Search

Development of Raman spectroscopy, profiting from surface-enhanced Raman scattering and tip-enhanced Raman scattering techniques, has inspired extensive research interest for trace analysis and dynamic measurements up to single-molecule level. For another, Raman spectroscopy has also been recognized of significance in solving some important issues relating to molecule aggregates in chemistry and biology, owing to the capability of non-destructive detection and high-resolution fingerprints by which molecules and their aggregates can be identified. Herein, we summarize the recent progress of Raman spectroscopy in probing single molecules and molecular aggregates and block out a future prospective of Raman spectroscopy applied in cluster science. Copyright © 2015 John Wiley & Sons, Ltd.

The Temporal Experiment for Storms and Tropical Systems Technology Demonstration (TEMPEST-D) mission is to demonstrate the capability of 6U-Class satellite constellations to perform repeat-pass radiometry to measure clouds and precipitation with high temporal resolution on a global basis. The TEMPEST mission concept is to improve understanding of clouds and precipitation by providing critical information on their time evolution in different climatic regimes. Measuring at five frequencies from 89 to 182 GHz, TEMPEST-D millimeter-wave radiometers are capable of penetrating into the cloud to observe changes as precipitation begins or ice accumulates inside the storm. The TEMPEST-D flight model radiometer instrument has been completed, passed functional testing, vibration testing and self-compatibility testing with the XB1 spacecraft bus. The next steps for the TEMPEST-D millimeter-wave radiometer are thermal vacuum testing and antenna pattern measurements. The complete TEMPEST-D flight system will be delivered to NanoRacks for launch integration in the autumn of 2017, in preparation for launch to the ISS in the second quarter of 2018, with deployment shortly thereafter into a nominal orbit at 400-km altitude and 51.6° inclination.

Met literatuuropgave

We report a photoassisted method to magnetize microcrystal fullerene C(60) at room temperature by exciting it to triplet states via a proper laser radiation and then trapping the spin-polarized states under a strong magnetic field. Novel changes on Raman scattering of the C(60) microcrystals were observed in the presence and absence of the magnetic field. In particular, the Raman spectra were found to exhibit a "hysteresis" phenomenon when the external magnetic field was removed. In light of this, we propose magnetic-field-trapped Raman spectroscopy (MFTRS) and employ first-principle calculations to reproduce the Raman activities of C(60) at different states. Further, MFTRS of the fullerene is demonstrated to originate from its photoassisted magnetization (PAM). The PAM strategy enables the magnetization of materials which consist of only light elements; meanwhile, the MFTRS investigation may open a new research field in Raman spectroscopy.

We achieved single-molecule surface-enhanced Raman scattering (SM-SERS) spectra from ultralow concentrations (10−15 M) of fullerene C60 on uniformly assembled Au nanoparticles. It was found that resonant excitation at 785 nm is a powerful tool to probe SM-SERS in this system. The appearance of additional bands and splitting of some vibrational modes were observed because of the symmetry reduction of the adsorbed molecule and a relaxation in the surface selection rules. Time-evolved spectral fluctuation and ‘hot spot’ dependence in the SM-SERS spectra were demonstrated to result from the single-molecule Raman behavior of the spherical C60 on Au nanoparticles. Copyright © 2010 John Wiley & Sons, Ltd.

The applicability of surface-enhanced Raman spectroscopy is demonstrated to probe the adsorption behavior of individual molecules on a Ag electrode. High-quality SERS spectra of (R)-di-2-naphthylpr ...

Morphological evolution from organic molecules to metallosupramolecules to nanoscale structures is reported. Specifically, bis(iminopyrrole)benzene molecules are coordinated with the ZnII ions to give the characteristic metallosupramolecular architectures of double helicates, triangles and squares. These metallosupramolecules then, as building blocks, aggregate into particular shaped nanostructures such as nanospheres, nanobelts and nanorods. These nanostructures finally coalesce into macroparticles without a variation in shape. The optical properties of the fabricated nanostructures are comparable to those of solution and bulk materials.

High-density ordered arrays of core–shell nano-pillars of Ag–perylene were fabricated using an anodic aluminium oxide (AAO) template which was first embedded with the perylene molecules, followed by an electrochemical deposition of Ag. The surface-enhanced Raman scattering (SERS) spectrum obtained from this system showed well-resolved Raman peaks with good signal-to-noise ratios and little fluorescence background. This is in sharp contrast to the SERS of the individual Ag–perylene nanorods removed from the same AAO template, and the SERS of perylene molecules adsorbed on Ag colloidal nanoparticles. In the latter two cases, the SERS spectra consisted of broad and not-so-well-resolved Raman peaks with a strong fluorescence background. It is believed that the orderly assembly of the perylene molecules on the inner walls of the pores of the AAO template along the Ag nano-pillars led to fluorescence quenching. The high-density ordered arrays of Ag nano-pillars brought forth a surface plasmon resonance for the SERS effect. The present AAO template system offers a new substrate for studying SERS of highly fluorescing molecules.