molecules (DNA, antidig-antibody etc.) were also exploited for the fabrication of dimers of colloidal NPs, as widely reported [21][22][23]. However, such an approach is not suited to obtain interparticle distance shorter than few nm, due to the nature of the used molecules [24].…”

Investigation of Performance Parameters of Spherical Gold Nanoparticles in Localized Surface Plasmon Resonance Biosensing

“…With this d s = 1 nm distance, the sensitivity is 2.8 times higher compared to the single d = 60 nm AuNPs, and it is 2 times higher compared to the AuNPs dimers of diameter d = 20 nm. The gap between the two nanoparticles (dimer) can be controlled by various methods, such as DNA origami [ 23 , 24 ] and solid phase approaches [ 25 , 26 ].…”

Surface‐enhanced Raman spectroscopy with gold nanoparticle dimers created by sacrificial DNA origami technique

“…1 and explained as follows. The details of the experimental procedure were previously reported [18].…”

“…In our previous study, we devised a 'sacrificial DNA origami technique' for forming AuNP dimers with nanogaps by decomposing DNA origami using vacuum ultraviolet (VUV) light irradiation [18]. The AuNPs with a diameter of 15 nm were connected to the counter-faces of a rectangular DNA origami structure, and then the DNA origami was removed with a cleaning process using VUV irradiation and an ultrapure water (UPW) rinse.…”