Patterned silver island paths as high-contrast optical sensing platforms

2021 ◽  
Vol 268 ◽  
pp. 115124
Author(s):  
Karolina Sulowska ◽  
Ewa Roźniecka ◽  
Kamil Wiwatowski ◽  
Marta Janczuk-Richter ◽  
Martin Jönsson-Niedziółka ◽  
...  
The Analyst ◽  
2019 ◽  
Vol 144 (9) ◽  
pp. 2849-2866 ◽  
Author(s):  
Yi-Han Wang ◽  
Liu-Liu He ◽  
Ke-Jing Huang ◽  
Ying-Xu Chen ◽  
Shu-Yu Wang ◽  
...  

This review describes recent efforts in the application of nanomaterials as sensing elements in electrochemical and optical miRNAs assays.


Nanophotonics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 249-261 ◽  
Author(s):  
SeokJae Yoo ◽  
Q-Han Park

AbstractChirality, a property of broken mirror symmetry, prevails in nature. Chiral molecules show different biochemical behaviors to their mirror molecules. For left or right circularly polarized lights, the fundamental chiral states of electromagnetic fields interact differently with chiral matter, and this effect has been used as a powerful tool for the detection of chiral molecules. This optical sensing, also termed chiral sensing, is not only easy to implement but also non-invasive to the analytes. However, the measurements made by the optical sensing of chiral molecules are challenging, as chiroptical signals are extremely weak. Recent years have seen active research efforts into metamaterial and plasmonic platforms for manipulating local fields to enhance chiroptical signals. This metamaterial approach offers new possibilities of chiral sensing with high sensitivity. Here, we review the recent advances in chiral sensing using metamaterial and plasmonic platforms. In addition, we explain the underlying principles behind the enhancement of chiroptical signals and highlight practically efficient chiral sensing platforms. We also provide perspectives that shed light on design considerations for chiral sensing metamaterials and discuss the possibility of other types of chiral sensing based on resonant metamaterials.


Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1385
Author(s):  
Youqiao Ma ◽  
Jinhua Li ◽  
Zhanghua Han ◽  
Hiroshi Maeda ◽  
Yuan Ma

A Bragg-mirror-assisted terahertz (THz) high-contrast and broadband plasmonic interferometer is proposed and theoretically investigated for potential sensing applications. The central microslit couples the incident THz wave into unidirectional surface plasmon polaritons (SPPs) waves travelling to the bilateral Bragg gratings, where they are totally reflected over a wide wavelength range back towards the microslit. The properties of interference between the SPPs waves and transmitted THz wave are highly dependent on the surrounding material, offering a flexible approach for the realization of refractive index (RI) detection. The systematic study reveals that the proposed interferometric sensor possesses wavelength sensitivity as high as 167 μm RIU−1 (RIU: RI unit). More importantly, based on the intensity interrogation method, an ultrahigh Figure-of-Merit (FoM) of 18,750% RIU−1, surpassing that of previous plasmonic sensors, is obtained due to the high-contrast of interference pattern. The results also demonstrated that the proposed sensors are also quite robust against the oblique illumination. It is foreseen the proposed configuration may open up new horizons in developing THz plasmonic sensing platforms and next-generation integrated THz circuits.


Small ◽  
2020 ◽  
Vol 16 (11) ◽  
pp. 1906459 ◽  
Author(s):  
Xuejing Wang ◽  
Xuedan Ma ◽  
Enzheng Shi ◽  
Ping Lu ◽  
Letian Dou ◽  
...  

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Cong Wang ◽  
Ding Wang ◽  
Valery Kozhevnikov ◽  
Xingyi Dai ◽  
Graeme Turnbull ◽  
...  

ACS Nano ◽  
2020 ◽  
Vol 14 (7) ◽  
pp. 9021-9031 ◽  
Author(s):  
Zhixin Zhou ◽  
Yang Sung Sohn ◽  
Rachel Nechushtai ◽  
Itamar Willner

Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.


Author(s):  
J.N. Turner ◽  
M. Siemens ◽  
D. Szarowski ◽  
D.N. Collins

A classic preparation of central nervous system tissue (CNS) is the Golgi procedure popularized by Cajal. The method is partially specific as only a few cells are impregnated with silver chromate usualy after osmium post fixation. Samples are observable by light (LM) or electron microscopy (EM). However, the impregnation is often so dense that structures are masked in EM, and the osmium background may be undesirable in LM. Gold toning is used for a subtle but high contrast EM preparation, and osmium can be omitted for LM. We are investigating these preparations as part of a study to develop correlative LM and EM (particularly HVEM) methodologies in neurobiology. Confocal light microscopy is particularly useful as the impregnated cells have extensive three-dimensional structure in tissue samples from one to several hundred micrometers thick. Boyde has observed similar preparations in the tandem scanning reflected light microscope (TSRLM).


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