Journal articles: 'LSPR TUNING'

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Balitskii, Olexiy, Oleksandr Mashkov, Anastasiia Barabash, Viktor Rehm, Hany A. Afify, Ning Li, Maria S. Hammer, et al. "Ligand Tuning of Localized Surface Plasmon Resonances in Antimony-Doped Tin Oxide Nanocrystals." Nanomaterials 12, no. 19 (October 4, 2022): 3469. http://dx.doi.org/10.3390/nano12193469.

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Aliovalent-doped metal oxide nanocrystals exhibiting localized surface plasmons (LSPRs) are applied in systems that require reflection/scattering/absorption in infrared and optical transparency in visible. Indium tin oxide (ITO) is currently leading the field, but indium resources are known to be very restricted. Antimony-doped tin oxide (ATO) is a cheap candidate to substitute the ITO, but it exhibits less advantageous electronic properties and limited control of the LSPRs. To date, LSPR tuning in ATO NCs has been achieved electrochemically and by aliovalent doping, with a significant decrease in doping efficiency with an increasing doping level. Here, we synthesize plasmonic ATO nanocrystals (NCs) via a solvothermal route and demonstrate ligand exchange to tune the LSPR energies. Attachment of ligands acting as Lewis acids and bases results in LSPR peak shifts with a doping efficiency overcoming those by aliovalent doping. Thus, this strategy is of potential interest for plasmon implementations, which are of potential interest for infrared upconversion, smart glazing, heat absorbers, or thermal barriers.

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Lopatynskyi, A. M. "Smart nanocarriers for drug delivery: controllable LSPR tuning." Semiconductor Physics Quantum Electronics and Optoelectronics 19, no. 4 (December 5, 2016): 358–65. http://dx.doi.org/10.15407/spqeo19.04.358.

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Chen, Chih-Yao, Ching-Yun Chien, Chih-Ming Wang, Rong-Sheng Lin, and I.-Chen Chen. "Plasmon Tuning of Liquid Gallium Nanoparticles through Surface Anodization." Materials 15, no. 6 (March 15, 2022): 2145. http://dx.doi.org/10.3390/ma15062145.

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In this work, tunable plasmonic liquid gallium nanoparticles (Ga NPs) were prepared through surface anodizing of the particles. Shape deformation of the Ga NPs accompanied with dimpled surface topographies could be induced during electrochemical anodization, and the formation of the anodic oxide shell helps maintain the resulting change in the particle shape. The nanoscale dimple-like textures led to changes in the localized surface plasmon resonance (LSPR) wavelength. A maximal LSPR red-shift of ~77 nm was preliminarily achieved using an anodization voltage of 0.7 V. The experimental results showed that an increase in the oxide shell thickness yielded a negligible difference in the observed LSPR, and finite-difference time-domain (FDTD) simulations also suggested that the LSPR tunability was primarily determined by the shape of the deformed particles. The extent of particle deformation could be adjusted in a very short period of anodization time (~7 s), which offers an efficient way to tune the LSPR response of Ga NPs.

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Demydov, P. V., A. M. Lopatynskyi, І. І. Hudzenko, and V. I. Chegel. "The approaches for localized surface plasmon resonance wavelength position tuning. Short review." Semiconductor Physics, Quantum Electronics and Optoelectronics 24, no. 3 (August 26, 2021): 304–11. http://dx.doi.org/10.15407/spqeo24.03.304.

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A unique feature of nanoparticles made from highly conductive materials (plasmonic nanoparticles) is that their localized surface plasmon resonance (LSPR) wavelength position can be tuned by changing the shape, size, composition and environment in accordance with the purpose of the application. In this paper, the main mechanisms of LSPR tuning that are available at the present time are reviewed. In particular, a widely used method for tuning the LSPR wavelength position is based on selecting the type of a plasmonic nanoparticle material such as gold, silver, copper, aluminum and gold-silver alloy. The examples of changing the resonance absorption position by using nanoparticles with different shapes and dimensions have been аlso demonstrated. Furthermore, works with less used LSPR tuning methods, such as controlled regulation of the distance between nanoparticles in one and two dimensions have been considered. The number of works is given, where the LSPR wavelength position can be also controlled by changing the environment in the vicinity of plasmonic nanoparticle: the substrate thickness, the thickness and dielectric parameters of the layer on the surface of the nanoparticle. Examples of active influence on the change in the wave position of LSPR by applying an electric potential and regulating plasma modes have been also discussed.

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Piantanida, Luca, Denys Naumenko, Emanuela Torelli, Monica Marini, Dennis M. Bauer, Ljiljana Fruk, Giuseppe Firrao, and Marco Lazzarino. "Plasmon resonance tuning using DNA origami actuation." Chemical Communications 51, no. 23 (2015): 4789–92. http://dx.doi.org/10.1039/c5cc00778j.

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Ye, Shuai, Jun Song, Yuliang Tian, Linchun Chen, Dong Wang, Hanben Niu, and Junle Qu. "Photochemically grown silver nanodecahedra with precise tuning of plasmonic resonance." Nanoscale 7, no. 29 (2015): 12706–12. http://dx.doi.org/10.1039/c5nr03652f.

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Li, Wei, Chao Ma, Ling Zhang, Bin Chen, Luyang Chen, and Heping Zeng. "Tuning Localized Surface Plasmon Resonance of Nanoporous Gold with a Silica Shell for Surface Enhanced Raman Scattering." Nanomaterials 9, no. 2 (February 12, 2019): 251. http://dx.doi.org/10.3390/nano9020251.

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We report the tuning of localized surface plasmon resonance (LSPR) of nanoporous gold (NPG) by silica coating, which also affects the surface enhanced Raman scattering (SERS) of NPG. In this study, controllable silica shell is assembled on the NPG surface, and a fully silica thin layer causes more than 50 nm red-shift of LSPR band due to dielectric medium dependence. Additionally, ~1 nm silica coated NPG film shows excellent SERS enhancement, which is due to electromagnetic coupling between ligaments and local surface plasmon field enhancement within pores, and theoretical analysis indicates that silica coating further improves the coupling effect, which demonstrates the electromagnetic origin of the tuning of SERS effect.

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Hou, Hui, Limei Chen, Haili He, Lizhen Chen, Zhenlu Zhao, and Yongdong Jin. "Fine-tuning the LSPR response of gold nanorod–polyaniline core–shell nanoparticles with high photothermal efficiency for cancer cell ablation." Journal of Materials Chemistry B 3, no. 26 (2015): 5189–96. http://dx.doi.org/10.1039/c5tb00556f.

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Mahapatra, Niharendu, and Mintu Halder. "Facile reversible LSPR tuning through additive-induced self-aggregation and dissemination of Ag NPs: role of cyclodextrins and surfactants." RSC Adv. 4, no. 36 (2014): 18724–30. http://dx.doi.org/10.1039/c4ra01523a.

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An easy and economical protocol for the reversible LSPR tuning of Ag NPs through cyclodextrin-induced self-aggregation and color fading, followed by surfactant-induced dissemination of self-assembly and consequent color reappearance.

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Lie, Shao Qing, Hong Yan Zou, Yong Chang, and Cheng Zhi Huang. "Tuning of the near-infrared localized surface plasmon resonance of Cu2−xSe nanoparticles with lysozyme-induced selective aggregation." RSC Adv. 4, no. 98 (2014): 55094–99. http://dx.doi.org/10.1039/c4ra05828c.

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Poly(styrene sulfonic acid)sodium stabilized Cu_2−xSe nanoparticles (PSS–Cu_2−xSe NPs) with localized surface plasmon resonance (LSPR) absorption centered at 980 nm can be selectively aggregated by lysozyme (Lys) through the electrostatic attraction, giving rise to a red shift of the LSPR in the near-infrared (NIR) region.

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Han, Bingbing, Sila Jin, Qi Chu, Yang Jin, Xiangxin Xue, Shuang Guo, Yeonju Park, Lei Chen, and Young Mee Jung. "New insight into SPR modulating by two-dimensional correlation spectroscopy: the case for an Ag/ITO system." Nanoscale 12, no. 48 (2020): 24357–61. http://dx.doi.org/10.1039/d0nr06256a.

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The localized surface plasmon resonance (LSPR) of Ag/indium tin oxide (ITO)@polystyrene (PS) in the visible-NIR region was dependent on the tuning of the carrier density caused by adjusting the thickness of the ITO layer.

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Wolf, Andreas, Torben Kodanek, and Dirk Dorfs. "Tuning the LSPR in copper chalcogenide nanoparticles by cation intercalation, cation exchange and metal growth." Nanoscale 7, no. 46 (2015): 19519–27. http://dx.doi.org/10.1039/c5nr05425g.

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Xiang, Junhuai, Chu Wang, Huilin Li, Dandan Men, Xiaofang Qiu, and Honghua Zhang. "Highly efficient production of ordered wafer-scale gold nanoparticle arrays film by simple heat treatment based on colloidal monolayer." International Journal of Modern Physics B 32, no. 15 (June 18, 2018): 1850192. http://dx.doi.org/10.1142/s0217979218501928.

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Periodic hexagonal gold crystal spherical nanoparticle arrays with controllable size and periodicity are fabricated by physical vapor deposition and further heat treatment based on monolayer colloidal crystal template. The size and center-to-center spacing of nanoparticles (NPs) were manipulated conveniently by tuning the deposition thickness of Au film and the size of colloidal spheres of the template, respectively. The thickness range of deposited Au film dependent on the size of colloidal spheres was investigated comprehensively. Dewetting model was established and employed to analyze the whole process of the evolution from gold film to spherical nanoparticle with uniform size. Additionally, localized surface plasmon resonance (LSPR) responses of these Au nanoparticle arrays were systematically measured. It is found that the extinction properties are significantly influenced by the particle size and periodicity of arrays. With the increase of particle size, the LSPR peak shows a red shift due to the quantum size effect of the nanoscaled Au particle. Meanwhile, the diffraction peaks also show small red shift due to a slight increase of average refractive index of arrays. This is highly helpful to improve its practical applications for detecting biochemical molecules based on LSPR and diffraction peak sensing.

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Rodríguez-Lorenzo, Laura, José M. Romo-Herrera, Jorge Pérez-Juste, Ramón A. Alvarez-Puebla, and Luis M. Liz-Marzán. "Reshaping and LSPR tuning of Au nanostars in the presence of CTAB." Journal of Materials Chemistry 21, no. 31 (2011): 11544. http://dx.doi.org/10.1039/c1jm10603a.

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Hidayah, A. N., and Y. Herbani. "Tuning Localized Surface Plasmon Resonance (LSPR) of Au-Ag Nanoalloys by Femtosecond Laser." Journal of Physics: Conference Series 1436 (January 2020): 012107. http://dx.doi.org/10.1088/1742-6596/1436/1/012107.

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Katyal, Jyoti. "Al-Au Heterogeneous Dimer-trimer Nanostructure for SERS." Nanoscience & Nanotechnology-Asia 10, no. 1 (January 23, 2020): 21–28. http://dx.doi.org/10.2174/2210681208666180821141727.

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: Tunability in resonance wavelength and the enhancement of the electromagnetic field intensities around the surface are two unique properties which make metal as a plasmonic material. A theoretical investigation on the LSPR and field enhancement for heterogeneous dimer–trimer metallic nanostructure by constituting Al and Au as two different plamsonic materials has been studied. Since electrons in Al exhibit free behavior for LSPR of Au, therefore, they influence the electric field magnitude generated by Au LSPR. Methods: The electromagnetic simulations reported in this paper were performed using the FDTD Solutions (version 7.5.1), a product of Lumerical Solutions Inc., Vancouver, Canada. We adopted a cubic Yee cell of 1 nm side and a time step Δt= 1.31•10-18 s, bounded by Courant condition. Results: The extinction spectrum shows LSPR peak over UV-visible region for isotropic nanostructure which shifts to NIR region for anisotropic shape nanostructure. The spherical shape hetero dimer nanostructure shows enhancement factor ~ 3.9 X 105 whereas it increases to ~ 6.2 X 106 for anisotropic shape at 610 nm. The field distribution corresponding to the trimer nanostructure reveals a large dipolar field distribution on each of the three nanoparticles, oscillating approximately in-phase. The spherical shape Al-Au-Al shows enhancement factor ~ 8.5 X 106 at 571 nm. The anisotropic shape increase the enhancement factor to ~ 2.4 X 107 at peak wavelength 700 nm i.e. tuning the plasmon wavelength towards NIR region. Conclusion: The tunability in plasmon wavelength and field enhancement factor has been evaluated for heterogeneous nanostructure over wider spectrum range i.e. DUV-Visible-NIR using Au-Al dimer and trimer nanostructure. The isotropic shape Au-Al hetero nanostructure shows larger enhancement in the UV-visible region, whereas the anisotropic shape nanostructure contributes towards the NIR region.

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Raja-Mogan, Tharishinny, Bunsho Ohtani, and Ewa Kowalska. "Photonic Crystals for Plasmonic Photocatalysis." Catalysts 10, no. 8 (July 23, 2020): 827. http://dx.doi.org/10.3390/catal10080827.

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Noble metal (NM)-modified wide-bandgap semiconductors with activity under visible light (Vis) irradiation, due to localized surface plasmon resonance (LSPR), known as plasmonic photocatalysts, have been intensively studied over the last few years. Despite the novelty of the topic, a large number of reports have already been published, discussing the optimal properties, synthesis methods and mechanism clarification. It has been proposed that both efficient light harvesting and charge carriers’ migration are detrimental for high and stable activity under Vis irradiation. Accordingly, photonic crystals (PCs) with photonic bandgap (PBG) and slow photon effects seem to be highly attractive for efficient use of incident photons. Therefore, the study on PCs-based plasmonic photocatalysts has been conducted, mainly on titania inverse opal (IO) modified with nanoparticles (NPs) of NM. Although, the research is quite new and only several reports have been published, it might be concluded that the matching between LSPR and PBG (especially at red edge) by tuning of NMNPs size and IO-void diameter, respectively, is the most crucial for the photocatalytic activity.

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Koleva, M. E., A. O. Dikovska, N. N. Nedyalkov, and D. Karashanova. "Effect of laser annealing on the properties of Ag/ZnO nanostructures." Journal of Physics: Conference Series 2240, no. 1 (March 1, 2022): 012008. http://dx.doi.org/10.1088/1742-6596/2240/1/012008.

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Abstract Ag/ZnO nanostructures were synthesized using pulsed laser deposition (PLD) in open air (at atmospheric pressure). The deposition was carried out by a Nd:YAG laser, with the Ag layer composed of nanoparticles grown on SiO2 (001) substrates by the laser wavelength of 355 nm; this layer was covered by ZnO deposited by using the laser wavelength of 1064 nm. The samples were laser annealed, which led to a modification of the nanoparticles. The nanocomposites produced were characterized by TEM, UV-Vis and PL spectroscopy. The annealing procedures influence the optical properties of the Ag/ZnO nanocomposites. The laser annealing under certain parameters changes the emission behavior of the Ag/ZnO nanocomposite heterostructures. By employing localized surface plasmon resonance (LSPR), the near band edge (NBE) emission intensity of the ZnO films composed of nanoparticles was varied. An enhancement of the UV emission located at about 383 nm, commonly attributed to an excitonic transition, was registered after laser annealing with one pulse at the wavelength of 355 nm. The results obtained demonstrate that the annealing of Ag/ZnO composite nanostructures plays a key role in tuning the PL performance of a semiconductor material where an LSPR occurs.

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Pandit, Pallavi, Matthias Schwartzkopf, André Rothkirch, Stephan V. Roth, Sigrid Bernstorff, and Ajay Gupta. "Structure–Function Correlations in Sputter Deposited Gold/Fluorocarbon Multilayers for Tuning Optical Response." Nanomaterials 9, no. 9 (September 3, 2019): 1249. http://dx.doi.org/10.3390/nano9091249.

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A new strategy to nanoengineer gold/fluorocarbon multilayer (ML) nanostructures is reported. We have investigated the morphological changes occurring at the metal–polymer interface in ML structures with varying volume fraction of gold (Au) and the kinetic growth aspect of the microscale properties of nano-sized Au in plasma polymer fluorocarbon (PPFC). Investigations were carried out at various temperatures and annealing times by means of grazing incidence small-angle and wide-angle X-ray scattering (GISAXS and GIWAXS). We have fabricated a series of MLs with varying volume fraction (0.12, 0.27, 0.38) of Au and bilayer periodicity in ML structure. They show an interesting granular structure consisting of nearly spherical nanoparticles within the polymer layer. The nanoparticle (NP) morphology changes due to the collective effects of NPs diffusion within ensembles in the in-plane vicinity and interlayer with increasing temperature. The in-plane NPs size distinctly increases with increasing temperature. The NPs become more spherical, thus reducing the surface energy. Linear growth of NPs with temperature and time shows diffusion-controlled growth of NPs in the ML structure. The structural stability of the multilayer is controlled by the volume ratio of the metal in polymer. At room temperature, UV-Vis shows a blue shift of the plasmon peak from 560 nm in ML Au/PTFE_1 to 437 nm in Au/PTFE_3. We have identified the fabrication and postdeposition annealing conditions to limit the local surface plasmon resonance (LSPR) shift from Δ λ L S P R = 180 nm (Au/PTFE_1) to Δ λ L S P R = 67 nm (Au/PTFE_3 ML)) and their optical response over a wide visible wavelength range. A variation in the dielectric constant of the polymer in presence of varying Au inclusion is found to be a possible factor affecting the LSPR frequency. Our findings may provide insights in nanoengineering of ML structure that can be useful to systematically control the growth of NPs in polymer matrix.

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Ghosh, Piue, Varsha Thambi, Ashish Kar, Arup Lal Chakraborty, and Saumyakanti Khatua. "Light-induced in situ active tuning of the LSPR of gold nanorods over 90 nm." Optics Letters 46, no. 18 (September 10, 2021): 4562. http://dx.doi.org/10.1364/ol.435242.

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Jia, Shuo, Aiwen Ma, Hanpeng Dong, and Shanhong Xia. "Quantifiable Effect of Interparticle Plasmonic Coupling on Sensitivity and Tuning Range for Wavelength-Mode LSPR Fiber Sensor Fabricated by Simple Immobilization Method." Sensors 22, no. 23 (November 23, 2022): 9075. http://dx.doi.org/10.3390/s22239075.

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Herein a gold nanosphere (AuNS)-coated wavelength-mode localized surface plasmon resonance (LSPR) fiber sensor was fabricated by a simple and time-saving electrostatic self-assembly method using poly(allylamine hydrochloride). Based on the localized enhanced coupling effect between AuNSs, the LSPR spectrums of the AuNS monolayer with good dispersity and high density exhibited a favourable capability for refractive index (RI) measurement. Based on the results obtained from the optimization for AuNS distribution, sensing length, and RI range, the best RI sensitivity of the fiber modified by 100 nm AuNS reached up to about 2975 nm/RIU, with the surrounding RI range from 1.3322 to 1.3664. Using an 80 nm AuNS-modified fiber sensor, the RI sensitivity of 3953 nm/RIU was achieved, with the RI range increased from 1.3744 to 1.3911. The effect of sensing length to RI sensitivity was proven to be negligible. Furthermore, the linear relationship between the RI sensitivity and plasma resonance frequency of the bulk metal, which was dependent on the interparticle plasmon coupling effect, was quantified. Additionally, the resonance peak was tuned from 539.18 nm to 820.48 nm by different sizes of AuNSs-coated fiber sensors at a RI of 1.3322, which means the spectrum was extended from VIS to NIR. It has enormous potential in hypersensitive biochemistry detection at VIS and NIR ranges.

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Gong, Jie, Zhixue Li, Ting Zhang, Runze Chen, Xiaoying Zheng, and Gaoke Zhang. "Morphology-dependent catalytic activity of plasmonic MoO3−x for hydrolytic dehydrogenation of ammonia borane." Functional Materials Letters 10, no. 06 (December 2017): 1750079. http://dx.doi.org/10.1142/s1793604717500795.

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Series of plasmonic MoO[Formula: see text] particles have been prepared by a facile solvothermal method to produce hydrogen via hydrolytic dehydrogenation of ammonia borane. Interestingly, the as-prepared MoO[Formula: see text] particles present various morphologies, i.e. flower, schistose and nanorod by simply tuning the reaction temperature and solvent volume ratio of distilled water and acetic acid. More importantly, these MoO[Formula: see text] particles with different morphologies exhibit various catalytic performances of NH3BH3 under the irradiation of visible light. Particularly, the flower-like MoO[Formula: see text] microstructure possesses the best catalytic activity for hydrogen production probably owing to the relatively large surface area and strong LSPR in the visible region.

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Yoon, Bo Kyeong, Gamaliel Junren Ma, Hyeonjin Park, Abdul Rahim Ferhan, Nam-Joon Cho, and Joshua A. Jackman. "Solvent-induced conformational tuning of lysozyme protein adlayers on silica surfaces: A QCM-D and LSPR study." International Journal of Biological Macromolecules 182 (July 2021): 1906–14. http://dx.doi.org/10.1016/j.ijbiomac.2021.05.113.

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Vahdatkhah, Parisa, and Sayed Khatiboleslam Sadrnezhaad. "Pulsed Electrodeposition of Gold Nanoparticles on Fluorine-Doped Tin Oxide Glass and Absorption-Based Surface Plasmon Resonance Evaluation." Journal of Nano Research 33 (June 2015): 11–26. http://dx.doi.org/10.4028/www.scientific.net/jnanor.33.11.

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Synthesis and immobilization of Au nanoparticles (AuNPs) was performed on transparent fluorine-doped tin oxide (FTO) substrate by pulse electrodeposition method. The method was cost effective, simple and capable of producing nanoparticles strongly attached to the substrate. Effects of several influencing factors such as duty cycle, pulse frequency, current density, solution concentration, deposition period and annealing procedure on the optical properties of AuNPs-FTO electrode were investigated. AuNPs-FTO electrodes were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM) and UV-Vis absorption analysis. Controllability of the plasmon absorption of the electrodeposited film by tuning of the electrodeposition conditions and thermal annealing procedure was important achievements helpful to the progress of the AuNP film applications in the tunable localized surface plasmon resonance spectroscopy (LSPR) manufacturing industry.

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Ryu, Jae-Hoon, Ha Young Lee, Jeong-Yeon Lee, Han-Sol Kim, Sung-Hyun Kim, Hyung Soo Ahn, Dong Han Ha, and Sam Nyung Yi. "Enhancing SERS Intensity by Coupling PSPR and LSPR in a Crater Structure with Ag Nanowires." Applied Sciences 11, no. 24 (December 13, 2021): 11855. http://dx.doi.org/10.3390/app112411855.

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The sensitive characteristics of surface-enhanced Raman scattering (SERS) can be applied to various fields, and this has been of interest to many researchers. Propagating surface plasmon resonance (PSPR) was initially utilized but, recently, it has been studied coupled with localized surface plasmon resonance that occurs in metal nanostructures. In this study, a new type of metal microstructure, named crater, was used for generating PSPR and Ag nanowires (AgNWs) for the generation of LSPR. A crater structure was fabricated on a GaAs (100) wafer using the wet chemical etching method. Then, a metal film was deposited inside the crater, and AgNWs were uniformly coated inside using the spray coating method. Metal films were used to enhance the electromagnetic field when coupled with AgNWs to obtain a high SERS intensity. The SERS intensity measured inside the crater structure with deposited AgNWs was up to 17.4 times higher than that of the flat structure with a deposited Ag film. These results suggest a new method for enhancing the SERS phenomenon, and it is expected that a larger SERS intensity can be obtained by fine-tuning the crater size and diameter and the length of the AgNWs.

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He, Meng-Qi, Shuai Chen, Kan Yao, Jie Meng, Kun Wang, Yong-Liang Yu, and Jian-Hua Wang. "Precisely Tuning LSPR Property via “Peptide-Encoded” Morphological Evolution of Gold Nanorods for Quantitative Visualization of Enzyme Activity." Analytical Chemistry 92, no. 1 (December 13, 2019): 1395–401. http://dx.doi.org/10.1021/acs.analchem.9b04573.

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Inwati, Gajendra Kumar, Promod Kumar, W. D. Roos, H. C. Swart, and Man Singh. "UV-irradiation effects on tuning LSPR of Cu/Ag nanoclusters in ion exchanged glass matrix and its thermodynamic behaviour." Journal of Alloys and Compounds 823 (May 2020): 153820. http://dx.doi.org/10.1016/j.jallcom.2020.153820.

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Velu, Karthick, Rekha Goswami Shrestha, Lok Kumar Shrestha, and Katsuhiko Ariga. "Recent Advancements in Novel Sensing Systems through Nanoarchitectonics." Biosensors 13, no. 2 (February 16, 2023): 286. http://dx.doi.org/10.3390/bios13020286.

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The fabrication of various sensing devices and the ability to harmonize materials for a higher degree of organization is essential for effective sensing systems. Materials with hierarchically micro- and mesopore structures can enhance the sensitivity of sensors. Nanoarchitectonics allows for atomic/molecular level manipulations that create a higher area-to-volume ratio in nanoscale hierarchical structures for use in ideal sensing applications. Nanoarchitectonics also provides ample opportunities to fabricate materials by tuning pore size, increasing surface area, trapping molecules via host–guest interactions, and other mechanisms. Material characteristics and shape significantly enhance sensing capabilities via intramolecular interactions, molecular recognition, and localized surface plasmon resonance (LSPR). This review highlights the latest advancements in nanoarchitectonics approaches to tailor materials for various sensing applications, including biological micro/macro molecules, volatile organic compounds (VOC), microscopic recognition, and the selective discrimination of microparticles. Furthermore, different sensing devices that utilize the nanoarchitectonics concept to achieve atomic-molecular level discrimination are also discussed.

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Laha, Ranjit. "Nurturing Plasmonic Properties of Nanocomposite Thin Films: The Importance of Optimum Oblate Shape." Journal of Materials and Applications 10, no. 2 (November 15, 2021): 73–82. http://dx.doi.org/10.32732/jma.2021.10.2.73.

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Metal nanoparticles (MNPs) embedded dielectric thin films are very crucial for many optoelectronic applications. This report investigates various ways of tuning the plasmonic properties of such nanocomposite thin films. For this, the well-known plasmon resonance condition was first generalized to include the shape and volume fraction of MNPs. This was followed by deriving an empirical formula for the resonance position (λR) which was worked out to be the positive root of a quadratic equation. The coefficients of the deduced quadratic relation involve the parameters obtained from the empirical fit to some of the experimental dielectric functions of MNPs available in literature. The derived working formula enables research community to tune the LSPR of nanocomposites in the whole range of visible wavelengths. The derived formula also concluded that with known lower volume fractions, shape of MNPs affects λR the most, compared to the other parameters. The derived formula was validated by calculating the full extinction spectra. It was shown for the first time that there exists an optimum value of oblate shape to give maximum resonance for a given nanocomposite.

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Potejanasak, Potejana, and Sethavut Duangchan. "Gold Nanoisland Agglomeration upon the Substrate Assisted Chemical Etching Based on Thermal Annealing Process." Crystals 10, no. 6 (June 23, 2020): 533. http://dx.doi.org/10.3390/cryst10060533.

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In this study, we proposed the self-organization process and its localized surface plasmon resonance property (LSPR) to study the effect of chemically treated quartz glass substrates for gold nanoisland array formation. Firstly, we etched a quartz glass substrate using a sputter etching machine. Secondly, n-butanol was treated on the surface of the substrate. Then, we deposited a gold thin film on the substrate with assisted chemical etching. Finally, the self-organization method examined the thermal annealing of gold nanoisland arrays on a substrate. The results showed that the gold nanoisland that was aggregated on an etched quartz glass substrate was large and sparse, while the gold nanoisland aggregated on a chemically treated substrate was small and dense. Further, it was revealed that a substrate’s surface energy reduced chemical treating and increased the gold nanoisland contact angle on the substrate via the thermal annealing process. It was also confirmed that chemical treatment was useful to control the morphology of gold nanoisland arrays on a substrate, particularly when related to tuning their optical property.

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Soosaimanickam, Ananthakumar, and Moorthy Babu Sridharan. "Developments in Colloidal Synthesis of Cu2-xS (0 ≤ x ≤ 1) Nanocrystals—An Overview." Journal of Nanoscience and Nanotechnology 20, no. 6 (June 1, 2020): 3659–82. http://dx.doi.org/10.1166/jnn.2020.17534.

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Colloidal synthesis of Cu2-xS (x = 0 ≤ x ≤ 1) nanocrystals (NCs) has been developed in recent years as broad context and its applications for energy harvesting is widely analyzed. Exciting properties of Cu2-xS NCs such as cation exchange, localized surface plasmon resonance (LSPR) in near infra-red (NIR) region are well manipulated by altering the stoichiometry through facile colloidal method. Due to their size, shape, phase tunability and self-assembly nature, synthesis of Cu2-xS NCs through colloidal medium has many advantages. Desired phase with desired composition can be achieved through facile tuning of solvent atmosphere and physical parameters of the synthesis conditions. In this regard, the present review summarizes recent achievements made in the colloidal synthesis of Cu2-xS NCs. Their structural and phase transformation in presence of different solvents and reaction conditions have been reviewed. The crucial role of phosphine-free solvents in synthesizing various phases, morphology of Cu2-xS NCs has been discussed. Applications of these Cu2-xS NCs for solar energy harvesting in third generation solar cells have also been reviewed.

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Shi, Weihong, Justin Casas, Meenakshi Venkataramasubramani, and Liang Tang. "Synthesis and Characterization of Gold Nanoparticles with Plasmon Absorbance Wavelength Tunable from Visible to Near Infrared Region." ISRN Nanomaterials 2012 (October 15, 2012): 1–9. http://dx.doi.org/10.5402/2012/659043.

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Gold nanorods with localized surface plasmon resonance (LSPR) can be chemically synthesized. We systematically investigated the effects of reaction parameters and centrifugation on the fine tuning of the rod dimension in scale-up production (80–100 mL). Nanorods of absorption bands from 600–1050 nm were fabricated with precise control of the aspect ratio (AR) from 1.5 to 8.9. Although all chemicals are important in directing the nanostructure, silver ion concentration and seed/Au3+ ratio were the most effective variations to adjust the absorption wavelength. With a single surfactant under the influence of silver nitrate, short nanorods up to AR of 5 were synthesized with corresponding maximum absorption wavelength at 902 nm. To achieve higher aspect ratio with absorption band beyond 1,000 nm, two-surfactant growth solution was sought to further elongate the rod length. Centrifugation speed and times were found to exert significant influences on the final rod dimension, which is important during the purification process. In a relatively large quantity nanorod synthesis, even distribution and sufficient mixing of chemical ingredients play an essential role in determining the yield, uniformity, and stability of the final nanorod formation.

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Zhu, Shao Li, and Wei Zhou. "Optical Sensing Based on Localized Surface Plasmon Resonance." Key Engineering Materials 447-448 (September 2010): 584–89. http://dx.doi.org/10.4028/www.scientific.net/kem.447-448.584.

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Localized surface plasmon resonance (LSPR)-based nano-biosensors are of great interest in various applications such as environmental protection, biotechnology, and food safety. It is well known that types of materials and shapes of the nanostructures have significant influence on the sensitivity and the resolution in nanobiosensor application field. The conventional nanostructure array used for nanobiosensor is fabricated by chemical method, so it is difficult to control the shape and the inter-particle space. Focused ion beam (FIB) can be used to produce any shapes with a very high level of regularity and reproducibility. This makes it possible to optimize the shape of nanostructures and the inter-particle distance to achieve the full potential application in nanobiosensor. Using focused ion beam (FIB) nanofabrication method, we have fabricated the regularly shaped hybrid Ag-Au nanostructures distributed on the surface of the glass substrate. Gold-coating was used to tuning the optical characteristics of the silver nanostructure array. Discrete dipole approximation (DDA) method was used to optimize geometrical parameters of the hybrid Ag-Au nanostructures. The design and experiment results show that the sensitivity and resolution have been improved considerably compared to the chemically synthesized nanostructures. The nano-biosensor demonstrates the potential applications in monitoring, detection and identiﬁcation of biological agents, and characterization of intermolecular interactions.

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Cathcart, Nicole, Jennifer I. L. Chen, and Vladimir Kitaev. "LSPR Tuning from 470 to 800 nm and Improved Stability of Au–Ag Nanoparticles Formed by Gold Deposition and Rebuilding in the Presence of Poly(styrenesulfonate)." Langmuir 34, no. 2 (January 5, 2018): 612–21. http://dx.doi.org/10.1021/acs.langmuir.7b03537.

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Yamada, Makoto, and Masashi Sugiyama. "Dependence Minimizing Regression with Model Selection for Non-Linear Causal Inference under Non-Gaussian Noise." Proceedings of the AAAI Conference on Artificial Intelligence 24, no. 1 (July 3, 2010): 643–48. http://dx.doi.org/10.1609/aaai.v24i1.7655.

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The discovery of non-linear causal relationship under additive non-Gaussian noise models has attracted considerable attention recently because of their high flexibility. In this paper, we propose a novel causal inference algorithm called least-squares independence regression (LSIR). LSIR learns the additive noise model through minimization of an estimator of the squared-loss mutual information between inputs and residuals. A notable advantage of LSIR over existing approaches is that tuning parameters such as the kernel width and the regularization parameter can be naturally optimized by cross-validation, allowing us to avoid overfitting in a data-dependent fashion. Through experiments with real-world datasets, we show that LSIR compares favorably with the state-of-the-art causal inference method.

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Shao, Rong Lin, Bo Li, Liu Yang, and Yong Jin Zhou. "Electrically small multiband antenna based on spoof localized surface plasmons." EPJ Applied Metamaterials 6 (2019): 11. http://dx.doi.org/10.1051/epjam/2019009.

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Here an electrically small multiband antenna based on spoof localized surface plasmons (LSPs) has been proposed using corrugated ring resonator printed on a thin dielectric substrate with complementary metallic spiral structure (MSS) on the ground plane. It has been found that the resonant frequencies of spoof LSPs redshift by tuning the arm length of the complementary MSS, which leads to the miniaturization of the antenna. The fabricated multiband antenna has a small size of only 0.11λ × 0.1λ, covering GSM900, GSM1800, and WiFi bands. Such electrically small multiband antenna with high gain is necessary for efficient wireless energy harvesting (WEH), which can find more applications in various areas including Internet of Things (IoT), wireless sensor network (WSN), etc.

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Memon, Najma, Huma I. Shaikh, and Amber R. Solangi. "Selectivity of Brij-35 in Micellar Liquid Chromatographic Separation of Positional Isomers." Chromatography Research International 2012 (February 12, 2012): 1–6. http://dx.doi.org/10.1155/2012/458153.

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Implementation of Brij-35, a nonionic surfactant, as a mobile phase for separation of positional isomers is investigated. Chromolith C-18 SpeedROD is used as a stationary phase. The effect of surfactant and organic modifier (propanol) concentration on the separation of some selected isomers is studied and evaluated in terms of linear solvation energy relationship (LSER). Shape selectivity is assessed by α value of sorbic and benzoic acid, which is found to be 1.339 by using mobile phase composed of 0.5% aqueous solutions of Brij-35 and propanol in 9 : 1. Isomers of parabens, nitroanilines, nitrophenols, and quinolinols are successfully separated using mobile phases composed of various percentages of surfactant and propanol. System constants for nonionic MLC using LSER analysis show that hydrogen bond basicity and dipolarity may be major contributors to selectivity, while excess molar refraction helps fine-tuning the separation which also imparts unique selectivity to nonionic surfactants as compared to ionic ones.

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Ulfarsson, Magnus O., and Victor Solo. "Tuning Parameter Selection for Underdetermined Reduced-Rank Regression." IEEE Signal Processing Letters 20, no. 9 (September 2013): 881–84. http://dx.doi.org/10.1109/lsp.2013.2272463.

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Huaqiang Shu, Eric Pierre Simon, and Laurent Ros. "Third-Order Kalman Filter: Tuning and Steady-State Performance." IEEE Signal Processing Letters 20, no. 11 (November 2013): 1082–85. http://dx.doi.org/10.1109/lsp.2013.2277668.

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Park, Tae Jin, Kyu J. Han, Manoj Kumar, and Shrikanth Narayanan. "Auto-Tuning Spectral Clustering for Speaker Diarization Using Normalized Maximum Eigengap." IEEE Signal Processing Letters 27 (2020): 381–85. http://dx.doi.org/10.1109/lsp.2019.2961071.

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Fontana, F., and M. Karjalainen. "A digital bandpass/bandstop complementary equalization filter with independent tuning characteristics." IEEE Signal Processing Letters 10, no. 4 (April 2003): 119–22. http://dx.doi.org/10.1109/lsp.2003.808546.

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Bello-Ortí, Bernardo, Virginia Aragon, Sonia Pina-Pedrero, and Albert Bensaid. "Genome comparison of three serovar 5 pathogenic strains of Haemophilus parasuis: insights into an evolving swine pathogen." Microbiology 160, no. 9 (September 1, 2014): 1974–84. http://dx.doi.org/10.1099/mic.0.079483-0.

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Haemophilus parasuis is the causative agent of Glässer’s disease, a systemic disorder characterized by polyarthritis, polyserositis and meningitis in pigs. Although it is well known that H. parasuis serovar 5 is the most prevalent serovar associated with the disease, the genetic differences among strains are only now being discovered. Genomes from two serovar 5 strains, SH0165 and 29755, are already available. Here, we present the draft genome of a third H. parasuis serovar 5 strain, the formal serovar 5 reference strain Nagasaki. An in silico genome subtractive analysis with full-length predicted genes of the three H. parasuis serovar 5 strains detected 95, 127 and 95 strain-specific genes (SSGs) for Nagasaki, SH0165 and 29755, respectively. We found that the genomic diversity within these three strains was high, in part because of a high number of mobile elements. Furthermore, a detailed analysis of large sequence polymorphisms (LSPs), encompassing regions ranging from 2 to 16 kb, revealed LSPs in virulence-related elements, such as a Toll-IL receptor, the AcrA multidrug efflux protein, an ATP-binding cassette (ABC) transporter, lipopolysaccharide-synthetizing enzymes and a tripartite ATP-independent periplasmic (TRAP) transporter. The whole-genome codon adaptation index (CAI) was also calculated and revealed values similar to other well-known bacterial pathogens. In addition, whole-genome SNP analysis indicated that nucleotide changes tended to be increased in membrane-related genes. This analysis provides further evidence that the genome of H. parasuis has been subjected to multiple lateral gene transfers (LGTs) and to fine-tuning of virulence factors, and has the potential for accelerated genome evolution.

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Zaidan, Al-Dulaimi Omar. "DEVELOPMENT OF A CLASSIFICATION ALGORITHM BASED ON AN ACADEMIC DATA MODEL USING HYPERPARAMETRIC TUNING FOR HIRING TEACHERS AT IRAQI UNIVERSITIES." T-Comm 16, no. 9 (2022): 33–38. http://dx.doi.org/10.36724/2072-8735-2022-16-9-33-38.

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In this paper, the researcher proposes a classification method for any employment opportunity in Iraqi universities using complete placement data by category for a dataset of employment in Iraqi educational institutions. The analysis of the scientific literature shows that this problem has not been sufficiently investigated and requires its solution. Developing a classification method based on genetic algorithms to get the best results to solve the problem of hiring new professors in Iraqi universities, getting accurate results and comparing several methods to solve this problem. The researcher tries to study learning classification algorithms with a teacher, such as logistic regression, Support Vector Classifier (SVC), Closest Neighbors KNN, Gaussian Naive Bayes algorithm, decision tree, random forest, gradient boosting and linear factor analysis (LDA). Hyperparameter optimization is also used for controlled algorithms to achieve better results. According to the proposed algorithms, the reliability and accuracy of the results obtained was ensured by a five-fold check. Results. Experimental results have shown that by adjusting hyperparameters in Linear Discriminant Analysis (LDA), it is possible to increase the accuracy of the results, as well as get a better result compared to other algorithms. The analysis criteria such as average accuracy, average score, G-Mean and Average ROC AUC were taken into account. It is according to the first three criteria that linear discriminant analysis demonstrates the highest accuracy of evaluation. It is established that among all the classification algorithms used, the classification of linear discriminant analysis is comparatively more accurate in all other scenarios of classification algorithms. It was found that adding the lsqr parameter solver and 0.81 shrinkage to linear discriminant analysis can improve performance. The article proves that the proposed classification algorithm based on the academic data model is able to solve the problem of hiring teachers at the university.

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Xiong, Lei, Hong-Wei Ding, and Guang-Yuan Li. "Quadrupolar lattice plasmon modes induced by diffraction of high-quality factors in silver nanoparticle arrays." Acta Physica Sinica 71, no. 4 (2022): 047802. http://dx.doi.org/10.7498/aps.71.20211629.

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Periodic nanoparticle arrays with lower loss or high-quality (Q) factor resonances have made great advances in numerous applications. Such arrays can support narrow resonance modes by the hybridization of plasmonic-photonic modes, known as lattice plasmon modes (LPMs). The LPMs arise from the diffraction-induced coupling between localized surface plasmon resonances (LSPRs) of nanoparticles in symmetric or quasi-symmetric refractive index environment. To date, the great majority of researches have focused on the coupling of dipolar modes to in-plane orthogonal diffraction waves in nanoparticle arrays, resulting in dipolar lattice plasmon modes (DLPMs). However, there are few studies about quadrupolar lattice plasmon modes (QLPMs) for parallel coupling in symmetric environment, especially for high Q-factor QLPMs. In this work, we explore the sharp QLPMs of the silver nanodisk arrays by x-polarized light at normal incidence. In the first place, the scattering cross-section and near-field electric field distribution of single silver nanodisk indicate the existence of dipolar and quadrupolar LSPRs, thus, the optical responses of silver nanodisk arrays exhibit the peak-and-dip profiles of DLPMs and QLPMs at different wavelengths. Also, the electromagnetic field distributions confirm that the parallel propagating electric field introduces QLPM and results in electric field delocalization, while DLPM is existent in another way in periodic silver nanodisk arrays. Moreover, the position, linewidth and lineshape of the QLPM strongly depend on the role of lattice period. We enable these resonance modes to be selectively accessed and individually optimized by tuning lattice periods in the x- or y-direction. By changing the lattice period in the x-direction from 300 to 550 nm in steps of 50 nm, the dip of transmission intensity increases gradually, and when periods in the two directions are equal, the transmission dip exhibits a narrow-band QLPM resonance with a linewidth of 0.4 nm, corresponding quality factor is as high as Q = 1815 under the x-polarized light. In particular, by varying periods in the y-direction, the QLPM can also be manipulated in a range from an asymmetric Fano-like lineshape peak to a dip. The acquisition of these results may provide a design strategy for high-Q factor resonance in nanolaser, sensing, and nonlinear optics.

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Zheng, Yue Bing, Vincent K. S. Hsiao, and Tony Jun Huang. "All-Optical Active Plasmonics Based on Ordered Au Nanodisk Array Embedded in Photoresponsive Liquid Crystals." MRS Proceedings 1077 (2008). http://dx.doi.org/10.1557/proc-1077-l01-04.

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ABSTRACTWe propose a new approach towards all-optical active plasmonics based on ordered Au nanodisk arrays embedded in azobenzene-doped liquid crystals (LCs). Upon photoirradiation, the doped LCs went through phase transition induced by trans-cis photoisomerization of the azobenzene molecules. The phase transition led to the change in the refractive index of the LCs experienced by incident light, and enabled reversible tuning of the localized surface plasmon resonance (LSPR) of the embedded Au nanodisks. The tuning utilized the sensitivity of the LSPR of the Au nanodisks to the change in the surroundings' refractive index. Experimental observations on both peak shift and intensity change of the LSPR matched those from discrete dipole approximation (DDA) calculations.

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Charles, Denise E., Damian Aherne, Deirdre M. Ledwith, Yurii K. Gun'ko, John M. Kelly, Werner J. Blau, and Margaret E. Brennan-Fournet. "Key Role of Aspect Ratio in Optimising Local Surface Plasmon Sensitivities of Solution Phase Triangular Silver Nanoplates." MRS Proceedings 1208 (2009). http://dx.doi.org/10.1557/proc-1208-o18-23.

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AbstractSolution phase triangular silver nanoplate (TSNP) ensembles are herein presented as tunable, highly sensitive, LSPR sensors with excellent potential for versatile amply responsive biosensing applications. The recorded LSPR refractive index sensitivities for the highest aspect ratio TSNPs examined are amongst the highest reported to date for various other nanostructures. Calculations demonstrate that sensitivities of the TSNP sols, as high as the theoretical upper limit, are achievable by tuning the aspect ratio parameter, without any significant diminution observed due to ensemble averaging. Theoretical studies identify the aspect ratio of the nanoplates as a key parameter in controlling the LSPR sensitivity of the TSNPs.

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Kedia, Abhitosh, Ranjan Singhal, and Pandian Senthil Kumar. "Shape Trimming And LSPR Tuning of Colloidal Gold Nanostars." Chemical Physics Letters, October 2022, 140101. http://dx.doi.org/10.1016/j.cplett.2022.140101.

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Alizar, Yola Yolanda, and Ji Won Ha. "Single-particle spectroelectrochemistry: electrochemical tuning of plasmonic properties via mercury amalgamation in mesoporous silica coated gold nanorods without structural deformation." Analyst, 2022. http://dx.doi.org/10.1039/d2an00559j.

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This paper presented the possibility of the in situ tuning of the LSPR properties of AuNRs@mSiO2 by Hg deposition via electrochemical potential manipulations without the disturbance of the structural variations of AuNR cores.

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Katyal, Jyoti, and Shivani Gautam. "Tuning the Localized Surface Plasmon Resonance of Al-Al2O3 Nanosphere Towards NIR Region by Gold Coating." Micro and Nanosystems 12 (July 27, 2020). http://dx.doi.org/10.2174/1876402912999200727173140.

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Background: A relatively narrow LSPR peak and a strong inter band transition ranging around 800 nm makes Al strongly plasmonic active material. Usually, Al nanoparticles are preferred for UV-plasmonic as the SPR of small size Al nanoparticles locates in deep UV-UV region of the optical spectrum. This paper focused on tuning the LSPR of Al nanostructure towards infrared region by coating Au layer. The proposed structure has Au as outer layer which prevent the further oxidation of Al nanostructure. Methods: The Finite Difference Time Domain (FDTD) and Plasmon Hybridization Theory has been used to evaluated the LSPR and field enhancement of single and dimer Al-Al2O3-Au MDM nanostructure. Results: It is observed that the resonance mode show dependence on the thickness of Al2O3 layer and also on the composition of nanostructure. The Au layered MDM nanostructure shows two peak of equal intensities simultaneously in UV and visible region tuned to NIR region. The extinction spectra and electric field distribution profiles of dimer nanoparticles are compared with monomer to reveal the extent of coupling. The dimer configuration shows higher field enhancement ~107 at 1049 nm. By optimizing the thickness of dielectric layer the MDM nanostructure can be used over UV-visible-NIR region. Conclusion: The LSPR peak shows dependence on the thickness of dielectric layer and also on the composition of nanostructure. It has been observed that optimization of size and thickness of dielectric layer can provide two peaks of equal intensities in UV and Visible region which is advantageous for many applications. The electric field distribution profiles of dimer MDM nanostructure enhanced the field by ~107 in visible and NIR region shows its potential towards SERS substrate. The results of this study will provide valuable information for the optimization of LSPR of Al-Al2O3-Au MDM nanostructure to have high field enhancement.

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Shimanoe, Kohei, Soshi Endo, Tetsuya Matsuyama, Kenji Wada, and Koichi Okamoto. "Localized surface plasmon resonance in deep ultraviolet region below 200 nm using a nanohemisphere on mirror structure." Scientific Reports 11, no. 1 (March 4, 2021). http://dx.doi.org/10.1038/s41598-021-84550-w.

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AbstractLocalized surface plasmon resonance (LSPR) was performed in the deep ultraviolet (UVC) region with Al nanohemisphere structures fabricated by means of a simple method using a combination of vapor deposition, sputtering, and thermal annealing without top-down nanofabrication technology such as electron beam lithography. The LSPR in the UV region was obtained and tuned by the initial metal film thickness, annealing temperature, and dielectric spacer layer thickness. Moreover, we achieved a flexible tuning of the LSPR in a much deeper UVC region below 200 nm using a nanohemisphere on a mirror (NHoM) structure. NHoM is a structure in which a metal nanohemisphere is formed on a metal substrate that is interposed with an Al2O3 thin film layer. In the experimental validation, Al and Ga were used for the metal hemispheres. The LSPR spectrum of the NHoM structures was split into two peaks, and the peak intensities were enhanced and sharpened. The shorter branch of the LSPR peak appeared in the UVC region below 200 nm. Both the peak intensities and linewidth were flexibly tuned by the spacer thickness. This structure can contribute to new developments in the field of deep UV plasmonics.

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Journal articles on the topic 'LSPR TUNING'

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