scholarly journals Tyrosinase-Immobilized Biosensor Based on the Functionalized Hydroxyl Group-MWNT and Detection of Phenolic Compounds in Red Wines

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Ji-Hoon Yang ◽  
Jae-Chan Lee ◽  
Seong-Ho Choi
Keyword(s):  
Phenolic Compounds ◽  
Graft Polymerization ◽  
Phosphate Buffer Solution ◽  
Hydroxyl Group ◽  
Multiwall Carbon Nanotube ◽  
Hydroxyethyl Methacrylate ◽  
Red Wines ◽  
Buffer Solution ◽  
Radiation Induced ◽  
Multiwall Carbon

The tyrosinase-immobilized biosensor was developed with the hydroxyl group-functionalized multiwall carbon nanotube (MWNT) for phenol detection. The hydroxyl group-modified MWNT was modified to include poly(GVPB)-g-MWNT, or poly(HEMA), by a radiation-induced graft polymerization of glucosyl 4-vinylphenylboronate (GVPB) or 2-hydroxyethyl methacrylate (HEMA) on the surface of MWNT. The response of biosensor was in the range of 0.6–7.0 mM for concentration and in the range of 0.05–0.35 mM for phenol in a phosphate buffer solution, respectively. Various parameters influencing biosensor performance have been optimized: for pH, temperature, and the response to various phenolic compounds. The biosensor was then tested on phenolic compounds contained in three different commercial red wines.

Kinetic and isotherm studies on adsorption of methylene blue using polyacrylonitrile/hydroxyl group functionalized multiwall carbon nanotube multilayered nanofibrous composite

2020 ◽  
pp. 009524431989728
Author(s):  
S Swaminathan ◽  
NM Imayathamizhan ◽  
A Muthumanickkam
Keyword(s):  
Methylene Blue ◽  
Kinetic Study ◽  
Dye Adsorption ◽  
Freundlich Isotherm ◽  
Isotherm Model ◽  
Hydroxyl Group ◽  
Isotherm Models ◽  
Multiwall Carbon Nanotube ◽  
Methylene Blue Adsorption ◽  
Multiwall Carbon

Nanofibrous composite mat was prepared using polyacrylonitrile hard yarn waste and hydroxyl group functionalized multiwall carbon nanotubes (MWCNTs-OH) by electrospinning technique and exploit for methylene blue dye adsorption from aqueous solution. The nanofibrous composite mat was characterized by Fourier transform (FT) infrared spectroscopy, FT-Raman, scanning electron microscopy, X-ray diffractometer and thermogravimetric analyser. The adsorption experiments were studied to investigate the effect of MWCNT-OH weight percentage, initial solution pH, contact time and initial dye concentration on the adsorption. The higher percentage of methylene blue adsorption was found to be 80.05% under optimal condition. The adsorption equilibrium data were studied with Langmuir and Freundlich isotherm models. The R2 value was found to be higher in the Freundlich isotherm model which was clearly indicated that the Freundlich isotherm model is most suitable for the adsorption of methylene blue on nanofibrous composite mat. The kinetic study was carried out to explain the adsorption rate of methylene blue on nanofibrous composite. The kinetic study of methylene blue adsorption was favourable to the pseudo second-order equation.

Influence of Multiwall Carbon Nanotube on mechanical and wear properties of Copper – Iron composite

2020 ◽  
Vol 17 (1) ◽  
pp. 7570-7576 ◽  
Author(s):  
H. Sh. Hammood ◽  
S. S. Irhayyim ◽  
A. Y. Awad ◽  
H. A. Abdulhadi
Keyword(s):  
Carbon Nanotubes ◽  
Volume Fraction ◽  
Hybrid Composites ◽  
Hydraulic Press ◽  
Dry Sliding Wear ◽  
Multiwall Carbon Nanotube ◽  
Wear Properties ◽  
Sem Images ◽  
Wear Rates ◽  
Multiwall Carbon

Multiwall Carbon nanotubes (MWCNTs) are frequently attractive due to their novel physical and chemical characteristics, as well as their larger aspect ratio and higher conductivity. Therefore, MWCNTs can allow tremendous possibilities for the improvement of the necessarily unique composite materials system. The present work deals with the fabrication of Cu-Fe/CNTs hybrid composites manufactured by powder metallurgy techniques. Copper powder with 10 vol. % of iron powder and different volume fractions of Multi-Wall Carbon Nanotubes (MWCNTs) were mixed to get hybrid composites. The hybrid composites were fabricated by adding 0.3, 0.6, 0.9, and 1.2 vol.% of MWCNTs to Cu- 10% Fe mixture using a mechanical mixer. The samples were compressed under a load of 700 MPa using a hydraulic press to compact the samples. Sintering was done at 900°C for 2 h at 5ºC/min heating rate. The microscopic structure was studied using a Scanning Electron Microscope (SEM). The effect of CNTs on the mechanical and wear properties, such as micro-hardness, dry sliding wear, density, and porosity were studied in detail. The wear tests were carried out at a fixed time of 20 minutes while the applied loads were varied (5, 10, 15, and 20 N). SEM images revealed that CNTs were uniformly distributed with relative agglomeration within the Cu/Fe matrix. The results showed that the hardness, density, and wear rates decreased while the percentage of porosity increased with increasing the CNT volume fraction. Furthermore, the wear rate for all the CNTs contents increased with the applied load.

Detection of Hepatitis a Virus in Drinking Water by Enzyme -Immunoassay Using Ultracentrifugation for Virus Concentration

1985 ◽  
Vol 17 (10) ◽  
pp. 39-41 ◽  
Author(s):  
A. Schnattinger
Keyword(s):  
Membrane Filtration ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Phosphate Buffer Solution ◽  
Enzyme Linked Immunosorbent Assay ◽  
Virus Concentration ◽  
Buffer Solution ◽  
Solution Ph ◽  
Two Stage

Ten litres of tapwater were seeded with 200 µl (8×108 HAV particles) of a commercial (Organon Teknika) suspension of hepatitis A virus. Following WALTER and RÜDIGER (1981), the contaminated tapwater was treated with a two-stage technique for concentration of viruses from solutions with low virus titers. The two-stage technique consists of aluminium hydroxideflocculation (200 mg/l Al2(SO4)3. 18 H2O, pH 5,4-5,6) as first stage, the second stage of a lysis of aluminium hydroxidegel with citric acid/sodium citrate-buffer (pH 4,7; 1 ml/l sample), separation of viruses from the lysate by ultracentrifugation and suspension in 1 ml phosphate buffer solution (pH 7,2). A commercial solid phase enzyme-linked immunosorbent assay (ELISA) was used for the detection of HAV. HAV was detecterl in the 10.000:1 concentrates, but not in the seeded 101 samples. Approximately 4×108 of the inoculated 8×108 HAV particles were found in the 1 ml concentrates. The efficiency of detection is about 50%, the virus concentration 5000-fold. Although the percentage loss of HAV in comparison with concentration by means of membrane filtration is similar, the ultracentrifugation method yields a larger sample/concentrate ratio, so that smaller amounts of HAV can be detected more efficiently because of the smaller end-volume.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

scholarly journals All-Fiber Pyro- and Piezo-electric Nanogenerator for IoT Based Self-Powered Health-Care Monitoring

2021 ◽  
Author(s):  
Biswajit Mahanty ◽  
Sujoy Kumar Ghosh ◽  
Kuntal Maity ◽  
KRITTISH ROY ◽  
Subrata Sarkar ◽  
...  
Keyword(s):  
Health Care ◽  
Carbon Nanotube ◽  
Vinylidene Fluoride ◽  
Electrospun Nanofibers ◽  
Multiwall Carbon Nanotube ◽  
Poly Vinylidene Fluoride ◽  
Self Powered ◽  
Health Care Monitoring ◽  
Multiwall Carbon ◽  
Piezo Electric

In this work, an all-fiber pyro- and piezo-electric nanogenerator (PPNG) is designed by multiwall carbon nanotube (MWCNT) doped poly(vinylidene fluoride) (PVDF) electrospun nanofibers as the active layer and interlocked conducting...

scholarly journals Electro-Polymerized Titan Yellow Modified Carbon Paste Electrode for the Analysis of Curcumin

Surfaces ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 191-204
Author(s):  
Edwin S. D’Souza ◽  
Jamballi G. Manjunatha ◽  
Chenthattil Raril ◽  
Girish Tigari ◽  
Huligerepura J. Arpitha ◽  
...  
Keyword(s):  
Carbon Paste Electrode ◽  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Modified Carbon Paste Electrode ◽  
Carbon Paste ◽  
Buffer Solution ◽  
Solution Ph ◽  
Real Sample Analysis ◽  
Titan Yellow ◽  
Paste Electrode

A modest, efficient, and sensitive chemically modified electrode was fabricated for sensing curcumin (CRC) through an electrochemically polymerized titan yellow (TY) modified carbon paste electrode (PTYMCPE) in phosphate buffer solution (pH 7.0). Cyclic voltammetry (CV) linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV) approaches were used for CRC detection. PTYMCPE interaction with CRC suggests that the electrode exhibits admirable electrochemical response as compared to bare carbon paste electrode (BCPE). Under the optimized circumstances, a linear response of the electrode was observed for CRC in the concentration range 2 × 10−6 M to 10 × 10−6 M with a limit of detection (LOD) of 10.94 × 10−7 M. Moreover, the effort explains that the PTYMCPE electrode has a hopeful approach for the electrochemical resolution of biologically significant compounds. Additionally, the proposed electrode has demonstrated many advantages such as easy preparation, elevated sensitivity, stability, and enhanced catalytic activity, and can be successfully applied in real sample analysis.

scholarly journals Radiation-Induced Asymmetric Grafting of Different Monomers into Base Films to Prepare Novel Bipolar Membranes

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2028
Author(s):  
Shin-ichi Sawada ◽  
Yasunari Maekawa
Keyword(s):  
Acrylic Acid ◽  
Anion Exchange ◽  
Graft Polymerization ◽  
The Other ◽  
Practical Applications ◽  
Bipolar Membranes ◽  
Graft Polymers ◽  
Grafting Reactions ◽  
Radiation Induced

We prepared novel bipolar membranes (BPMs) consisting of cation and anion exchange layers (CEL and AEL) using radiation-induced asymmetric graft polymerization (RIAGP). In this technique, graft polymers containing cation and anion exchange groups were introduced into a base film from each side. To create a clear CEL/AEL boundary, grafting reactions were performed from each surface side using two graft monomer solutions, which are immiscible in each other. Sodium p-styrenesulfonate (SSS) and acrylic acid (AA) in water were co-grafted from one side of the base ethylene-co-tetrafluoroethylene film, and chloromethyl styrene (CMS) in xylene was simultaneously grafted from the other side, and then the CMS units were quaternized to afford a BPM. The distinct SSS + AA- and CMS-grafted layers were formed owing to the immiscibility of hydrophilic SSS + AA and hydrophobic CMS monomer solutions. This is the first BPM with a clear CEL/AEL boundary prepared by RIAGP. However, in this BPM, the CEL was considerably thinner than the AEL, which may be a problem in practical applications. Then, by using different starting times of the first SSS+AA and second CMS grafting reactions, the CEL and AEL thicknesses was found to be controlled in RIAGP.

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