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Oliveira-Silva R, Wang Y, Nooteboom SW, Prazeres DMF, Paulo PMR, Zijlstra P. Single-Particle Plasmon Sensor to Monitor Proteolytic Activity in Real Time. ACS APPLIED OPTICAL MATERIALS 2023; 1:1661-1669. [PMID: 37915971 PMCID: PMC10616847 DOI: 10.1021/acsaom.3c00226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/22/2023] [Accepted: 08/23/2023] [Indexed: 11/03/2023]
Abstract
We have established a label-free plasmonic platform that monitors proteolytic activity in real time. The sensor consists of a random array of gold nanorods that are functionalized with a design peptide that is specifically cleaved by thrombin, resulting in a blueshift of the longitudinal plasmon. By monitoring the plasmon of many individual nanorods, we determined thrombin's proteolytic activity in real time and inferred relevant kinetic parameters. Furthermore, a comparison to a kinetic model revealed that the plasmon shift is dictated by a competition between peptide cleavage and thrombin binding, which have opposing effects on the measured plasmon shift. The dynamic range of the sensor is greater than two orders of magnitude, and it is capable of detecting physiologically relevant levels of active thrombin down to 3 nM in buffered conditions. We expect these plasmon-mediated label-free sensors to open the window to a range of applications stretching from the diagnostic and characterization of bleeding disorders to fundamental proteolytic and pharmacological studies.
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Affiliation(s)
- Rui Oliveira-Silva
- MBx
Molecular Biosensing, Department of Applied Physics and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- iBB
− Institute for Biotechnology and Bioengineering, Instituto
Superior Técnico, Universidade de
Lisboa, 1049-001 Lisboa, Portugal
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, Instituto
Superior Técnico, Universidade de
Lisboa, 1049-001 Lisboa, Portugal
| | - Yuyang Wang
- MBx
Molecular Biosensing, Department of Applied Physics and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Sjoerd W. Nooteboom
- MBx
Molecular Biosensing, Department of Applied Physics and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Duarte M. F. Prazeres
- iBB
− Institute for Biotechnology and Bioengineering, Instituto
Superior Técnico, Universidade de
Lisboa, 1049-001 Lisboa, Portugal
- Associate
Laboratory i4HB—Institute for Health and Bioeconomy, Instituto
Superior Técnico, Universidade de
Lisboa, 1049-001 Lisboa, Portugal
| | - Pedro M. R. Paulo
- CQE—Centro
de Química Estrutural, Institute of Molecular Sciences, Instituto
Superior Técnico, Universidade de
Lisboa, Avenida Rovisco Pais 1, 1049-001 Lisboa, Portugal
| | - Peter Zijlstra
- MBx
Molecular Biosensing, Department of Applied Physics and Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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2
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Searles EK, Gomez E, Lee S, Ostovar B, Link S, Landes CF. Single-Particle Photoluminescence and Dark-Field Scattering during Charge Density Tuning. J Phys Chem Lett 2023; 14:318-325. [PMID: 36603176 DOI: 10.1021/acs.jpclett.2c03566] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Single-particle spectroelectrochemistry provides optical insight into understanding physical and chemical changes occurring on the nanoscale. While changes in dark-field scattering during electrochemical charging are well understood, changes to the photoluminescence of plasmonic nanoparticles under similar conditions are less studied. Here, we use correlated single-particle photoluminescence and dark-field scattering to compare their plasmon modulation at applied potentials. We find that changes in the emission of a single gold nanorod during charge density tuning of intraband photoluminescence can be attributed to changes in the Purcell factor and absorption cross section. Finally, modulation of interband photoluminescence provides an additional constructive observable, giving promise for establishing dual channel sensing in spectroelectrochemical measurements.
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Affiliation(s)
- Emily K Searles
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas77005, United States
| | - Eric Gomez
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas77005, United States
| | - Stephen Lee
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas77005, United States
| | - Behnaz Ostovar
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas77005, United States
| | - Stephan Link
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas77005, United States
| | - Christy F Landes
- Department of Chemistry, Rice University, 6100 Main Street, Houston, Texas77005, United States
- Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas77005, United States
- Smalley-Curl Institute, Rice University, 6100 Main Street, Houston, Texas77005, United States
- Department of Chemical and Biomolecular Engineering, Rice University, 6100 Main Street, Houston, Texas77005, United States
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3
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Zheng J, Cheng X, Zhang H, Bai X, Ai R, Shao L, Wang J. Gold Nanorods: The Most Versatile Plasmonic Nanoparticles. Chem Rev 2021; 121:13342-13453. [PMID: 34569789 DOI: 10.1021/acs.chemrev.1c00422] [Citation(s) in RCA: 148] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Gold nanorods (NRs), pseudo-one-dimensional rod-shaped nanoparticles (NPs), have become one of the burgeoning materials in the recent years due to their anisotropic shape and adjustable plasmonic properties. With the continuous improvement in synthetic methods, a variety of materials have been attached around Au NRs to achieve unexpected or improved plasmonic properties and explore state-of-the-art technologies. In this review, we comprehensively summarize the latest progress on Au NRs, the most versatile anisotropic plasmonic NPs. We present a representative overview of the advances in the synthetic strategies and outline an extensive catalogue of Au-NR-based heterostructures with tailored architectures and special functionalities. The bottom-up assembly of Au NRs into preprogrammed metastructures is then discussed, as well as the design principles. We also provide a systematic elucidation of the different plasmonic properties associated with the Au-NR-based structures, followed by a discussion of the promising applications of Au NRs in various fields. We finally discuss the future research directions and challenges of Au NRs.
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Affiliation(s)
- Jiapeng Zheng
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
| | - Xizhe Cheng
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
| | - Han Zhang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
| | - Xiaopeng Bai
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
| | - Ruoqi Ai
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
| | - Lei Shao
- Beijing Computational Science Research Center, Beijing 100193, China
| | - Jianfang Wang
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR 999077, China
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4
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Beuwer MA, Zijlstra P. Correlative microscopy of single self-assembled nanorod dimers for refractometric sensing. J Chem Phys 2021; 155:044701. [PMID: 34340368 DOI: 10.1063/5.0055135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Single metallic particles and dimers of nanospheres have been used extensively for sensing, but dimers of particles provide attractive advantages because they exhibit multiple modes that can be tuned by the dimer geometry. Here, we employ correlative microscopy of single self-assembled dimers of gold nanorods to study their performance as refractometric sensors. The correlation between atomic force microscopy and single-particle white-light spectroscopy allows us to relate the measured sensitivity to numerical simulations taking into account the exact geometry of the construct. The sensitivity of the antibonding mode is in good agreement with simulations, whereas the bonding mode exhibits a reduced sensitivity related to the accessibility of the gap region between the particles. We find that the figure of merit is a trade-off between the resonance linewidth and its refractive index sensitivity, which depend in opposite ways on the interparticle angle. The presence of two narrow plasmon resonances in the visible to near-infrared wavelength regime makes nanorod dimers exciting candidates for multicolor and multiplexed sensing.
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Affiliation(s)
- Michael A Beuwer
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven The Netherlands and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven The Netherlands
| | - Peter Zijlstra
- Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven The Netherlands and Institute for Complex Molecular Systems, Eindhoven University of Technology, 5600 MB Eindhoven The Netherlands
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5
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Staniszewska T, Szkulmowski M, Morawiec S. Computational Optimization of the Size of Gold Nanorods for Single-Molecule Plasmonic Biosensors Operating in Scattering and Absorption Modes. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2021; 125:14765-14777. [PMID: 34484550 PMCID: PMC8411831 DOI: 10.1021/acs.jpcc.1c02510] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 06/17/2021] [Indexed: 06/13/2023]
Abstract
We present a comprehensive computational study on the optimization of the size of gold nanorods for single-molecule plasmonic sensing in terms of optical refractive index sensitivity. We construct an experimentally relevant model of single-molecule-single-nanoparticle sensor based on spherically capped gold nanorods, tip-specific functionalization and passivation layers, and biotin-streptavidin affinity system. We introduce a universal figure of merit for the sensitivity, termed contrast-to-noise ratio (CNR), which relates the change of measurable signal caused by the discrete molecule binding events to the inherent measurement noise. We investigate three distinct sensing modalities relying on direct spectral measurements, monitoring of scattering intensity at fixed wavelength and photothermal effect. By considering a shot-noise-limited performance of an experimental setup, we demonstrate the existence of an optimum nanorod size providing the highest sensitivity for each sensing technique. The optimization at constant illumination intensity (i.e., low-power applications) yields similar values of approximately 20 × 80 nm2 for each considered sensing technique. Second, we investigate the impact of geometrical and material parameters of the molecule and the functionalization layer on the sensitivity. Finally, we discuss the variable illumination intensity for each nanorod size with the steady-state temperature increase as its limiting factor (i.e., high-power applications).
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6
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Celiksoy S, Ye W, Ahijado-Guzmán R, Sönnichsen C. Single Out-of-Resonance Dielectric Nanoparticles as Molecular Sensors. ACS Sens 2021; 6:716-721. [PMID: 33617229 DOI: 10.1021/acssensors.0c02629] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Light scattering from single nanoparticles and nanostructures is a commonly used readout method for nanosensors. Increasing the spectral sensitivity of resonant nanosensors to changes in their local surrounding has been the focus of many studies. Switching from spectral to intensity monitoring allows one to investigate nonresonant or out-of-resonance dielectric nanoparticles. Here, we systematically compared such dielectric silica nanoparticles with plasmonic gold nanorods by deriving analytical expressions and by performing experiments. The experiments show a similar sensitivity for the detection of an adsorbate layer for both particle types, which is in good agreement with theory. The flat spectral response of dielectric silica nanoparticles simplifies the choice of illumination wavelength. Furthermore, such dielectric nanoparticles can be made from many oxides, polymers, and even biological assemblies, broadening the choice of materials for the nanosensor.
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Affiliation(s)
- Sirin Celiksoy
- Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Weixiang Ye
- Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
- Graduate School of Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany
| | - Rubén Ahijado-Guzmán
- Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
| | - Carsten Sönnichsen
- Department of Chemistry, University of Mainz, Duesbergweg 10-14, 55128 Mainz, Germany
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7
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Farka Z, Mickert MJ, Pastucha M, Mikušová Z, Skládal P, Gorris HH. Fortschritte in der optischen Einzelmoleküldetektion: Auf dem Weg zu höchstempfindlichen Bioaffinitätsassays. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201913924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Zdeněk Farka
- CEITEC – Central European Institute of TechnologyMasaryk University 625 00 Brno Czech Republic
| | - Matthias J. Mickert
- Institut für Analytische Chemie, Chemo- und BiosensorikUniversität Regensburg Universitätsstraße 31 93040 Regensburg Deutschland
| | - Matěj Pastucha
- CEITEC – Central European Institute of TechnologyMasaryk University 625 00 Brno Czech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University 625 00 Brno Czech Republic
| | - Zuzana Mikušová
- CEITEC – Central European Institute of TechnologyMasaryk University 625 00 Brno Czech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University 625 00 Brno Czech Republic
| | - Petr Skládal
- CEITEC – Central European Institute of TechnologyMasaryk University 625 00 Brno Czech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University 625 00 Brno Czech Republic
| | - Hans H. Gorris
- Institut für Analytische Chemie, Chemo- und BiosensorikUniversität Regensburg Universitätsstraße 31 93040 Regensburg Deutschland
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8
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Farka Z, Mickert MJ, Pastucha M, Mikušová Z, Skládal P, Gorris HH. Advances in Optical Single-Molecule Detection: En Route to Supersensitive Bioaffinity Assays. Angew Chem Int Ed Engl 2020; 59:10746-10773. [PMID: 31869502 PMCID: PMC7318240 DOI: 10.1002/anie.201913924] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/20/2019] [Indexed: 12/11/2022]
Abstract
The ability to detect low concentrations of analytes and in particular low-abundance biomarkers is of fundamental importance, e.g., for early-stage disease diagnosis. The prospect of reaching the ultimate limit of detection has driven the development of single-molecule bioaffinity assays. While many review articles have highlighted the potentials of single-molecule technologies for analytical and diagnostic applications, these technologies are not as widespread in real-world applications as one should expect. This Review provides a theoretical background on single-molecule-or better digital-assays to critically assess their potential compared to traditional analog assays. Selected examples from the literature include bioaffinity assays for the detection of biomolecules such as proteins, nucleic acids, and viruses. The structure of the Review highlights the versatility of optical single-molecule labeling techniques, including enzymatic amplification, molecular labels, and innovative nanomaterials.
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Affiliation(s)
- Zdeněk Farka
- CEITEC – Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
| | - Matthias J. Mickert
- Institute of Analytical Chemistry, Chemo- and BiosensorsUniversity of RegensburgUniversitätsstraße 3193040RegensburgGermany
| | - Matěj Pastucha
- CEITEC – Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University625 00BrnoCzech Republic
| | - Zuzana Mikušová
- CEITEC – Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University625 00BrnoCzech Republic
| | - Petr Skládal
- CEITEC – Central European Institute of TechnologyMasaryk University625 00BrnoCzech Republic
- Department of BiochemistryFaculty of ScienceMasaryk University625 00BrnoCzech Republic
| | - Hans H. Gorris
- Institute of Analytical Chemistry, Chemo- and BiosensorsUniversity of RegensburgUniversitätsstraße 3193040RegensburgGermany
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9
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Clementi NC, Cooper CD, Barba LA. Computational nanoplasmonics in the quasistatic limit for biosensing applications. Phys Rev E 2019; 100:063305. [PMID: 31962460 DOI: 10.1103/physreve.100.063305] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Indexed: 06/10/2023]
Abstract
The phenomenon of localized surface plasmon resonance (LSPR) provides high sensitivity in detecting biomolecules through shifts in resonance frequency when a target is present. Computational studies in this field have used the full Maxwell equations with simplified models of a sensor-analyte system, or they neglected the analyte altogether. In the long-wavelength limit, one can simplify the theory via an electrostatics approximation while adding geometrical detail in the sensor and analytes (at moderate computational cost). This work uses the latter approach, expanding the open-source PyGBe code to compute the extinction cross section of metallic nanoparticles in the presence of any target for sensing. The target molecule is represented by a surface mesh, based on its crystal structure. PyGBe is research software for continuum electrostatics, written in python with computationally expensive parts accelerated on GPU hardware, via PyCUDA. It is also accelerated algorithmically via a treecode that offers O(NlogN) computational complexity. These features allow PyGBe to handle problems with half a million boundary elements or more. In this work, we demonstrate the suitability of PyGBe, extended to compute LSPR response in the electrostatic limit, for biosensing applications. Using a model problem consisting of an isolated silver nanosphere in an electric field, our results show grid convergence as 1/N, and accurate computation of the extinction cross section as a function of wavelength (compared with an analytical solution). For a model of a sensor-analyte system, consisting of a spherical silver nanoparticle and a set of bovine serum albumin (BSA) proteins, our results again obtain grid convergence as 1/N (with respect to the Richardson extrapolated value). Computing the LSPR response as a function of wavelength in the presence of BSA proteins captures a redshift of 0.5 nm in the resonance frequency due to the presence of the analytes at 1-nm distance. The final result is a sensitivity study of the biosensor model, obtaining the shift in resonance frequency for various distances between the proteins and the nanoparticle. All results in this paper are fully reproducible, and we have deposited in archival data repositories all the materials needed to run the computations again and recreate the figures. PyGBe is open source under a permissive license and openly developed. Documentation is available at http://pygbe.github.io/pygbe/docs/.
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Affiliation(s)
- Natalia C Clementi
- Department of Mechanical & Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
| | - Christopher D Cooper
- Department of Mechanical Engineering and Centro Científico Tecnológico de Valparaíso, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Lorena A Barba
- Department of Mechanical & Aerospace Engineering, The George Washington University, Washington, DC 20052, USA
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10
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Spitzberg JD, Zrehen A, van Kooten XF, Meller A. Plasmonic-Nanopore Biosensors for Superior Single-Molecule Detection. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2019; 31:e1900422. [PMID: 30941823 DOI: 10.1002/adma.201900422] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Revised: 02/19/2019] [Indexed: 05/26/2023]
Abstract
Plasmonic and nanopore sensors have separately received much attention for achieving single-molecule precision. A plasmonic "hotspot" confines and enhances optical excitation at the nanometer length scale sufficient to optically detect surface-analyte interactions. A nanopore biosensor actively funnels and threads analytes through a molecular-scale aperture, wherein they are interrogated by electrical or optical means. Recently, solid-state plasmonic and nanopore structures have been integrated within monolithic devices that address fundamental challenges in each of the individual sensing methods and offer complimentary improvements in overall single-molecule sensitivity, detection rates, dwell time and scalability. Here, the physical phenomena and sensing principles of plasmonic and nanopore sensing are summarized to highlight the novel complementarity in dovetailing these techniques for vastly improved single-molecule sensing. A literature review of recent plasmonic nanopore devices is then presented to delineate methods for solid-state fabrication of a range of hybrid device formats, evaluate the progress and challenges in the detection of unlabeled and labeled analyte, and assess the impact and utility of localized plasmonic heating. Finally, future directions and applications inspired by the present state of the art are discussed.
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Affiliation(s)
- Joshua D Spitzberg
- Department of Biomedical Engineering, Technion-IIT, Haifa, 32000, Israel
| | - Adam Zrehen
- Department of Biomedical Engineering, Technion-IIT, Haifa, 32000, Israel
| | | | - Amit Meller
- Department of Biomedical Engineering, Technion-IIT, Haifa, 32000, Israel
- Department of Biomedical Engineering, Boston University, Boston, MA, 02215, USA
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11
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Lu W, Cui X, Chow TH, Shao L, Wang H, Chen H, Wang J. Switching plasmonic Fano resonance in gold nanosphere-nanoplate heterodimers. NANOSCALE 2019; 11:9641-9653. [PMID: 31065663 DOI: 10.1039/c9nr01653h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The interference between spectrally overlapping superradiant and subradiant plasmon resonances generates plasmonic Fano resonance, which allows for attractive applications such as electromagnetically induced transparency, light trapping, and refractometric sensing with high figures of merit. The active switching of plasmonic Fano resonance holds great promise in modulating optical signals, dynamically harvesting light energy, and constructing switchable plasmonic sensors. However, structures enabling the active control of plasmonic Fano resonance have rarely been achieved because of the fabrication complexity and cost. Herein we report on the realization of active plasmonic Fano resonance switching on Au nanosphere-nanoplate heterodimers. The active switching is enabled by varying the refractive index of a layer of polyaniline that fills in the gap between the Au nanosphere and the Au nanoplate. A reversible spectral shift of 20 nm is observed on the individual heterodimers during switching. The maximal spectral shift decreases as the interparticle gap distance is enlarged, showing a strong dependence of the spectral shift on the local electric field intensity enhancement in the gap region. This trend agrees with the predicted dependence of the refractive index sensitivity on the local field intensity enhancement. Our results provide insights into the development of plasmonic structures supporting actively switchable Fano resonances, which can lead to new technological applications, such as switchable cloaking and display, dynamic coding of optical signals, color sorting and filtering. The Au heterodimers with polyaniline in the gap can also be applied for the sensing of local environmental parameters such as pH values and heavy metal ions.
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Affiliation(s)
- Wenzheng Lu
- Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
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12
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Szekrényes DP, Pothorszky S, Zámbó D, Deák A. Detecting spatial rearrangement of individual gold nanoparticle heterodimers. Phys Chem Chem Phys 2019; 21:10146-10151. [PMID: 31062803 DOI: 10.1039/c9cp01541h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The self-assembly of properly surface-modified gold nanorods and spherical gold nanoparticles in aqueous medium results in the formation of heterodimers, which show a unique optical scattering spectrum due to the plasmon coupling between the particles. While for the majority of the heterodimers, both particles are located at the substrate level, occasionally, some spherical particles are found to be located on top of the gold nanorods instead of the supporting substrate. Based on optical measurements on such individual heterodimers, it is shown that in contrast to the plain white-light scattering spectrum, the polarization-resolved spectra allow us to distinguish between the cases when the sphere is located on top or at the side of the nanorods. This finding is utilized to investigate the structure of heterodimers upon formation in situ in aqueous medium. It is demonstrated at the individual heterodimer level that both arrangements can be found upon assembly and that the nanosphere originally located on top of the rod right after assembly can indeed rearrange and move to substrate level during drying. The results underline the importance of low-level in situ characterization approaches in the field of nanoparticle self-assembly and can be utilized to assess the impact of different surface ligands, interfacial layers and liquid environments on the drying of nanoparticle-based systems.
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Affiliation(s)
- Dániel Péter Szekrényes
- Institute of Technical Physics and Materials Science, HAS Centre for Energy Research, P.O. Box 49, H-1525 Budapest, Hungary.
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13
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Wang Y, Li X, Su Z, Wang H, Xia H, Chen H, Zhou J. Single Plasmonic Particle with Exposed Sensing Hot Spot for Exploring Gas Molecule Adsorption in Nanolocalized Space. Anal Chem 2019; 91:4063-4069. [DOI: 10.1021/acs.analchem.8b05653] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Yangyang Wang
- Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Xuemeng Li
- Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Zhenning Su
- Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Hao Wang
- State Key Lab of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Hongqi Xia
- Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China
| | - Huanjun Chen
- State Key Lab of Optoelectronic Materials and Technologies, Guangdong Province Key Laboratory of Display Material and Technology, School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510275, China
| | - Jianhua Zhou
- Key Laboratory of Sensing Technology and Biomedical Instruments of Guangdong Province, School of Biomedical Engineering, Sun Yat-sen University, Guangzhou 510275, China
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14
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Subramanian S, Wu HY, Constant T, Xavier J, Vollmer F. Label-Free Optical Single-Molecule Micro- and Nanosensors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1801246. [PMID: 30073717 DOI: 10.1002/adma.201801246] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/23/2018] [Indexed: 05/12/2023]
Abstract
Label-free optical sensor systems have emerged that exhibit extraordinary sensitivity for detecting physical, chemical, and biological entities at the micro/nanoscale. Particularly exciting is the detection and analysis of molecules, on miniature optical devices that have many possible applications in health, environment, and security. These micro- and nanosensors have now reached a sensitivity level that allows for the detection and analysis of even single molecules. Their small size enables an exceedingly high sensitivity, and the application of quantum optical measurement techniques can allow the classical limits of detection to be approached or surpassed. The new class of label-free micro- and nanosensors allows dynamic processes at the single-molecule level to be observed directly with light. By virtue of their small interaction length, these micro- and nanosensors probe light-matter interactions over a dynamic range often inaccessible by other optical techniques. For researchers entering this rapidly advancing field of single-molecule micro- and nanosensors, there is an urgent need for a timely review that covers the most recent developments and that identifies the most exciting opportunities. The focus here is to provide a summary of the recent techniques that have either demonstrated label-free single-molecule detection or claim single-molecule sensitivity.
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Affiliation(s)
- Sivaraman Subramanian
- Living Systems Institute, Department of Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
| | - Hsin-Yu Wu
- Living Systems Institute, Department of Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
| | - Tom Constant
- Living Systems Institute, Department of Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
| | - Jolly Xavier
- Living Systems Institute, Department of Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
| | - Frank Vollmer
- Living Systems Institute, Department of Physics and Astronomy, University of Exeter, Exeter, EX4 4QD, UK
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