Tunable Plasmonic Response from Alkanethiolate-Stabilized Gold Nanoparticle Superlattices:  Evidence of Near-Field Coupling

Abstract

We report on the self-assembly of large-area, highly ordered 2D superlattices of alkanethiolate-stabilized gold nanoparticles ( approximately 10.5 nm in core diameter) onto quartz substrates with varying lattice constants, which can be controlled by the alkyl chain lengths, ranging from C12 (1-dodecanethiolate), C14 (1-tetradecanethiolate), C16 (1-hexadecanethiolate), to C18 (1-octadecanethiolate). These 2D nanoparticle superlattices exhibit strong collective surface plasmon resonance that is tunable via the near-field coupling of adjacent nanoparticles. The approach presented here provides a unique and viable means of building artificial "plasmonic crystals" with precisely designed optical properties, which can be useful for the emerging fields of plasmonics, such as subwavelength integrated optics.

Anderson Insulators in Self-Assembled Gold Nanoparticles Thin Films: Single Electron Hopping between Charge Puddles Originated from Disorder

“…Great variations in resistance R for devices with different surface modification molecules were found at room temperature. The resistances are enlisted in Table 1, showing a highly correlation to the interparticle distance s, which is estimated from s/nm=0.54 +0.12 n. [27] For most of the devices, the exponential dependence R~ exp(βxs) are found, with βx~11.8 nm -1 .…”

Polypeptide functionalized gold nanoparticles for bioanalytical applications

“…These shifts occur gradually and can be roughly described by an exponential function of the interparticle distance, where denser aggregates with smaller interparticle distances results in larger shifts. [132][133][134] This phenomenon is termed plasmon coupling and can be used for sensor applications if the change in colloid stability can be linked to the presence of the species intended for detection. Plasmon coupling is used in all four papers included in this thesis as a transducer mechanisms resulting in a tunable colorimetric response for the detection of various proteins, biomolecules and enzymatic reactions.…”

Optical Simulations of Self-assembly Relevant Gold Aggregates: A Comparative Study

“…There are several literature examples, where assignment of the evolved nanoparticle cluster structure has been carried out solely based on spectroscopic characterization (or by naked eye due to the color change) and the identification of dimers, trimers [13], chains [18,19] or larger clusters [15] based on the extinction spectra has been claimed. Two-dimensional nanoparticle arrays have been also reported with potentially useful optical properties due to the collective plasmonic oscillations [20,21].…”

“…There are several literature examples, where assignment of the evolved nanoparticle cluster structure has been carried out solely based on spectroscopic characterization (or by naked eye due to the color change) and the identification of dimers, trimers [13], chains [18,19] or larger clusters [15] based on the extinction spectra has been claimed. Two-dimensional nanoparticle arrays have been also reported with potentially useful optical properties due to the collective plasmonic oscillations [20,21].Besides the structure or size [22] of the particle cluster, the interparticle distance between the building blocks [21,23] has also a profound effect on the evolving coupled mode. It has to be emphasized that in a real experiment -independently of the resulting structure -the clustering process usually generates a distribution of structures.…”