Indium Tin Oxide-coated Glass Research Articles

Fabrication of surface-modified poly(3-aminobenzoic acid)/multiwalled carbon nanotubes composite thin films for hydrogen peroxide sensing

ABSTRACTThis work reports the fabrication of poly(3-aminobenzoic acid), (PABA)/multiwalled carbon nanotubes (MWNTs) composite thin film modified with layer-by-layer (LbL) self-assembled multilayers of cytochrome C (Cyt C) and poly(diallyldimethylammonium chloride) (PDADMAC) for hydrogen peroxide (H2O2) sensing on indium tin oxide-coated glass substrate. An electropolymerized PABA/MWNTs composite thin film was employed for the covalent attachment of Cyt C. The subsequent multilayers of PDADMAC and Cyt C were then fabricated using LbL deposition technique. The fabricated film was characterized by UV-vis spectroscopy, Raman spectroscopy, SEM and AFM. The modified thin film was finally used for successive detection of H2O2 at constant applied potential through an electrochemical method.

Highly sensitive [Ru(bpy)3]2 +/Nafion® modified indium tin oxide-based sensor for heavy metal detection

Indium tin oxide-coated glass substrates were modified with tris (2,2′-bipyridyl) ruthenium (II) dichloride hexahydrate [Ru(bpy)3]2+/Nafion® solution via dip-coating. The Nafion®—[Ru(bpy)3]2+ ratio was varied to optimize the sensitivity of the modified electrodes in detecting lead (Pb2+) and cadmium (Cd2+). The surface morphology of the deposited thin film was characterized by scanning electron microscopy (SEM). The lowest concentration detected was 0.007μM (0.001μg/mL) and 4.91μM (0.552μg/mL) for lead and cadmium, respectively. The optimum Nafion® volume concentration in the film was 0.4% which gave an average film thickness of 217.90nm.

Growth of Well-Aligned ZnO Nanorod Arrays and Their Application for Photovoltaic Devices

We have fabricated well-aligned ZnO nanorod arrays (ZNRAs) on indium tin oxide-coated glass substrates by a facile chemical bath deposition method. We used field-emission scanning electron microscope, x-ray diffraction and UV–Vis absorption spectroscopy to study the morphology, crystalline structure and optical absorption of the fabricated ZNRAs, respectively. The results showed that ZnO nanorods stood almost perpendicularly on the substrate, were about 30–50 nm in diameter and 800–900 nm in length, and were wurtzite-structured (hexagonal) ZnO. In addition, well-aligned ZNRAs exhibited a weak absorption in the visible region and had an optical band gap value of 3.28 eV. Furthermore, a hybrid ZNRAs/polymer photovoltaic device was made, under 1 sun AM 1.5 illumination (light intensity, ∼100 mW/cm2), and the device showed an open circuit voltage (V oc) of 0.32 V, a short circuit current density (J sc) of 7.67 mA/cm2, and a fill factor (FF) of 0.37, yielding an overall power conversion efficiency of 0.91%. Also, the exciton dissociation and transportation processes of charge carriers in the device under illumination were explained according to its current density–voltage (J–V) curve and the energy level diagram.

Hybrid PbS Quantum Dot/Nanoporous NiO Film Nanostructure: Preparation, Characterization, and Application for a Self-Powered Cathodic Photoelectrochemical Biosensor.

This work reports the first preparation and characterization of a hybrid PbS quantum dot (QD)/nanoporous NiO film nanostructure as well as its application for novel self-powered cathodic photoelectrochemical (PEC) sensing. Specifically, we synthesized the thioglycolic acid-capped PbS QDs and then assembled them onto the hydrothermally fabricated three-dimensional (3D) NiO nanostructured films on the transparent indium tin oxide-coated glass substrates, followed by the subsequent conjugation with the glucose oxidase as a model biocatalyst. Favorable alignment existed between the NiO and PbS QDs, and the as-obtained p-type heterostructure was characterized by various techniques and found to have good PEC activities. In the self-powered PEC biosensing of glucose, the system exhibited high sensitivity toward the presence of dissolved oxygen in the electrolyte, and thereby, a novel PEC enzymatic sensor was developed. With a PbS QD/3D NiO nanofilm, this work manifested the great promise of a heterostructure photocathode for a self-powered PEC biosensor that to the best of our knowledge has not been reported. We believe that it could inspire more interest in the design and development of numerous other p-type heterostructures for advanced self-powered PEC biosensors.

Voltammetric determination of copper and zinc in water using a Ruthenium bipyridyl/Nafion-modified indium tin oxide-coated glass electrode

Chemically-modified Indium Tin Oxide (ITO) coated glass substrates were fabricated by depositing Nafion thin films doped with tris (2,2’-bipyridyl) ruthenium(II) dichloride hexahydrate via drop coating deposition technique. The Nafion volume concentration in the film is 1% (v/v) and the mediator concentration is 5 mg per 1 mL Nafion. The chemically-modified electrodes were characterized by cyclic voltammetry (CV) and were used as working electrodes to detect varying concentrations of copper (Cu2+) and zinc (Zn2+) in a 0.1 M NaCl supporting electrolyte solution via Anodic Stripping Voltammetry (ASV). Cu2+ and Zn2+ ions were successfully determined by ASV. The limits of detection for Cu2+ and Zn2+ were 0.1 ppm and 0.7 ppm, respectively. The modified electrodes were used to determine the presence of Cu2+ and Zn2+ in different real water samples. The presence of Cu2+ was successfully determined in deep well, lake, and tap water samples, while the presence of Zn2+ was successfully determined in sea and tap water samples. Atomic Absorption Spectroscopy (AAS) results confirm the presence of Cu2+ and Zn2+ in the samples.

Electrostatic-Force-Assisted Dispensing Printing of Electrochromic Gels for Low-Voltage Displays.

In this study, low-voltage, printed, ion gel-based electrochromic devices (ECDs) were successfully fabricated. While conventional dispensing printing provides irregularly printed electrochromic (EC) gels, we improved the adhesion between the printed gel and the substrate by applying an external voltage. This is called electrostatic-force-assisted dispensing printing. As a result, we obtained well-defined, printed, EC gels on substrates such as indium tin oxide-coated glass. We fabricated a gel-based ECD by simply sandwiching the printed EC gel between two transparent electrodes. The resulting ECD, which required a low coloration voltage (∼0.6 V), exhibited a high coloration efficiency (η) of 161 cm2/C and a large transmittance contrast (∼82%) between the bleached and colored states at -0.7 V. In addition, electrostatic-force-assisted dispensing printing was utilized to fabricate directly patterned ECDs.

The optical properties of a novel metal-free phthalocyanine

In the present work, 4-(4′-dodecyloxycarbonyl) phenoxy phthalonitrile was synthesized and then this phthalonitrile derivative was cyclotetramerized in dodecanol resulting a new metal-free phthalocyanine. The optical properties of this phthalocyanine were investigated. Novel metal-free phthalocyanine thin films were deposited on indium tin oxide-coated glass substrates by spinning method. Surface and microstructural properties of the films were characterized by atomic force microscopy and scanning electron microscopy. Both the transmittance and reflectance spectra of the deposited films were recorded using an NKD analyser. The optical band gap energy, the thickness of thin films, refractive index (n) and extinction coefficient (k) were calculated as 2.7 eV, 300 nm, 1.47 and 0.02, respectively.

PoPD Modified ITO Based Capacitive Immunosensor for Sulphathiazole

AbstractA capacitive immunosensor for determination of sulphathaizole (STZ) has been developed on polymer coated indium tin oxide glass chip (ITO). The immunosensor chip was fabricated by polymerizing, ortho‐phenylenediamine (oPD) on ITO followed by surface modification with anti‐sulphathiazole antibody. The developed immunosensor chip was characterized by using Atomic force microscopy (AFM), Cyclicvoltammetry (CV) and Electrochemical impedance spectroscopy (EIS). The capacitive measurement of the developed immunosensor was performed by using EIS in spiked drinking water and milk. The developed sensor showed liner detection range 0.1‐100 μgL−1for STZ with a limit of detection 0.01 μgL−1 in water with recovery between 95–106 %. The biosensor showed excellent selectivity and storage stability upto 4 weeks when preserved at 4 °C.

Versatile Bottom-Up Synthesis of Tethered Bilayer Lipid Membranes on Nanoelectronic Biosensor Devices.

Interfacing nanoelectronic devices with cell membranes can enable multiplexed detection of fundamental biological processes (such as signal transduction, electrophysiology, and import/export control) even down to the single ion channel level, which can lead to a variety of applications in pharmacology and clinical diagnosis. Therefore, it is necessary to understand and control the chemical and electrical interface between the device and the lipid bilayer membrane. Here, we develop a simple bottom-up approach to assemble tethered bilayer lipid membranes (tBLMs) on silicon wafers and glass slides, using a covalent tether attachment chemistry based on silane functionalization, followed by step-by-step stacking of two other functional molecular building blocks (oligo-poly(ethylene glycol) (PEG) and lipid). A standard vesicle fusion process was used to complete the bilayer formation. The monolayer synthetic scheme includes three well-established chemical reactions: self-assembly, epoxy-amine reaction, and EDC/NHS cross-linking reaction. All three reactions are facile and simple and can be easily implemented in many research labs, on the basis of common, commercially available precursors using mild reaction conditions. The oligo-PEG acts as the hydrophilic spacer, a key role in the formation of a homogeneous bilayer membrane. To explore the broad applicability of this approach, we have further demonstrated the formation of tBLMs on three common classes of (nano)electronic biosensor devices: indium-tin oxide-coated glass, silicon nanoribbon devices, and high-density single-walled carbon nanotubes (SWNT) networks on glass. More importantly, we incorporated alemethicin into tBLMs and realized the real-time recording of single ion channel activity with high sensitivity and high temporal resolution using the tBLMs/SWNT network transistor hybrid platform. This approach can provide a covalently bonded lipid coating on the oxide layer of nanoelectronic devices, which will enable a variety of applications in the emerging field of nanoelectronic interfaces to electrophysiology.

Sol-gel preparation of Zn-V-Mn-O thin films for low voltage varistor applications

Abstract ZnO-based thin films in the Zn-V-Mn-O system have been synthesised by a sol-gel process and characterised for use in low voltage varistor applications. The films were prepared through multi-layer deposition of a precursor solution onto indium tin oxide-coated borosilicate glass substrates by spin-coating and subsequent annealing. Current-voltage characteristics measured for the films annealed at 700 °C showed varistor action with nonlinear coefficients (α) above 4.

Synthesis and Properties of Fully Triphenylamine-based Polyamides Bearing 3,5-bis(Trifluoromethyl) and/or 3,5-dimethyl Substituents on the Pendent Phenyl Units

ABSTRACTFour new fully triphenylamine-based polyamides coded as polyamide (CF3,CF3), polyamide (CF3,CH3), polyamide (CH3,CF3), and polyamide (CH3,CH3) were synthesized by the phosphorylation polyamidation reaction from various combinations of 3,5-bis(trifluoromethyl)-4′,4″-dicarboxytriphenylamine, 3,5-dimethyl-4′,4″-dicarboxytriphenylamine, 3,5-bis(trifluoromethyl)-4′,4″-diaminotriphenylamine, and 3,5-dimethyl-4′,4″-diaminotriphenylamine. All the polyamides were amorphous and readily soluble in many common organic solvents and could be solution-cast into transparent, flexible, and strong films with good mechanical properties. They had useful levels of thermal stability associated with high glass-transition temperatures of 268–287°C and 10 wt%-loss temperatures in excess of 500°C. Cyclic voltammograms of the film of polyamide (CH3,CH3) on the indium-tin oxide-coated glass substrates exhibited two oxidation redox couples with E1/2 around 0.82 and 1.29 V vs. Ag/AgCl in tetrabutylammonium perchlorate/acetonitrile solution, accompanied by a color change from pale yellow neutral state to dark green oxidized state. The CF3-substituted polyamides displayed a higher oxidation potential and less electrochemical stability as compared to the CH3-substituted analogues.

Effect of halide-mixing on the switching behaviors of organic-inorganic hybrid perovskite memory

Mixed halide perovskite materials are actively researched for solar cells with high efficiency. Their hysteresis which originates from the movement of defects make perovskite a candidate for resistive switching memory devices. We demonstrate the resistive switching device based on mixed-halide organic-inorganic hybrid perovskite CH3NH3PbI3−xBrx (x = 0, 1, 2, 3). Solvent engineering is used to deposit the homogeneous CH3NH3PbI3−xBrx layer on the indium-tin oxide-coated glass substrates. The memory device based on CH3NH3PbI3−xBrx exhibits write endurance and long retention, which indicate reproducible and reliable memory properties. According to the increase in Br contents in CH3NH3PbI3−xBrx the set electric field required to make the device from low resistance state to high resistance state decreases. This result is in accord with the theoretical calculation of migration barriers, that is the barrier to ionic migration in perovskites is found to be lower for Br− (0.23 eV) than for I− (0.29–0.30 eV). The resistive switching may be the result of halide vacancy defects and formation of conductive filaments under electric field in the mixed perovskite layer. It is observed that enhancement in operating voltage can be achieved by controlling the halide contents in the film.

Nucleation Mechanism and Optoelectronic Properties of Cu2O onto ITO Electrode in the Electrochemical Deposition Process

Cyclic voltammetry and chronoamperometry were used to study the deposition process at the initial stage of Cu2O electrodeposition on indium tin oxide-coated glass. The current transient data and predicted values were analyzed by the instantaneous and progressive nucleation models under different electrolyte concentrations. The effects of the Cu2O nucleation mechanism on microstructure and photoelectric properties of Cu2O were investigated by X-ray photoelectron spectroscopy, X-ray diffractometry, scanning electron microscopy, ultraviolet visible spectrophotometry and fluorescence spectrophotometry. The results show that the electrochemical deposition process of Cu2O is irreversible and controlled by diffusion, and the diffusion coefficient was calculated to be 2.2 × 10−6 cm2·s−1. The nucleation mechanism of Cu2O is related to the electrolyte concentration. When the concentrations of Cu(AC)2 were 5 mM and 15 mM, the nucleation processes of Cu2O were consistent with the progressive nucleation and instantaneous nucleation models, respectively. Under the instantaneous nucleation mechanism, the prepared Cu2O displayed a uniform structure, composed of sword-shaped dendritic crystal. Compared to the progressive nucleation, the purity of the Cu2O was higher, the bandgap narrower (2.006 eV), and the photoluminescence intensity higher. The Cu2O had a high carrier density (4.9 × 1022 cm−3) and a low charge transfer resistance (127.27 KΩ·cm2). It exhibits superior photoelectric performance.

Nickel-metal organic framework/MWCNT composite electrode for non-enzymatic urea detection

A porous composite catalyst based on nickel-metal organic framework (Ni-MOF) and multiwalled carbon nanotubes (MWCNTs) was synthesized for non-enzymatic urea detection. The Ni-MOF was characterized by Fourier transform infrared spectroscopy, X-ray photo electron spectroscopy and X-ray diffraction techniques. The morphology and the structure of the Ni-MOF were studied using scanning electron microscopy and transmission electron microscopy. The Ni-MOF/MWCNTs coated indium tin oxide glass was used as a novel electrochemical sensor for urea detection. The Ni-MOF/MWCNT electrode showed a very high sensitivity of 685μAmM−1cm−2, low detection limit of 3μM and a response time of 10s. Moreover, the sensor showed remarkable stability with no loss in activity after 30days of storage under ambient conditions. Overall, the novel hybrid inorganic–organic material showed notable potential for designing of micro-scale point of care diagnostic devices for urea sensing applications.

Stability of Indium Gallium Zinc Aluminum Oxide Thin-Film Transistors with Treatment Processes

The indium-gallium-zinc-aluminum-oxide (IGZAO) channel layer of the bottom-gate-type thin-film transistors (TFTs) was deposited on indium tin oxide-coated glass substrates using a magnetron radio frequency co-sputtering system with dual targets of indium gallium zinc oxide and Al. The 3 s orbital of Al cations provided an extra transport pathway and widened the bottom of the conduction band, thus increasing the electron mobility in the IGZAO films. The Al-O bonds could sustain the stability of oxygen of the IGZAO films. The IGZAO TFTs were processed by O2 plasma and post-annealing treatments. Hysteresis analysis was carried out in order to study the stability of the resulting IGZAO TFTs, the positive bias temperature stress (PBTS) performance, and the hot carrier effect were also measured. For the IGZAO TFTs, the threshold voltage shift of the PBTS performance and the hot carrier effect were 0.1 V and 0.06 V, respectively. Overall, the IGZAO TFTs exhibited good stability in this study.

Absolute asymmetric electrochemical polymerization

Electrochemical polymerization of thiophene-based achiral monomer having azobenzene as a chromophore irradiated by circular polarized light (CPL) was carried out to obtain chiroptically active polymer film on indium-tin oxide-coated glass. Circular dichroism and optical absorption spectroscopy measurements indicate the samples show chiroptical activity. This result indicates occurrence of absolute asymmetric polymerization by laser CPL.

Imaging and mapping of mouse bone using MALDI-imaging mass spectrometry

Matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS) is an advanced method used globally to analyze the distribution of biomolecules on tissue cryosections without any probes. In bones, however, hydroxyapatite crystals make it difficult to determine the distribution of biomolecules using MALDI-IMS. Additionally, there is limited information regarding the use of this method to analyze bone tissues. To determine whether MALDI-IMS analysis of bone tissues can facilitate comprehensive mapping of biomolecules in mouse bone, we first dissected femurs and tibiae from 8-week-old male mice and characterized the quality of multiple fixation and decalcification methods for preparation of the samples. Cryosections were mounted on indium tin oxide-coated glass slides, dried, and then a matrix solution was sprayed on the tissue surface. Images were acquired using an iMScope at a mass-to-charge range of 100–1000. Hematoxylin-eosin, Alcian blue, Azan, and periodic acid-Schiff staining of adjacent sections was used to evaluate histological and histochemical features. Among the various fixation and decalcification conditions, sections from trichloroacetic acid-treated samples were most suitable to examine both histology and comprehensive MS images. However, histotypic MS signals were detected in all sections. In addition to the MS images, phosphocholine was identified as a candidate metabolite. These results indicate successful detection of biomolecules in bone using MALDI-IMS. Although analytical procedures and compositional adjustment regarding the performance of the device still require further development, IMS appears to be a powerful tool to determine the distribution of biomolecules in bone tissues.

Fabrication of 10 µm-scale conductive Cu patterns by selective laser sintering of Cu complex ink

A Cu complex ink was synthesized using copper formate as a precursor and its potential for laser patterning was investigated. The Cu ink was spin-coated onto a substrate and the coated film was space-selectively sintered using a nanosecond-pulsed ultraviolet laser. The unexposed Cu ink could be removed from the film by rinsing it with the dispersing agent used to synthesize the ink, disclosing a conductive Cu pattern. A minimum resistivity of 8.46×10−5Ωcm was obtained for the Cu lines with 10–20µm widths. The feasibility of this method for metallization was demonstrated by fabricating a complex Cu electric circuit on an indium tin oxide-coated glass substrate. The selective laser sintering approach provides a simple, cost-effective alternative to conventional lithography for the production of electrode or metallization patterns.

Synthesis and properties of electroactive aromatic polyimides with methyl- or trifluoromethyl-protecting triphenylamine units

Two series of new redox-active aromatic polyimides with methyl- (–CH3) or trifluoromethyl (–CF3)-protecting triphenylamine moieties were prepared from 4,4′-diamino-4″-methyltriphenylamine and 4,4′-diamino-4″-(trifluoromethyl)triphenylamine with aromatic tetracarboxylic dianhydrides via the conventional two-step polycondensation technique. Flexible and strong polyimide films could be obtained via the thermal curing of their precursor poly(amic acid) films or direct solution cast from some organosoluble polyimides. The polyimides showed high glass-transition temperatures between 269°C and 312°C, and they did not show significant decomposition before 500°C in air or under nitrogen atmosphere. Cyclic voltammograms of the polyimide films on the indium–tin oxide-coated glass substrate exhibited a pair of reversible redox waves with half-wave oxidation potentials of 1.08–1.10 V (for the –CH3 series) and 1.23–1.26 V (vs. silver/silver chloride; for the –CF3 series) in acetonitrile solution. The polyimide films showed anodic electrochromism from pale yellow neutral state to purplish blue (for the –CH3 series) and chrome yellow (for the –CF3 series) when oxidized.

Effect of a static magnetic field on Escherichia coli adhesion and orientation.

This preliminary study focused on the effect of exposure to 0.5 T static magnetic fields on Escherichia coli adhesion and orientation. We investigated the difference in bacterial adhesion on the surface of glass and indium tin oxide-coated glass when exposed to a magnetic field either perpendicular or parallel to the adhesion surface (vectors of magnetic induction are perpendicular or parallel to the adhesion surface, respectively). Control cultures were simultaneously grown under identical conditions but without exposure to the magnetic field. We observed a decrease in cell adhesion after exposure to the magnetic field. Orientation of bacteria cells was affected after exposure to a parallel magnetic field. On the other hand, no effect on the orientation of bacteria cells was observed after exposure to a perpendicular magnetic field.