Covalent immobilization of urease on polypyrrole microspheres for application as a urea biosensor

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Anamika Gambhir ◽  
Arun Kumar ◽  
Bansi D. Malhotra ◽  
Beata Miksa ◽  
Stanislaw Slomkowski
Keyword(s):  
Indium Tin Oxide ◽  
Reference Electrode ◽  
Covalent Immobilization ◽  
Constant Current ◽  
Ammonium Ion ◽  
Standard Calomel Electrode ◽  
Ito Glass ◽  
Polymer Electrodes ◽  
Covalently Linked ◽  
Aldehyde Groups

AbstractUrease has been covalently immobilized on polypyrrole microspheres chemically linked to conducting polypyrrole-polyvinyl sulfonate (PPY-PVS) films. These films were electrochemically prepared during 5 - 7 min at a constant current of 2 mA using indium - tin oxide (ITO) glass plates as the working electrode, and a standard calomel electrode as the reference electrode. Urease covalently linked to polypyrrole microspheres (by reaction of protein amino groups with aldehyde groups on the surface of the microspheres) was entrapped/adsorbed onto electrochemically prepared conducting PPY-PVS films deposited on ITO. Potentiometric measurements undertaken on these conducting polymer electrodes using an ammonium ion analyzer reveal that they can be used for estimating the urea concentration in solutions from 5·10-3 mol/l to 6·10-2 mol/l.

Controllable Electrochemical Synthesis of Ag Hierarchical Micro/Nanostructures with High SERS-Activity

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050043
Author(s):  
Huayu Zhou ◽  
Jingjing Wang ◽  
Qiong Yang ◽  
Menglei Chen ◽  
Changsheng Song ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Current System ◽  
Three Dimensional ◽  
Constant Current ◽  
Localized Surface Plasmon ◽  
Excitation Wavelength ◽  
Raman Signal ◽  
Mixed Solution ◽  
Raman Enhancement ◽  
One Step

We report a one-step electrochemical deposition technique to prepare three-dimensional (3D) Ag hierarchical micro/nanostructured film consisting of well-crystallized Ag nanosheets grown on an indium tin oxide (ITO) conductive substrate. The Ag hierarchical micro/nanostructures were fabricated in the mixed solution of AgNO3 and sodium citrate in a constant current system at room temperature. Through reduction of Ag[Formula: see text] electrodeposited on the surface of ITO substrate, nanoparticles were grown to form nanosheets which further combined into 3D sphere-like microstructures. The 3D Ag micro/nanostructures have many sharp edges and nanoscale gaps which can give rise to good Raman-enhanced effect. Due to localized surface plasmon resonance (LSPR) effects, these special Ag micro/nanostructures exhibited good Raman-enhanced performance. Using Rhodamine 6G (R6G) molecules as probe molecule, we studied the influence of excitation wavelength on Raman enhancement. The results showed that the 532[Formula: see text]nm excitation wavelength is the best to obtain the strongest Raman signal and to reduce the influence of other impurity peaks. Using the as-synthesized Ag hierarchical micro/nanostructures, we can detect the 10[Formula: see text][Formula: see text]mol/L R6G aqueous solution, exhibiting great Raman-enhanced effect.

scholarly journals Black Phosphorus-Molybdenum Disulfide Hetero-Junctions Formed with Ink-Jet Printing for Potential Solar Cell Applications with Indium-Tin-Oxide

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 560
Author(s):  
Ravindra Ketan Mehta ◽  
Anupama Bhat Kaul
Keyword(s):  
Electrical Properties ◽  
Molybdenum Disulfide ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Cost Effective ◽  
Contact Materials ◽  
Ito Glass ◽  
The Future ◽  
Potential Applications ◽  
Jet Printing

In this work, we implemented liquid exfoliation to inkjet-print two-dimensional (2D) black phosphorous (BP) and molybdenum disulfide (MoS2) p–n heterojunctions on a standard indium tin oxide (ITO) glass substrate in a vertical architecture. We also compared the optical and electrical properties of the inkjet-printed BP layer with that of the MoS2 and the electrical properties of the mechanically exfoliated MoS2 with that of the inkjet-printed MoS2. We found significant differences in the optical characteristics of the inkjet-printed BP and MoS2 layers attributed to the differences in their underlying crystal structure. The newly demonstrated liquid exfoliated and inkjet-printed BP–MoS2 2D p–n junction was also compared with previous reports where mechanically exfoliated BP–MoS2 2D p–n junction were used. The electronic transport properties of mechanically exfoliated MoS2 membranes are typically better compared to inkjet-printed structures but inkjet printing offers a cost-effective and quicker way to fabricate heterostructures easily. In the future, the performance of inkjet-printed structures can be further improved by employing suitable contact materials, amongst other factors such as modifying the solvent chemistries. The architecture reported in this work has potential applications towards building solar cells with solution processed 2D materials in the future.

Fabrication of Micro-OLEDs by Room-temperature Curing Nanocontact-print Lithography Using DLC Molds

2012 ◽  
Vol 1511 ◽  
Author(s):  
Ippei Ishikawa ◽  
Keisuke Sakurai ◽  
Shuji Kiyohara ◽  
Taisuke Okuno ◽  
Hideto Tanoue ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Nanoimprint Lithography ◽  
Room Temperature ◽  
Hole Transport ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Insulating Layer ◽  
Light Emitting ◽  
Light Emitting Devices ◽  
Ito Glass

ABSTRACTThe microfabrication technologiesfor organic light-emitting devices (OLEDs) are essential to the fabrication of the next generation of light-emitting devices. The micro-OLEDs fabricated by room-temperature curing nanoimprint lithography (RTC-NIL) using diamond molds have been investigated. However, light emissions from 10 μm-square-dot OLEDs fabricated by the RTC-NIL method have not been uniform. Therefore, we proposed the fabrication of micro-OLEDs by room-temperature curing nanocontact-print lithography (RTC-NCL) using the diamond-like carbon (DLC) mold. The DLC molds used in RTC-NCL were fabricated by an electron cyclotron resonance (ECR) oxygen ion shower with polysiloxane oxide mask in electron beam (EB) lithography technology. The mold patterns are square and rectangle dots which has 10 µm-width, 10 µm-width and50 µm-length, respectively. The height of the patterns is 500 nm. The DLC molds were used to form the insulating layer of polysiloxane in RTC-NCL. We carried out the RTC-NCL process using the DLC mold under the following optimum conditions: 0.1 MPa-pressure for coating DLC mold with polysiloxane film, 2.1 MPa-pressure for transferring polysiloxane from DLC mold pattern to indium tin oxide (ITO) glass substrate. We deposited N, N'-Diphenyl -N, N'-di (m-tolyl)benzidine (TPD) [40 nm-thickness] as hole transport layer / Tris(8-quinolinolato)aluminum (Alq3) [40 nm-thickness] as electron transport layer / Al [200 nm-thickness] as cathode on ITO glass substrateas anode in this order. We succeeded in formation of the insulating layer with square and rectangle dots which has 10 µm-width,10 µm-width and 50 µm-length, and operation of micro-OLEDs by RTC-NIL using DLC molds.

An Automatic Polarization Apparatus for Electrochemical Corrosion Studies

CORROSION ◽  
1969 ◽  
Vol 25 (12) ◽  
pp. 515-519 ◽  
Author(s):  
W. D. HENRY ◽  
B. E. WILDE
Keyword(s):  
Cathodic Polarization ◽  
Reference Electrode ◽  
Electrochemical Corrosion ◽  
304 Stainless Steel ◽  
Constant Current ◽  
Voltage Source ◽  
Potential Range ◽  
Alloy Development ◽  
Corrosion Studies ◽  
Potentiodynamic Anodic Polarization

Abstract Statistical alloy development programs in which electrochemical screening techniques are used require facilities to produce precision polarization data. Conventional equipment and techniques presently available for such programs are not entirely satisfactory. Therefore, modifications were made to readily available commercial equipment to significantly improve the attainable sensitivity and reproducibility. This paper describes in detail the procedures necessary to produce an apparatus that automatically measures and records anodic and cathodic polarization curves over an applied potential range of ±2.0 volts. Traverse rates between 2 × 10−3 and 3 × 104 volts per hour are attainable and can be used to polarize electrodes through zero volts (with respect to reference electrode) without the necessity of manual switching. A special mode switch is described in detail with which the basic electronic potentiostat can be used as a constant current or constant voltage source by manual selection. The results obtained from three typical polarization experiments: (1) potentiodynamic anodic polarization, (2) galvanodynamic cathodic polarization, and (3) galvanodynamic linear polarization of AISI Type 304 stainless steel in hydrogen saturated 1N H2SO4 at 25 C (77 F), showed the performance of the apparatus to be equal to or superior to that of conventional manual procedures.

scholarly journals Microwave Spectroscopic Detection of Human Hsp70 Protein on Annealed Gold Nanostructures on ITO Glass Strips

Biosensors ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 118
Author(s):  
Rodica Ionescu ◽  
Raphael Selon ◽  
Nicolas Pocholle ◽  
Lan Zhou ◽  
Anna Rumyantseva ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Stress Disorders ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Conductive Glass ◽  
Hsp70 Protein ◽  
Atomic Force ◽  
Ito Glass ◽  
First Time ◽  
Human Heat Shock Protein

Conductive indium-tin oxide (ITO) and non-conductive glass substrates were successfully modified with embedded gold nanoparticles (AuNPs) formed by controlled thermal annealing at 550 °C for 8 h in a preselected oven. The authors characterized the formation of AuNPs using two microscopic techniques: scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analytical performances of the nanostructured-glasses were compared regarding biosensing of Hsp70, an ATP-driven molecular chaperone. In this work, the human heat-shock protein (Hsp70), was chosen as a model biomarker of body stress disorders for microwave spectroscopic investigations. It was found that microwave screening at 4 GHz allowed for the first time the detection of 12 ng/µL/cm2 of Hsp70.

scholarly journals Structural and Electrical Properties of Sprayed In2S3 Films on ITO/Glass Substrate

2021 ◽  
Author(s):  
J. Koaib ◽  
N. Bouguila ◽  
M. Kraini ◽  
I. Halidou ◽  
K. Khirouni ◽  
...  
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Indium Tin Oxide ◽  
Glass Substrate ◽  
Spray Pyrolysis Technique ◽  
Electrical Conductance ◽  
Average Crystallite Size ◽  
Chemical Spray Pyrolysis ◽  
Electrical Equivalent Circuit ◽  
Ito Glass

Abstract In2S3 thin films were grown on indium tin oxide (ITO) glass substrate by chemical spray pyrolysis technique at 360°C. The structural analysis of the deposited films shows a combination of tetragonal and cubic structures. The average crystallite size is about 25 nm. The electrical properties of In2S3 thin films have been investigated in a wide frequency (40Hz-100MHz) and temperature (400 K-660 K) ranges.We find that the electrical conductance of the In2S3 thin films is frequency and temperature dependent. The dc conductance shows a semi-conductor behavior for In2S3 films over the explored range of temperature and it follows the Arrhenius law with different activation energies. The variation of ac conductance and the frequency exponent `s’ are explained by the correlated barrier hopping (CBH) model. The Nyquist plots of impedance exhibit semicircle arcs and an electrical equivalent circuit has been suggested to interpret the impedance results.

scholarly journals Opto-Electronic Properties of Epoxy/Silicone Blend Based Thin Films

2021 ◽  
Author(s):  
Younes Ziat ◽  
Hamza Belkhanchi ◽  
Maryama Hammi ◽  
Charaf Laghlimi ◽  
A Moutcine
Keyword(s):  
Thin Films ◽  
Indium Tin Oxide ◽  
Optical Transition ◽  
Sol Gel ◽  
Glass Substrates ◽  
Nanostructured Thin Films ◽  
Ito Glass ◽  
Potential Applications ◽  
Optical Applications ◽  
Nitrogen Doped Carbon

Abstract Recently, the rise of two dimensional amorphous nanostructured thin films have ignited a big interest because of their intriguingly isotropic structural and physical properties leading to potential applications in the nano-optoelectronics. However, according to literature, most of optoelectronic properties are investigated on chalcogenides related heterostructures. This has motivated the present work aiming to provide a new platform for the fabrication, examination of the properties and the applications of 2D nanostructured thin films based on epoxy/silicone blend. Thin films of Epoxy/Silicone loaded with nitrogen doped carbon nanotubes (N-CNTs) were prepared by sol-gel method and deposited on Indium Tin Oxide (ITO) glass substrates at room temperature. Further examination of optical properties aimed the investigation of optical pseudo-gap and Urbach energy and enabled the determination of processed films thickness based on Manifacier and Swanepol method. The results indicated that the unloaded thin films have a direct optical transition with a value of 3.61 eV followed by noticeable shift towards narrowing gaps depending on the loading rate. Urbach's energy is 0.19 eV for the unloaded thin films, and varies from 0.43 to 1.33 eV for the loaded thin films with increasing the rate of N-CNTs. It is inversely variable with the optical pseudo-gap. Finally, Epoxy/Silicone loaded with N-CNTs nanocomposites films can be developed as active layers with specific optical characteristics, giving the possibility to be used in electro-optical applications.

scholarly journals Temperature effect on optical properties of nickel (ii) phthalocyanine tetrasulfonic acid tetrasodium salt (NiPcTs) organic thin films

2019 ◽  
Vol 13 (28) ◽  
pp. 44-51
Author(s):  
Ameer F. Abdulameer
Keyword(s):  
Thin Films ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Annealing Temperature ◽  
Optical Band Gap ◽  
Organic Thin Films ◽  
Effect Of Temperature ◽  
Good Information ◽  
Energy Gaps ◽  
Ito Glass

This study describe the effect of temperature on the opticalproperties of nickel(ii) phthalocyanine tetrasulfonic acid tetrasodiumsalt (NiPcTs) organic thin films which are prepared by spin coatingon indium tin oxide (ITO-glass). The optical absorption spectra ofthese thin films are measured. Present studies reveal that the opticalband gap energies of NiPcTs thin films are dependent on theannealing temperatures. The optical band gap decreases with increasein annealing temperature, then increased when the temperature risingto 473K. To enhance the results of Uv-Vis measurements and getmore accurate values of optical energy gaps; the Photoluminescencespectra of as-deposited and annealed NiPcTs thin films was studied.FTIR measurements for NiPcTs thin films also carried out in thiswork and gave good information about the NiPcTs bonds and itslocations as a compared with H2Pc as a reference.

Fabrication of the ZnS-ZnO Composite Film by Sulfurizing the as-Electrodeposited ZnO Film

2014 ◽  
Vol 881-883 ◽  
pp. 909-913
Author(s):  
Zi Feng Wang ◽  
Yong Zhao Liu ◽  
Yu Shan Liu ◽  
Jian Min Zhang
Keyword(s):  
Composite Film ◽  
Indium Tin Oxide ◽  
Zinc Nitrate ◽  
Hexagonal Structure ◽  
X Ray Diffraction ◽  
Zno Film ◽  
X Ray ◽  
Ito Glass ◽  
Sodium Sulfide Solution ◽  
Sulfide Solution

The ZnS-ZnO composite film was successfully prepared by sulfidation of the as-electrodeposited ZnO film in the aqueous solution of zinc nitrate and hexamethylenetetramine. The ZnO film was electrodeposited on the substrate of indium-tin oxide (ITO) glass, and then the sodium sulfide solution was used to convert the ZnO film into the ZnS-ZnO composite film. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometer (EDS) and UVvisible absorption. The experimental results show that the composite film on ITO glass still retained the morphology of as-electrodeposited ZnO coating, and is composed of ZnS with cubic structure and ZnO with hexagonal structure.

Electrochromic Performance of NiO Films in Alkaline Medium

2013 ◽  
Vol 748 ◽  
pp. 51-55 ◽  
Author(s):  
Siti Zairyn Fakurol Rodzi ◽  
Yusairie Mohd
Keyword(s):  
Nickel Sulfate ◽  
Annealing Process ◽  
Constant Current ◽  
Porous Films ◽  
Electrochromic Material ◽  
Ito Glass ◽  
Smooth Film ◽  
The Stability ◽  
Temperature Heating ◽  
Nio Films

An investigation on the electrochromic performance of NiO films in 1M KOH was carried out using cyclic voltammetric technique. The NiO films were deposited on ITO glass substrate using bath solution containing nickel sulfate, sodium acetate and sodium sulfate at pH 6.7 by applying constant current of 0.2 mA cm-2for 300 s at different deposition temperatures (ie: 25 °C, 40 °C and 80 °C). The as-deposited films were undergone post treatment through annealing process at 300 °C for 900 s. The surface morphology of the NiO thin films was characterized by field-emission scanning electron microscopy (FESEM) and the electrochemical properties of both NiO films were measured in 1M KOH electrolyte by cyclic voltammetry (CV). Deposition at 25 °C produced a smooth and compact thin film on the ITO surface. However, when higher temperatures were used (ie: 40 °C and 80 °C), porous structure of NiO formed. The electrochromic performance of the smooth film prepared at 25 ° C showed is better than the porous films. The annealing process has enhanced the stability of NiO film for intercalation and de-intercalation of OH-ions during cycling in 1M KOH. These results show that the temperature (heating and annealing process) has significantly influenced the formation of NiO films on ITO substrates which affected the performance of the electrochromic material.

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