scholarly journals Enhanced optical magnetism for reversed optical binding forces between silicon nanoparticles in the visible region

2017 ◽  
Vol 25 (1) ◽  
pp. 431 ◽  
Author(s):  
Taka-aki Yano ◽  
Yuta Tsuchimoto ◽  
Remo Proietti Zaccaria ◽  
Andrea Toma ◽  
Alejandro Portela ◽  
...  
2021 ◽  
Author(s):  
Sudipta Biswas ◽  
Roksana Khanam Rumi ◽  
Tasnia Rahman Raima ◽  
Saikat Chandra Das ◽  
M. R. C. Mahdy

2010 ◽  
Vol 18 (24) ◽  
pp. 25389 ◽  
Author(s):  
O. Brzobohatý ◽  
T. Čižmár ◽  
V. Karásek ◽  
M. Šiler ◽  
K. Dholakia ◽  
...  

2006 ◽  
Vol 31 (22) ◽  
pp. 3378 ◽  
Author(s):  
Tomasz M. Grzegorczyk ◽  
Brandon A. Kemp ◽  
Jin Au Kong

Author(s):  
Jillian M Buriak

Crystalline silicon forms the basis of just about all computing technologies on the planet, in the form of microelectronics. An enormous amount of research infrastructure and knowledge has been developed over the past half-century to construct complex functional microelectronic structures in silicon. As a result, it is highly probable that silicon will remain central to computing and related technologies as a platform for integration of, for instance, molecular electronics, sensing elements and micro- and nanoelectromechanical systems. Porous nanocrystalline silicon is a fascinating variant of the same single crystal silicon wafers used to make computer chips. Its synthesis, a straightforward electrochemical, chemical or photochemical etch, is compatible with existing silicon-based fabrication techniques. Porous silicon literally adds an entirely new dimension to the realm of silicon-based technologies as it has a complex, three-dimensional architecture made up of silicon nanoparticles, nanowires, and channel structures. The intrinsic material is photoluminescent at room temperature in the visible region due to quantum confinement effects, and thus provides an optical element to electronic applications. Our group has been developing new organic surface reactions on porous and nanocrystalline silicon to tailor it for a myriad of applications, including molecular electronics and sensing. Integration of organic and biological molecules with porous silicon is critical to harness the properties of this material. The construction and use of complex, hierarchical molecular synthetic strategies on porous silicon will be described.


2020 ◽  
Vol 37 (5) ◽  
pp. 1273 ◽  
Author(s):  
Naima Binte Ahsan ◽  
Rafia Shamim ◽  
M. R. C. Mahdy ◽  
Saikat Chandra Das ◽  
Hamim Mahmud Rivy ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shulamit Edelstein ◽  
Antonio García-Martín ◽  
Pedro A. Serena ◽  
Manuel I. Marqués

AbstractIn this paper we show analytically and numerically the formation of a near-field stable optical binding between two identical plasmonic particles, induced by an incident plane wave. The equilibrium binding distance is controlled by the angle between the polarization plane of the incoming field and the dimer axis, for which we have calculated an explicit formula. We have found that the condition to achieve stable binding depends on the particle’s dielectric function and happens near the frequency of the dipole plasmonic resonance. The binding stiffness of this stable attaching interaction is four orders of magnitude larger than the usual far-field optical binding and is formed orthogonal to the propagation direction of the incident beam (transverse binding). The binding distance can be further manipulated considering the magneto-optical effect and an equation relating the desired equilibrium distance with the required external magnetic field is obtained. Finally, the effect induced by the proposed binding method is tested using molecular dynamics simulations. Our study paves the way to achieve complete control of near-field binding forces between plasmonic nanoparticles.


Author(s):  
Nina V. Sharonova ◽  
Anatoly A. Ischenko ◽  
Elena Yu. Yagudaeva ◽  
Svetlana V. Sizova ◽  
Evgeniya V. Smirnova ◽  
...  

In this paper, it is proposed to use polymer-modified composite materials based on nanocrystalline silicon (nc-Si) as an alternative to organic fluorescent quantum dots traditionally used in medicine. A distinctive feature of nc-Si is a high absorption coefficient in the near UV and blue-violet range and the ability to transmit light in the visible region of the spectrum. The main advantage of silicon-based nanoparticles for in vivo use is their biodegradability and the absence of toxic properties. For hydrophilization of silicon nanoparticles, their surface was modified by amphiphilic biocompatible polymers: polyvinylpyrrolidone, a copolymer of maleic anhydride and 1-octadecene, cremophore, which is a polyoxyethylene derivative of hydrogenated castor oil. Silicon nanoparticles (nc-Si) with an average diameter of 4.5 nm, synthesized by annealing of SiO at 1150 °C, and functionalized with 1-octadecene photoluminescent in the red-infrared spectral region were used. The presence of the polymer shell on the surface of the nanoparticles was confirmed by FTIR spectroscopy. The sedimentation and aggregative stability of the particles in water were analyzed. It is shown that after the nc-Si polymer modification, the photoluminescent properties of nanoparticles are retained although the photoluminesce maxima were shifted to the blue region. Colorimetric MTT-assay of the cytotoxicity of the nanoparticles modified with polymers to monoclonal cells of human erythroleukemia K562 showed no toxicity for cells in culture at a particle concentration of up to 50 μg/ml. Subcellular localization of silicon nanoparticles into the human cervical carcinoma cell line HeLa was shown by means of fluorescence microscopy. The obtained polymer-modified nc-Si particles can be recommended for the purposes of bioimaging in in vitro and in vivo applications.


2006 ◽  
Vol 96 (11) ◽  
Author(s):  
Tomasz M. Grzegorczyk ◽  
Brandon A. Kemp ◽  
Jin Au Kong

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