Sol-Gel TiO Thin Film on Au Nanoparticles for Heterogeneous Plasmonic Photocatalysis.

A new, simple method for preparing substrates for photocatalytic applications under visible light is presented. It is based on the preparation of a dense array of gold nanoparticles (AuNPs) by thermal dewetting of a thin gold film followed by spin-coating of a thin TiO film prepared by sol-gel chemistry. The photocatalytic properties of these nanocomposite films are studied by surface-enhanced Raman spectroscopy (SERS) following the N-demethylation reaction of methylene blue as a model reaction.

Synthesis and Integration of Hybrid Metal Nanoparticles Covered with a Molecularly Imprinted Polymer Nanolayer by Photopolymerization.

Interfacing recognition materials with transducers has consistently presented a challenge in the development of sensitive and specific chemical sensors. In this context, a method based on near-field photopolymerization is proposed to functionalize gold nanoparticles, which are prepared by a very simple process. This method allows in situ preparation of a molecularly imprinted polymer for sensing by surface-enhanced Raman scattering (SERS).

Life at high temperature observed in vitro upon laser heating of gold nanoparticles.

Thermophiles are microorganisms that thrive at high temperature. Studying them can provide valuable information on how life has adapted to extreme conditions. However, high temperature conditions are difficult to achieve on conventional optical microscopes.

Are bacteria claustrophobic? The problem of micrometric spatial confinement for the culturing of micro-organisms.

Culturing cells confined in microscale geometries has been reported in many studies this last decade, in particular following the development of microfluidic-based applications and lab-on-a-chip devices. Such studies usually examine growth of In this article, we show that may be a poor model and that spatial confinement can severely prevent the growth of many micro-organisms. By studying different bacteria and confinement geometries, we determine that the growth inhibition observed for some bacteria results from fast dioxygen depletion, inherent to spatial confinement, and not to any depletion of nutriments.

Interfacial charges drive the organization of supported lipid membranes and their interaction with nanoparticles.

In this work, we investigated the interaction of cationic gold nanoparticles (AuNPs) with an anionic solid-supported lipid bilayer (SSLB) prepared via the spontaneous fusion of vesicles of phosphatidylserine (DPPS) and phosphatidylcholine (DPPC) on SiO. We combined sum frequency generation (SFG) spectroscopy at the SSLBs interfaces with electrophoretic light scattering at the vesicles/liquid interfaces, and we provided further insight into the formation of organized DPPS-DPPC films on SiO and their interaction with NPs. We found that there is a critical threshold of the relative vesicles/substrate interfacial zeta potentials, beyond which the conformational organization of SSLBs failed.

From plasmon-induced luminescence enhancement in gold nanorods to plasmon-induced luminescence turn-off: a way to control reshaping.

Two-photon luminescence (TPL) turn-off in small single gold nanorods (GNRs) exposed to increased resonant femtosecond laser excitation (800 nm wavelength, pulse energy density varying from 125 μJ cm to 2.5 mJ cm) is investigated. The origin is shown to be a photo-induced decrease of the rod aspect ratio.