A current-driven source of long-range surface plasmons(LRSPs)on a duplex metal nanolayer is reported.Electrical excitation of LRSPs was experimentally observed in a planar structure,where an organic light-emitting fil...A current-driven source of long-range surface plasmons(LRSPs)on a duplex metal nanolayer is reported.Electrical excitation of LRSPs was experimentally observed in a planar structure,where an organic light-emitting film was sandwiched between two metal nanolayers that served as electrodes.To achieve the LRSP propagation in these metal nanolayers at the interface with air,the light-emitting structure was bordered by a one-dimensional photonic crystal(PC)on the other side.The dispersion of the light emitted by such a hybrid PC/organic-light-emitting-diode structure(PC/OLED)comprising two thin metal electrodes was obtained,with a clearly identified LRSP resonance peak.展开更多
A reflecting diffraction grating has been etched onto the backside of a standard cantilever for atomic force microscopy, and the diffracted light has been used to monitor the angular position of the cantilever. It is ...A reflecting diffraction grating has been etched onto the backside of a standard cantilever for atomic force microscopy, and the diffracted light has been used to monitor the angular position of the cantilever. It is shown experimentally that for small angles of incidence and for large reflection angles, the force sensitivity can be improved by few times when an appropriate detection scheme based on the position sensitive (duolateral) detector is used. The first demonstration was performed with a one micron period amplitude diffraction grating onto the backside of an Al-coated cantilever etched by a focused ion beam milling for the experiments in air and an analogous 600 nm-period grating for the experiments in air and in water.展开更多
Plasmonic nanoantennas offer new applications in mid-infrared(mid-IR)absorption spectroscopy with ultrasensitive detection of structural signatures of biomolecules,such as proteins,due to their strong resonant near-fi...Plasmonic nanoantennas offer new applications in mid-infrared(mid-IR)absorption spectroscopy with ultrasensitive detection of structural signatures of biomolecules,such as proteins,due to their strong resonant near-fields.The amide I fingerprint of a protein contains conformational information that is greatly important for understanding its function in health and disease.Here,we introduce a non-invasive,label-free mid-IR nanoantenna-array sensor for secondary structure identification of nanometer-thin protein layers in aqueous solution by resolving the content of plasmonically enhanced amide I signatures.We successfully detect random coil to crossβ-sheet conformational changes associated withα-synuclein protein aggregation,a detrimental process in many neurodegenerative disorders.Notably,our experimental results demonstrate high conformational sensitivity by differentiating subtle secondary-structural variations in a nativeβ-sheet protein monolayer from those of crossβ-sheets,which are characteristic of pathological aggregates.Our nanoplasmonic biosensor is a highly promising and versatile tool for in vitro structural analysis of thin protein layers.展开更多
基金supported by the Swiss National Science Foundation (Grant 200021_162767)
文摘A current-driven source of long-range surface plasmons(LRSPs)on a duplex metal nanolayer is reported.Electrical excitation of LRSPs was experimentally observed in a planar structure,where an organic light-emitting film was sandwiched between two metal nanolayers that served as electrodes.To achieve the LRSP propagation in these metal nanolayers at the interface with air,the light-emitting structure was bordered by a one-dimensional photonic crystal(PC)on the other side.The dispersion of the light emitted by such a hybrid PC/organic-light-emitting-diode structure(PC/OLED)comprising two thin metal electrodes was obtained,with a clearly identified LRSP resonance peak.
文摘A reflecting diffraction grating has been etched onto the backside of a standard cantilever for atomic force microscopy, and the diffracted light has been used to monitor the angular position of the cantilever. It is shown experimentally that for small angles of incidence and for large reflection angles, the force sensitivity can be improved by few times when an appropriate detection scheme based on the position sensitive (duolateral) detector is used. The first demonstration was performed with a one micron period amplitude diffraction grating onto the backside of an Al-coated cantilever etched by a focused ion beam milling for the experiments in air and an analogous 600 nm-period grating for the experiments in air and in water.
基金supported by the European Research Council(ERC)under the European Union’s Horizon 2020 research and innovation programme(Grant No.682167)European Commission Horizon 2020(grant no.FETOPEN-737071)Swiss National Foundation for Science(Grant No.152958,SNF31003A_146680,P2ELP2_162116 and P300P2_171219).
文摘Plasmonic nanoantennas offer new applications in mid-infrared(mid-IR)absorption spectroscopy with ultrasensitive detection of structural signatures of biomolecules,such as proteins,due to their strong resonant near-fields.The amide I fingerprint of a protein contains conformational information that is greatly important for understanding its function in health and disease.Here,we introduce a non-invasive,label-free mid-IR nanoantenna-array sensor for secondary structure identification of nanometer-thin protein layers in aqueous solution by resolving the content of plasmonically enhanced amide I signatures.We successfully detect random coil to crossβ-sheet conformational changes associated withα-synuclein protein aggregation,a detrimental process in many neurodegenerative disorders.Notably,our experimental results demonstrate high conformational sensitivity by differentiating subtle secondary-structural variations in a nativeβ-sheet protein monolayer from those of crossβ-sheets,which are characteristic of pathological aggregates.Our nanoplasmonic biosensor is a highly promising and versatile tool for in vitro structural analysis of thin protein layers.