scholarly journals Development of non-enzymatic glucose electrode based on Au nanoparticles decorated single-walled carbon nanohorns

2021 ◽  
Author(s):  
Cheng Bi ◽  
Hong-Wei Lv ◽  
Hui-Ling Peng ◽  
Quan-Fu Li
Keyword(s):  
Au Nanoparticles ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Glucose Sensing ◽  
Average Particle ◽  
Carbon Nanohorns ◽  
Single Walled Carbon ◽  
Potential Alternative ◽  
Bonding Method ◽  
Glucose Electrode

Abstract A composite with gold nanoparticles (AuNPs) decorating single-walled carbon nano-horns (SWCNHs) is synthesized and used to modify a gold electrode for non-enzymatic glucose detection. The composite was synthesized by a simple covalent bonding method. The AuNPs with an average particle size of 40 nm are dispersed homogeneously on the surface of the SWCNHs. Therefore, the synergistic effect of the AuNPs and the SWCNHs leads to an excellent glucose sensing performance. The glucose sensing tests indicate that the electrode fabricated has a linear response in the 0.5-2 mM and 4–12 mM glucose concentration range, a high sensitivity (275.33 and 352.5 µA cm− 2 mM− 1), and a low detection limit (0.72 µM) (S/N = 3) at + 0.3 V, as well as strong resistance to the interference by ascorbic acid (AA), uric acid (UA), dopamine (DA), galactose, and lactose. When the electrode was used for the detection of glucose in blood samples, the glucose contents detected by the electrode was in right agreement with real. The performance level reached makes the electrode a potential alternative tool for the detection of glucose.

Grain Size Control and Ethanol Sensing Properties of Calcined SnO2 Nanoparticles

2011 ◽  
Vol 266 ◽  
pp. 76-79
Author(s):  
Yu Wang ◽  
Xiao Lin Jia ◽  
Lin Dong ◽  
Shao Kang Guan
Keyword(s):  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Average Particle Size ◽  
Size Control ◽  
High Sensitivity ◽  
Average Particle ◽  
Nanocrystal Growth ◽  
Grain Size Control ◽  
Concentration Detection Limit ◽  
Ethanol Sensing

SnO2 nanoparticles were prepared via a sol-gel method by heating the mixture of hydrous SnO2 nanoparticles and SiO2 nanospheres at 600 °C. The average particle size of the obtained SnO2 nanoparticles is 3.3 nm, smaller than that of the SnO2 nanoparticles (~ 6.4 nm) prepared by calcining the pure hydrous SnO2 at 600 °C. The SiO2 nanospheres play an important role in restricting SnO2 nanocrystal growth. The ~3.3 nm-sized SnO2 nanoparticles exhibited high sensitivity for ethanol as well as quick response and recovery time. The concentration detection limit can be as low as 5 ppm at room temperature.

SYNTHESIS AND MANIPULATION OF WO3 NANO PARTICLES FOR GAS SENSING APPLICATIONS

2012 ◽  
Vol 05 ◽  
pp. 227-233
Author(s):  
Elham kamali Heidari ◽  
Seyed Reza Mahmoodi ◽  
Ehsan Marzbanrad ◽  
Babak Raisi ◽  
Cyrus Zmani
Keyword(s):  
Gas Sensing ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Nano Particles ◽  
Average Particle ◽  
Monoclinic Structure ◽  
Template Removal ◽  
Sensing Applications ◽  
Low Concentrations ◽  
Nanocasting Route

Ultra fine WO 3 nanoparticles were synthesized by nanocasting route, using mesoporous SiO 2 as a template. BET measurements showed a specific surface area of 700m2/gr for synthesized SiO 2 while after impregnation and template removal, this area was reduced to 43m2/gr for WO 3 nanoparticles. HRTEM results showed single crystalline nanoparticles with average particle size of about 5nm possessing a monoclinic structure which is the favorite crystal structure for gas sensing applications. Alternative electric field was applied to align synthesized WO 3 nanoparticles between electrodes. Gas sensing measurements showed that this material has a high sensitivity to very low concentrations of NO 2 at 250°C.

scholarly journals Semiconductor Sensor With Loaded SnO2 Nanoparticles For Early Warning Of Indoor Fires

2019 ◽  
Vol Vol. 14, No.1 ◽  
pp. 37-42 ◽  
Author(s):  
Nelly Maksymovyc ◽  
Ludmila Oleksenko ◽  
Georgiy Fedorenko ◽  
Ganna Arinarkhova ◽  
Keyword(s):  
Early Warning ◽  
Tin Dioxide ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Average Particle ◽  
Sensitive Layer ◽  
Semiconductor Sensor ◽  
Wide Range

Nanosized tin dioxide material with an average particle size of 10-11 nm was prepared by a sol-gel method. The material has been tested as a gas sensitive layer of a semiconductor sensor. Platinum was introduced into the gas sensitive layer to increase the sensor response to hydrogen. It was shown that the Pt-containing sensor has high sensitivity to hydrogen: its electrical resistance changes in 9.2 times in the presence of 22 ppm H2 in air. It was demonstrated that the sensor applicable to a wide range of H2 measurements in air (3-935 ppm) and has a fast dynamic response. The sensor demonstrates rather good reproducibility of its signal to H2 and withstands hydrogen overload (935 ppm) without a loss of its sensitivity to H2 microconcentration (22 ppm). The results are prospective for applying the sensor in the detectors for early warning of indoor fires.

scholarly journals Adsorption-Semiconductor Sensor Based on Nanosized SnO2 for Early Warning of Indoor Fires

2021 ◽  
Author(s):  
Nelli Maksymovych ◽  
Ludmila Oleksenko ◽  
George Fedorenko
Keyword(s):  
Tin Dioxide ◽  
Early Stage ◽  
Dynamic Properties ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Average Particle ◽  
Semiconductor Sensor ◽  
Wide Range

The paper is devoted for a solution of indoors fires prevention at early stage by determination of H2 (fire precursor gas) in air using a semiconductor sensor. A material based on Pt-containing nanosized tin dioxide with an average particle size of 10–11 nm obtained via a sol–gel method was created for a gas sensitive layer of the sensor. The developed sensor has high sensitivity to H2 micro concentration, a wide range of its detectable content in air, selectivity of H2 measuring in the presence of СО and СН4, good dynamic properties. The combination of these properties is very important for prevention of inflammations on their early stages before the open fires appearance. Economic benefit of the proposed sensor is due to a lower cost and higher reliability of the fire situation detection.

scholarly journals Improving the CO and CH4 Gas Sensor Response at Room Temperature of α-Fe2O3(0001) Epitaxial Thin Films Grown on SrTiO3(111) Incorporating Au(111) Islands

2021 ◽  
Author(s):  
Aída Serrano ◽  
Jesus López-Sánchez ◽  
Iciar Arnay ◽  
Rosalía Cid ◽  
Maria Vila ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Room Temperature ◽  
Au Nanoparticles ◽  
Gas Sensing ◽  
Average Particle Size ◽  
Average Particle ◽  
Epitaxial Thin Films ◽  
Island Type ◽  
Before And After ◽  
Crystallographic Axes

In this work epitaxial Au islands have been grown on epitaxial α-Fe2O3 thin film by pulsed laser deposition on SrTiO3(111) substrate. Both Au and α-Fe2O3 layer show an island-type growth with an average particle size of 40 and 62 nm, respectively. The crystallographic coupling of lattices is confirmed with a rotation of 30º between the in-plane crystallographic axes of α-Fe2O3(0001) structure and those of SrTiO3(111) substrate and between the in-plane crystallographic axes of Au(111) and those of α-Fe2O3(0001) structure. α-Fe2O3 is the only phase of iron oxide identified before and after its functionalization with Au nanoparticles. In addition, its structural character-istics are also preserved after Au deposition, with minor changes at short-range order. The func-tional character of the complex systems as gas sensor has been proven at room temperature. Con-ductance measurements of Au(111)/α-Fe2O3(0001)/ SrTiO3(111) system show that the incorpora-tion of Au islands on top of the α-Fe2O3(0001) layer induces an enhancement of the gas-sensing ac-tivity for CO and CH4 gas in comparison to a bare α-Fe2O3(0001) layer grown on SrTiO3(111).

Preparation of Silver Nanoparticles-Loaded Gel Fibers Based on Microfluidic Method and its Application as SERS Substrates

2020 ◽  
Vol 993 ◽  
pp. 701-708
Author(s):  
Wan Ying Li ◽  
Jia Hao Li ◽  
Jing Hong Ma ◽  
Jing Hua Gong
Keyword(s):  
Surface Science ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Reduction Reaction ◽  
Noble Metal Nanoparticles ◽  
Enhancement Effect ◽  
Average Particle ◽  
Destructive Testing ◽  
Sers Substrates ◽  
Relative Standard

Surface-enhanced Raman scattering (SERS) spectroscopy technology has broad application prospects in food safety, environmental monitoring, surface science and material analysis because of the characteristics of ultra-high sensitivity and non-destructive testing. However, there are still some challenges in the preparation of SERS substrates. As SERS substrates, the common colloidal noble metal nanoparticles usually show low storage stability and poor repeatability of analytical results. In order to overcome these limitations, a coaxial microfluidic spinning device was designed to prepare flexible SERS substrates in this paper. Based on the microfluidic spinning and subsequent in-situ reduction reaction of AgNO3, novel gel fibers uniformly loaded with AgNPs were successfully prepared. The effects of the concentration of AgNO3 solution and UV irradiation duration on the formation of AgNPs were investigated. Transmission electron microscopy (TEM) showed that the average particle size was about 2.7 nm. The gel fibers loaded with AgNPs were used as SERS substrates to detect 4-mercaptobenzoic acid (4-MBA), which showed obvious Raman enhancement effect and good repeatability. The relative standard deviation of 10 test results was 4.75%, and the detection line range was 10-14-10-5 mol·L-1.

scholarly journals Structure and Optical Property of Gold Nanoparticles Synthesized by Modified Polyol Method

2021 ◽  
Vol 31 (3) ◽  
Author(s):  
Long Nguyen Viet
Keyword(s):  
Gold Nanoparticles ◽  
Au Nanoparticles ◽  
Average Particle Size ◽  
Nir Spectroscopy ◽  
Polyol Method ◽  
Average Particle ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Modified Polyol Method

In this research, Au nanoparticles were successfully synthesized by modified polyol method with commercial precursors to be gold (III) chloride trihydrate (HAuCl4·3H2O), ethylene glycol (EG), poly(vinylpyrrolidone) (PVP), sodium borohydride (NaBH4). The structure and properties of as-prepared Au nanoparticles have been investigated by X ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis-NIR spectroscopy. As a result, Au nanoparticles with the average particle size of 28.80 nm were successfully synthesized in the range of about 50 nm. It is evidenced that the assembly of gold nanoparticles was presented in their nucleation, growth, and formation. 

scholarly journals Detection of Fe3+ and Hg2+ ions by using High Fluorescent Carbon Dots Doped With S and N as Fluorescence Probes

2021 ◽  
Author(s):  
Huadong Liu ◽  
Haoxuan Xu ◽  
Hewei Li
Keyword(s):  
Water Solubility ◽  
Tap Water ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Carbon Quantum Dots ◽  
Fluorescence Probes ◽  
Average Particle ◽  
Nacl Solution ◽  
Blue Fluorescence ◽  
Fluorescent Carbon Dots

Abstract In this paper, carbon quantum dots (S-N-CDs) containing sulfur and nitrogen were synthesized using citric acid and thiourea. The average particle size of N-S-CDs is 8nm. The N-S-CDs surface contains various of functional groups, which has good water solubility. The fluorescence quantum yield of N-S-CDs is as high as 36.8%. N-S-CDs emits strong blue fluorescence in aqueous solution and has good photostability in neutral and alkaline Nacl solution. N-S-CDs has unique selectivity and high sensitivity to Fe3+ and Hg2+ ions, and the lowest detection limits are 1.4μM and 0.16μM, respectively. Under the interference of other metal ions, Fe3+ and Hg2+ ions can still effectively and stably quench the fluorescence of N-S-CDs. In addition, in the detection of actual samples, N-S-CDs can effectively detect Fe3+ and Hg2+ ions in tap water and lake water.

scholarly journals An Ultrahigh Sensitivity Acetone Sensor Enhanced by Light Illumination

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2318 ◽  
Author(s):  
Heng Zhang ◽  
Hongwei Qin ◽  
Chengyong Gao ◽  
Jifan Hu
Keyword(s):  
Operating Temperature ◽  
Sol Gel ◽  
Average Particle Size ◽  
High Sensitivity ◽  
Optimum Operating ◽  
Average Particle ◽  
Light Illumination ◽  
Acetone Vapor ◽  
Optimum Operating Temperature ◽  
Ultrahigh Sensitivity

Au:SmFe0.9Zn0.1O3 is synthesized by a sol-gel method and annealed at 750 °C. Through XRD, SEM and XPS analysis methods, the microstructure of the material has been observed. The average particle size is about 50 nm. The sensor shows a high sensitivity toward acetone vapor. As the relative humidity increases, the resistance and sensitivity of the sensor decline. To obtain a low optimum operating temperature, light illumination with different wavelengths has been introduced. The sensitivity toward acetone is improved at lower operating temperature when the sensor is irradiated by light. The smaller the wavelengths, the better the sensitivity of the sensor. Compared with other gases, the sensor shows excellent selectivity to acetone vapor, with better sensitivity, selectivity and stability when under light illumination.

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