1
|
Polley N, Sardar S, Werner P, Gersonde I, Kanehira Y, Bald I, Repp D, Pertsch T, Pacholski C. Photothermomechanical Nanopump: A Flow-Through Plasmonic Sensor at the Fiber Tip. ACS NANO 2022; 17:1403-1413. [PMID: 36414479 PMCID: PMC9878711 DOI: 10.1021/acsnano.2c09938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 11/11/2022] [Indexed: 06/16/2023]
Abstract
Optical fibers equipped with plasmonic flow sensors at their tips are fabricated and investigated as photothermomechanical nanopumps for the active transport of target analytes to the sensor surface. The nanopumps are prepared using a bottom-up strategy: i.e., by sequentially stacking a monolayer of a thermoresponsive polymer and a plasmonic nanohole array on an optical fiber tip. The temperature-dependent collapse and swelling of the polymer is used to create a flow-through pumping mechanism. The heat required for pumping is generated by exploiting the photothermal effect in the plasmonic nanohole array upon irradiation with laser light (405 nm). Simultaneous detection of analytes by the plasmonic sensor is achieved by monitoring changes in its optical response at longer wavelengths (∼500-800 nm). Active mass transport by pumping through the holes of the plasmonic nanohole array is visualized by particle imaging velocimetry. Finally, the performance of the photothermomechanical nanopumps is investigated for two types of analytes, namely nanoscale objects (gold nanoparticles) and molecules (11-mercaptoundecanoic acid). In the presence of the pumping mechanism, a 4-fold increase in sensitivity was observed compared to the purely photothermal effect, demonstrating the potential of the presented photothermomechanical nanopumps for sensing applications.
Collapse
Affiliation(s)
- Nabarun Polley
- University
of Potsdam, Institute of Chemistry,
Physical Chemistry−innoFSPEC, 14476 Potsdam, Germany
- University
of Potsdam, Institute of Chemistry, 14476 Potsdam, Germany
| | - Samim Sardar
- Center
for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, 20133 Milan, Italy
| | - Peter Werner
- University
of Potsdam, Institute of Chemistry,
Physical Chemistry−innoFSPEC, 14476 Potsdam, Germany
- University
of Potsdam, Institute of Chemistry, 14476 Potsdam, Germany
| | - Ingo Gersonde
- University
of Potsdam, Institute of Chemistry,
Physical Chemistry−innoFSPEC, 14476 Potsdam, Germany
| | - Yuya Kanehira
- University
of Potsdam, Institute of Chemistry, 14476 Potsdam, Germany
| | - Ilko Bald
- University
of Potsdam, Institute of Chemistry,
Physical Chemistry−innoFSPEC, 14476 Potsdam, Germany
- University
of Potsdam, Institute of Chemistry, 14476 Potsdam, Germany
| | - Daniel Repp
- Institute
of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, 07745 Jena, Germany
| | - Thomas Pertsch
- Institute
of Applied Physics, Abbe Center of Photonics, Friedrich Schiller University Jena, 07745 Jena, Germany
- Max
Planck School of Photonics, 07745 Jena, Germany
| | - Claudia Pacholski
- University
of Potsdam, Institute of Chemistry,
Physical Chemistry−innoFSPEC, 14476 Potsdam, Germany
- University
of Potsdam, Institute of Chemistry, 14476 Potsdam, Germany
| |
Collapse
|
2
|
Morales RTT, Ko J. Future of Digital Assays to Resolve Clinical Heterogeneity of Single Extracellular Vesicles. ACS NANO 2022; 16:11619-11645. [PMID: 35904433 PMCID: PMC10174080 DOI: 10.1021/acsnano.2c04337] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Extracellular vesicles (EVs) are complex lipid membrane vehicles with variable expressions of molecular cargo, composed of diverse subpopulations that participate in the intercellular signaling of biological responses in disease. EV-based liquid biopsies demonstrate invaluable clinical potential for overhauling current practices of disease management. Yet, EV heterogeneity is a major needle-in-a-haystack challenge to translate their use into clinical practice. In this review, existing digital assays will be discussed to analyze EVs at a single vesicle resolution, and future opportunities to optimize the throughput, multiplexing, and sensitivity of current digital EV assays will be highlighted. Furthermore, this review will outline the challenges and opportunities that impact the clinical translation of single EV technologies for disease diagnostics and treatment monitoring.
Collapse
Affiliation(s)
- Renee-Tyler T Morales
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Jina Ko
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| |
Collapse
|
3
|
Mekawey H, Ismail Y, Swillam M. Extraordinary optical transmission in silicon nanoholes. Sci Rep 2021; 11:21546. [PMID: 34732796 PMCID: PMC8566559 DOI: 10.1038/s41598-021-01068-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 10/22/2021] [Indexed: 11/20/2022] Open
Abstract
In this work, for the first time, a study was conducted of the existence of Extraordinary Optical Transmission (EOT) in Silicon (Si) thin films with subwavelength holes array and high excess carrier concentration. Typically EOT is studied in opaque perforated metal films. Using Si would bring EOT and its many applications to the silicon photonics realm and the mid-IR range. Since Si thin film is a semi-transparent film in mid-IR, a generalization was proposed of the normalized transmission metric used in literature for EOT studies in opaque films. The plasma dispersion effect was introduced into the studied perforated Si film through either doping or carriers' generation. Careful consideration for the differences in optical response modeling in both cases was given. Full-wave simulation and analysis showed an enhanced transmission when using Si with excess carriers, mimicking the enhancement reported in perforated metallic films. EOT was found in the mid-IR instead of the visible range which is the case in metallic films. The case of Si with generated excess carriers showed a mid-IR EOT peak reaching 157% around 6.68 µm, while the phosphorus-doped Si case showed a transmission enhancement of 152% around 8.6 µm. The effect of varying the holes' dimensions and generated carriers' concentration on the transmission was studied. The analogy of the relation between the fundamental mode cutoff and the EOT peak wavelength in the case of Si to the case of metal such as silver was studied and verified. The perforated Si thin film transmission sensitivity for a change in the refractive index of the holes and surroundings material was investigated. Also, a study of the device potential in sensing the hole and surroundings materials that have almost the same refractive index yet with different absorption fingerprints was performed as well.
Collapse
Affiliation(s)
- Hosam Mekawey
- School of Science and Engineering, Center of Nanoelectronics and Devices (CND), The American University in Cairo, New Cairo, Egypt.
| | - Yehea Ismail
- School of Science and Engineering, Center of Nanoelectronics and Devices (CND), The American University in Cairo, New Cairo, Egypt
| | - Mohamed Swillam
- Department of Physics, School of Science and Engineering, The American University in Cairo, New Cairo, 11835, Egypt
| |
Collapse
|
4
|
Bury AG, Vincent AE, Turnbull DM, Actis P, Hudson G. Mitochondrial isolation: when size matters. Wellcome Open Res 2021; 5:226. [PMID: 33718619 PMCID: PMC7931255 DOI: 10.12688/wellcomeopenres.16300.2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial vitality is critical to cellular function, with mitochondrial dysfunction linked to a growing number of human diseases. Tissue and cellular heterogeneity, in terms of genetics, dynamics and function means that increasingly mitochondrial research is conducted at the single cell level. Whilst there are several technologies that are currently available for single-cell analysis, each with their advantages, they cannot be easily adapted to study mitochondria with subcellular resolution. Here we review the current techniques and strategies for mitochondrial isolation, critically discussing each technology's limitations for future mitochondrial research. Finally, we highlight and discuss the recent breakthroughs in sub-cellular isolation techniques, with a particular focus on nanotechnologies that enable the isolation of mitochondria from subcellular compartments. This allows isolation of mitochondria with unprecedented spatial precision with minimal disruption to mitochondria and their immediate cellular environment.
Collapse
Affiliation(s)
- Alexander G Bury
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK.,Biosciences Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK.,Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Amy E Vincent
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK.,Translational and Clinical Research Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Doug M Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK.,Translational and Clinical Research Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Paolo Actis
- Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Gavin Hudson
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK.,Biosciences Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| |
Collapse
|
5
|
Siedlik MJ, Yang Z, Kadam PS, Eberwine J, Issadore D. Micro- and Nano-Devices for Studying Subcellular Biology. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2005793. [PMID: 33345457 PMCID: PMC8258219 DOI: 10.1002/smll.202005793] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 10/20/2020] [Indexed: 05/27/2023]
Abstract
Cells are complex machines whose behaviors arise from their internal collection of dynamically interacting organelles, supramolecular complexes, and cytoplasmic chemicals. The current understanding of the nature by which subcellular biology produces cell-level behaviors is limited by the technological hurdle of measuring the large number (>103 ) of small-sized (<1 μm) heterogeneous organelles and subcellular structures found within each cell. In this review, the emergence of a suite of micro- and nano-technologies for studying intracellular biology on the scale of organelles is described. Devices that use microfluidic and microelectronic components for 1) extracting and isolating subcellular structures from cells and lysate; 2) analyzing the physiology of individual organelles; and 3) recreating subcellular assembly and functions in vitro, are described. The authors envision that the continued development of single organelle technologies and analyses will serve as a foundation for organelle systems biology and will allow new insight into fundamental and clinically relevant biological questions.
Collapse
Affiliation(s)
- Michael J Siedlik
- Department of Bioengineering, 335 Skirkanich Hall, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA, 19104, USA
| | - Zijian Yang
- Department of Mechanical Engineering and Applied Science, 335 Skirkanich Hall, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA, 19104, USA
| | - Parnika S Kadam
- Systems Pharmacology and Translational Therapeutics, 38 John Morgan Building, University of Pennsylvania, 3620 Hamilton Walk, Philadelphia, PA, 19104, USA
| | - James Eberwine
- Systems Pharmacology and Translational Therapeutics, 38 John Morgan Building, University of Pennsylvania, 3620 Hamilton Walk, Philadelphia, PA, 19104, USA
| | - David Issadore
- Department of Bioengineering, 335 Skirkanich Hall, University of Pennsylvania, 210 South 33rd Street, Philadelphia, PA, 19104, USA
| |
Collapse
|
6
|
Bury AG, Vincent AE, Turnbull DM, Actis P, Hudson G. Mitochondrial isolation: when size matters. Wellcome Open Res 2020; 5:226. [PMID: 33718619 PMCID: PMC7931255 DOI: 10.12688/wellcomeopenres.16300.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 01/31/2024] Open
Abstract
Mitochondrial vitality is critical to cellular function, with mitochondrial dysfunction linked to a growing number of human diseases. Tissue and cellular heterogeneity, in terms of genetics, dynamics and function means that increasingly mitochondrial research is conducted at the single cell level. Whilst there are several technologies that are currently available for single-cell analysis, each with their advantages, they cannot be easily adapted to study mitochondria with subcellular resolution. Here we review the current techniques and strategies for mitochondrial isolation, critically discussing each technology's limitations for future mitochondrial research. Finally, we highlight and discuss the recent breakthroughs in sub-cellular isolation techniques, with a particular focus on nanotechnologies that enable the isolation of mitochondria from subcellular compartments. This allows isolation of mitochondria with unprecedented spatial precision with minimal disruption to mitochondria and their immediate cellular environment.
Collapse
Affiliation(s)
- Alexander G. Bury
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
- Biosciences Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
- Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Amy E. Vincent
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
- Translational and Clinical Research Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Doug M. Turnbull
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
- Translational and Clinical Research Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| | - Paolo Actis
- Pollard Institute, School of Electronic and Electrical Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Gavin Hudson
- Wellcome Trust Centre for Mitochondrial Research, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
- Biosciences Institute, Medical School, Newcastle University, Newcastle-upon-Tyne, NE1 7RU, UK
| |
Collapse
|
7
|
Wu Y, Fu A, Yossifon G. Active Particle Based Selective Transport and Release of Cell Organelles and Mechanical Probing of a Single Nucleus. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1906682. [PMID: 32363783 DOI: 10.1002/smll.201906682] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/27/2020] [Accepted: 03/27/2020] [Indexed: 06/11/2023]
Abstract
Self-propelling micromotors are emerging as a promising microscale tool for single-cell analysis. The authors have recently shown that the field gradients necessary to manipulate matter via dielectrophoresis can be induced at the surface of a polarizable active ("self-propelling") metallo-dielectric Janus particle (JP) under an externally applied electric field, acting essentially as a mobile floating microelectrode. Here, the application of the mobile floating microelectrode to trap and transport cell organelles in a selective and releasable manner is successfully extended. This selectivity is driven by the different dielectrophoretic (DEP) potential wells on the JP surface that is controlled by the frequency of the electric field, along with the hydrodynamic shearing and size of the trapped organelles. Such selective and directed loading enables purification of targeted organelles of interest from a mixed biological sample while their dynamic release enables their harvesting for further analysis such as gene/RNA sequencing or proteomics. Moreover, the electro-deformation of the trapped nucleus is shown to be in correlation with the DEP force and hence, can act as a promising label-free biomechanical marker. Hence, the active carrier constitutes an important and novel ex vivo platform for manipulation and mechanical probing of subcellular components of potential for single cell analysis.
Collapse
Affiliation(s)
- Yue Wu
- Faculty of Mechanical Engineering, Micro- and Nano-Fluidics Laboratory, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Afu Fu
- Technion Integrated Cancer Center, The Rappaport Faculty of Medicine and Research Institute, Technion-Israel Institute of Technology, Haifa, 3525433, Israel
| | - Gilad Yossifon
- Faculty of Mechanical Engineering, Micro- and Nano-Fluidics Laboratory, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| |
Collapse
|
8
|
Martin WE, Ge N, Srijanto BR, Furnish E, Collier CP, Trinkle CA, Richards CI. Real-Time Sensing of Single-Ligand Delivery with Nanoaperture-Integrated Microfluidic Devices. ACS OMEGA 2017; 2:3858-3867. [PMID: 28782052 PMCID: PMC5537690 DOI: 10.1021/acsomega.7b00934] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Accepted: 07/11/2017] [Indexed: 05/28/2023]
Abstract
The measurement of biological events on the surface of live cells at the single-molecule level is complicated by several factors including high protein densities that are incompatible with single-molecule imaging, cellular autofluorescence, and protein mobility on the cell surface. Here, we fabricated a device composed of an array of nanoscale apertures coupled with a microfluidic delivery system to quantify single-ligand interactions with proteins on the cell surface. We cultured live cells directly on the device and isolated individual epidermal growth factor receptors (EGFRs) in the apertures while delivering fluorescently labeled epidermal growth factor. We observed single ligands binding to EGFRs, allowing us to quantify the ligand turnover in real time. These results demonstrate that this nanoaperture-coupled microfluidic device allows for the spatial isolation of individual membrane proteins while maintaining them in their cellular environment, providing the capability to monitor single-ligand binding events while maintaining receptors in their physiological environment. These methods should be applicable to a wide range of membrane proteins.
Collapse
Affiliation(s)
- W. Elliott Martin
- Department
of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - Ning Ge
- Department
of Mechanical Engineering, University of
Kentucky, 151 Ralph G.
Anderson Building, Lexington, Kentucky 40506, United
States
| | - Bernadeta R. Srijanto
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge Tennessee 37831, United States
| | - Emily Furnish
- Department
of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| | - C. Patrick Collier
- Center
for Nanophase Materials Sciences, Oak Ridge
National Laboratory, Oak Ridge Tennessee 37831, United States
| | - Christine A. Trinkle
- Department
of Mechanical Engineering, University of
Kentucky, 151 Ralph G.
Anderson Building, Lexington, Kentucky 40506, United
States
| | - Christopher I. Richards
- Department
of Chemistry, University of Kentucky, 505 Rose Street, Lexington, Kentucky 40506, United States
| |
Collapse
|
9
|
Luo J, Muratore KA, Arriaga EA, Ros A. Deterministic Absolute Negative Mobility for Micro- and Submicrometer Particles Induced in a Microfluidic Device. Anal Chem 2016; 88:5920-7. [PMID: 27149097 PMCID: PMC5316477 DOI: 10.1021/acs.analchem.6b00837] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Efficient separations of particles with micron and submicron dimensions are extremely useful in preparation and analysis of materials for nanotechnological and biological applications. Here, we demonstrate a nonintuitive, yet efficient, separation mechanism for μm and subμm colloidal particles and organelles, taking advantage of particle transport in a nonlinear post array in a microfluidic device under the periodic action of electrokinetic and dielectrophoretic forces. We reveal regimes in which deterministic particle migration opposite to the average applied force occurs for a larger particle, a typical signature of deterministic absolute negative mobility (dANM), whereas normal response is obtained for smaller particles. The coexistence of dANM and normal migration was characterized and optimized in numerical modeling and subsequently implemented in a microfluidic device demonstrating at least 2 orders of magnitude higher migration speeds as compared to previous ANM systems. We also induce dANM for mouse liver mitochondria and envision that the separation mechanisms described here provide size selectivity required in future separations of organelles, nanoparticles, and protein nanocrystals.
Collapse
Affiliation(s)
- Jinghui Luo
- School of Molecular Sciences, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
| | - Katherine A. Muratore
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Edgar A. Arriaga
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
- Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Alexandra Ros
- School of Molecular Sciences, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
- Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, Arizona 85287, United States
| |
Collapse
|
10
|
Peer A, Biswas R. Extraordinary optical transmission in nanopatterned ultrathin metal films without holes. NANOSCALE 2016; 8:4657-4666. [PMID: 26853881 DOI: 10.1039/c5nr07903a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We experimentally and theoretically demonstrate that a continuous gold film on a periodically textured substrate exhibits extraordinary optical transmission, even though no holes were etched in the film. Our film synthesis started by nanoimprinting a periodic array of nanocups with a period of ∼750 nm on a polystyrene film over a glass substrate. A thin non-conformal gold film was sputter-deposited on the polystyrene by angle-directed deposition. The gold film was continuous with spatial thickness variation, the film being thinnest at the bottom of the nanocup. Measurements revealed an extraordinary transmission peak at a wavelength just smaller than the period, with an enhancement of ∼2.5 compared to the classically expected value. Scattering matrix simulations model well the transmission and reflectance measurements when an ultrathin gold layer (∼5 nm), smaller than the skin depth is retained at the bottom of the nanocups. Electric field intensities are enhanced by >100 within the nanocup, and ∼40 in the ultrathin gold layer causing transmission through it. We show a wavelength red-shift of ∼30 nm in the extraordinary transmission peak when the nanocups are coated with a thin film of a few nanometers, which can be utilized for biosensing. The continuous corrugated metal films are far simpler structures to observe extraordinary transmission, circumventing the difficult process of etching the metal film. Such continuous metal films with ultrathin regions are simple platforms for non-linear optics, plasmonics, and biological and chemical sensing.
Collapse
Affiliation(s)
- Akshit Peer
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA. and Ames Laboratory, Ames, Iowa 50011, USA
| | - Rana Biswas
- Department of Electrical and Computer Engineering, Iowa State University, Ames, Iowa 50011, USA. and Ames Laboratory, Ames, Iowa 50011, USA and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA
| |
Collapse
|