scholarly journals LSPR Biosensing Approach for the Detection of Microtubule Nucleation

Sensors ◽  
2019 ◽  
Vol 19 (6) ◽  
pp. 1436 ◽  
Author(s):  
Keisuke Hasegawa ◽  
Otabek Nazarov ◽  
Evan Porter
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Theoretical Model ◽  
Density Measurement ◽  
Localized Surface Plasmon ◽  
Proof Of Concept ◽  
Microtubule Nucleation ◽  
Cellular Processes ◽  
Microtubule Formation ◽  
Local Refractive Index

Microtubules are dynamic protein filaments that are involved in a number of cellular processes. Here, we report the development of a novel localized surface plasmon resonance (LSPR) biosensing approach for investigating one aspect of microtubule dynamics that is not well understood, namely, nucleation. Using a modified Mie theory with radially variable refractive index, we construct a theoretical model to describe the optical response of gold nanoparticles when microtubules form around them. The model predicts that the extinction maximum wavelength is sensitive to a change in the local refractive index induced by microtubule nucleation within a few tens of nanometers from the nanoparticle surface, but insensitive to a change in the refractive index outside this region caused by microtubule elongation. As a proof of concept to demonstrate that LSPR can be used for detecting microtubule nucleation experimentally, we induce spontaneous microtubule formation around gold nanoparticles by immobilizing tubulin subunits on the nanoparticles. We find that, consistent with the theoretical model, there is a redshift in the extinction maximum wavelength upon the formation of short microtubules around the nanoparticles, but no significant change in maximum wavelength when the microtubules are elongated. We also perform kinetic experiments and demonstrate that the maximum wavelength is sensitive to the microtubule nuclei assembly even when microtubules are too small to be detected from an optical density measurement.

THEORETICAL MODEL FOR THE CALCULATION OF OPTICAL PROPERTIES OF GOLD NANOPARTICLES

2010 ◽  
Vol 19 (03) ◽  
pp. 427-436
Author(s):  
A. MENDOZA-GARCÍA ◽  
A. ROMERO-DEPABLOS ◽  
M. A. ORTEGA ◽  
J. L. PAZ ◽  
L. ECHEVARRÍA
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Optical Properties ◽  
Theoretical Model ◽  
Absorption Coefficient ◽  
Molecular System ◽  
Two Dimensional ◽  
Box Models ◽  
Solvent Environment ◽  
Absorption And Dispersion

We have developed an analytical method to describe the optical properties of nanoparticles, whose results are in agreement with the observed experimental behavior according to the size of the nanoparticle under analysis. Our considerations to describe plasmonic absorption and dispersion are based on the combination of the two-level molecular system and the two-dimensional quantum box models. Employing the optical stochastic Bloch equations, we have determined the system's coherence, from which we have calculated expressions for the absorption coefficient and refractive index. The innovation of this methodology is that it allows us to take into account the solvent environment, which induce quantum effects not considered by classical treatments.

Optical Properties and Detection Sensitivity of Noble Metal Nanoparticles

2018 ◽  
Vol 10 (3) ◽  
pp. 346-350
Author(s):  
Hongyan Zhao ◽  
Xin Liu ◽  
Shoubao Zhang ◽  
Xiaoli Liu ◽  
Rende Ma ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Silver Nanoparticles ◽  
Refractive Index ◽  
Extinction Spectrum ◽  
Spectral Characteristics ◽  
Resonance Wavelength ◽  
Detection Sensitivity ◽  
Noble Metal Nanoparticles ◽  
Localized Surface Plasmon ◽  
Refractive Indices

By using the finite difference time domain method, the localized surface plasmon extinction spectrum of different sizes of spherical gold and silver nanoparticles were simulated and analyzed in external environments with various refractive indices. It was observed that the changes in the position of the resonance wavelength were linearly proportional to the external refractive index, while the sensitivity increased with nanoparticle size. The sensitivity of the spherical silver nanoparticles with a radius of 40 nm reached 122 nm/RIU. For the silver and gold nanoparticles of the same size, the sensitivity of the silver nanoparticles was greater than that of the gold nanoparticles. In the experiment, the spectral characteristics of the silver nanoparticles with different sizes under various external refractive indices were measured. The experimental results were consistent with the simulation results. The resonance wavelength and the concentration of the solution showed a good linear relationship. By using the sensitive properties of the nanoparticles such as external refractive index, the amount of sucrose in the solution can be measured.

Tuning the plasmon resonance of gold nanoparticles in phase-separated glass via the local refractive index change

2021 ◽  
Vol 566 ◽  
pp. 120893
Author(s):  
G. Shakhgildyan ◽  
L. Avakyan ◽  
M. Ziyatdinova ◽  
G. Atroshchenko ◽  
N. Presnyakova ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Plasmon Resonance ◽  
Refractive Index Change ◽  
Index Change ◽  
Local Refractive Index

Implications of sample aging on the formation of internally etched silica coated gold nanoparticles

RSC Advances ◽  
2015 ◽  
Vol 5 (5) ◽  
pp. 3774-3780 ◽  
Author(s):  
Anna A. Volkert ◽  
Marie Carmelle S. Pierre ◽  
Binaya Shrestha ◽  
Amanda J. Haes
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Storage Conditions ◽  
Gold Nanospheres ◽  
Refractive Index Sensitivity ◽  
Index Sensitivity ◽  
Sample Age ◽  
And Storage ◽  
Local Refractive Index

Local refractive index sensitivity modelling using the plasmonic properties of gold nanospheres assists in the elucidation of the nanoparticle-rattle formation as a function of sample age and storage conditions.

scholarly journals Shape Effect on the Refractive Index Sensitivity at Localized Surface Plasmon Resonance Inflection Points of Single Gold Nanocubes with Vertices

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Hui Bin Jeon ◽  
Philippe Vuka Tsalu ◽  
Ji Won Ha
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Localized Surface Plasmon ◽  
Shape Effect ◽  
Frequency Shifts ◽  
Inflection Points

Abstract Plasmonic gold nanoparticles with sharp tips and vertices, such as gold bipyramids (AuBPs) and gold nanocubes (AuNCs), have been widely used for high-sensitivity localized surface plasmon resonance (LSPR) sensing. However, conventional LSPR sensors based on frequency shifts have a major disadvantage: the asymmetry and broadening of LSPR peaks because of instrumental, environmental, and chemical noises that limit the precise determination of shift positions. Herein, we demonstrated an alternative method to improve the efficiency of the sensors by focusing on homogeneous LSPR scattering inflection points (IFs) of single gold nanoparticles with a single resonant mode. In addition, we investigated the effect of the shape and vertices of AuNCs on the refractive index (RI) sensitivity of homogeneous LSPR IFs by comparing with gold nanospheres (AuNSs) of similar size. The results show that for both AuNCs and AuNSs, tracking homogeneous LSPR IFs allows for higher RI sensitivity than tracking the frequency shifts of the LSPR peaks. Furthermore, single AuNCs with vertices exhibited higher RI sensitivity than single AuNSs of similar size in the homogeneous LSPR IFs. Therefore, we provided a deeper insight into the RI sensitivity of homogeneous LSPR IFs of AuNCs with vertices for their use in LSPR-based biosensors.

scholarly journals Morphological and in situ local refractive index change induced tuning of the optical properties of titania coated porous gold nanoparticles

2020 ◽  
Vol 128 (5) ◽  
pp. 054303
Author(s):  
Laura Juhász ◽  
Bence Parditka ◽  
Shenouda Shanda Shenouda ◽  
Misumi Kadoi ◽  
Kei-ichi Fukunaga ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Optical Properties ◽  
Refractive Index Change ◽  
Index Change ◽  
Porous Gold ◽  
Local Refractive Index

Electrical Control of LSPR from Gold Nanoparticles Using Electrochemical Oxidation

2009 ◽  
Vol 1208 ◽  
Author(s):  
Takashi Miyazaki ◽  
Rei Hasegawa ◽  
Hajime Yamaguchi ◽  
Hitoshi Nagato ◽  
Haruhi Oh-oka ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Refractive Index ◽  
Electrochemical Oxidation ◽  
Indium Tin Oxide ◽  
Localized Surface Plasmon ◽  
Water Medium ◽  
Large Shift ◽  
Positive Voltage ◽  
A Cell ◽  
Spectrum Shift

AbstractLarge shift of localized surface plasmon resonance (LSPR) spectrum of gold nanoparticles was attained by electrochemical oxidation of the nanoparticle surface. This oxidation occurred in a cell consisting of a pair of indium tin oxide (ITO) electrodes with water medium between the electrodes. On one side of the ITO electrode, the gold nanoparticles were adsorbed. The LSPR spectrum was moved consecutively to the red by increasing the applied positive voltage. By the application of 5 V to the cell, the spectrum shift as large as 55 nm was obtained. Though the spectrum shift has already been observed by changing liquid crystal (LC) orientation surrounding gold nanoparticles, the amount of the shift was not large (11 nm). That was because the variation of the effective refractive index of LC was rather small. Our large shift due to electrochemical oxidation resulted from the large refractive index of Au-O. The upper limit of the LSPR spectrum shift by our method is estimated to be 138 nm.

scholarly journals Strategy for fast manufacturing of 3D hydrodynamic focusing multilayer microfluidic chips and its application for flow-based synthesis of gold nanoparticles

2021 ◽  
Vol 25 (8) ◽  
Author(s):  
Yanwei Wang ◽  
Michael Seidel
Keyword(s):  
Gold Nanoparticles ◽  
Microfluidic Devices ◽  
Microfluidic Chips ◽  
Proof Of Concept ◽  
Hydrodynamic Focusing ◽  
Pressure Sensitive Adhesive ◽  
Pmma Sheet ◽  
Pressure Sensitive ◽  
Working Device ◽  
Channel Structures

AbstractFabrication of 3D microfluidic devices is normally quite expensive and tedious. A strategy was established to rapidly and effectively produce multilayer 3D microfluidic chips which are made of two layers of poly(methyl methacrylate) (PMMA) sheets and three layers of double-sided pressure sensitive adhesive (PSA) tapes. The channel structures were cut in each layer by cutting plotter before assembly. The structured channels were covered by a PMMA sheet on top and a PMMA carrier which contained threads to connect with tubing. A large variety of PMMA slides and PSA tapes can easily be designed and cut with the help of a cutting plotter. The microfluidic chip was manually assembled by a simple lamination process.The complete fabrication process from device design concept to working device can be completed in minutes without the need of expensive equipment such as laser, thermal lamination, and cleanroom. This rapid frabrication method was applied for design of a 3D hydrodynamic focusing device for synthesis of gold nanoparticles (AuNPs) as proof-of-concept. The fouling of AuNPs was prevented by means of a sheath flow. Different parameters such as flow rate and concentration of reagents were controlled to achieve AuNPs of various sizes. The sheet-based fabrication method offers a possibility to create complex microfluidic devices in a rapid, cheap and easy way.

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