Publications by authors named "J Sala Pedros"

A new method for radionuclide labeling by the use of graphene thin films was previously presented. In this work, a comparison among low energy radioactive sources supported on carbonaceous thin films on polyvinyl chloride-polyvinyl acetate copolymer (VYNS), based on the use of aqueous solutions is investigated as a feasible alternative to the traditional metallized films avoiding the downside of the loss of many broken films. Graphene-based materials were prepared by both oxidation-exfoliation-reduction and direct graphite exfoliation routes.

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Surface plasmon polaritons in graphene can enhance the performance of mid-infrared spectroscopy, which is key for the study of both the composition and the conformation of organic molecules via their vibrational resonances. In this paper, a plasmonic biosensor using a graphene-based van der Waals heterostructure on a piezoelectric substrate is theoretically demonstrated, where far-field light is coupled to surface plasmon-phonon polaritons (SPPPs) through a surface acoustic wave (SAW). The SAW creates an electrically-controlled virtual diffraction grating, suppressing the need for patterning the 2D materials, that limits the polariton lifetime, and enabling differential measurement schemes, which increase the signal-to-noise ratio and allow a quick commutation between reference and sample signals.

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The interaction of two types of fragmented graphene particles (30-160 nm) with human macrophages is studied. Since macrophages have significant phagocytic activity, the incorporation of graphene particles into cells has an effect on the response to functional polarization stimuli, favoring an anti-inflammatory profile. Incubation of macrophages with graphene foam particles, prepared by chemical vapor deposition, and commercially available graphene nanoplatelet particles does not affect cell viability when added at concentrations up to 100 µg mL ; macrophages exhibit differential quantitative responses to each type of graphene particles.

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The long-distance quantum transfer between electron-spin qubits in semiconductors is important for realising large-scale quantum computing circuits. Electron-spin to photon-polarisation conversion is a promising technology for achieving free-space or fibre-coupled quantum transfer. In this work, using only regular lithography techniques on a conventional 15 nm GaAs quantum well, we demonstrate acoustically-driven generation of single photons from single electrons, without the need for a self-assembled quantum dot.

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We experimentally demonstrate that the Raman-active optical phonon modes of single-layer graphene can be modulated by the dynamic local strain created by surface acoustic waves (SAWs). In particular, the dynamic strain field of the SAW is shown to induce a Raman scattering intensity variation as large as 15% and a phonon frequency shift of up to 10 cm for the G band, for instance, for an effective hydrostatic strain of 0.24% generated in single-layer graphene atop a LiNbO piezoelectric substrate with a SAW resonator operating at a frequency of ∼400 MHz.

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