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Naomi J Halas - One of the best experts on this subject based on the ideXlab platform.

  • Nanogapped Au Antennas for Ultrasensitive Surface-Enhanced Infrared Absorption Spectroscopy
    Nano Letters, 2017
    Co-Authors: Liangliang Dong, Benjamin Cerjan, Ming Lun Tseng, Alessandro Alabastri, Linan Zhou, Peter Nordlander, Yu Zhang, Chao Zhang, Xiao Yang, Naomi J Halas
    Abstract:

    Surface-enhanced Infrared Absorption (SEIRA) spectroscopy has outstanding potential in chemical detection as a complement to surface-enhanced Raman spectroscopy (SERS), yet it has historically lagged well behind SERS in detection sensitivity. Here we report a new ultrasensitive Infrared antenna designed to bring SEIRA spectroscopy into the few-molecule detection range. Our antenna consists of a bowtie-shaped Au structure with a sub-3 nm gap, positioned to create a cavity above a reflective substrate. This three-dimensional geometry tightly confines incident mid-Infrared radiation into its ultrasmall junction, yielding a hot spot with a theoretical SEIRA enhancement factor of more than 107, which can be designed to span the range of frequencies useful for SEIRA. We quantitatively evaluated the IR detection limit of this antenna design using mixed monolayers of 4-nitrothiophenol (4-NTP) and 4-methoxythiolphenol (4-MTP). The optimized antenna structure allows the detection of as few as ∼500 molecules of 4-NT...

  • fan shaped gold nanoantennas above reflective substrates for surface enhanced Infrared Absorption seira
    Nano Letters, 2015
    Co-Authors: Lisa V Brown, Peter Nordlander, Xiao Yang, Ke Zhao, Bob Zheng, Naomi J Halas
    Abstract:

    Here, we report a new nanoantenna for surface-enhanced Infrared Absorption (SEIRA) detection, consisting of a fan-shaped Au structure positioned at a well-specified distance above a reflective plane with an intervening silica spacer layer. We examine how to optimize both the antenna dimensions and the spacer layer for optimal SEIRA enhancement of the C–H stretching mode. This tunable 3D geometry yields a theoretical SEIRA enhancement factor of 105, corresponding to the experimental detection of 20–200 zeptomoles of octadecanethiol, using a standard commercial FTIR spectrometer. Experimental studies illustrate the sensitivity of the observed SEIRA signal to the gap dimensions. The optimized antenna structure exhibits an order of magnitude greater SEIRA sensitivity than previous record-setting designs.

  • surface enhanced Infrared Absorption using individual cross antennas tailored to chemical moieties
    Journal of the American Chemical Society, 2013
    Co-Authors: Lisa V Brown, Peter Nordlander, Ke Zhao, Nicholas S King, Heidar Sobhani, Naomi J Halas
    Abstract:

    The development of antenna structures for surface-enhanced Infrared Absorption spectroscopy (SEIRA) is a topic of intense and growing interest for extending IR spectroscopy to zeptomolar quantities and ultimately to the single-molecule level. Here we show that strong Infrared spectroscopic enhancements can be obtained from individual gold nanoantennas using conventional IR spectrometric sources. The antenna structure dimensions can be tuned to enhance the IR modes of specific chemical moieties. Simulations of the electric field intensity in the antenna junction region reveal a maximum SEIRA enhancement factor of more than 12 000. These findings open new opportunities for analyzing IR vibrations of exceptionally small quantities of molecules using widely accessible light sources.

  • surface enhanced Infrared Absorption seira spectroscopy on nanoshell aggregate substrates
    Chemical Physics Letters, 2008
    Co-Authors: Janardan Kundu, Fei Le, Peter Nordlander, Naomi J Halas
    Abstract:

    Abstract Aggregates of Au nanoshells on silicon substrates with plasmon resonances tuned to the Infrared region of the spectrum provide a remarkably high-quality substrate for surface enhanced Infrared Absorption (SEIRA) spectroscopy. SEIRA spectra spanning the chemical fingerprint region of 700–3300 cm −1 with strong enhancement across this entire spectral range are obtained. SEIRA enhancement factors obtained for para- mercaptoaniline on these substrates are evaluated to be in the 10 4 range, based on a statistical evaluation of aggregate geometries combined with finite difference time domain modeling of the Infrared ‘hot spots’ characteristic of the constituent structures.

Frédéric Verger - One of the best experts on this subject based on the ideXlab platform.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    Optical Materials Express, 2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Emeline Baudet, Radwan Chahal, Emmanuel Rinnert, Kada Boukerma, Isabelle Péron
    Abstract:

    The primary objective of this study is the development of transparent thin film materials in the IR enabling strong Infrared Absorption of organic compounds in the vicinity of metal nanoparticles by the surface plasmon effect. For developing these optical micro-sensors, hetero-structures combining gold nanoparticles and chalcogenide planar waveguides are fabricated and adequately characterized. Single As2S3 and Ge25Sb10Se65 amorphous chalcogenide thin films are prepared by radio-frequency magnetron sputtering. For the fabrication of gold nanoparticles on a chalcogenide planar waveguide, direct current sputtering is employed. Fabricated single layers or hetero-structures are characterized using various techniques to investigate the influence of deposition parameters. The nanoparticles of gold are functionalized by a self-assembled monolayer of 4-nitrothiophenol. Finally, the surface enhanced Infrared Absorption spectra of 4-nitrothiophenol self-assembled on fabricated Au/Ge-Sb-Se thin films hetero-structures are measured and analyzed. This optical component presents a ~24 enhancement factor for the detection of NO2 symmetric stretching vibration band of 4-nitrothiophenol at 1336 cm−1.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Radwan Chahal, Emmanuel Rinnert, Isabelle Péron, Bruno Bureau, Stéphanie Députier
    Abstract:

    In this work, the fabrication of amorphous chalcogenide thin films (As2S3 and Ge25Sb10Se65) by radio-frequency sputtering was studied. The morphology, chemical composition, optical properties and structure of fabricated layers as well as bonding arrangement at the surface of the films were investigated by scanning electron microscope with an energy-dispersive X ray analyzer, atomic force microscopy, transmittance measurements, variable angle spectroscopic ellipsometry, prism coupling technique, X-ray reflectometry, profilometry, conductivity measurements, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. As2S3 thin films show some crystals formation on the surface indicating the ageing (oxidation) of the films. Ge25Sb10Se65 layers are more stable against oxidation and the morphology of the layers seems to be influenced by the sputtering pressure. Moreover, gold nanoparticles were deposited onto Ge25Sb10Se65 thin films by direct-current sputtering to assess surface enhanced Infrared Absorption spectroscopy of prepared structures. The morphology and thickness of gold films were also investigated. The Infrared transmission spectra of a self-assembled monolayer of 4-nitrothiophenol deposited on gold are enhanced according to surface selection rules

  • Surface enhanced Infrared Absorption (SEIRA) spectroscopy using gold nanoparticles on As2S3 glass
    Sensors and Actuators B: Chemical, 2012
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Emmanuel Rinnert, Thierry Pain, Catherine Boussard-plédel, Bruno Bureau, K. Boukerma, C. Compère, Maryline Guilloux-viry
    Abstract:

    The development of Infrared sensing platform requires adapted materials. In this work, we used sputtered gold nanoparticles on a chalcogenide glass to demonstrate that these Infrared materials can be used as substrate for surface enhanced Infrared Absorption (SEIRA) spectroscopy. The sputtering parameters were optimized to get the highest possible enhancement. To assess it, a self-assembled monolayer of 4-nitrothiophenol was used. These preliminary results are promising and pave the way for various configurations of waveguide for integrated optical components.

Isabelle Péron - One of the best experts on this subject based on the ideXlab platform.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    Optical Materials Express, 2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Emeline Baudet, Radwan Chahal, Emmanuel Rinnert, Kada Boukerma, Isabelle Péron
    Abstract:

    The primary objective of this study is the development of transparent thin film materials in the IR enabling strong Infrared Absorption of organic compounds in the vicinity of metal nanoparticles by the surface plasmon effect. For developing these optical micro-sensors, hetero-structures combining gold nanoparticles and chalcogenide planar waveguides are fabricated and adequately characterized. Single As2S3 and Ge25Sb10Se65 amorphous chalcogenide thin films are prepared by radio-frequency magnetron sputtering. For the fabrication of gold nanoparticles on a chalcogenide planar waveguide, direct current sputtering is employed. Fabricated single layers or hetero-structures are characterized using various techniques to investigate the influence of deposition parameters. The nanoparticles of gold are functionalized by a self-assembled monolayer of 4-nitrothiophenol. Finally, the surface enhanced Infrared Absorption spectra of 4-nitrothiophenol self-assembled on fabricated Au/Ge-Sb-Se thin films hetero-structures are measured and analyzed. This optical component presents a ~24 enhancement factor for the detection of NO2 symmetric stretching vibration band of 4-nitrothiophenol at 1336 cm−1.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Radwan Chahal, Emmanuel Rinnert, Isabelle Péron, Bruno Bureau, Stéphanie Députier
    Abstract:

    In this work, the fabrication of amorphous chalcogenide thin films (As2S3 and Ge25Sb10Se65) by radio-frequency sputtering was studied. The morphology, chemical composition, optical properties and structure of fabricated layers as well as bonding arrangement at the surface of the films were investigated by scanning electron microscope with an energy-dispersive X ray analyzer, atomic force microscopy, transmittance measurements, variable angle spectroscopic ellipsometry, prism coupling technique, X-ray reflectometry, profilometry, conductivity measurements, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. As2S3 thin films show some crystals formation on the surface indicating the ageing (oxidation) of the films. Ge25Sb10Se65 layers are more stable against oxidation and the morphology of the layers seems to be influenced by the sputtering pressure. Moreover, gold nanoparticles were deposited onto Ge25Sb10Se65 thin films by direct-current sputtering to assess surface enhanced Infrared Absorption spectroscopy of prepared structures. The morphology and thickness of gold films were also investigated. The Infrared transmission spectra of a self-assembled monolayer of 4-nitrothiophenol deposited on gold are enhanced according to surface selection rules

Virginie Nazabal - One of the best experts on this subject based on the ideXlab platform.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    Optical Materials Express, 2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Emeline Baudet, Radwan Chahal, Emmanuel Rinnert, Kada Boukerma, Isabelle Péron
    Abstract:

    The primary objective of this study is the development of transparent thin film materials in the IR enabling strong Infrared Absorption of organic compounds in the vicinity of metal nanoparticles by the surface plasmon effect. For developing these optical micro-sensors, hetero-structures combining gold nanoparticles and chalcogenide planar waveguides are fabricated and adequately characterized. Single As2S3 and Ge25Sb10Se65 amorphous chalcogenide thin films are prepared by radio-frequency magnetron sputtering. For the fabrication of gold nanoparticles on a chalcogenide planar waveguide, direct current sputtering is employed. Fabricated single layers or hetero-structures are characterized using various techniques to investigate the influence of deposition parameters. The nanoparticles of gold are functionalized by a self-assembled monolayer of 4-nitrothiophenol. Finally, the surface enhanced Infrared Absorption spectra of 4-nitrothiophenol self-assembled on fabricated Au/Ge-Sb-Se thin films hetero-structures are measured and analyzed. This optical component presents a ~24 enhancement factor for the detection of NO2 symmetric stretching vibration band of 4-nitrothiophenol at 1336 cm−1.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Radwan Chahal, Emmanuel Rinnert, Isabelle Péron, Bruno Bureau, Stéphanie Députier
    Abstract:

    In this work, the fabrication of amorphous chalcogenide thin films (As2S3 and Ge25Sb10Se65) by radio-frequency sputtering was studied. The morphology, chemical composition, optical properties and structure of fabricated layers as well as bonding arrangement at the surface of the films were investigated by scanning electron microscope with an energy-dispersive X ray analyzer, atomic force microscopy, transmittance measurements, variable angle spectroscopic ellipsometry, prism coupling technique, X-ray reflectometry, profilometry, conductivity measurements, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. As2S3 thin films show some crystals formation on the surface indicating the ageing (oxidation) of the films. Ge25Sb10Se65 layers are more stable against oxidation and the morphology of the layers seems to be influenced by the sputtering pressure. Moreover, gold nanoparticles were deposited onto Ge25Sb10Se65 thin films by direct-current sputtering to assess surface enhanced Infrared Absorption spectroscopy of prepared structures. The morphology and thickness of gold films were also investigated. The Infrared transmission spectra of a self-assembled monolayer of 4-nitrothiophenol deposited on gold are enhanced according to surface selection rules

  • Surface enhanced Infrared Absorption (SEIRA) spectroscopy using gold nanoparticles on As2S3 glass
    Sensors and Actuators B: Chemical, 2012
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Emmanuel Rinnert, Thierry Pain, Catherine Boussard-plédel, Bruno Bureau, K. Boukerma, C. Compère, Maryline Guilloux-viry
    Abstract:

    The development of Infrared sensing platform requires adapted materials. In this work, we used sputtered gold nanoparticles on a chalcogenide glass to demonstrate that these Infrared materials can be used as substrate for surface enhanced Infrared Absorption (SEIRA) spectroscopy. The sputtering parameters were optimized to get the highest possible enhancement. To assess it, a self-assembled monolayer of 4-nitrothiophenol was used. These preliminary results are promising and pave the way for various configurations of waveguide for integrated optical components.

Emmanuel Rinnert - One of the best experts on this subject based on the ideXlab platform.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    Optical Materials Express, 2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Emeline Baudet, Radwan Chahal, Emmanuel Rinnert, Kada Boukerma, Isabelle Péron
    Abstract:

    The primary objective of this study is the development of transparent thin film materials in the IR enabling strong Infrared Absorption of organic compounds in the vicinity of metal nanoparticles by the surface plasmon effect. For developing these optical micro-sensors, hetero-structures combining gold nanoparticles and chalcogenide planar waveguides are fabricated and adequately characterized. Single As2S3 and Ge25Sb10Se65 amorphous chalcogenide thin films are prepared by radio-frequency magnetron sputtering. For the fabrication of gold nanoparticles on a chalcogenide planar waveguide, direct current sputtering is employed. Fabricated single layers or hetero-structures are characterized using various techniques to investigate the influence of deposition parameters. The nanoparticles of gold are functionalized by a self-assembled monolayer of 4-nitrothiophenol. Finally, the surface enhanced Infrared Absorption spectra of 4-nitrothiophenol self-assembled on fabricated Au/Ge-Sb-Se thin films hetero-structures are measured and analyzed. This optical component presents a ~24 enhancement factor for the detection of NO2 symmetric stretching vibration band of 4-nitrothiophenol at 1336 cm−1.

  • RF sputtered amorphous chalcogenide thin films for surface enhanced Infrared Absorption spectroscopy
    2013
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Petr Nemec, Christophe Cardinaud, Radwan Chahal, Emmanuel Rinnert, Isabelle Péron, Bruno Bureau, Stéphanie Députier
    Abstract:

    In this work, the fabrication of amorphous chalcogenide thin films (As2S3 and Ge25Sb10Se65) by radio-frequency sputtering was studied. The morphology, chemical composition, optical properties and structure of fabricated layers as well as bonding arrangement at the surface of the films were investigated by scanning electron microscope with an energy-dispersive X ray analyzer, atomic force microscopy, transmittance measurements, variable angle spectroscopic ellipsometry, prism coupling technique, X-ray reflectometry, profilometry, conductivity measurements, Raman scattering spectroscopy and X-ray photoelectron spectroscopy. As2S3 thin films show some crystals formation on the surface indicating the ageing (oxidation) of the films. Ge25Sb10Se65 layers are more stable against oxidation and the morphology of the layers seems to be influenced by the sputtering pressure. Moreover, gold nanoparticles were deposited onto Ge25Sb10Se65 thin films by direct-current sputtering to assess surface enhanced Infrared Absorption spectroscopy of prepared structures. The morphology and thickness of gold films were also investigated. The Infrared transmission spectra of a self-assembled monolayer of 4-nitrothiophenol deposited on gold are enhanced according to surface selection rules

  • Surface enhanced Infrared Absorption (SEIRA) spectroscopy using gold nanoparticles on As2S3 glass
    Sensors and Actuators B: Chemical, 2012
    Co-Authors: Frédéric Verger, Virginie Nazabal, Florent Colas, Emmanuel Rinnert, Thierry Pain, Catherine Boussard-plédel, Bruno Bureau, K. Boukerma, C. Compère, Maryline Guilloux-viry
    Abstract:

    The development of Infrared sensing platform requires adapted materials. In this work, we used sputtered gold nanoparticles on a chalcogenide glass to demonstrate that these Infrared materials can be used as substrate for surface enhanced Infrared Absorption (SEIRA) spectroscopy. The sputtering parameters were optimized to get the highest possible enhancement. To assess it, a self-assembled monolayer of 4-nitrothiophenol was used. These preliminary results are promising and pave the way for various configurations of waveguide for integrated optical components.