scholarly journals Tuning and Sensitivity Improvement of Bi-metallic Structure-based Surface Plasmon Resonance Biosensor with 2-D ξ-Tin Selenide nanosheets

Author(s):  
Natarajan Sathya ◽  
Bhishma Karki ◽  
Kantilal Pitambar Rane ◽  
Ankit Jha ◽  
Amrindra Pal

Abstract This manuscript aims to visualize the effect of tin selenide (SnSe) on the sensing application of the SPR biosensors. Tin selenide is the 2-Dimensional material transition metal dichalcogenide family element. By utilizing the extraordinary properties of the SnSe, high sensitivity and high performance of the biosensor is analyzed by utilizing the extraordinary properties of the SnSe. A unique two-dimensional substantial heterostructure, \({\epsilon }\)-tin selenide (SnSe) /graphene layer has been deposited over the metal surface to improve the sensitivity; moreover, the sensitivity is limited to a certain extent. The \({\epsilon }-\text{S}\text{n}\text{S}\text{e}\) nanosheet is placed in between two layers of gold (Au) in the Kretschmann arrangement. The proposed configuration has a maximum sensitivity of 214°/RIU, which is 93.81% higher than the conventional sensor. The performance parameters like FWHM, detection accuracy and quality factor have been analysed. The \({\epsilon }-\text{S}\text{n}\text{S}\text{e}\) material is an air-stable 2-D nanosheet and has application in chemical, medical, and biological sensors.

2021 ◽  
Author(s):  
Bhishma Karki ◽  
Arun Uniyal ◽  
Amrindra Pal ◽  

Abstract A biosensor based on the modified Kretschmann configuration is proposed here. The sensitivity of the conventional prism-based sensor using angular interrogation is low. To enhance the sensor's performance, layers of zinc sulfide (ZnS) and graphene have been deposited over the metal layer. The angular interrogation technique is used to analyze the performance of the sensor. The thickness of the Ag metal has been optimized. The thickness of the Ag metal is taken as 50 nm because minimum reflectance has been achieved. With the combinations of the four layers of ZnS and one graphene layer, the maximum sensitivity attained is 305o/RU. Performance parameters such as detection accuracy, FWHM, and quality factor of the sensor have been evaluated as obtained as 0.33 deg-1, 3.05 deg, 100.7 RIU-1, respectively. The proposed sensor has potential application in the field of biochemical and biological analyte detection.


2020 ◽  
Vol 23 (10) ◽  
pp. 1010-1022
Author(s):  
Emrah Dural

Aim and scope: Due to the serious toxicological risks and their widespread use, quantitative determination of phthalates in cosmetic products have importance for public health. The aim of this study was to develop a validated simple, rapid and reliable high-performance liquid chromatography (HPLC) method for the determination of phthalates which are; dimethyl phthalate (DMP), diethyl phthalate (DEP), benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP), di(2- ethylhexyl) phthalate (DEHP), in cosmetic products and to investigate these phthalate (PHT) levels in 48 cosmetic products marketing in Sivas, Turkey. Materials and Methods: Separation was achieved by a reverse-phase ACE-5 C18 column (4.6 x 250 mm, 5.0 μm). As the mobile phase, 5 mM KH2PO4 and acetonitrile were used gradiently at 1.5 ml min-1. All PHT esters were detected at 230 nm and the run time was taking 21 minutes. Results: This method showed the high sensitivity value the limit of quantification (LOQ) values for which are below 0.64 μg mL-1 of all phthalates. Method linearity was ≥0.999 (r2). Accuracy and precision values of all phthalates were calculated between (-6.5) and 6.6 (RE%) and ≤6.2 (RSD%), respectively. Average recovery was between 94.8% and 99.6%. Forty-eight samples used for both babies and adults were successfully analyzed by the developed method. Results have shown that, DMP (340.7 μg mL-1 ±323.7), DEP (1852.1 μg mL-1 ± 2192.0), and DBP (691.3 μg mL-1 ± 1378.5) were used highly in nail polish, fragrance and cream products, respectively. Conclusion: Phthalate esters, which are mostly detected in the content of fragrance, cream and nail polish products and our research in general, are DEP (1852.1 μg mL-1 ± 2192.0), DBP (691.3 μg mL-1 ± 1378.5) and DMP (340.7 μg mL-1 ±323.7), respectively. Phthalates were found in the content of all 48 cosmetic products examined, and the most detected phthalates in general average were DEP (581.7 μg mL-1 + 1405.2) with a rate of 79.2%. The unexpectedly high phthalate content in the examined cosmetic products revealed a great risk of these products on human health. The developed method is a simple, sensitive, reliable and economical alternative for the determination of phthalates in the content of cosmetic products, it can be used to identify phthalate esters in different products after some modifications.


Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2163
Author(s):  
Dongjin Kim ◽  
Seungyong Han ◽  
Taewi Kim ◽  
Changhwan Kim ◽  
Doohoe Lee ◽  
...  

As the safety of a human body is the main priority while interacting with robots, the field of tactile sensors has expanded for acquiring tactile information and ensuring safe human–robot interaction (HRI). Existing lightweight and thin tactile sensors exhibit high performance in detecting their surroundings. However, unexpected collisions caused by malfunctions or sudden external collisions can still cause injuries to rigid robots with thin tactile sensors. In this study, we present a sensitive balloon sensor for contact sensing and alleviating physical collisions over a large area of rigid robots. The balloon sensor is a pressure sensor composed of an inflatable body of low-density polyethylene (LDPE), and a highly sensitive and flexible strain sensor laminated onto it. The mechanical crack-based strain sensor with high sensitivity enables the detection of extremely small changes in the strain of the balloon. Adjusting the geometric parameters of the balloon allows for a large and easily customizable sensing area. The weight of the balloon sensor was approximately 2 g. The sensor is employed with a servo motor and detects a finger or a sheet of rolled paper gently touching it, without being damaged.


Author(s):  
Antonia Perju ◽  
Nongnoot Wongkaew

AbstractLateral flow assays (LFAs) are the best-performing and best-known point-of-care tests worldwide. Over the last decade, they have experienced an increasing interest by researchers towards improving their analytical performance while maintaining their robust assay platform. Commercially, visual and optical detection strategies dominate, but it is especially the research on integrating electrochemical (EC) approaches that may have a chance to significantly improve an LFA’s performance that is needed in order to detect analytes reliably at lower concentrations than currently possible. In fact, EC-LFAs offer advantages in terms of quantitative determination, low-cost, high sensitivity, and even simple, label-free strategies. Here, the various configurations of EC-LFAs published are summarized and critically evaluated. In short, most of them rely on applying conventional transducers, e.g., screen-printed electrode, to ensure reliability of the assay, and additional advances are afforded by the beneficial features of nanomaterials. It is predicted that these will be further implemented in EC-LFAs as high-performance transducers. Considering the low cost of point-of-care devices, it becomes even more important to also identify strategies that efficiently integrate nanomaterials into EC-LFAs in a high-throughput manner while maintaining their favorable analytical performance.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Md Hasibul Alam ◽  
Zifan Xu ◽  
Sayema Chowdhury ◽  
Zhanzhi Jiang ◽  
Deepyanti Taneja ◽  
...  

2021 ◽  
Author(s):  
Zong-Mu Dong ◽  
Lu Cheng ◽  
Tong Sun ◽  
Guang-Chao Zhao ◽  
Xianwen Kan

An efficient SPME method using the carbon aerogel as fiber coating was developed for tetracycline detection, and the performance parameters of the analysis are optimized via the BBD software.


2021 ◽  
Vol 22 (8) ◽  
pp. 4000
Author(s):  
Emilia Marchei ◽  
Maria Alias Ferri ◽  
Marta Torrens ◽  
Magí Farré ◽  
Roberta Pacifici ◽  
...  

The use of the new psychoactive substances is continuously growing and the implementation of accurate and sensible analysis in biological matrices of users is relevant and fundamental for clinical and forensic purposes. Two different analytical technologies, high-sensitivity gas chromatography-mass spectrometry (GC-MS) and ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS) were used for a screening analysis of classic drugs and new psychoactive substances and their metabolites in urine of formed heroin addicts under methadone maintenance therapy. Sample preparation involved a liquid-liquid extraction. The UHPLC-HRMS method included Accucore™ phenyl Hexyl (100 × 2.1 mm, 2.6 μm, Thermo, USA) column with a gradient mobile phase consisting of mobile phase A (ammonium formate 2 mM in water, 0.1% formic acid) and mobile phase B (ammonium formate 2 mM in methanol/acetonitrile 50:50 (v/v), 0.1% formic acid) and a full-scan data-dependent MS2 (ddMS2) mode for substances identification (mass range 100–1000 m/z). The GC-MS method employed an ultra-Inert Intuvo GC column (HP-5MS UI, 30 m, 250 µm i.d, film thickness 0.25 µm; Agilent Technologies, Santa Clara, CA, USA) and electron-impact (EI) mass spectra were recorded in total ion monitoring mode (scan range 40–550 m/z). Urine samples from 296 patients with a history of opioid use disorder were examined. Around 80 different psychoactive substances and/or metabolites were identified, being methadone and metabolites the most prevalent ones. The possibility to screen for a huge number of psychotropic substances can be useful in suspected drug related fatalities or acute intoxication/exposure occurring in emergency departments and drug addiction services.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1304
Author(s):  
Raquel Fernández de Cabo ◽  
David González-Andrade ◽  
Pavel Cheben ◽  
Aitor V. Velasco

Efficient power splitting is a fundamental functionality in silicon photonic integrated circuits, but state-of-the-art power-division architectures are hampered by limited operational bandwidth, high sensitivity to fabrication errors or large footprints. In particular, traditional Y-junction power splitters suffer from fundamental mode losses due to limited fabrication resolution near the junction tip. In order to circumvent this limitation, we propose a new type of high-performance Y-junction power splitter that incorporates subwavelength metamaterials. Full three-dimensional simulations show a fundamental mode excess loss below 0.1 dB in an ultra-broad bandwidth of 300 nm (1400–1700 nm) when optimized for a fabrication resolution of 50 nm, and under 0.3 dB in a 350 nm extended bandwidth (1350–1700 nm) for a 100 nm resolution. Moreover, analysis of fabrication tolerances shows robust operation for the fundamental mode to etching errors up to ± 20 nm. A proof-of-concept device provides an initial validation of its operation principle, showing experimental excess losses lower than 0.2 dB in a 195 nm bandwidth for the best-case resolution scenario (i.e., 50 nm).


Geosciences ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 60
Author(s):  
Viacheslav Glinskikh ◽  
Oleg Nechaev ◽  
Igor Mikhaylov ◽  
Kirill Danilovskiy ◽  
Vladimir Olenchenko

This paper is dedicated to the topical problem of examining permafrost’s state and the processes of its geocryological changes by means of geophysical methods. To monitor the cryolithozone, we proposed and scientifically substantiated a new technique of pulsed electromagnetic cross-well sounding. Based on the vector finite-element method, we created a mathematical model of the cross-well sounding process with a pulsed source in a three-dimensional spatially heterogeneous medium. A high-performance parallel computing algorithm was developed and verified. Through realistic geoelectric models of permafrost with a talik under a highway, constructed following the results of electrotomography field data interpretation, we numerically simulated the pulsed sounding on the computing resources of the Siberian Supercomputer Center of SB RAS. The simulation results suggest the proposed system of pulsed electromagnetic cross-well monitoring to be characterized by a high sensitivity to the presence and dimensions of the talik. The devised approach can be oriented to addressing a wide range of issues related to monitoring permafrost rocks under civil and industrial facilities, buildings, and constructions.


2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhuang Hui ◽  
Ming Xiao ◽  
Daozhi Shen ◽  
Jiayun Feng ◽  
Peng Peng ◽  
...  

Abstract With the increase in the use of electronic devices in many different environments, a need has arisen for an easily implemented method for the rapid, sensitive detection of liquids in the vicinity of electronic components. In this work, a high-performance power generator that combines carbon nanoparticles and TiO2 nanowires has been fabricated by sequential electrophoretic deposition (EPD). The open-circuit voltage and short-circuit current of a single generator are found to exceed 0.7 V and 100 μA when 6 μL of water was applied. The generator is also found to have a stable and reproducible response to other liquids. An output voltage of 0.3 V was obtained after 244, 876, 931, and 184 μs, on exposure of the generator to 6 μL of water, ethanol, acetone, and methanol, respectively. The fast response time and high sensitivity to liquids show that the device has great potential for the detection of small quantities of liquid. In addition, the simple easily implemented sequential EPD method ensures the high mechanical strength of the device. This compact, reliable device provides a new method for the sensitive, rapid detection of extraneous liquids before they can impact the performance of electronic circuits, particularly those on printed circuit board.


Sign in / Sign up

Export Citation Format

Share Document