Fast optoelectric printing of plasmonic nanoparticles into tailored circuits

Plasmonic nanoparticles are able to control light at nanometre-scale by coupling electromagnetic fields to the oscillations of free electrons in metals. Deposition of such nanoparticles onto substrates with tailored patterns is essential, for example, in fabricating plasmonic structures for enhanced sensing. This work presents an innovative micro-patterning technique, based on optoelectic printing, for fast and straightforward fabrication of curve-shaped circuits of plasmonic nanoparticles deposited onto a transparent electrode often used in optoelectronics, liquid crystal displays, touch screens, etc. We experimentally demonstrate that this kind of plasmonic structure, printed by using silver nanoparticles of 40 nm, works as a plasmonic enhanced optical device allowing for polarized-color-tunable light scattering in the visible. These findings have potential applications in biosensing and fabrication of future optoelectronic devices combining the benefits of plasmonic sensing and the functionality of transparent electrodes

Ultrathin Gold Nanowire-Functionalized Carbon Nanotubes for Hybrid Molecular Sensing

Carbon nanotubes (CNTs) have shown great potential as sensing component in the electrochemical, field effect transistor and optical sensors, because of their extraordinary onedimensional electronic structure, thermal conductivity, tunable and stable near-infrared emission. However, the insolubility of CNTs due to strong van der Waals interactions limits their use in the field of nanotechnology. In this study, we demonstrate that non-covalent ultrathin gold nanowires functionalized multi-walled carbon nanotube (GNW-CNT) hybrid sensing agents show highly efficient and selective immune molecular sensing in electrochemical and near-infrared photoacoustic imaging methods. A detection limit of 0.01 ng/mL for the Alpha-Fetoprotein (AFP) antigen with high selectivity is shown. The extraordinary optical absorption, thermal and electric conductivity of hybrid GNW-CNTs presented in this study could be an effective tactic to integrate imaging, sensing and treatment functionalities

Characterization of Oxygen-Enriched Layers of TA6V, Titanium, and Zirconium by Scanning Microwave Microscopy

International audienceA technique based on scanning microwave microscopy (SMM) has recently been developed to analyze solid solutions of light elements. This technique consists in local measurements of effects produced by electrical conductivity variations produced by light elements solutions in metals. The penetration of the microwaves into the metals depends on their frequency and the material parameters. Information regarding the local conductivity of the material at different depths can be recorded using various frequencies. In this paper, SMM measurements of the oxygen-enriched zone are presented for several materials: TA6V, pure Ti, and pure Zr. Comparisons with concentration measurements made by nuclear reaction analysis allow one to affirm that for all the materials investigated here the phase shift measured by SMM is proportional to the oxygen concentration dissolved into the metal. Calibration functions are proposed for each material and frequency used. After calibration, the SMM can be used to measure local enrichments