An efficient urea biosensor based on laser ablated ZnO thin film

2013 ◽  
Vol 1530 ◽  
Author(s):  
Neha Batra ◽  
Monika Tomar ◽  
Vinay Gupta
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
High Electron ◽  
Zno Thin Film ◽  
Detection Range ◽  
Response Characteristics ◽  
Glass Substrates ◽  
Enhanced Sensitivity ◽  
Ito Glass ◽  
The Matrix

ABSTRACTZinc oxide (ZnO) thin film deposited onto indium tin oxide (ITO) coated Corning glass substrates using pulsed laser deposition (PLD) technique has been used as a matrix for realization of an efficient urea biosensor after immobilization of urease (Urs) enzyme onto the surface of ZnO. The bioelectrode (Urs/ZnO/ITO/glass) is found to be exhibiting an enhanced sensitivity of 22μΑmΜ−1cm−2 towards urea over a wide detection range of 5-200 mg/dl. The relatively low value of Michaelis menten constant (Km= 0.94mM) indicates high affinity of the immobilized urease towards the analyte (urea). The prepared biosensor retains 90% of its activity for more than 10 weeks. The observed enhanced response characteristics of bioelectrode are attributed to the growth of the matrix (highly c-axis oriented ZnO thin film) with desired surface morphology and high electron communication feature. The results confirm the promising application of PLD grown ZnO thin film as an efficient matrix for urea detection.

Different Photoresponses for Positive and Negative Biases of CuPc/C60 Heterojunction Nanostructures

2015 ◽  
Vol 1103 ◽  
pp. 61-68 ◽  
Author(s):  
Theerasak Juagwon ◽  
Kittitat Subannajui ◽  
Tanakorn Osotchan
Keyword(s):  
Indium Tin Oxide ◽  
Copper Phthalocyanine ◽  
Monochromatic Light ◽  
Positive Bias ◽  
Response Characteristics ◽  
Glass Substrates ◽  
Double Peaks ◽  
Ito Glass ◽  
Current Characteristics ◽  
Response Current

Photoresponse characteristic from efficient exciton dissociated heterojunction based on copper phthalocyanine (CuPc) and fullerene (C60) layers was observed the different spectrum responses under positive and negative biases. The nanostructures of CuPc and C60 thin films were fabricated between transparent indium tin oxide (ITO) and aluminum (Al) electrodes. The 100 nm thick of CuPc and C60 layers were deposited on patterned ITO glass substrates by thermal evaporation with quartz thickness monitor. Photoresponses of the fabricated devices were investigated by current measuring as a function of wavelength in range of 400 to 700 nm. Measured current in Al/C60/CuPc/ITO structure when applied negative voltage to ITO electrode is higher than that of positive voltage case. Under monochromatic light, the photoresponse characteristic of Al/C60/CuPc/ITO structure under negative bias shows dominate response current peak at around 450 nm and double peaks in range of 500-700 nm originated from C60 and CuPc layers, respectively. These two response characteristics can be described by the combination of responses from Al/C60/ITO and Al/CuPc/ITO structures. The response current characteristics of Al/C60/ITO and Al/CuPc/ITO structures also agree with the optical absorptions of C60 and CuPc layers, respectively. By applying positive bias to Al/C60/CuPc/ITO structure, the photoresponse characteristic has only one peak at about 450 nm that is similar to the response in Al/C60/ITO structure only. This indicates that under positive bias, the photocurrent only from C60 layer can be observed.

PH SENSITIVITY DEPENDENCY ON THE ANNEALING TEMPERATURE OF SPIN-COATED TITANIUM DIOXIDE THIN FILMS

2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Khairul Aimi Yusof ◽  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Wan Fazlida Hanim Abdullah
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Titanium Dioxide ◽  
Indium Tin Oxide ◽  
Ph Sensor ◽  
Tio2 Thin Films ◽  
Glass Substrates ◽  
Ito Glass ◽  
Ito Thin Films ◽  
Sensing Membrane

Titanium dioxide (TiO2) thin films were fabricated on indium tin oxide (ITO) glass substrates using the spin coating technique and further were implemented as sensing membranes of the extended gate field effect transistor (EGFET) based pH sensor. The as-deposited thin films were annealed at different temperatures from 200 - 600 °C in room ambient for 20 min. The effects of different annealing temperatures on electrical and crystalline properties were analyzed by I-V two point probes measurement and X-ray diffraction respectively. Meanwhile, the surface morphology of thin films was observed by field emission scanning electron microscope (FESEM). We then measured the transfer characteristics (ID-VG) of the TiO2/ITO sensing membrane using a semiconductor parametric device analyzer for sensor characterization. It was found that, TiO2/ITO sensing membrane annealed at 300 °C achieved higher sensitivity and good linearity of 51.48 mV/pH and 0.99415, respectively in the pH buffer solutions of 4, 7, 10, and 12. Thin film annealed at 300 °C gives higher conductivity thin film of 384.62 S/m. We found that the conductivity of TiO2/ITO thin films was proportional with the sensitivity of sensing membrane.  

Preparation and Properties of Multiferroic La-Doped BiFeO3 Thin Film

2012 ◽  
Vol 486 ◽  
pp. 417-421 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jian Quan Qi ◽  
Xuan Wang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Indium Tin Oxide ◽  
Remanent Polarization ◽  
Sol Gel ◽  
Secondary Phases ◽  
Glass Substrates ◽  
Ito Glass ◽  
Sol Gel Process ◽  
La Doped

Multiferroic La-doped Bi1-xLaxFeO3 thin films were prepared on conductive indium tin oxide (ITO)/glass substrates through a simple sol-gel process. The crystal structure of La-doped Bi1-xLaxFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases. The grain size of La-doped BiFeO3 thin films tends to become larger and the grain boundary is gradually ambiguous compared to pure BiFeO3. The double remanent polarization 2Pr of Bi0.9La0.1FeO3 thin film annealed at 500°C is 6.66 µC/cm2, which is slightly improved than that of pure BiFeO3 thin film. With the increase of La-doping levels, the dielectric constant is increased and the dielectric loss is obviously decreased.

Preparation and Properties of Dy Doped La and Sc Solution of BiFeO3 Film

2013 ◽  
Vol 537 ◽  
pp. 109-113
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi
Keyword(s):  
Thin Film ◽  
Indium Tin Oxide ◽  
Doping Level ◽  
Sol Gel ◽  
Second Phase ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Ito Glass ◽  
Dy Doping

A series of Dy doped La and Sc solution of BiFeO3 thin films have been prepared by using spin-coating process on conductive indium tin oxide (ITO)/glass substrates, which a simple sol-gel possess is applied and annealed at 500°C. With the increase of content of Dy, the strongest peak (110) of La and Sc solution BiFeO3 film tends to further broaden. There is no second phase existence within the present Dy doping level. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 film was about 370 nm. For Dy doping level is 0.05, the maximum double remanent polarization 2Pr of as-prepared BiFeO3 thin film is15.44 μC/cm2. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of as-prepared BiFeO3 thin film is 2.11 nm. The dielectric constant of as-prepared films tends to firstly increase and then decrease with the increase of Dy content

Preparation and Characterization of BiFeO3 Film via Sol-Gel Spin-Coating Process

2011 ◽  
Vol 492 ◽  
pp. 202-205 ◽  
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Indium Tin Oxide ◽  
Sol Gel ◽  
Secondary Phases ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Ito Glass

BiFeO3 thin films were spin-coated on conductive indium tin oxide (ITO)/glass substrates by a simple sol-gel possess annealed at 470-590°C. The crystal structure of as-prepared BiFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases was also confirmed. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 thin film was about 320 nm. The double remanent polarization 2Pr of BiFeO3 thin film annealed at 500°C is 2.5 μC/cm2 without applied field at room temperature. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of BiFeO3 thin film was 6.13 nm.

Low-temperature fabrication of VO2 thin film on ITO glass with a Mott transition

2016 ◽  
Vol 09 (05) ◽  
pp. 1650062 ◽  
Author(s):  
Tiegui Lin ◽  
Langping Wang ◽  
Xiaofeng Wang ◽  
Yufen Zhang
Keyword(s):  
Thin Film ◽  
Bias Voltage ◽  
Indium Tin Oxide ◽  
Transition Process ◽  
Mott Transition ◽  
Average Crystalline Size ◽  
Glass Substrates ◽  
Ito Glass ◽  
Xrd Patterns ◽  
And Control

Polycrystalline Vanadium dioxide (VO2) thin film can be fabricated on glass substrates by high power impulse magnetron sputtering at a relative high temperature. In order to apply an effective bias voltage on substrate and control the energy of the ions impinged to the substrate, conductive indium-tin oxide (ITO) glass was used as the substrate. UV-visible-near IR transmittance spectra and X-ray diffraction (XRD) patterns of the as-deposited films exhibited that M-VO2 thin film with a metal–insulator transition temperature of 37[Formula: see text]C was fabricated successfully at 300[Formula: see text]C with a bias voltage of [Formula: see text]200[Formula: see text]V, and the calculated average crystalline size of this film was about 12[Formula: see text]nm. XRD patterns at varied temperatures showed that the structural change of MIT of the VO2 thin film was suppressed during the phase transition process, and a pure Mott transition was obtained.

Effect of Sc Doping on Ferroelectric and Dielectric Properties of Bi0.9La0.1FeO3 Thin Film by Sol-Gel Process

2012 ◽  
Vol 538-541 ◽  
pp. 78-82
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jian Quan Qi ◽  
Xuan Wang ◽  
Huan Huan Chen ◽  
...  
Keyword(s):  
Thin Film ◽  
Dielectric Constant ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Remanent Polarization ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Glass Substrates ◽  
Ito Glass ◽  
Sol Gel Process

Pure Bi0.9La0.1Fe1-xScxO3 (x = 0, 0.05, 0.10, 0.15, 0.20) (BLFSO) thin films were deposited on conductive indium tin oxide (ITO)/glass substrates through a simple sol-gel process. The effect of Sc doping on the XRD, microstructure, dielectric and ferroelectric properties of BLFO films was studied. Compared to counterparts of Bi0.9La0.1FeO3 (BLFO) film, the grain refinement of all films is obvious. When the value of Sc is 0.15, the double remanent polarization 2Pr is effectively enhanced with the extreme value of 17.7µC/cm2. The dielectric constant exhibits a trends of increase firstly and then decrease with the increase amount of scandium level.

scholarly journals Properties of InGaN deposited on Glass at Low Temperature

1997 ◽  
Vol 2 ◽  
Author(s):  
Tilman Beierlein ◽  
S. Strite ◽  
A. Dommann ◽  
D. J. Smith
Keyword(s):  
Low Temperature ◽  
Indium Tin Oxide ◽  
High Electron ◽  
Transparent Conductor ◽  
High Background ◽  
X Ray ◽  
Substrate Heating ◽  
Glass Substrates ◽  
High Electron Concentration ◽  
Background Absorption

We have investigated the properties of InGaN grown at low temperature on glass substrates by a plasma enhanced MBE process. The goal of this study was to evaluate the potential of InGaN as an oxide-free, transparent conductor material which could be deposited at or slightly above room temperature with minimal interaction or damage to the underlying material. InxGa1−xN films deposited on glass, even without substrate heating, are highly crystalline, but the crystallinity as measured by x-ray degrades at x < 0.5. The microstructure observed by TEM of InGaN films deposited on unheated substrates is highly columnar, with typical column widths of ~10 nm. The optical absorption spectra of InGaN/glass have a distinct absorption edge at the bandgap, but also high background absorption in the bandgap. InxGa1−xN grown on glass (x > 0.5) is conductive due to its high electron concentration. InN electron Hall mobilities > 20 cm2/Vs when grown at 400°C, and ~ 7 cm2/Vs on unheated substrates were obtained. The addition of GaN degraded the electrical properties of the films to a greater extent than it improved the transparency. As a result, the best transparent conductor films were pure InN which, when deposited at 400°C, were half as transparent in the green as an indium tin oxide film having the same sheet resistance.

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 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.

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