scholarly journals Review of Recent Microwave Planar Resonator-Based Sensors: Techniques of Complex Permittivity Extraction, Applications, Open Challenges and Future Research Directions

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2267
Author(s):  
Rammah Ali Alahnomi ◽  
Zahriladha Zakaria ◽  
Zulkalnain Mohd Yussof ◽  
Ayman Abdulhadi Althuwayb ◽  
Ammar Alhegazi ◽  
...  
Keyword(s):  
Complex Permittivity ◽  
Low Cost ◽  
High Sensitivity ◽  
Future Research ◽  
Beverage Industry ◽  
Compact Size ◽  
Industry Applications ◽  
Recent Developments ◽  
Sensitivity And Selectivity ◽  
Permittivity Measurements

Recent developments in the field of microwave planar sensors have led to a renewed interest in industrial, chemical, biological and medical applications that are capable of performing real-time and non-invasive measurement of material properties. Among the plausible advantages of microwave planar sensors is that they have a compact size, a low cost and the ease of fabrication and integration compared to prevailing sensors. However, some of their main drawbacks can be considered that restrict their usage and limit the range of applications such as their sensitivity and selectivity. The development of high-sensitivity microwave planar sensors is required for highly accurate complex permittivity measurements to monitor the small variations among different material samples. Therefore, the purpose of this paper is to review recent research on the development of microwave planar sensors and further challenges of their sensitivity and selectivity. Furthermore, the techniques of the complex permittivity extraction (real and imaginary parts) are discussed based on the different approaches of mathematical models. The outcomes of this review may facilitate improvements of and an alternative solution for the enhancement of microwave planar sensors’ normalized sensitivity for material characterization, especially in biochemical and beverage industry applications.

Schottky diodes based on 2D materials for environmental gas monitoring: a review on emerging trends, recent developments and future perspectives

2021 ◽  
Author(s):  
Minu Mathew ◽  
Chandra Sekhar Rout
Keyword(s):  
Gas Sensing ◽  
2D Materials ◽  
Schottky Diodes ◽  
High Sensitivity ◽  
Future Perspectives ◽  
Working Temperature ◽  
Emerging Trends ◽  
Gas Sensing Properties ◽  
Recent Developments ◽  
Sensitivity And Selectivity

This review details the fundamentals, working principles and recent developments of Schottky junctions based on 2D materials to emphasize their improved gas sensing properties including low working temperature, high sensitivity, and selectivity.

Modern nanobiotechnologies for efficient detection and remediation of mercury

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mulayam Singh Gaur ◽  
Rajni Yadav ◽  
Mamta Kushwah ◽  
Anna Nikolaevna Berlina
Keyword(s):  
Heavy Metals ◽  
Water Samples ◽  
Low Cost ◽  
High Sensitivity ◽  
Environmental Water ◽  
Mercury Ions ◽  
Content Type ◽  
Efficient Detection ◽  
Sensitivity And Selectivity ◽  
Selection Of

Purpose This information will be useful in the selection of materials and technology for the detection and removal of mercury ions at a low cost and with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity. The purpose of this study is to provide the useful information for selection of materials and technology to detect and remove the mercury ions from water with high sensitivity and selectivity. Design/methodology/approach Different nano- and bio-materials allowed for the development of a variety of biosensors – colorimetric, chemiluminescent, electrochemical, whole-cell and aptasensors – are described. The materials used for their development also make it possible to use them in removing heavy metals, which are toxic contaminants, from environmental water samples. Findings This review focuses on different technologies, tools and materials for mercury (heavy metals) detection and remediation to environmental samples. Originality/value This review gives up-to-date and systemic information on modern nanotechnology methods for heavy metal detection. Different recognition molecules and nanomaterials have been discussed for remediation to water samples. The present review may provide valuable information to researchers regarding novel mercury ions detection sensors and encourage them for further research/development.

scholarly journals A Review of Supercapacitors Based on Graphene and Redox-Active Organic Materials

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 703 ◽  
Author(s):  
Qi Li ◽  
Michael Horn ◽  
Yinong Wang ◽  
Jennifer MacLeod ◽  
Nunzio Motta ◽  
...  
Keyword(s):  
Electrode Materials ◽  
Low Cost ◽  
Lithium Ion ◽  
Dimensional Structure ◽  
Future Research ◽  
Synthesis Methods ◽  
Energy Storage Devices ◽  
Storage Devices ◽  
Redox Active ◽  
Recent Developments

Supercapacitors are a highly promising class of energy storage devices due to their high power density and long life cycle. Conducting polymers (CPs) and organic molecules are potential candidates for improving supercapacitor electrodes due to their low cost, large specific pseudocapacitance and facile synthesis methods. Graphene, with its unique two-dimensional structure, shows high electrical conductivity, large specific surface area and outstanding mechanical properties, which makes it an excellent material for lithium ion batteries, fuel cells and supercapacitors. The combination of CPs and graphene as electrode material is expected to boost the properties of supercapacitors. In this review, we summarize recent reports on three different CP/graphene composites as electrode materials for supercapacitors, discussing synthesis and electrochemical performance. Novel flexible and wearable devices based on CP/graphene composites are introduced and discussed, with an eye to recent developments and challenges for future research directions.

scholarly journals The Advent of Salivary Breast Cancer Biomarker Detection Using Affinity Sensors

Sensors ◽  
2019 ◽  
Vol 19 (10) ◽  
pp. 2373 ◽  
Author(s):  
Imad Abrao Nemeir ◽  
Joseph Saab ◽  
Walid Hleihel ◽  
Abdelhamid Errachid ◽  
Nicole Jafferzic-Renault ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Low Cost ◽  
Current Trend ◽  
High Sensitivity ◽  
Breast Cancer Diagnosis ◽  
Current Status ◽  
Attractive Alternative ◽  
Early Screening ◽  
Screening Programs ◽  
Sensitivity And Selectivity

Breast Cancer is one of the world’s most notorious diseases affecting two million women in 2018 worldwide. It is a highly heterogeneous disease, making it difficult to treat. However, its linear progression makes it a candidate for early screening programs, and the earlier its detection the higher the chance of recovery. However, one key hurdle for breast cancer screening is the fact that most screening techniques are expensive, time-consuming, and cumbersome, making them impractical for use in several parts of the world. One current trend in breast cancer detection has pointed to a possible solution, the use of salivary breast cancer biomarkers. Saliva is an attractive medium for diagnosis because it is readily available in large quantities, easy to obtain at low cost, and contains all the biomarkers present in blood, albeit in lower quantities. Affinity sensors are devices that detect molecules through their interactions with biological recognition molecules. Their low cost, high sensitivity, and selectivity, as well as rapid detection time make them an attractive alternative to traditional means of detection. In this review article, we discuss the current status of breast cancer diagnosis, its salivary biomarkers, as well as the current trends in the development of affinity sensors for their detection.

scholarly journals An Effective Optical Dual Gas Sensor for Simultaneous Detection of Oxygen and Ammonia

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5124 ◽  
Author(s):  
Sajal Biring ◽  
Annada Sankar Sadhu ◽  
Moumita Deb
Keyword(s):  
Gas Sensor ◽  
Fluorescent Dyes ◽  
Low Cost ◽  
Simultaneous Detection ◽  
High Sensitivity ◽  
Eosin Y ◽  
Practical Applications ◽  
Sensing Material ◽  
Dual Sensor ◽  
Sensitivity And Selectivity

The development of a simple, low-cost sensor for the effective sensing of multiple gases in industrial or residential zones has been in high demand in recent days. In this article, we have proposed an optical sensor for the dual sensing of oxygen (O2) and ammonia (NH3) gases, which consists of oxygen and ammonia-sensitive fluorescent dyes coated individually on both sides of a glass substrate. An ethyl cellulose (EC) matrix doped with platinum (II) meso-tetrakis (pentafluorophenyl) porphyrin (PtTFPP) serves as the oxygen-sensing material, whereas the NH3-sensing material includes an eosin Y fluorescent indicator immobilized within a cellulose acetate (CA) matrix. Both the oxygen and ammonia-sensitive materials were excited by the same LED light source with a 405 nm peak wavelength, while the corresponding emissions were detected separately for the selective sensing of the gases under study. The dual gas sensor exhibits maximum sensitivities of around 60 and 20 for oxygen and ammonia gases, respectively. The high sensitivity and selectivity of the proposed optical dual sensor suggests the feasibility of the simultaneous sensing of oxygen and ammonia for practical applications.

scholarly journals State-of-the-Art Optical Devices for Biomedical Sensing Applications—A Review

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 973
Author(s):  
N. L. Kazanskiy ◽  
S. N. Khonina ◽  
M. A. Butt ◽  
A. Kaźmierczak ◽  
R. Piramidowicz
Keyword(s):  
Optical Sensors ◽  
Low Cost ◽  
High Sensitivity ◽  
Sensor Technology ◽  
Biomedical Sensors ◽  
Plasmonic Sensors ◽  
Biomedical Sensing ◽  
Sensing Applications ◽  
Compact Size ◽  
Pros And Cons

Optical sensors for biomedical applications have gained prominence in recent decades due to their compact size, high sensitivity, reliability, portability, and low cost. In this review, we summarized and discussed a few selected techniques and corresponding technological platforms enabling the manufacturing of optical biomedical sensors of different types. We discussed integrated optical biosensors, vertical grating couplers, plasmonic sensors, surface plasmon resonance optical fiber biosensors, and metasurface biosensors, Photonic crystal-based biosensors, thin metal films biosensors, and fiber Bragg grating biosensors as the most representative cases. All of these might enable the identification of symptoms of deadly illnesses in their early stages; thus, potentially saving a patient’s life. The aim of this paper was not to render a definitive judgment in favor of one sensor technology over another. We presented the pros and cons of all the major sensor systems enabling the readers to choose the solution tailored to their needs and demands.

scholarly journals Graphene and its Derivatives-Based Optical Sensors

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiao-Guang Gao ◽  
Ling-Xiao Cheng ◽  
Wen-Shuai Jiang ◽  
Xiao-Kuan Li ◽  
Fei Xing
Keyword(s):  
Optical Sensors ◽  
Low Cost ◽  
High Sensitivity ◽  
Fast Response ◽  
Cell Detection ◽  
Single Cell Detection ◽  
Sensing Applications ◽  
Wide Range ◽  
Surface Enhanced Raman ◽  
Recent Developments

Being the first successfully prepared two-dimensional material, graphene has attracted extensive attention from researchers due to its excellent properties and extremely wide range of applications. In particular, graphene and its derivatives have displayed several ideal properties, including broadband light absorption, ability to quench fluorescence, excellent biocompatibility, and strong polarization-dependent effects, thus emerging as one of the most popular platforms for optical sensors. Graphene and its derivatives-based optical sensors have numerous advantages, such as high sensitivity, low-cost, fast response time, and small dimensions. In this review, recent developments in graphene and its derivatives-based optical sensors are summarized, covering aspects related to fluorescence, graphene-based substrates for surface-enhanced Raman scattering (SERS), optical fiber biological sensors, and other kinds of graphene-based optical sensors. Various sensing applications, such as single-cell detection, cancer diagnosis, protein, and DNA sensing, are introduced and discussed systematically. Finally, a summary and roadmap of current and future trends are presented in order to provide a prospect for the development of graphene and its derivatives-based optical sensors.

scholarly journals Smartphone-Based Microfluidic Colorimetric Sensor for Gaseous Formaldehyde Determination with High Sensitivity and Selectivity

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3141 ◽  
Author(s):  
Xiao-Liang Guo ◽  
Yan Chen ◽  
Hong-Lan Jiang ◽  
Xian-Bo Qiu ◽  
Du-Li Yu
Keyword(s):  
Microfluidic Chip ◽  
Limit Of Detection ◽  
Low Cost ◽  
Sick Building Syndrome ◽  
High Sensitivity ◽  
Colorimetric Sensor ◽  
World Health ◽  
Formaldehyde Determination ◽  
Sensitivity And Selectivity ◽  
Gaseous Formaldehyde

Formaldehyde is one of the most dangerous air pollutants, which can cause sick building syndrome. Thus, it is very crucial to precisely determine formaldehyde with a low cost and simple operation. In this paper, a smartphone-based microfluidic colorimetric sensor is devised for gaseous formaldehyde determination with high sensitivity and selectivity. Specifically, a novel microfluidic chip is proposed based on the 4-aminohydrazine-5-mercapto-1,2,4-triazole (AHMT) method to determine formaldehyde; the chip consists of two reagent reservoirs, one reaction reservoir and a mixing column. In this design to prevent the fluid from flowing out while letting the gas molecule in, a hydrophobic porous poly tetra fluoroethylene (PTFE) membrane is put on the top of the reaction reservoir. Using the microfluidic chip sensor, a smartphone-based formaldehyde determination system is developed, which makes the measuring process automated and simple. As per the experiment results, the limit-of-detection (LOD) of the system is as low as 0.01 ppm, which is much lower than the maximum exposure concentration (0.08 ppm) recommended by the World Health Organization (WHO). Moreover, the sensor is hardly affected by acetaldehyde, volatile organic compounds (VOCs) or acidic-alkaline, which shows great selectivity. Finally, the performance of the proposed sensor is verified by using it for the determination of formaldehyde in a newly decorated house.

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