scholarly journals Non-Enzymatic Glucose Biosensor Based on Highly Pure TiO2 Nanoparticles

Biosensors ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 149
Author(s):  
Hongin Jeong ◽  
Jhongryul Yoo ◽  
Seokyung Park ◽  
Jiling Lu ◽  
Sungho Park ◽  
...  
Keyword(s):  
Tio2 Nanoparticles ◽  
Structural Properties ◽  
Polymer Films ◽  
Photoelectron Spectroscopy ◽  
Glucose Sensor ◽  
Conductive Polymer ◽  
Glucose Biosensor ◽  
Pure Tio2 ◽  
Xps Spectra ◽  
X Ray

This study proposes a non-enzymatic glucose sensor fabricated by synthesizing high-purity TiO2 nanoparticles in thermal plasma and depositing it directly on a substrate and then depositing chitosan–polypyrrole (CS-PPy) conductive polymer films by electrochemical method. The structural properties of the deposited TiO2 nanoparticles were analyzed by X-ray diffraction (XRD) and dynamic light scattering (DLS) system. The chemical composition and structural properties of the TiO2 nanoparticle layer and the conductive polymer films were confirmed by X-ray photoelectron spectroscopy (XPS) spectra and scanning electron microscope (SEM). The glucose detection characteristics of the fabricated biosensor were determined by cyclic voltammetry (CV). CS-PPy/TiO2 biosensor showed high sensitivity of 302.0 µA mM−1 cm−2 (R2 = 0.9957) and low detection limit of 6.7 μM. The easily manufactured CS-PPy/TiO2 biosensor showed excellent selectivity and reactivity.

X-Ray Photoelectron Spectroscopy Sputter Depth Profile Analysis of Spatially Controlled Microstructures in Conductive Polymer Films

1991 ◽  
Vol 63 (1) ◽  
pp. 60-65 ◽  
Author(s):  
Susan G. MacKay ◽  
Mohammad. Bakir ◽  
Inga H. Musselman ◽  
Thomas J. Meyer ◽  
Richard W. Linton
Keyword(s):  
Depth Profile ◽  
Polymer Films ◽  
Photoelectron Spectroscopy ◽  
Profile Analysis ◽  
Conductive Polymer ◽  
Depth Profile Analysis ◽  
X Ray

scholarly journals Interdigitated Electrode Biosensor Based on Plasma-Deposited TiO2 Nanoparticles for Detecting DNA

Biosensors ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 212
Author(s):  
Jhongryul Yoo ◽  
Hongin Jeong ◽  
Seo Kyung Park ◽  
Sungho Park ◽  
Je Seung Lee
Keyword(s):  
Tio2 Nanoparticles ◽  
Structural Properties ◽  
Photoelectron Spectroscopy ◽  
Bacterial Species ◽  
Metal Oxide Nanoparticles ◽  
Electrical Signal ◽  
Dna Biosensor ◽  
Interdigitated Electrode ◽  
X Ray ◽  
Target Dna

Bioelectrodes mediated by metal oxide nanoparticles have facilitated the development of new sensors in medical diagnosis. High-purity TiO2 nanoparticles (NPs) were synthesized through thermal plasma and deposited directly on an interdigitated electrode. The surface of the TiO2-deposited electrode was activated with (3-aminopropyl) triethoxysilane (APTES) followed by fixing the single-stranded probe deoxyribonucleic acid (DNA) to fabricate the DNA biosensor. The structural properties of the deposited TiO2 nanoparticles were analyzed using a transmission electron microscope (TEM), X-ray diffraction (XRD), and a dynamic light scattering (DLS) system. The chemical composition and structural properties of the TiO2 nanoparticle layer and the fixed layer were analyzed by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). E. coli O157:H7, a well-known pernicious pathogenic bacterial species, was detected as a target DNA of the prepared DNA biosensor, and the characteristics of DNA detection were determined by the current change using a picoammeter. The degree of binding between the probe DNA and the target DNA was converted into an electrical signal using the picoammeter method to quantitatively analyze the concentration of the target DNA. With the specificity experiment, it was confirmed that the biosensor was able to discriminate between nucleotides with mismatched, non-complementary, or complementary sequences.

scholarly journals Optical, XPS and XRD Studies of Semiconducting Copper Sulfide Layers on a Polyamide Film

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius
Keyword(s):  
Photoelectron Spectroscopy ◽  
Copper Sulfide ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Xrd Studies ◽  
Polyamide Film ◽  
Indirect Band Gap ◽  
Xrd Method

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .

scholarly journals Enhanced Photocatalytic Activity of CuWO4 Doped TiO2 Photocatalyst Towards Carbamazepine Removal under UV Irradiation

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 25
Author(s):  
Chukwuka Bethel Anucha ◽  
Ilknur Altin ◽  
Emin Bacaksız ◽  
Tayfur Kucukomeroglu ◽  
Masho Hilawie Belay ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Sol Gel ◽  
Pure Tio2 ◽  
Component Part ◽  
Energy Yield ◽  
Mechanical Agitation ◽  
X Ray

Abatement of contaminants of emerging concerns (CECs) in water sources has been widely studied employing TiO2 based heterogeneous photocatalysis. However, low quantum energy yield among other limitations of titania has led to its modification with other semiconductor materials for improved photocatalytic activity. In this work, a 0.05 wt.% CuWO4 over TiO2 was prepared as a powder composite. Each component part synthesized via the sol-gel method for TiO2, and CuWO4 by co-precipitation assisted hydrothermal method from precursor salts, underwent gentle mechanical agitation. Homogenization of the nanopowder precursors was performed by zirconia ball milling for 2 h. The final material was obtained after annealing at 500 °C for 3.5 h. Structural and morphological characterization of the synthesized material has been achieved employing X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, Brunauer–Emmett–Teller (BET) N2 adsorption–desorption analysis, Scanning electron microscopy-coupled Energy dispersive X-ray spectroscopy (SEM-EDS), Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV-Vis diffuse reflectance spectroscopy (UV-vis DRS) for optical characterization. The 0.05 wt.% CuWO4-TiO2 catalyst was investigated for its photocatalytic activity over carbamazepine (CBZ), achieving a degradation of almost 100% after 2 h irradiation. A comparison with pure TiO2 prepared under those same conditions was made. The effect of pH, chemical scavengers, H2O2 as well as contaminant ion effects (anions, cations), and humic acid (HA) was investigated, and their related influences on the photocatalyst efficiency towards CBZ degradation highlighted accordingly.

scholarly journals Green Synthesis of N/Zr Co-Doped TiO2 for Photocatalytic Degradation of p-Nitrophenol in Wastewater

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 235
Author(s):  
Hayette Benkhennouche-Bouchene ◽  
Julien G. Mahy ◽  
Cédric Wolfs ◽  
Bénédicte Vertruyen ◽  
Dirk Poelman ◽  
...  
Keyword(s):  
Visible Light ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Visible Region ◽  
Chemical Properties ◽  
Pure Tio2 ◽  
Molar Ratio ◽  
Xps Spectra ◽  
Doped Tio2 ◽  
Co Doped

TiO2 prepared by a green aqueous sol–gel peptization process is co-doped with nitrogen and zirconium to improve and extend its photoactivity to the visible region. Two nitrogen precursors are used: urea and triethylamine; zirconium (IV) tert-butoxide is added as a source of zirconia. The N/Ti molar ratio is fixed regardless of the chosen nitrogen precursor while the quantity of zirconia is set to 0.7, 1.4, 2, or 2.8 mol%. The performance and physico-chemical properties of these materials are compared with the commercial Evonik P25 photocatalyst. For all doped and co-doped samples, TiO2 nanoparticles of 4 to 8 nm of size are formed of anatase-brookite phases, with a specific surface area between 125 and 280 m2 g−1 vs. 50 m2 g−1 for the commercial P25 photocatalyst. X-ray photoelectron (XPS) measurements show that nitrogen is incorporated into the TiO2 materials through Ti-O-N bonds allowing light absorption in the visible region. The XPS spectra of the Zr-(co)doped powders show the presence of TiO2-ZrO2 mixed oxide materials. Under visible light, the best co-doped sample gives a degradation of p-nitrophenol (PNP) equal to 70% instead of 25% with pure TiO2 and 10% with P25 under the same conditions. Similarly, the photocatalytic activity improved under UV/visible reaching 95% with the best sample compared to 50% with pure TiO2. This study suggests that N/Zr co-doped TiO2 nanoparticles can be produced in a safe and energy-efficient way while being markedly more active than state-of-the-art photocatalytic materials under visible light.

29Si NMR and XPS Investigation of the Structure of Silicon Oxycarbide Glasses Derived from Polysiloxane Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
R.J.P. Corriu ◽  
D. Leclercq ◽  
P.H. Mutin ◽  
A. Vioux
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Random Distribution ◽  
Silicon Oxycarbide ◽  
29Si Nmr ◽  
Xps Spectra ◽  
Excess Carbon ◽  
X Ray ◽  
Silicon Oxycarbide Glasses

ABSTRACTTwo silicon oxycarbide glasses with different compositions (O/Si ratio 1.2 and 1.8) were prepared by pyrolysis at moderate temperature (900 °C) of polysiloxane precursors. Their structure was investigated using quantitative 29Si solid-state NMR and X-ray photoelectron spectroscopy (XPS). The environment of the silicon atoms in the oxycarbide phase corresponded to a purely random distribution of Si-O and Si-C bonds depending on the O/Si ratio of the glass only and not on the structure of the precursors. At the light of the NMR results, the Si2p XPS spectra of the glasses may be interpreted using the contribution of the five possible SiOxC4-x tetrahedra. The Cls spectra of these glasses indicated the presence of oxycarbide carbon in CSi4 tetrahedra, similar to carbide carbon, and graphitic-like excess carbon.

Preparation and Characterization of Ni2+-Montmorillonite/Polyvinyl Alcohol Water-Soluble Nanocomposite Film

2005 ◽  
Vol 13 (8) ◽  
pp. 839-846 ◽  
Author(s):  
Li-Ping Wang ◽  
Yun-Pu Wang ◽  
Fa-Ai Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Photoelectron Spectroscopy ◽  
Thermal Characteristics ◽  
Water Soluble ◽  
Scanning Calorimetry ◽  
Xps Spectra ◽  
X Ray ◽  
Alcohol Water ◽  
Ft Ir ◽  
Silicate Layers

A new type of nano-composite film was prepared from polyvinyl alcohol, Ni2+-montmorillonite (Ni2+-MMT), defoamer, a levelling agent and a plasticizer. Its thermal characteristics were studied by Differential Scanning Calorimetry (DSC). The intermolecular interactions were measured by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS), and the tensile strength (TS) and elongation at break (%E) were measured. The microstructures were studied by X-ray diffraction (XRD) and atomic force microscopy (AFM). FT-IR and XPS spectra indicated that cross-linking has taken place between PVA and Ni2+-MMT. XRD and AFM indicate that the PVA molecules had inserted themselves into the silicate layers of MMT, exfoliating them and dispersing them randomly into the PVA matrix. Compared to pure PVA film, the TS of the films was increased and %E decreased when the Ni2+-Montmorillonite was added and the dissolution temperature of the film was also reduced.

scholarly journals 3D Modeling of Silver Doped ZrO2 Coupled Graphene-Based Mesoporous Silica Quaternary Nanocomposite for a Nonenzymatic Glucose Sensing Effects

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 193
Author(s):  
Kamrun Nahar Fatema ◽  
Chang-Sung Lim ◽  
Yin Liu ◽  
Kwang-Youn Cho ◽  
Chong-Hun Jung ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Mesoporous Silica ◽  
Photoelectron Spectroscopy ◽  
Glucose Sensor ◽  
Diffuse Reflectance Spectroscopy ◽  
Active Material ◽  
Glucose Sensing ◽  
X Ray ◽  
Transmission Electron

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10−3 mAcm−2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

scholarly journals Following excited-state chemical shifts in molecular ultrafast x-ray photoelectron spectroscopy

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
D. Mayer ◽  
F. Lever ◽  
D. Picconi ◽  
J. Metje ◽  
S. Alisauskas ◽  
...  
Keyword(s):  
Excited State ◽  
Chemical Shift ◽  
Photoelectron Spectroscopy ◽  
Chemical Shifts ◽  
Excited Molecule ◽  
Charge Motion ◽  
Core Electron ◽  
Xps Spectra ◽  
X Ray ◽  
State Chemical

AbstractThe conversion of photon energy into other energetic forms in molecules is accompanied by charge moving on ultrafast timescales. We directly observe the charge motion at a specific site in an electronically excited molecule using time-resolved x-ray photoelectron spectroscopy (TR-XPS). We extend the concept of static chemical shift from conventional XPS by the excited-state chemical shift (ESCS), which is connected to the charge in the framework of a potential model. This allows us to invert TR-XPS spectra to the dynamic charge at a specific atom. We demonstrate the power of TR-XPS by using sulphur 2p-core-electron-emission probing to study the UV-excited dynamics of 2-thiouracil. The method allows us to discover that a major part of the population relaxes to the molecular ground state within 220–250 fs. In addition, a 250-fs oscillation, visible in the kinetic energy of the TR-XPS, reveals a coherent exchange of population among electronic states.

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