scholarly journals Comparison of Different Oxidation Techniques for Biofunctionalization of Pyrolyzed Carbon

2014 ◽  
Vol 11 (1) ◽  
pp. 01-08 ◽  
Author(s):  
Varun Penmatsa ◽  
Hiroshi Kawarada ◽  
Yin Song ◽  
Chunlei Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Vacuum Ultraviolet ◽  
Covalent Binding ◽  
Covalent Attachment ◽  
Carbon Surface ◽  
Electrochemical Activation ◽  
Carbon Substrate ◽  
Carboxyl Group ◽  
Nano Structures ◽  
Pretreatment Time

Pyrolyzed carbon micro/nano-structures have great potential as functional units in biosensors where biofunctionalization of the carbon surface is a requisite. In this work, we present a comparison of four different oxidation pretreatments, i.e. vacuum ultraviolet (VUV), electrochemical activation (EA), oxygen reactive ion etching (RIE), and ultraviolet/ozone (UV/O3) pretreatments on pyrolyzed carbon surface. X-ray photoelectron spectroscopy (XPS) results indicated that all the oxidation techniques except UV/O3 pretreatment yielded identical oxidation levels. The percentage of the carboxyl group which is suitable for covalent attachment of amine terminated biomolecules increased with pretreatment time, and was highest in the case of VUV pretreatment (15%) followed by oxygen RIE (12.5%) and EA pretreatments (12.5%) and UV/O3 pretreatment showed significantly lower carboxyl group percentage at 6%. This study helps to optimize the surface functionalization conditions for covalent binding of bioreceptors on the pyrolyzed carbon substrate for biosensing applications.

scholarly journals Radiation-Induced Graft Immobilization (RIGI): Covalent Binding of Non-Vinyl Compounds on Polymer Membranes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1849
Author(s):  
Martin Schmidt ◽  
Stefan Zahn ◽  
Florian Gehlhaar ◽  
Andrea Prager ◽  
Jan Griebel ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Polyvinylidene Fluoride ◽  
Covalent Binding ◽  
Polymer Surface ◽  
Experimental Studies ◽  
Polymeric Materials ◽  
Covalent Attachment ◽  
Minor Role ◽  
Water Radiolysis ◽  
Radiation Induced

Radiation-induced graft immobilization (RIGI) is a novel method for the covalent binding of substances on polymeric materials without the use of additional chemicals. In contrast to the well-known radiation-induced graft polymerization (RIGP), RIGI can use non-vinyl compounds such as small and large functional molecules, hydrophilic polymers, or even enzymes. In a one-step electron-beam-based process, immobilization can be performed in a clean, fast, and continuous operation mode, as required for industrial applications. This study proposes a reaction mechanism using polyvinylidene fluoride (PVDF) and two small model molecules, glycine and taurine, in aqueous solution. Covalent coupling of single molecules is achieved by radical recombination and alkene addition reactions, with water radiolysis playing a crucial role in the formation of reactive solute species. Hydroxyl radicals contribute mainly to the immobilization, while solvated electrons and hydrogen radicals play a minor role. Release of fluoride is mainly induced by direct ionization of the polymer and supported by water. Hydrophobic chains attached to cations appear to enhance the covalent attachment of solutes to the polymer surface. Computational work is complemented by experimental studies, including X-ray photoelectron spectroscopy (XPS) and fluoride high-performance ion chromatography (HPIC).

Vacuum ultraviolet photoelectron spectroscopy of transient species

1981 ◽  
Vol 44 (5) ◽  
pp. 1059-1066 ◽  
Author(s):  
J.M. Dyke ◽  
N.B.H. Jonathan ◽  
A. Morris ◽  
M.J. Winter
Keyword(s):  
Photoelectron Spectroscopy ◽  
Vacuum Ultraviolet ◽  
Ultraviolet Photoelectron Spectroscopy ◽  
Transient Species

scholarly journals Non-Covalent Binding of Tripeptides-Containing Tryptophan to Polynucleotides and Photochemical Deamination of Modified Tyrosine to Quinone Methide Leading to Covalent Attachment

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4315
Author(s):  
Antonija Erben ◽  
Igor Sviben ◽  
Branka Mihaljević ◽  
Ivo Piantanida ◽  
Nikola Basarić
Keyword(s):  
Quantum Yield ◽  
Photophysical Properties ◽  
Covalent Binding ◽  
Quinone Methide ◽  
Covalent Attachment ◽  
Dna And Rna ◽  
Pair Composition ◽  
Aqueous Solvent ◽  
Fluorometric Study ◽  
Spectral Responses

A series of tripeptides TrpTrpPhe (1), TrpTrpTyr (2), and TrpTrpTyr[CH2N(CH3)2] (3) were synthesized, and their photophysical properties and non-covalent binding to polynucleotides were investigated. Fluorescent Trp residues (quantum yield in aqueous solvent ΦF = 0.03–0.06), allowed for the fluorometric study of non-covalent binding to DNA and RNA. Moreover, high and similar affinities of 2×HCl and 3×HCl to all studied double stranded (ds)-polynucleotides were found (logKa = 6.0–6.8). However, the fluorescence spectral responses were strongly dependent on base pair composition: the GC-containing polynucleotides efficiently quenched Trp emission, at variance to AT- or AU-polynucleotides, which induced bisignate response. Namely, addition of AT(U) polynucleotides at excess over studied peptide induced the quenching (attributed to aggregation in the grooves of polynucleotides), whereas at excess of DNA/RNA over peptide the fluorescence increase of Trp was observed. The thermal denaturation and circular dichroism (CD) experiments supported peptides binding within the grooves of polynucleotides. The photogenerated quinone methide (QM) reacts with nucleophiles giving adducts, as demonstrated by the photomethanolysis (quantum yield ΦR = 0.11–0.13). Furthermore, we have demonstrated photoalkylation of AT oligonucleotides by QM, at variance to previous reports describing the highest reactivity of QMs with the GC reach regions of polynucleotides. Our investigations show a proof of principle that QM precursor can be imbedded into a peptide and used as a photochemical switch to enable alkylation of polynucleotides, enabling further applications in chemistry and biology.

scholarly journals One-step chemical vapor deposition synthesis and supercapacitor performance of nitrogen-doped porous carbon–carbon nanotube hybrids

2017 ◽  
Vol 8 ◽  
pp. 2669-2679 ◽  
Author(s):  
Egor V Lobiak ◽  
Lyubov G Bulusheva ◽  
Ekaterina O Fedorovskaya ◽  
Yury V Shubin ◽  
Pavel E Plyusnin ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Hybrid Materials ◽  
Vapor Deposition ◽  
Porous Carbon ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Carbon Surface ◽  
Simultaneous Formation ◽  
Nitrogen Doped

Novel nitrogen-doped carbon hybrid materials consisting of multiwalled nanotubes and porous graphitic layers have been produced by chemical vapor deposition over magnesium-oxide-supported metal catalysts. CN x nanotubes were grown on Co/Mo, Ni/Mo, or Fe/Mo alloy nanoparticles, and MgO grains served as a template for the porous carbon. The simultaneous formation of morphologically different carbon structures was due to the slow activation of catalysts for the nanotube growth in a carbon-containing gas environment. An analysis of the obtained products by means of transmission electron microscopy, thermogravimetry and X-ray photoelectron spectroscopy methods revealed that the catalyst's composition influences the nanotube/porous carbon ratio and concentration of incorporated nitrogen. The hybrid materials were tested as electrodes in a 1M H2SO4 electrolyte and the best performance was found for a nitrogen-enriched material produced using the Fe/Mo catalyst. From the electrochemical impedance spectroscopy data, it was concluded that the nitrogen doping reduces the resistance at the carbon surface/electrolyte interface and the nanotubes permeating the porous carbon provide fast charge transport in the cell.

Electronic structure of hexafluorobenzene by high-resolution vacuum ultraviolet photo-absorption and He(I) photoelectron spectroscopy

2006 ◽  
Vol 328 (1-3) ◽  
pp. 183-189 ◽  
Author(s):  
C. Motch ◽  
A. Giuliani ◽  
J. Delwiche ◽  
P. Limão-Vieira ◽  
N.J. Mason ◽  
...  
Keyword(s):  
Electronic Structure ◽  
High Resolution ◽  
Photoelectron Spectroscopy ◽  
Vacuum Ultraviolet

Vacuum–ultraviolet photoelectron spectroscopy of hexatriacontane (n‐C36H74) polycrystal: A model compound of polyethylene

1977 ◽  
Vol 66 (8) ◽  
pp. 3644-3649 ◽  
Author(s):  
Kazuhiko Seki ◽  
Shimpei Hashimoto ◽  
Naoki Sato ◽  
Yoshiya Harada ◽  
Kikujiro Ishii ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Model Compound ◽  
Vacuum Ultraviolet ◽  
Ultraviolet Photoelectron Spectroscopy

scholarly journals Hydrothermal Activation of Porous Nitrogen-Doped Carbon Materials for Electrochemical Capacitors and Sodium-Ion Batteries

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2163 ◽  
Author(s):  
Yuliya V. Fedoseeva ◽  
Egor V. Lobiak ◽  
Elena V. Shlyakhova ◽  
Konstantin A. Kovalenko ◽  
Viktoriia R. Kuznetsova ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nanomaterials ◽  
Carbon Materials ◽  
Sodium Ion ◽  
Carbon Surface ◽  
Energy Storage And Conversion ◽  
Sodium Ion Batteries ◽  
X Ray ◽  
Nitrogen Doped ◽  
Nitrogen Doped Carbon

Highly porous nitrogen-doped carbon nanomaterials have distinct advantages in energy storage and conversion technologies. In the present work, hydrothermal treatments in water or ammonia solution were used for modification of mesoporous nitrogen-doped graphitic carbon, synthesized by deposition of acetonitrile vapors on the pyrolysis products of calcium tartrate. Morphology, composition, and textural characteristics of the original and activated materials were studied by transmission electron microscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, infrared spectroscopy, and nitrogen gas adsorption method. Both treatments resulted in a slight increase in specific surface area and volume of micropores and small mesopores due to the etching of carbon surface. Compared to the solely aqueous medium, activation with ammonia led to stronger destruction of the graphitic shells, the formation of larger micropores (1.4 nm vs. 0.6 nm), a higher concentration of carbonyl groups, and the addition of nitrogen-containing groups. The tests of nitrogen-doped carbon materials as electrodes in 1M H2SO4 electrolyte and sodium-ion batteries showed improvement of electrochemical performance after hydrothermal treatments especially when ammonia was used. The activation method developed in this work is hopeful to open up a new route of designing porous nitrogen-doped carbon materials for electrochemical applications.

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