Plasmon-Enhanced Quantum Dot Fluorescence Induced by Brownian Motion

ASME 2009 Second International Conference on Micro/Nanoscale Heat and Mass Transfer, Volume 3 ◽

10.1115/mnhmt2009-18185 ◽

2009 ◽

Author(s):

Bong Jae Lee ◽

Willard Hanson ◽

Bumsoo Han

Keyword(s):

Brownian Motion ◽

Near Field ◽

Interparticle Distance ◽

Distance Estimation ◽

Medical Diagnostics ◽

Plasmonic Nanostructures ◽

Fluorescence Sensing ◽

Enhanced Fluorescence ◽

Deep Tissue ◽

Thermally Induced

Metal-enhanced fluorescence has been extensively studied over the past three decades due to numerous opportunities for enhanced fluorescence sensing and imaging in microfluidics and medical diagnostics. Since the interaction between plasmonic nanoparticles and quantum dots (QDs) is the near-field phenomenon, most of past studies employed dielectric spacers to maintain the nanoscale interparticle distance. In the present study, however, we investigate the enhanced fluorescence from QDs that are mixed with plasmonic nanostructures, such as gold nanoshell (GNS), in the aquatic medium without confining inter-particle distances. Although the near-field interaction could not occur according to the distance estimation based on the particle concentrations, the experimental results indicate that the QD fluorescence can be greatly enhanced. A simple two-dimensional model based on Monte Carlo simulation reveals that there exist considerable probability that QDs reach the near-field region of GNSs due to the thermally induced Brownian motion. The results obtained from this study will facilitate the development of QD-mediated thermometry and ultimately enable image-guided deep-tissue thermal therapy.

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Recent Developments in Plasmonic Nanostructures for Metal Enhanced Fluorescence-Based Biosensing

Nanomaterials ◽

10.3390/nano10091749 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1749 ◽

Cited By ~ 1

Author(s):

Mohsin Ali Badshah ◽

Na Yoon Koh ◽

Abdul Wasy Zia ◽

Naseem Abbas ◽

Zahra Zahra ◽

...

Keyword(s):

Forensic Science ◽

Basic Mechanism ◽

Medical Diagnostics ◽

Plasmonic Nanostructures ◽

Fluorescence Signal ◽

Enhanced Fluorescence ◽

Metal Enhanced Fluorescence ◽

Research Areas ◽

Design Flexibility ◽

Recent Developments

Metal-enhanced fluorescence (MEF) is a unique phenomenon of surface plasmons, where light interacts with the metallic nanostructures and produces electromagnetic fields to enhance the sensitivity of fluorescence-based detection. In particular, this enhancement in sensing capacity is of importance to many research areas, including medical diagnostics, forensic science, and biotechnology. The article covers the basic mechanism of MEF and recent developments in plasmonic nanostructures fabrication for efficient fluorescence signal enhancement that are critically reviewed. The implications of current fluorescence-based technologies for biosensors are summarized, which are in practice to detect different analytes relevant to food control, medical diagnostics, and forensic science. Furthermore, characteristics of existing fabrication methods have been compared on the basis of their resolution, design flexibility, and throughput. The future projections emphasize exploring the potential of non-conventional materials and hybrid fabrication techniques to further enhance the sensitivity of MEF-based biosensors.

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Optical near-field mapping of plasmonic nanostructures prepared by nanosphere lithography

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.144 ◽

2018 ◽

Vol 9 ◽

pp. 1536-1543 ◽

Cited By ~ 1

Author(s):

Gitanjali Kolhatkar ◽

Alexandre Merlen ◽

Jiawei Zhang ◽

Chahinez Dab ◽

Gregory Q Wallace ◽

...

Keyword(s):

Numerical Simulations ◽

Hot Spots ◽

Near Field ◽

Nanosphere Lithography ◽

Plasmonic Nanostructures ◽

Far Field ◽

Optical Images ◽

Spatial Frequencies ◽

Comparison Of The Results ◽

Non Destructive

We introduce a simple, fast, efficient and non-destructive method to study the optical near-field properties of plasmonic nanotriangles prepared by nanosphere lithography. Using a rectangular Fourier filter on the blurred signal together with filtering of the lower spatial frequencies to remove the far-field contribution, the pure near-field contributions of the optical images were extracted. We performed measurements using two excitation wavelengths (532.1 nm and 632.8 nm) and two different polarizations. After the processing of the optical images, the distribution of hot spots can be correlated with the topography of the structures, as indicated by the presence of brighter spots at the apexes of the nanostructures. This technique is validated by comparison of the results to numerical simulations, where agreement is obtained, thereby confirming the near-field nature of the images. Our approach does not require any advanced equipment and we suggest that it could be applied to any type of sample, while keeping the measurement times reasonably short.

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Improving SERS Detection of Bacillus thuringiensis Using Silver Nanoparticles Reduced with Hydroxylamine and with Citrate Capped Borohydride

International Journal of Spectroscopy ◽

10.1155/2011/989504 ◽

2011 ◽

Vol 2011 ◽

pp. 1-9 ◽

Cited By ~ 16

Author(s):

Hilsamar Félix-Rivera ◽

Roxannie González ◽

Gabriela Del Mar Rodríguez ◽

Oliva M. Primera-Pedrozo ◽

Carlos Ríos-Velázquez ◽

...

Keyword(s):

Bacillus Thuringiensis ◽

Surface Charge ◽

Near Field ◽

Medical Diagnostics ◽

Biological Warfare Agents ◽

Surface Enhanced ◽

Surface Enhanced Raman ◽

Sers Detection ◽

Warfare Agents ◽

Enhanced Raman Scattering

The development of techniques that could be useful in fields other than biological warfare agents countermeasures such as medical diagnostics, industrial microbiology, and environmental applications have become a very important subject of research. Raman spectroscopy can be used in near field or at long distances from the sample to obtain fingerprinting information of chemical composition of microorganisms. In this research, biochemical components of the cell wall and endospores of Bacillus thuringiensis (Bt) were identified by surface-enhanced Raman scattering (SERS) spectroscopy using silver (Ag) nanoparticles (NPs) reduced by hydroxylamine and borohydride capped with sodium citrate. Activation of “hot spots”, aggregation and surface charge modification of the NPs, was studied and optimized to obtain signal enhancements from Bt by SERS. Slight aggregation of the NPs as well as surface charge modification to a more acidic ambient was induced using small-size borohydride-reduced NPs in the form of metallic suspensions aimed at increasing the Ag NP-Bt interactions. Hydroxylamine-reduced NPs required slight aggregation and no pH modifications in order to obtain high spectral quality results in bringing out SERS signatures of Bt.

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Single Molecule Techniques Can Distinguish the Photophysical Processes Governing Metal-Enhanced Fluorescence

10.32920/17466002 ◽

2022 ◽

Author(s):

Stefania Impellizzeri ◽

Gregory J, Hodgson ◽

Nicholas P. Dogantzis

Keyword(s):

Single Molecule ◽

Organic Molecules ◽

Near Field ◽

Comprehensive Understanding ◽

Enhanced Fluorescence ◽

Metal Enhanced Fluorescence ◽

Maximum Enhancement ◽

Molecular Systems ◽

Photophysical Processes ◽

Underlying Processes

<p>Plasmonic metal nanoparticles can impact the behaviour of organic molecules in a number of ways, including enhancing or quenching fluorescence. Only through a comprehensive understanding of the fundamental photophysical processes regulating nano-molecular interactions can these effects be controlled, and exploited to the fullest extent possible. Metal-enhanced fluorescence (MEF) is governed by two underlying processes, increased rate of fluorophore excitation and increased fluorophore emission, the balance between which has implications for optimizing hybrid nanoparticle-molecular systems for various applications. We report groundbreaking work on the use of single molecule fluorescence microscopy to distinguish between the two mechanistic components of MEF, in a model system consisting of two analogous boron dipyrromethene (BODIPY) fluorophores and triangular silver nanoparticles (AgNP). We demonstrate that the increased excitation MEF mechanism occurs to approximately the same extent for both dyes, but that the BODIPY with the higher quantum yield of fluorescence experiences a greater degree of MEF via the increased fluorophore emission mechanism, and higher overall enhancement, as a result of its superior ability to undergo near-field interactions with AgNP. We foresee that this knowledge and methodology will be used to tailor MEF to meet the needs of different applications, such as those requiring maximum enhancement of fluorescence intensity or instead prioritizing excited-state photochemistry. </p>

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Metal–dielectric hybrid nanoantennas for efficient frequency conversion at the anapole mode

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.9.215 ◽

2018 ◽

Vol 9 ◽

pp. 2306-2314 ◽

Cited By ~ 23

Author(s):

Valerio F Gili ◽

Lavinia Ghirardini ◽

Davide Rocco ◽

Giuseppe Marino ◽

Ivan Favero ◽

...

Keyword(s):

Frequency Conversion ◽

Near Infrared ◽

Strong Field ◽

Second Harmonic ◽

Near Field ◽

Field Enhancement ◽

High Refractive Index ◽

Plasmonic Nanostructures ◽

Ohmic Losses ◽

Order Of Magnitude

Background: Dielectric nanoantennas have recently emerged as an alternative solution to plasmonics for nonlinear light manipulation at the nanoscale, thanks to the magnetic and electric resonances, the strong nonlinearities, and the low ohmic losses characterizing high refractive-index materials in the visible/near-infrared (NIR) region of the spectrum. In this frame, AlGaAs nanoantennas demonstrated to be extremely efficient sources of second harmonic radiation. In particular, the nonlinear polarization of an optical system pumped at the anapole mode can be potentially boosted, due to both the strong dip in the scattering spectrum and the near-field enhancement, which are characteristic of this mode. Plasmonic nanostructures, on the other hand, remain the most promising solution to achieve strong local field confinement, especially in the NIR, where metals such as gold display relatively low losses. Results: We present a nonlinear hybrid antenna based on an AlGaAs nanopillar surrounded by a gold ring, which merges in a single platform the strong field confinement typically produced by plasmonic antennas with the high nonlinearity and low loss characteristics of dielectric nanoantennas. This platform allows enhancing the coupling of light to the nanopillar at coincidence with the anapole mode, hence boosting both second- and third-harmonic generation conversion efficiencies. More than one order of magnitude enhancement factors are measured for both processes with respect to the isolated structure. Conclusion: The present results reveal the possibility to achieve tuneable metamixers and higher resolution in nonlinear sensing and spectroscopy, by means of improved both pump coupling and emission efficiency due to the excitation of the anapole mode enhanced by the plasmonic nanoantenna.

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Enhanced fluorescence detection of enrofloxacin with curved-surface responsive inverse opal polymers and molecular imprinting

Analytical Methods ◽

10.1039/c8ay02329h ◽

2019 ◽

Vol 11 (8) ◽

pp. 1043-1052 ◽

Cited By ~ 3

Author(s):

Zhenhe Chen ◽

Jianling Sun ◽

Yong He ◽

Tingting Zhang ◽

Run Hao ◽

...

Keyword(s):

Fluorescence Detection ◽

Molecular Imprinting ◽

Curved Surface ◽

Inverse Opal ◽

Fluorescence Sensing ◽

Enhanced Fluorescence

Enhanced fluorescence sensing of enrofloxacin has been realized by molecular imprinting on curved-surface responsive inverse opal polymers.

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Thermally Induced Structural Transition of Peptide Nanofibers into Nanoparticles with Enhanced Fluorescence Properties

ChemPlusChem ◽

10.1002/cplu.202000116 ◽

2020 ◽

Vol 85 (7) ◽

pp. 1523-1528

Author(s):

Qing Li ◽

Xin Yang ◽

Liwei Zhang ◽

Yuefei Wang ◽

Jia Kong ◽

...

Keyword(s):

Structural Transition ◽

Fluorescence Properties ◽

Enhanced Fluorescence ◽

Thermally Induced ◽

Peptide Nanofibers

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Electrodynamics of microwave near-field probing: Application to medical diagnostics

Journal of Applied Physics ◽

10.1063/1.2138798 ◽

2005 ◽

Vol 98 (11) ◽

pp. 114701 ◽

Cited By ~ 32

Author(s):

Alexander N. Reznik ◽

Nadezhda V. Yurasova

Keyword(s):

Near Field ◽

Medical Diagnostics

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Plasmon response evaluation based on image-derived arbitrary nanostructures

Nanoscale ◽

10.1039/c8nr02783h ◽

2018 ◽

Vol 10 (21) ◽

pp. 9830-9839 ◽

Cited By ~ 9

Author(s):

S. Trautmann ◽

M. Richard-Lacroix ◽

A. Dathe ◽

H. Schneidewind ◽

J. Dellith ◽

...

Keyword(s):

Near Field ◽

Interparticle Distance ◽

Optical Response ◽

Response Evaluation ◽

Distance Distributions ◽

Optical Effects

The optical response of realistic 3D plasmonic substrates composed of randomly shaped particles of different size and interparticle distance distributions is modelled by parametrizing large areas, allowing to investigate far- and near-field optical effects.

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