No abstract

The growing demand for new global resources of clean and sustainable energy emerges as the greatest challenge in today's society. For numerous applications such as hybrid vehicles, electrochemical storage systems simultaneously require high energy and high power. For this reason, intensive researches focus on proposing alternative devices to conventional Li battery and supercapacitors. Here, we report a proof of concept based on non-covalent redox functionalization of composite electrodes that may occur either during the calendar life or during the device functioning. The active material, a multi-redox pyrene derivative, is initially contained in the electrolyte. No additional benchmarking step is therefore required, and it can, in principle, be readily applied to any type of composite electrode (supercapacitors, battery, semi-solid flow cell etc.). Accordingly, a practical carbon fiber electrode that is 10 mg cm À2 loaded can deliver up to 130 kW kg electrode À1 and 130 Wh kg electrode À1 with negligible capacity loss over the first 60 000 charge/discharge cycles.

International audienceGenerally, the immobilization of two-dimensional nanoparticles in immersion procedures is time-consuming (over 24 h). In this paper, we report a very effective and simple method to fabricate two-dimensional gold nanoparticle patterns over large areas with high regularity for surface-enhanced Raman scattering (SERS). We achieved a highly sensitive SERS colloid surface by optimizing temperature and immersion time. The surfaces were characterized by X-ray photoelectron spectroscopy, UV-Vis, atomic force microscopy, and scanning electron microscopy. The SERS activity of surfaces was compared by using two techniques: "dip" and "dip and dry" in an aqueous solution of 10(-6) M crystal violet. The influence of the morphology of the surface was investigated with both the dip and dip and dry techniques

Surface-enhanced Raman spectroscopy (SERS) has enormous potential for a range of applications where high sensitivity needs to be combined with good discrimination between molecular targets. However, the SERS technique has trouble finding its industrial development, as was the case with the surface plasmon resonance technology. The main reason is the difficulty to produce stable, reproducible, and highly efficient substrates for quantitative measurements. In this paper, we report a method to obtain two-dimensional regular nanopatterns of gold nanoparticles (AuNPs). The resulting patterns were evaluated by SERS. Our bottom-up strategy was divided into two steps: (a) nanopatterning of the substrate by e-beam lithography and (b) electrostatic adsorption of AuNPs on functionalized substrates. This approach enabled us to highlight the optimal conditions to obtain monolayer, rows, or ring of AuNPs, with homogeneous distribution and high density (800 AuNPs/μm 2 ). The nanostructure distributions on the substrates were displayed by scanning electron microscopy and atomic force microscopy images. Optical properties of our nanostructures were characterized by visible extinction spectra and by the measured enhancements of Raman scattering. Finally, we tried to demonstrate experimentally that, to observe a significant enhancement of SERS, the gold diffusers must be extremely closer. If electron beam lithography is a very attractive technique to perform reproducible SERS substrates, the realization of pattern needs a very high resolution, with distances between nanostructures probably of less than 20 nm.

Molecular recognition events driven by protein–carbohydrate interactions play fundamental roles in various physiological and pathological processes in living organisms, including cohesion inside tissues, innate immune response, cancer cell metastasis, and infections. Unlike widely investigated carbohydrates, detailed knowledge of both the spatial organization of specific lectins and their identification on cell surfaces remains an essential prerequisite for the understanding of pathogen adhesion to host tissues and subsequent infection prevention. In this study, the spatially resolved localization, identification, and quantification of multiple carbohydrate‐binding sites are directly revealed on the surface of fungal pathogen Aspergillus fumigatus. Nanoscale reconstructed mapping from several recognition maps, corresponding each to a unique specific interaction probed by single‐molecule force spectroscopy, shows the distribution of carbohydrate‐binding sites on the pathogen surface. The identified binding sites are then blocked with the appropriate carbohydrate, attesting the possibility to control lectin‐mediated host–pathogen interactions. Germination markedly affects both the spatial distribution of carbohydrate‐binding sites, mostly expressed at the apex of hyphae, and the identity of the predominant ones, which depend on the location on germ tubes. These insights clearly open exciting avenues in nanomedicine to control host–pathogen interactions with the development of vaccines or inhibitory drugs that preferentially target the identified carbohydrate‐binding sites.

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