Nanoarchitectonics for Analytical Science at Interfaces and with Supramolecular Nanostructures

For materials development with high-level structural regulations, the emerging concept of nanoarchitectonics has been proposed. Analytical sciences, including sensing/detection, sensors, and related device construction, are active targets of the nanoarchitectonics approach. This review article focuses on the two features of interface and nanostructures are especially focused to discuss nanoarchitectonics for analytical science. Especially, two selected topics, (i) analyses on molecular sensing at interfaces and (ii) sensors using self-assembled supramolecular nanostructures, are exemplified in this review article. In addition to recent general examples, specific molecular recognition at the air-water interface and fabrication of sensing materials upon self-assembly of fullerene units are discussed. Descriptions of these examples indicate that nanoarchitectonics and analytical science share common benefits, and therefore, developments in both research fields should lead to synergies.

Phonon propagation scale and nanoscale order in vitreous silica from Raman spectroscopy

For nanoscale systems such as nanoparticles and 3D-bonded networks, the range of spatial coherence is well reflected in the Raman spectral pattern. For confined, or localized, phonons, the range of q-points contributing to the spectrum depends on the phonon confinement length, which makes it possible to derive size information from the spectra. In this work, the Raman spectrum of vitreous silica is described as localized phonons of an SiO₂ network. The convergence of the spectral pattern with the confinement size is studied. It is shown that the phonon propagation scale in vitreous silica is within the 0.5-2 nm range.