We demonstrate a handheld on-chip biosensing technology that employs plasmonic microarrays coupled with a lens-free computational imaging system towards multiplexed and high-throughput screening of biomolecular intera...We demonstrate a handheld on-chip biosensing technology that employs plasmonic microarrays coupled with a lens-free computational imaging system towards multiplexed and high-throughput screening of biomolecular interactions for point-of-care applications and resource-limited settings.This lightweight and field-portable biosensing device,weighing 60 g and 7.5 cm tall,utilizes a compact optoelectronic sensor array to record the diffraction patterns of plasmonic nanostructures under uniform illumination by a single-light emitting diode tuned to the plasmonic mode of the nanoapertures.Employing a sensitive plasmonic array design that is combined with lens-free computational imaging,we demonstrate label-free and quantitative detection of biomolecules with a protein layer thickness down to 3 nm.Integrating large-scale plasmonic microarrays,our on-chip imaging platform enables simultaneous detection of protein mono-and bilayers on the same platform over a wide range of biomolecule concentrations.In this handheld device,we also employ an iterative phase retrieval-based image reconstruction method,which offers the ability to digitally image a highly multiplexed array of sensors on the same plasmonic chip,making this approach especially suitable for high-throughput diagnostic applications in field settings.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
Graphene is emerging as a promising material for photonic applications owing to its unique optoelectronic properties.Graphene supports tunable,long-lived and extremely confined plasmons that have great potential for a...Graphene is emerging as a promising material for photonic applications owing to its unique optoelectronic properties.Graphene supports tunable,long-lived and extremely confined plasmons that have great potential for applications such as biosensing and optical communications.However,in order to excite plasmonic resonances in graphene,this material requires a high doping level,which is challenging to achieve without degrading carrier mobility and stability.Here,we demonstrate that the infrared plasmonic response of a graphene multilayer stack is analogous to that of a highly doped single layer of graphene,preserving mobility and supporting plasmonic resonances with higher oscillator strength than previously explored single-layer devices.Particularly,we find that the optically equivalent carrier density in multilayer graphene is larger than the sum of those in the individual layers.Furthermore,electrostatic biasing in multilayer graphene is enhanced with respect to single layer due to the redistribution of carriers over different layers,thus extending the spectral tuning range of the plasmonic structure.The superior effective doping and improved tunability of multilayer graphene stacks should enable a plethora of future infrared plasmonic devices with high optical performance and wide tunability.展开更多
Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associ...Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes.However,the phase response of the plasmonic resonances have rarely been exploited,mainly because this requires a more sophisticated optical arrangement.Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics.It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration.This unique combination allows the detection of atomically thin(angstrom-level)topographical features over large areas,enabling simultaneous reading of thousands of microarray elements.As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components,the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes.Our research opens new horizons for on-site disease diagnostics and remote health monitoring.展开更多
基金Altug Research Group acknowledges National Science Foundation(NSF)CAREER Award,Presidential Early Career Award for Scientist and Engineers(PECASE)ECCS-0954790Office of Naval Research Young Investigator Award 11PR00755-00-P00001+1 种基金NSF Engineering Research Center on Smart Lighting EEC-0812056Massachusetts Life Sciences Center Young Investigator award and Ecole Polytechnique Federale de Lausanne.Ozcan Research Group acknowledges the support of PECASE,Army Research Office(ARO)Life Sciences Division,ARO Young Investigator Award,NSF CAREER Award,ONR Young Investigator Award and the National Institute of Health(NIH)Director’s New Innovator Award DP2OD006427 from the Office of The Director,NIH and the NSF EFRI Award.
文摘We demonstrate a handheld on-chip biosensing technology that employs plasmonic microarrays coupled with a lens-free computational imaging system towards multiplexed and high-throughput screening of biomolecular interactions for point-of-care applications and resource-limited settings.This lightweight and field-portable biosensing device,weighing 60 g and 7.5 cm tall,utilizes a compact optoelectronic sensor array to record the diffraction patterns of plasmonic nanostructures under uniform illumination by a single-light emitting diode tuned to the plasmonic mode of the nanoapertures.Employing a sensitive plasmonic array design that is combined with lens-free computational imaging,we demonstrate label-free and quantitative detection of biomolecules with a protein layer thickness down to 3 nm.Integrating large-scale plasmonic microarrays,our on-chip imaging platform enables simultaneous detection of protein mono-and bilayers on the same platform over a wide range of biomolecule concentrations.In this handheld device,we also employ an iterative phase retrieval-based image reconstruction method,which offers the ability to digitally image a highly multiplexed array of sensors on the same plasmonic chip,making this approach especially suitable for high-throughput diagnostic applications in field settings.
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.
基金the European Union Seventh Framework Programme under grant agreements no.625673 GRYPHON,no.604391European Union H2020 Programme under grant agreement no.696656 Graphene Flagship+2 种基金financial support from the Swiss National Science Foundation through project no.133583,NATO’s Public Diplomacy Division in the framework of‘Science for Peace’,European Union’s Horizon 2020 research and innovation program under grant agreement no.644956,FundacióPrivada Cellex,AGAUR 2014 SGR 1400 and 1623the Spanish Ministry of Economy and Competitiveness(grants SEV-2015-0522 and MAT2014-59096-P)the‘Fondo Europeo de Desarrollo Regional’(FEDER)through grant TEC2013-46168-R。
文摘Graphene is emerging as a promising material for photonic applications owing to its unique optoelectronic properties.Graphene supports tunable,long-lived and extremely confined plasmons that have great potential for applications such as biosensing and optical communications.However,in order to excite plasmonic resonances in graphene,this material requires a high doping level,which is challenging to achieve without degrading carrier mobility and stability.Here,we demonstrate that the infrared plasmonic response of a graphene multilayer stack is analogous to that of a highly doped single layer of graphene,preserving mobility and supporting plasmonic resonances with higher oscillator strength than previously explored single-layer devices.Particularly,we find that the optically equivalent carrier density in multilayer graphene is larger than the sum of those in the individual layers.Furthermore,electrostatic biasing in multilayer graphene is enhanced with respect to single layer due to the redistribution of carriers over different layers,thus extending the spectral tuning range of the plasmonic structure.The superior effective doping and improved tunability of multilayer graphene stacks should enable a plethora of future infrared plasmonic devices with high optical performance and wide tunability.
基金funded by the European Union’s Horizon 2020 research and innovation program under Grant Agreement No.644956(RAIS project)the North Atlantic Treaty Organization’s Public Diplomacy Division in the framework of‘Science for Peace’(NATO—SPS),École Polytechnique Fédérale de Lausanne research fund,FundacióPrivada Cellex+4 种基金the CERCA Programme/Generalitat de Catalunyasupport from the International PhD fellowship program‘la Caixa’—Severo Ochoa@ICFOsupport from the International PhD fellowship program'la Caixa'-Severo Ochoa@ICFOsupport from the Spanish Ministry of Economy and Competitiveness,through the‘Severo Ochoa’Programme for Centres of Excellence in R&D(SEV-2015-0522)project OPTO-SCREEN(TEC2016-75080-R).
文摘Nanophotonics,and more specifically plasmonics,provides a rich toolbox for biomolecular sensing,since the engineered metasurfaces can enhance light–matter interactions to unprecedented levels.So far,biosensing associated with high-quality factor plasmonic resonances has almost exclusively relied on detection of spectral shifts and their associated intensity changes.However,the phase response of the plasmonic resonances have rarely been exploited,mainly because this requires a more sophisticated optical arrangement.Here we present a new phase-sensitive platform for high-throughput and label-free biosensing enhanced by plasmonics.It employs specifically designed Au nanohole arrays and a large field-of-view interferometric lens-free imaging reader operating in a collinear optical path configuration.This unique combination allows the detection of atomically thin(angstrom-level)topographical features over large areas,enabling simultaneous reading of thousands of microarray elements.As the plasmonic chips are fabricated using scalable techniques and the imaging reader is built with low-cost off-the-shelf consumer electronic and optical components,the proposed platform is ideal for point-of-care ultrasensitive biomarker detection from small sample volumes.Our research opens new horizons for on-site disease diagnostics and remote health monitoring.
