scholarly journals Sensing of Oxygen Partial Pressure in Air with ZnO Nanoparticles

Sensors ◽  
2020 ◽  
Vol 20 (2) ◽  
pp. 562
Author(s):  
Xin Chang ◽  
Shunpu Li ◽  
Daping Chu
Keyword(s):  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Low Cost ◽  
Electrical Conductance ◽  
Zno Nanoparticle ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Sensitive Sensor ◽  
Micrometer Scale ◽  
Higher Sensitivity

The demand for sensors in response to oxygen partial pressure in air is increasingly high in recent years and small-size sensors on a micrometer scale and even a nanometer scale are particularly desirable. In this paper, the sensing of oxygen partial pressure in air was realized by a solution-processed ZnO nanoparticle (NP). Thin-film ZnO NP was prepared by spin-coating and a highly sensitive sensor was then fabricated. The oxygen sensing performance was characterized in air and compared with that in nitrogen, which showed an increase in electrical conductance by more than 100 times as a result of decreasing oxygen partial pressure from 103 mBar to 10−5 mBar. Moreover, higher sensitivity was achieved by increasing the annealing temperature and the effect of thermal annealing was also investigated. Furthermore, ZnO NP lines with 7 μm in width were successfully patterned with low cost by a mould-guided drying technique from ZnO NP dispersion, which makes ZnO NP extremely promising for miniaturized and integrated sensing applications.

Amperometric sensor for ascorbic acid using a gold electrode modified with ZnO@SiO2 nanospheres

2016 ◽  
Vol 40 (10) ◽  
pp. 8438-8443 ◽  
Author(s):  
Sher Bahadar Khan ◽  
Md Sameer Ahmed ◽  
Abdullah M. Asiri
Keyword(s):  
Ascorbic Acid ◽  
Gold Electrode ◽  
Low Cost ◽  
Amperometric Sensor ◽  
Highly Sensitive ◽  
Sensitive Sensor

A highly sensitive sensor based on ZnO@SiO2 nanospheres has been developed for the detection of ascorbic acid. The developed sensor is very simple and has been fabricated using low cost materials.

scholarly journals Trimodal Waveguide Demonstration and Its Implementation as a High Order Mode Interferometer for Sensing Application

Sensors ◽  
2019 ◽  
Vol 19 (12) ◽  
pp. 2821 ◽  
Author(s):  
Jhonattan C. Ramirez ◽  
Lucas H. Gabrielli ◽  
Laura M. Lechuga ◽  
Hugo E. Hernandez-Figueroa
Keyword(s):  
Free Spectral Range ◽  
Point Of Care ◽  
Low Cost ◽  
High Order Mode ◽  
Sio2 Substrate ◽  
Polymer Waveguide ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Different Types ◽  
Mode Order

This work implements and demonstrates an interferometric transducer based on a trimodal optical waveguide concept. The readout signal is generated from the interference between the fundamental and second-order modes propagating on a straight polymer waveguide. Intuitively, the higher the mode order, the larger the fraction of power (evanescent field) propagating outside the waveguide core, hence the higher the sensitivity that can be achieved when interfering against the strongly confined fundamental mode. The device is fabricated using the polymer SU-8 over a SiO2 substrate and shows a free spectral range of 20.2 nm and signal visibility of 5.7 dB, reaching a sensitivity to temperature variations of 0.0586 dB/ ∘ C. The results indicate that the proposed interferometer is a promising candidate for highly sensitive, compact and low-cost photonic transducer for implementation in different types of sensing applications, among these, point-of-care.

scholarly journals A Nanocomposite Based on Reduced Graphene and Gold Nanoparticles for Highly Sensitive Electrochemical Detection of Pseudomonas aeruginosa through Its Virulence Factors

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1180 ◽  
Author(s):  
Islem Gandouzi ◽  
Mihaela Tertis ◽  
Andreea Cernat ◽  
Dalila Saidane-Mosbahi ◽  
Aranka Ilea ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Gold Nanoparticles ◽  
Bacterial Infections ◽  
Electrochemical Sensors ◽  
Tap Water ◽  
Low Cost ◽  
Biological Contamination ◽  
Reduced Graphene ◽  
Highly Sensitive ◽  
Higher Sensitivity

Pyoverdine is a fluorescent siderophore produced by Pseudomonas aeruginosa that can be considered as a detectable marker in nosocomial infections. The presence of pyoverdine in water can be directly linked to the presence of the P. aeruginosa, thus being a nontoxic and low-cost marker for the detection of biological contamination. A novel platform was developed and applied for the electrochemical selective and sensitive detection of pyoverdine, based on a graphene/graphite-modified screen-printed electrode (SPE) that was electrochemically reduced and decorated with gold nanoparticles (NPs). The optimized sensor presenting higher sensitivity towards pyoverdine was successfully applied for its detection in real samples (serum, saliva, and tap water), in the presence of various interfering species. The excellent analytical performances underline the premises for an early diagnosis kit of bacterial infections based on electrochemical sensors.

Fabrication of a Low-Coercivity, Large-Magnetoresistance PVA/Fe/Co/Ni Nanofiber Composite Using an Electrospinning Technique and Its Characterization

2020 ◽  
Vol 20 (6) ◽  
pp. 3504-3511 ◽  
Author(s):  
A. Robertsam ◽  
N. Victor Jaya
Keyword(s):  
Low Cost ◽  
Cobalt Nitrate ◽  
Electrospinning Process ◽  
Poly Vinyl Alcohol ◽  
Ferric Nitrate ◽  
Electrospinning Technique ◽  
Nanofiber Composite ◽  
Sensing Applications ◽  
Heat Treated ◽  
Highly Sensitive

A nanofiber composite is a unique engineered material, which can impart new physical, chemical, and electrical properties. Among existing polymer composites, the metallic nanofiber composite has a significant role in biomedical applications. In this study, a metallic nanofiber composite was fabricated using poly vinyl alcohol [PVA-(C2H4O)n] reinforced with ferric nitrate [Fe(NO3)3·9H2O], cobalt nitrate [Co(NO3)2·6H2O], and nickel acetate [C4H6NiO4·4H2O] using a low-cost electrospinning process. The process parameters were optimized for fabricating uniform, bead-free, and substratefree fibers. The morphological features of the composite were evaluated using a scanning electron microscope (SEM). Hysteresis of the heat-treated composite was studied using a vibrating sample magnetometer (VSM). This study showed that the composite behaved as a ferromagnetic (intermediate) material with coercivity in the range 318–671 G for different wt.% of nickel. Pellets (8-mm diameter and 250-μm thickness) of this composite changed the resistance by 18% when dispensed in a magnetic field of 1200 G at an ambient temperature. Based on a thermogravimetric analysis, the thermal stability and magnetoresistance property showed that the fabricated composite was suitable for developing a highly sensitive magnetic sensor, which could be used in bio-sensing applications.

scholarly journals Aerogels for Biomedical, Energy and Sensing Applications

Gels ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 264
Author(s):  
Muhammad Tayyab Noman ◽  
Nesrine Amor ◽  
Azam Ali ◽  
Stanislav Petrik ◽  
Radek Coufal ◽  
...  
Keyword(s):  
High Performance ◽  
Structural Characteristics ◽  
Low Cost ◽  
Three Dimensional ◽  
Strain Sensors ◽  
High Porosity ◽  
Energy Materials ◽  
Sensing Applications ◽  
Highly Sensitive ◽  
Solid State Structures

The term aerogel is used for unique solid-state structures composed of three-dimensional (3D) interconnected networks filled with a huge amount of air. These air-filled pores enhance the physicochemical properties and the structural characteristics in macroscale as well as integrate typical characteristics of aerogels, e.g., low density, high porosity and some specific properties of their constituents. These characteristics equip aerogels for highly sensitive and highly selective sensing and energy materials, e.g., biosensors, gas sensors, pressure and strain sensors, supercapacitors, catalysts and ion batteries, etc. In recent years, considerable research efforts are devoted towards the applications of aerogels and promising results have been achieved and reported. In this thematic issue, ground-breaking and recent advances in the field of biomedical, energy and sensing are presented and discussed in detail. In addition, some other perspectives and recent challenges for the synthesis of high performance and low-cost aerogels and their applications are also summarized.

scholarly journals Highly Sensitive Amperometric Sensor Based on Laccase-Mimicking Metal-Based Hybrid Nanozymes for Adrenaline Analysis in Pharmaceuticals

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1510
Author(s):  
Olha Demkiv ◽  
Nataliya Stasyuk ◽  
Galina Gayda ◽  
Mykhailo Gonchar
Keyword(s):  
Catalytic Activity ◽  
Limit Of Detection ◽  
Chemical Reduction ◽  
Low Cost ◽  
Simple Method ◽  
Amperometric Sensors ◽  
Endocrine Hormone ◽  
Highly Sensitive ◽  
Good Catalytic Activity ◽  
Higher Sensitivity

Nanozymes are nanomaterials which exhibit artificial enzymatic activities and are considered as alternatives to natural enzymes. They are characterized by good catalytic activity and high stability, as well as ease and low cost of preparation. In this study, the mimetics of laccase or “nanolaccases” (NLacs) were synthesized by a simple method of chemical reduction of transition metal salts. The NLacs were tested for their catalytic activity in solution and on the electrode surface. The most effective NLacs, namely nAuCePt and nPtFe, were found to possess excellent laccase-like activities capable of oxidizing the endocrine hormone adrenaline (AD). These NLacs were characterized in detail and used for the development of amperometric sensors for AD determination. The amperometric sensors containing the best NLacs, as well as a natural fungal laccase, were constructed. The most effective nAuCePt-containing sensor had good specificity in relation to AD and improved analytical characteristics. It possessed a 384-fold higher sensitivity than adrenaline (230,137 A·M−1·m−2), a 64-fold lower limit of detection (0.025 µM), and a broader linear range (0.085–45 µM) in comparison with the sensor based on natural laccase. The constructed nAuCePt-containing sensor was successfully used for AD analysis in pharmaceutical formulation.

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