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 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.
