Super-resolution SERS imaging beyond the single-molecule limit: an isotope-edited approach.

Super-resolution imaging of single-molecule surface-enhanced Raman scattering (SM-SERS) reveals a spatial relationship between the SERS emission centroid and the corresponding intensity. Here, an isotope-edited bianalyte approach is used to confirm that shifts in the SERS emission centroid are directly linked to the changing position of the molecule on the nanoparticle surface. By working above the single-molecule limit and exploiting SERS intensity fluctuations, the SERS centroid positions of individual molecules are found to be spatially distinct.

Shedding Light on Surface-Enhanced Raman Scattering Hot Spots through Single-Molecule Super-Resolution Imaging.

Super-resolution imaging has recently been utilized to develop a better understanding of the properties of surface-enhanced Raman scattering (SERS) hot spots. SERS hot spots are much smaller than the diffraction limit of light, and therefore, obtaining a clear picture of the enhanced electromagnetic (EM) fields comprising these hot spots is a challenging task. In this Perspective, we discuss recent work applying super-resolution imaging to single-molecule SERS (SM-SERS) of rhodamine 6G (R6G) adsorbed to randomly assembled silver colloidal aggregates, allowing the shape, size, and local enhancement of the hot spots to be imaged with <5 nm resolution.

Polarized Raman spectroscopy of oligothiophene crystals to determine unit cell orientation.

Raman spectra were recorded experimentally and calculated theoretically for bithiophene, terthiophene, and quaterthiophene samples as a function of excitation polarization. Distinct spectral signatures were assigned and correlated to the molecular/unit cell orientation as determined by X-ray diffraction. The ability to predict molecular/unit cell orientation within organic crystals using polarized Raman spectroscopy was evaluated by predicting the unit cell orientation in a simulated terthiophene crystal given a random set of simulated polarized Raman spectra.

Discriminating nanoparticle dimers from higher order aggregates through wavelength-dependent SERS orientational imaging.

Surface-enhanced Raman scattering (SERS) orientational imaging is a recently developed all-optical technique able to determine SERS-active silver nanoparticle dimer orientations by observing lobe positions in SERS emission patterns formed by the directional polarization of SERS along the longitudinal axis of the dimer. Here we extend this technique to discriminate nanoparticle dimers from higher order aggregates by observing the wavelength dependence of SERS emission patterns, which are unchanged in nanoparticle dimers but show differences in higher order aggregates involving two or more nanoparticle junctions. The ability of SERS orientational imaging to identify stacked nanoparticles in higher order aggregates is also demonstrated.

The use of dreams in spiritual care.

This paper explores the use of dreams in the context of pastoral care. Although many people dream and consider their dreams to hold some significant spiritual meaning, spiritual care providers have been reluctant to incorporate patients' dreams into the therapeutic conversation. Not every dream can be considered insightful, but probing the meaning of some dreams can enhance spiritual care practice.