scholarly journals An Ethanol Vapor Sensor Based on a Microfiber with a Quantum-Dot Gel Coating

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 300 ◽  
Author(s):  
Siqi Hu ◽  
Guofeng Yan ◽  
Chunzhou Wu ◽  
Sailing He
Keyword(s):  
Quantum Dot ◽  
Low Cost ◽  
Temperature Response ◽  
High Sensitivity ◽  
Ethanol Vapor ◽  
Fast Response ◽  
Cost System ◽  
Sensing Applications ◽  
Vapor Sensor ◽  
Ethanol Sensing

An ethanol vapor sensor based on a microfiber with a quantum-dot (QD) gel coating is proposed and demonstrated. The QD gel was made from UV glue as the gel matrix and CdSe/ZnS QDs with a concentration of 1 mg/mL. The drawing and coating processes were conducted by using a simple and low-cost system developed for this study. Bending, ethanol sensing, temperature response, and time response tests were carried out, respectively. The experimental results showed that the fabricated sensor had a high sensitivity of −3.3%/ppm, a very low temperature cross-sensitivity of 0.17 ppm/°C, and a fast response time of 1.1 s. The easily fabricated robust structure and the excellent sensing performance render the sensor a promising platform for real ethanol sensing applications.

scholarly journals Ethanol Vapor Sensor Based on a Microfiber with Quantum- Dots Gel Coating

2018 ◽  
Author(s):  
Siqi Hu ◽  
Guofeng Yan ◽  
Chunzhou Wu ◽  
Sailing He
Keyword(s):  
Quantum Dots ◽  
Low Cost ◽  
Temperature Response ◽  
High Sensitivity ◽  
Ethanol Vapor ◽  
Fast Response ◽  
Coating Process ◽  
Vapor Sensor ◽  
Sensing Application ◽  
Ethanol Sensing

An ethanol vapor sensor based on a microfiber with quantum-dots (QDs) gel coating is proposed and demonstrated. The QDs gel was made from UV glue as the gel matrix and the CdSe/ZnS QDs with a concentration of 1mg/mL. The drawing and coating process were conducted by using a simple and low-cost home-made system. The bending, ethanol sensing, temperature response and time response tests were carried out, alternatively. The experimental results show that the fabricated sensor has a high sensitivity of -3.3%/ppm, a really low temperature cross-sensitivity of 0.17 ppm/℃ and a fast response time of 1.1s. The robust structure with ease of fabrication and excellent sensing performance render it a promising platform for real ethanol sensing application.

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 Facile Chemical Bath Synthesis of SnS Nanosheets and Their Ethanol Sensing Properties

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2581 ◽  
Author(s):  
Wei Shan ◽  
Zhengqian Fu ◽  
Mingsheng Ma ◽  
Zhifu Liu ◽  
Zhenggang Xue ◽  
...  
Keyword(s):  
High Performance ◽  
Gas Sensing ◽  
Raw Materials ◽  
Orthorhombic Phase ◽  
Ethanol Vapor ◽  
Fast Response ◽  
Sensing Applications ◽  
Recovery Times ◽  
Response And Recovery ◽  
Ethanol Sensing

Tin(II) monosulfide (SnS) nanosheets were synthesized using SnCl4•5H2O and S powders as raw materials in the presence of H2O via a facile chemical bath method. Orthorhombic phase SnS nanosheets with a thickness of ~100 nm and lateral dimensions of 2~10 μm were obtained by controlling the synthesis parameters. The formation of a SnO2 intermediate is key to the valence reduction of Sn ions (from IV to II) and the formation of SnS. The gas sensors fabricated from SnS nanosheets exhibited an excellent response of 14.86 to 100 ppm ethanol vapor when operating at 160 °C, as well as fast response and recovery times of 23 s and 26 s, respectively. The sensors showed excellent selectivity for the detection of ethanol over acetone, methanol, and ammonia gases, which indicates the SnS nanosheets are promising for high-performance ethanol gas sensing applications.

Nanocrystalline Phosphors for Lighting and Detection Applications

2010 ◽  
Vol 654-656 ◽  
pp. 1130-1133 ◽  
Author(s):  
Christopher J. Summers ◽  
Hisham M. Menkara ◽  
Richard A. Gilstrap ◽  
Mazen Menkara ◽  
Thomas Morris
Keyword(s):  
Quantum Dots ◽  
Quantum Dot ◽  
Shell Growth ◽  
Stokes Shift ◽  
Thermal Quenching ◽  
High Sensitivity ◽  
In Situ Monitoring ◽  
White Leds ◽  
Sensing Applications ◽  
Improved Stability

We report the development of new nanoparticle phosphors and quantum dot structures designed for applications to enhance the color rendering and efficiency of high brightness white LEDs, as well as for bio-sensing applications. The intrinsic problem of self-absorption, high toxicity, and high sensitivity to thermal quenching of conventional quantum dot systems has prevented their adoption to LED devices. Doped Cd-free quantum dots may circumvent these issues due to their distinct Stokes shift and improved stability at high temperature. We report on the modification of Mn-doped ZnSe/ZnS core-shell quantum dots for application to the (blue diode + yellow emitter) white LED system. Band gap tuning for 460 nm excitation, inorganic shell growth and in-situ monitoring for enhanced efficiency, and analysis of thermal stability will are reported.

scholarly journals MWCNT Devices Fabricated by Dielectrophoresis: Study of Their Electrical Behavior Related to Deposited Nanotube Amount for Gas Sensing Applications

2015 ◽  
Vol 10 (1) ◽  
pp. 13-20
Author(s):  
Elisabete Galeazzo ◽  
Marcos C. Moraes ◽  
Henrique E. M. Peres ◽  
Michel O. S. Dantas ◽  
Victor G. C. Lobo ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Gas Sensing ◽  
High Sensitivity ◽  
Cost Effective ◽  
Adsorbed Water ◽  
Fast Response ◽  
Process Time ◽  
Electrical Behavior ◽  
Glass Substrates ◽  
Sensing Applications

Intensive research has been focused on investigating new sensing materials, such as carbon nanotubes (CNT) because of their promising characteristics. However, there are challenges related to their application in commercial devices such as sensitivity, compatibility, and complexity of miniaturization, among others. We report the study of the electrical behavior of devices composed by multi-walled carbon nanotubes (MWCNT) deposited between aluminum electrodes on glass substrates by means of dielectrophoresis (DEP), which is a simple and cost-effective method. The devices were fabricated by varying the DEP process time. Remarkable changes in their electric resistance were noticed depending on the MWCNT quantities deposited. Other electrical properties of devices such as high sensitivity, fast response time and stability are also characterized in humid environment. A humidity sensing mechanism is proposed on the basis of charge transfer between adsorbed water molecules and the MWNTC surface or between water and the glass surface.

Gas Sensing Properties of TiO2 and SnO2 Nanopowders Obtained through Gel Combustion

2006 ◽  
Vol 45 ◽  
pp. 1828-1833
Author(s):  
Fabio A. Deorsola ◽  
P. Mossino ◽  
Ignazio Amato ◽  
Bruno DeBenedetti ◽  
A. Bonavita ◽  
...  
Keyword(s):  
Response Time ◽  
Metal Oxides ◽  
Gas Sensing ◽  
Low Cost ◽  
High Sensitivity ◽  
Fast Response ◽  
High Specific Surface Area ◽  
Research Field ◽  
Wide Range ◽  
Gel Combustion

Nanostructured semiconductor metal oxides have played a central role in the gas sensing research field, because of their high sensitivity, selectivity and low response time. Among all the processes, developed for the synthesis of nanostructured metal oxides, gel combustion seems to be the most promising route due to low-cost precursors and simplicity of the process. It combines chemical gelation and combustion, involving the formation of a gel from an acqueous solution and an exothermic redox reaction, yielding to very porous and softly agglomerated nanopowders. In this work, nanostructured tin oxide, SnO2, and titanium oxide, TiO2, have been synthesized through gel combustion. Powders showed nanometric particle size and high specific surface area. The so-obtained TiO2 and SnO2 nanopowders have been used as sensitive element of resistive λ sensor and ethanol sensor respectively, realized depositing films of nanopowders dispersed in water onto alumina substrates provided with Pt contacts and heater. TiO2-based sensors showed at high temperature good response, fast response time, linearity in a wide range of O2 concentration and long-term stability. SnO2-based sensors have shown high sensitivity to low concentrations of ethanol at moderate temperature.

scholarly journals A Schiff Base Fluorescence Enhancement Probe for Fe(III) and Its Sensing Applications in Cancer Cells

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2500 ◽  
Author(s):  
Na Hee Kim ◽  
Junho Lee ◽  
Sungnam Park ◽  
Junyang Jung ◽  
Dokyoung Kim
Keyword(s):  
Schiff Base ◽  
Laser Scanning ◽  
Fluorescence Enhancement ◽  
Aqueous Media ◽  
Cancer Cell Line ◽  
High Sensitivity ◽  
Fast Response ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Sensing Applications

We report a new Schiff base fluorescent probe which senses ferric ion, Fe(III), with a significant fluorescence enhancement response. The probe showed high sensitivity (0.8 ppb), and fast response time (<10 s) of Fe(III) in aqueous media. In addition, the probe showed the ability to sense Fe(III) in a HeLa cancer cell line, with very low cytotoxicity. As a new bio-imaging probe for Fe(III), it gave bright fluorescent images in confocal laser scanning microscopy (CLSM).

scholarly journals A MEMS-Based Multi-Parameter Integrated Chip and Its Portable System for Water Quality Detection

Micromachines ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 63 ◽  
Author(s):  
Ziyue Wu ◽  
Jiaqi Wang ◽  
Chao Bian ◽  
Jianhua Tong ◽  
Shanhong Xia
Keyword(s):  
Water Quality ◽  
Copper Ions ◽  
Detection System ◽  
Low Cost ◽  
Temperature Response ◽  
High Sensitivity ◽  
Integrated Sensor ◽  
Quality Detection ◽  
Portable Detection ◽  
Portable System

As an important means to protect water resources, water quality detection is of great social and economic significance. Water quality detection sensors processed by micro-electro-mechanical system (MEMS) technology have the advantages of low-cost, small size, and high sensitivity. In this paper, a multi-parameter water quality detection integrated sensor chip is further studied, and a portable detection system using this chip is developed. Temperature, pH, oxidation-reduction potential (ORP), conductivity and concentration of copper ions (Cu2+) are selected as typical water quality parameters. Experiments of sensor calibrations using this portable detection system were performed in standard solutions. The sensor has a sensitivity of −57.34 mV/pH in pH detection and 5.95 Ω/°C in temperature response. ORP is directly detected by Pt microelectrode on the chip and the relative error is less than 3%. The electrode constant of the sensor is 1.416 cm−1 and the linearity is 0.9995 in conductivity detection. With the gold nanoparticles deposited on the electrode, the detection peak of Cu2+ appears at 280 mV and the sensor shows good linearity to the concentration of Cu2+ in the range of 0–0.6 mg/L. The detection limit of Cu2+ concentration is 2.33 μg/L. Through measurement and calculation, the accuracy of the portable system is within 4%. This portable multi-parameter water quality detection system with the MEMS-based integrated chip shows great potential in the field and fast detection.

Micro-structured fibers and their applications in fiber-optic sensors and random fiber lasers

2018 ◽  
Vol 96 (4) ◽  
pp. 359-365
Author(s):  
Yanping Xu ◽  
Xiaoyi Bao
Keyword(s):  
Fiber Lasers ◽  
Fiber Optic ◽  
Axial Strain ◽  
Low Cost ◽  
High Sensitivity ◽  
Dynamic Parameter ◽  
Fiber Optic Sensors ◽  
Spectral Correlation ◽  
Sensing Applications ◽  
Micro Cantilever

Micro-structured fibers are important devices that have drawn intensive attentions and proved to be powerful platforms for various applications over the past decades due to their remarkable merits and advantages, such as small footprint, immunity to electromagnetic interferences, light weight, high physical flexibility, and low cost. Modifications in optical fibers can be used as light-steering elements to excite and couple back different core and cladding modes and form various in-fiber structures, including in-line fiber interferometer, fiber micro-cantilever, fiber random gratings, and so on. These micro-structures, when applied as fiber-optic sensors in the presence of external disturbances, show high sensitivity in terms of the significant changes in the guided light features. Novel micro-structured bend-insensitive fiber-based in-line fiber interferometer and micro-cantilever have been proposed to realize both static and dynamic parameter measurements, including temperature, axial strain, surrounding refractive index, and vibration. We have also developed a novel fiber random grating along with a spectral correlation algorithm for simultaneous measurement of three static measurands. To move a step forward, random fiber lasers based on fiber random grating are achieved for either improving the laser performances or sensing applications of temperature, strain, and ultrasound measurements with high sensitivity.

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.

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