scholarly journals Surfactant-Free Synthesis and Scalable Purification of Triangular Gold Nanoprisms with Low Non-Specific Cellular Uptake

Nanomaterials ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 539
Author(s):  
Rafael Ramírez-Jiménez ◽  
Álvaro Artiga ◽  
Scott G. Mitchell ◽  
Rafael Martín-Rapún ◽  
Jesús M. de la Fuente
Keyword(s):  
Photothermal Therapy ◽  
Resonance Wavelength ◽  
Scaling Up ◽  
Localized Surface Plasmon ◽  
Cellular Internalization ◽  
Purification Step ◽  
Purification Method ◽  
Direct Scaling ◽  
Gold Nanoprisms ◽  
Shape Selective

Gold nanoprisms possess remarkable optical properties that make them useful for medical biotechnology applications such as diagnosis and photothermal therapy. However, shape-selective synthesis of gold nanoprisms is not trivial and typically requires either toxic surfactants or time-consuming purification protocols, which can limit their applicability. Here, we show how triangular gold nanoprisms of different sizes can be purified by precipitation using the non-toxic glutathione ligand, thereby removing the need for toxic surfactants and bottleneck purification techniques. The protocol is amenable for direct scaling up as no instrumentation is required in the critical purification step. The new purification method provides a two-fold increased yield in gold nanoprisms compared to electrophoretic filtration, while providing nanoprisms of similar localized surface plasmon resonance wavelength. Crucially, the gold nanoprisms isolated using this methodology show fewer non-specific interactions with cells and lower cellular internalization, which paves the way for a higher selectivity in therapeutic applications.

scholarly journals Strong coupling of a plasmonic nanoparticle to a semiconductor nanowire

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yingying Jin ◽  
Liu Yang ◽  
Chenxinyu Pan ◽  
Zhangxing Shi ◽  
Bowen Cui ◽  
...  
Keyword(s):  
Strong Coupling ◽  
Coupled System ◽  
Resonance Wavelength ◽  
Transverse Magnetic ◽  
Spectral Shift ◽  
Au Nanoparticle ◽  
Localized Surface Plasmon ◽  
Nanowire Diameter ◽  
Plasmonic Nanoparticle ◽  
Au Nanosphere

Abstract By placing a single Au nanoparticle on the surface of a cadmium sulfide (CdS) nanowire, we demonstrate strong coupling of localized surface plasmon resonance (LSPR) modes in the nanoparticle and whispering gallery modes (WGMs) in the nanowire. For a 50-nm-diameter Au-nanosphere particle, strong coupling occurs when the nanowire diameter is between 300 and 600 nm, with a mode splitting up to 80 meV. Using a temperature-induced spectral shift of the resonance wavelength, we also observe the anticrossing behavior in the strongly coupled system. In addition, since the Au nanosphere has spherical symmetry, the supported LSPR mode can be selectively coupled with transverse electric (TE) and transverse magnetic (TM) WGMs in the nanowire. The ultracompact strong-coupling system shown here may provide a versatile platform for studying hybrid “photon–plasmon” nanolasers, nonlinear optical devices, and nanosensors.

scholarly journals Double-resonant enhancement of third-harmonic generation in graphene nanostructures

2017 ◽  
Vol 375 (2090) ◽  
pp. 20160313 ◽  
Author(s):  
Jian Wei You ◽  
Jie You ◽  
Martin Weismann ◽  
Nicolae C. Panoiu
Keyword(s):  
Harmonic Generation ◽  
Spectral Response ◽  
Near Field ◽  
Field Enhancement ◽  
Third Harmonic Generation ◽  
Resonance Wavelength ◽  
Localized Surface Plasmon ◽  
Third Harmonic ◽  
New Horizons ◽  
Geometry Dependence

Intriguing and unusual physical properties of graphene offer remarkable potential for advanced, photonics-related technological applications, particularly in the area of nonlinear optics at the deep-subwavelength scale. In this study, we use a recently developed numerical method to illustrate an efficient mechanism that can lead to orders of magnitude enhancement of the third-harmonic generation in graphene diffraction gratings. In particular, we demonstrate that by taking advantage of the geometry dependence of the resonance wavelength of localized surface-plasmon polaritons of graphene ribbons and discs one can engineer the spectral response of graphene gratings so that strong plasmonic resonances exist at both the fundamental frequency and third-harmonic (TH). As a result of this double-resonant mechanism for optical near-field enhancement, the intensity of the TH can be increased by more than six orders of magnitude. This article is part of the themed issue ‘New horizons for nanophotonics’.

scholarly journals Light harvesting enhancement using metal nanoparticles

2021 ◽  
Vol 2 (5 (110)) ◽  
Author(s):  
Mohammad Tariq Yaseen
Keyword(s):  
Silver Nanoparticles ◽  
Optical Properties ◽  
Metal Nanoparticles ◽  
Light Harvesting ◽  
Field Enhancement ◽  
Optical Response ◽  
Resonance Wavelength ◽  
Optical Field ◽  
Localized Surface Plasmon ◽  
Gold And Silver Nanoparticles

Metal nanoparticles are very important for their optical properties when they interact with light. Metal nanoparticles have the ability to confine the collective oscillation of electrons, which is called localized surface plasmon resonance (LSPR). In this work, silver nanoparticles have been proposed to enhance light harvesting, which could be useful for different applications. Metal nanoparticles such as gold and silver nanoparticles have the ability to concentrate field in a very small space. In this study, gold and silver nanoparticles optical response was investigated using frequency domain simulation. The resonance wavelength of gold and silver nanoparticles was about 550 nm and 400 nm, respectively. Silver nanoparticles showed better LSPR performance than gold nanoparticles. Therefore, silver nanoparticles were chosen for optical field enhancement. Here silver nanoparticles were placed on a silicon substrate for optical field enhancement. To study the effect of size on the optical response of silver nanoparticles, the optical properties of this structure with different silver nanoparticles diameter values were investigated. Silver nanoparticles with 40 nm diameters showed a better optical response. To study the effect of the distance between silver nanoparticles on the optical response, different gap values were put between silver nanoparticles. The gap value of 4 nm showed a better optical response. The obtained results showed that the localized field is strongly dependent on the metal type, size, and space between nanoparticles. In addition, the optical field concentration can be controlled by tuning the size and space between silver nanoparticles. This will support localized field enhancement. The enhanced localized field will increase the field absorption near the surface, which can be beneficial for energy harvesting applications such as solar cells and detectors

scholarly journals Low-dose X-ray enhanced tumor accumulation of theranostic nanoparticles for high-performance bimodal imaging-guided photothermal therapy

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qiaolin Wei ◽  
Jian He ◽  
Shuaifei Wang ◽  
Shiyuan Hua ◽  
Yuchen Qi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Photothermal Therapy ◽  
Low Dose ◽  
Rapid Development ◽  
Localized Surface Plasmon ◽  
Tumor Growth Inhibition ◽  
Tumor Site ◽  
X Ray ◽  
Bimodal Imaging ◽  
Theranostic Nanoparticles

Abstract Background Theranostic nanoparticles (NPs) have achieved rapid development owing to their capacity for personalized multimodal diagnostic imaging and antitumor therapy. However, the efficient delivery and bulk accumulation of NPs in tumors are still the decisive factors in improving therapeutic effect. It is urgent to seek other methods to alters tumor microenvironment (like vascular permeability and density) for enhancing the efficiency of nanoparticles delivery and accumulation at the tumor site. Methods Herein, we developed a Raman-tagged hollow gold nanoparticle (termed as HAuNP@DTTC) with surface-enhanced Raman scattering (SERS) property, which could be accumulated efficiently in tumor site with the pre-irradiation of low-dose (3 Gy) X-ray and then exerted highly antitumor effect in breast cancer model. Results The tumor growth inhibition (TGI) of HAuNP@DTTC-induced photothermal therapy (PTT) was increased from 60% for PTT only to 97%, and the lethal distant metastasis of 4T1 breast cancer (such as lung and liver) were effectively inhibited under the X-ray-assisted PTT treatment. Moreover, with the strong absorbance induced by localized surface plasmon resonance in near-infrared (NIR) region, the signals of Raman/photoacoustic (PA) imaging in tumor was also significantly enhanced after the administration of HAuNP@DTTC, indicating it could be used as the Raman/PA imaging and photothermal agent simultaneously under 808 nm laser irradiation. Conclusions Our studied of the as-prepared HAuNP@DTTC integrated the Raman/PA imaging and PTT functions into the single platform, and showed the good prospects for clinical applications especially with the low-dose X-ray irradiation as an adjuvant, which will be a productive strategy for enhancing drug delivery and accumulation in tumor theranostics. Graphic Abstract

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.

Zigzag Localized Surface Plasmon Resonance Wavelength Shift of Asymmetric V-Shape Ag Nanorods

2018 ◽  
Vol 122 (30) ◽  
pp. 17400-17405 ◽  
Author(s):  
Jianghao Li ◽  
Xiaotian Xue ◽  
Yihang Fan ◽  
Fei Zhu ◽  
Gen Li ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Resonance Wavelength ◽  
Localized Surface Plasmon ◽  
Wavelength Shift

scholarly journals Facilitating Hotspot Alignment in Tip-Enhanced Raman Spectroscopy via the Silver Photoluminescence of the Probe

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6687
Author(s):  
Yuan Fan ◽  
Dan Jin ◽  
Xiuju Wu ◽  
Hui Fang ◽  
Xiaocong Yuan
Keyword(s):  
Raman Spectroscopy ◽  
Plasmon Resonance ◽  
Near Field ◽  
Resonance Wavelength ◽  
Dark Field ◽  
Intensity Change ◽  
Localized Surface Plasmon ◽  
Excitation Wavelength ◽  
Alignment Procedure ◽  
Tip Enhanced Raman Spectroscopy

A tip-enhanced Raman spectroscopy (TERS) system based on an atomic force microscope (AFM) and radially polarized laser beam was developed. A TERS probe with plasmon resonance wavelength matching the excitation wavelength was prepared with the help of dark-field micrographs. The intrinsic photoluminescence (PL) from the silver (Ag)-coated TERS probe induced by localized surface plasmon resonance contains information about the near-field enhanced electromagnetic field intensity of the probe. Therefore, we used the intensity change of Ag PL to evaluate the stability of the Ag-coated probe during TERS experiments. Tracking the Ag PL of the TERS probe was helpful to detect probe damage and hotspot alignment. Our setup was successfully used for the TERS imaging of single-walled carbon nanotubes, which demonstrated that the Ag PL of the TERS probe is a good criterion to assist in the hotspot alignment procedure required for TERS experiments. This method lowers the risk of contamination and damage of the precious TERS probe, making it worthwhile for wide adoption in TERS experiments.

scholarly journals Active Accumulation of Spherical Analytes on Plasmonic Hot Spots of Double-Bent Au Strip Arrays by Multiple Dip-Coating

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 660 ◽  
Author(s):  
Jinhyung Lee ◽  
Eun-Ah You ◽  
Do Won Hwang ◽  
Shinill Kang ◽  
Jung-Sub Wi
Keyword(s):  
Hot Spots ◽  
Resonance Wavelength ◽  
Dip Coating ◽  
Localized Surface Plasmon ◽  
Plasmonic Nanostructures ◽  
Sensor Surface ◽  
Plasmonic Sensor ◽  
Target Analytes ◽  
Coating Method ◽  
Dip Coating Method

To achieve sensitive plasmonic biosensors, it is essential to develop an efficient method for concentrating analytes in hot spots, as well as to develop plasmonic nanostructures for concentrating light. In this study, target analytes were delivered to the surface of double-bent Au strip arrays by a multiple dip-coating method; they were self-aligned in the valleys between neighboring Au strips by capillary forces. As the valleys not only accommodate target analytes but also host strong electromagnetic fields due to the interaction between adjacent strips, sensitive measurement of target analytes was possible by monitoring changes in the wavelength of a localized surface plasmon resonance. Using the proposed plasmonic sensor and target delivery method, the adsorption and saturation of polystyrene beads 100 nm in size on the sensor surface were monitored by the shift of the resonance wavelength. In addition, the pH-dependent stability of exosomes accumulated on the sensor surface was successfully monitored by changing the pH from 7.4 to 4.0.

A thermally tunable single-band metamaterials with VO2 disks based on localized surface plasmon resonance

2019 ◽  
Vol 9 (7) ◽  
pp. 704-711
Author(s):  
Xingsheng Liu ◽  
Lijun Dong ◽  
Shouzhi Pu
Keyword(s):  
Room Temperature ◽  
Resonance Wavelength ◽  
Metamaterial Absorber ◽  
Single Band ◽  
Localized Surface Plasmon ◽  
Numerical Verification ◽  
Central Metal ◽  
Temperature Changes ◽  
Band Absorption ◽  
Parameter Condition

A thermal tunability metamaterial absorber with single-band absorption properties is proposed and numerical verification. An absorption peak can be revealed at resonant wavelength 1.54 m at room temperature. The metal parameter condition is optimized in simulation in order to improve the property of this absorber. Simulated results reveal that absorption performances can be modulated based on the refractive index changes. High FOM values are obtained based on water or glucose solution. Moreover, the resonance wavelength and amplitude are modulated based on the ambient temperature changes. Finally, the effect of central metal particle side width or dielectric layer thickness at room temperature on absorption performances are also revealed in simulation.

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