Surface Density-of-States Engineering of Anatase TiO by Small Polyols for Enhanced Visible-Light Photocurrent Generation.

Enhancement of visible-light photocurrent generation by sol-gel anatase TiO films was achieved by binding small polyol molecules to the TiO surface. Binding ethylene glycol onto the surface, enhancement factors up to 2.8 were found in visible-light photocurrent generation experiments.

Facet-Dependent Diol-Induced Density of States of Anatase TiO Crystal Surface.

Owing to their fundamental importance and practical applications, anatase TiO crystals with well-defined {001} and {101} facets attracted intensive research interests. In this study, we systematically investigated solvent dependence of the photoreaction of the different coexposed crystal facets during noble metal photodeposition. By examining the deposition position in each solvent, we revealed that solvents play a pivotal role on the facet selectivity.

Plasmon-Mediated Surface Engineering of Silver Nanowires for Surface-Enhanced Raman Scattering.

We reveal nanoscale morphological changes on the surface of a silver nanowire (AgNW) in the conventional surface-enhanced Raman scattering (SERS) measurement condition. The surface morphology changes are due to the surface plasmon-mediated photochemical etching of silver in the presence of certain Raman probes, resulting in a dramatic increase of Raman scattering intensity. This observation indicates that the measured SERS enhancement does not always originate from the as-designed/fabricated structures themselves, but sometimes with contribution from the morphological changes by plasmon-mediated photochemical reactions.

Au nanoparticle scaffolds modulating intermolecular interactions among the conjugated azobenzenes chemisorbed on curved surfaces: tuning the kinetics of cis-trans isomerisation.

π-π Intermolecular interactions among adjacent conjugated azobenzenes chemisorbed on (non-)flat Au surfaces can be tuned by varying the curvature of the Au nanoparticles. Here we show that such interactions rule the thermal cis-trans isomerization kinetics, towards a better control on the azobenzene bistability for its optimal integration as a responsive material.

Visualization of molecular fluorescence point spread functions via remote excitation switching fluorescence microscopy.

The enhancement of molecular absorption, emission and scattering processes by coupling to surface plasmon polaritons on metallic nanoparticles is a key issue in plasmonics for applications in (bio)chemical sensing, light harvesting and photocatalysis. Nevertheless, the point spread functions for single-molecule emission near metallic nanoparticles remain difficult to characterize due to fluorophore photodegradation, background emission and scattering from the plasmonic structure. Here we overcome this problem by exciting fluorophores remotely using plasmons propagating along metallic nanowires.

Live-cell SERS endoscopy using plasmonic nanowire waveguides.

Live-cell surface-enhanced Raman spectroscopy (SERS) endoscopy is developed by using plasmonic nanowire waveguides as endoscopic probes. It is demonstrated that the probe insertion does not stress the cell. Opposed to conventional SERS endoscopy, with excitation at the hotspot within the cell, the remote excitation method yields low-background SERS spectra from specific cell compartments with minimal associated photodamage.

Excitation polarization sensitivity of plasmon-mediated silver nanotriangle growth on a surface.

In this contribution, we report an effective and relatively simple route to grow triangular flat-top silver nanoparticles (NPs) directly on a solid substrate from smaller NPs through a wet photochemical synthesis. The method consists of fixing small, preformed nanotriangles (NTs) on a substrate and subsequently irradiating them with light in a silver seed solution. Furthermore, the use of linearly polarized light allows for exerting control on the growth direction of the silver nanotriangles on the substrate.

Mapping of surface-enhanced fluorescence on metal nanoparticles using super-resolution photoactivation localization microscopy.

Photoactivation localization microscopy (PALM) was applied to study surface-enhanced fluorescence (SEF) on metal nanostructures (SEF-PALM). The detection of fluorescence from individual single molecules can be used to image the point-spread-function and spatial distribution of the fluorescence emitted in the vicinity of a metal surface. Due to the strong scattering effect, the angular distribution of the fluorescence is altered by metals, resulting in a spatial shift of fluorescence spots with respect to the metal nanostructures, and has to be taken into account in the analysis.