Indium Tin Oxide Glass Slides Research Articles

Improving the Signal Intensity of Cryosections Using a Conductive Adhesive Film in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

The matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technique was used to obtain the molecular images of cryosections without labeling. Although MALDI-MSI has been widely used to detect small molecules from biological tissues, issues remain due to the technical process of cryosectioning and limited mass spectrometry parameters. The use of a conductive adhesive film is a unique method to obtain high-quality sections from cutting tissue, such as bone, muscle, adipose tissue, and whole body of mice or fish, and we have reported the utilization of the film for MALDI-MSI in previous. However, some signal of the small molecules using the conductive adhesive films was still lower than on the indium tin oxide (ITO) glass slide. Here, the sample preparation and analytical conditions for MALDI-MSI using an advanced conductive adhesive film were optimized to obtain strong signals from whole mice heads. The effects of tissue thickness and laser ionization power on signal intensity were verified using MALDI-MSI. The phospholipid signal intensity was measured for samples with three tissue thicknesses (5, 10, and 20 μm); compared to the signals from the samples on the ITO glass slides, the signals with conductive adhesive films exhibited significantly higher intensities when a laser with a higher range of power was used to ionize the small molecules. Thus, the technique using the advanced conductive adhesive film showed an improvement in MALDI-MSI analysis.

Fabrication of polyaniline/graphene oxide composites for implementation in humidity sensing.

This work reports the measurement of impedance variations under various humidity conditions at frequency ranges between 100 Hz and 5 MHz. An electrochemical polymerization process has been used in the synthesis including varying the mass ratios of graphene oxide (GO) in polyaniline. An electrochemical deposition method has been used to produce a sample film on an indium tin oxide glass slide. The percentage relative humidity (RH%) of the samples has been estimated to be 20-90%. Impedance and humidity had an inverse relationship, i.e. the impedance value decreased with an increase in humidity. In contrast with platinum capacitive humidity sensors (HS), the GO-based HS had a sensitivity of 75-99%, which was ~10-fold more than that of traditional sensors. With three different parameter weight % of GO, the frequency range have been 100 Hz to 5 MHz and RH% has been found to 20-90%. The HS showed a fast response and recovery time. Therefore, GO appears to be a useful material for building HS with high sensitivity for a comprehensive approach.

Electrospinning for building 3D structured photoactive biohybrid electrodes

We describe the development of biohybrid electrodes constructed via combination of electrospun (e-spun) 3D indium tin oxide (ITO) with the trimeric supercomplex photosystem I and the small electrochemically active protein cytochrome c (cyt c). The developed 3D surface of ITO has been created by electrospinning of a mixture of polyelthylene oxide (PEO) and ITO nanoparticles onto ITO glass slides followed by a subsequent elimination of PEO by sintering the composite. Whereas the photosystem I alone shows only small photocurrents at these 3D electrodes, the co-immobilization of cyt c to the e-spun 3D ITO results in well-defined photoelectrochemical signals.The scaling of thickness of the 3D ITO layers by controlling the time (10 min and 60 min) of electrospinning results in enhancement of the photocurrent. Several performance parameters of the electrode have been analyzed for different illumination intensities.

Electro-optic liquid crystal device employing two-dimensional WSe2 as the planar-alignment layers

Two-dimensional (2D) tungsten diselenide (WSe2) nanosheets were transferred onto indium tin oxide (ITO) coated glass slides. Two such 2D WSe2-covered ITO glass slides were placed together to fabricate an electro-optic liquid crystal (LC) cell. A nematic LC inside this WSe2-based device obtains uniform planar-alignment. The coherent overlay of the LC molecules along the armchair direction on the WSe2 lattice leads to this planar-alignment at the molecular scale. This WSe2-based LC device exhibits the typical electro-optical effect on the application of an electric field. A sharp Fréedericksz transition of the nematic director from this electro-optical effect confirms that the 2D WSe2 provides sufficient planar anchoring energy in the device. Finally, the WSe2/ITO slide exhibits more optical transparency than a standard polyimide alignment layer/ITO slide.

Proteases Immobilization for In Situ Time-Limited Proteolysis on MALDI Chips

A large number of different enzyme immobilization techniques are used in the field of life sciences, clinical diagnostics, or biotechnology. Most of them are based on a chemically mediated formation of covalent bond between an enzyme and support material. The covalent bond formation is usually associated with changes of the enzymes’ three-dimensional structure that can lead to reduction of enzyme activity. The present work demonstrates a potential of an ambient ion-landing technique to effectively immobilize enzymes on conductive supports for direct matrix-assisted laser desorption/ionization (MALDI) mass spectrometry analyses of reaction products. Ambient ion landing is an electrospray-based technique allowing strong and stable noncovalent and nondestructive enzyme deposition onto conductive supports. Three serine proteolytic enzymes including trypsin, α-chymotrypsin, and subtilisin A were immobilized onto conductive indium tin oxide glass slides compatible with MALDI mass spectrometry. The functionalized MALDI chips were used for in situ time-limited proteolysis of proteins and protein–ligand complexes to monitor their structural changes under different conditions. The data from limited proteolysis using MALDI chips fits to known or predicted protein structures. The results show that functionalized MALDI chips are sensitive, robust, and fast and might be automated for general use in the field of structural biology.

Conductive Adhesive Film Expands the Utility of Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry Imaging.

The matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) technique is a promising approach for detecting the distribution of small molecules in a section of biological tissue. However, when a cryosection is created from fragile, hard, or whole-body samples, obtaining a high-quality section that maintains the distribution of the various components has been difficult. Since adhesive films have the potential to obtain high-quality cryosections, we attempted to utilize a conductive adhesive film for MALDI-MSI. To this end, cryosections of the whole body of a 9-day-old mouse were directly prepared on indium tin oxide (ITO) glass slides, nonconductive adhesive films, or conductive adhesive films, and the signal intensities from each section were measured by MALDI-MSI. We measured the differences in the ion intensity among these three slides/films by means of multivariate analyses and found that both the nonconductive and conductive adhesive films gave rise to high-quality sections in comparison with the ITO glass slide. The conductive adhesive film gave higher signals that were comparable to those of the ITO glass slide in comparison with the nonconductive adhesive film. We divided the frozen sections into two groups, a freeze-dried group and a thawed group, to examine the freeze-thaw effect on the signals of representative compounds of amino acids, cholesterol, and phosphatidylcholines. The freeze-dried samples were found to be useful for the analysis. These results indicate that the sections made with the conductive adhesive film under a freeze-dried condition can expand the utility of the MALDI-MSI analysis.

Co-assembly of functional graphene and multiwall carbon nanotubes for supercapacitors by a vertical deposition technique

Graphene and carbon nanotubes (CNTs) are nanosized carbon materials with large specific surface areas, outstanding electrical conductivities, excellent mechanical properties, and other remarkable characteristics. Preparation of graphene oxide is by a redox method, followed by vertical deposition to prepare graphene oxide/carbon nanotube GO/CNT) composites. Scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the morphology and microstructure of the materials. Electrodes were made by deposition of graphene oxide/carbon nanotube composites on an indium tin oxide glass slide, and its electrical properties were characterized by cyclic voltammetry. The GO/CNT composites exhibit excellent energy and power densities and are ideal materials for the preparation of supercapacitor electrodes.

Optically-Induced Cell Fusion on Cell Pairing Microstructures.

Cell fusion is a critical operation for numerous biomedical applications including cell reprogramming, hybridoma formation, cancer immunotherapy, and tissue regeneration. However, unstable cell contact and random cell pairings have limited efficiency and yields when utilizing traditional methods. Furthermore, it is challenging to selectively perform cell fusion within a group of cells. This study reports a new approach called optically-induced cell fusion (OICF), which integrates cell-pairing microstructures with an optically-induced, localized electrical field. By projecting light patterns onto a photoconductive film (hydrogen-rich, amorphous silicon) coated on an indium-tin-oxide (ITO) glass while an alternating current electrical field was applied between two such ITO glass slides, “virtual” electrodes could be generated that could selectively fuse pairing cells. At 10 kHz, a 57% cell paring rate and an 87% fusion efficiency were successfully achieved at a driving voltage of 20 Vpp, suggesting that this new technology could be promising for selective cell fusion within a group of cells.

(Invited) Electropolymerized Polyaniline/Manganese Iron Oxide Hybrids with Enhanced Electrochemical Energy Storage and Color Switching Response

Polyaniline (PANI) nanocomposites embedded with manganese iron oxide (MnFe2O4) nanoparticles were prepared as thin films by electropolymerizing aniline monomers onto indium tin oxide (ITO) glass slides pre- spin-coated with MnFe2O4 nanoparticles. The UV-visible absorption spectra, FT-IR and SEM results confirmed the formation of the composite films and the chemical interaction between the PANI matrix and MnFe2O4 particles. A coloration efficiency of 206.2 cm2 C-1 was obtained for the PANI/MnFe2O4 nanocomposite film, higher than that of the pristine PANI film, 104.2 cm2 C-1, suggesting a synergistic effect between the MnFe2O4 particles and the PANI matrix. An enhanced areal capacitance as 4.46 mF cm-2 was also achieved in the PANI/MnFe2O4 nanocomposite film compared with that of 3.95 mF cm-2 in the pristine PANI film from the CV at a scan rate of 5 mV s-1. The enhanced capacitance of the composite films are attributed to the pseudocapacitive property of MnFe2O4 and the rougher morphology caused by the embedment of MnFe2O4 particles into the PANI matrix. Finally, the positive roles of decreasing H2SO4 concentration and increasing temperature during a low temperature range were also demonstrated, however relative higher temperatures can destroy the PANI structure and cause the degradation of PANI. Experimental 1.0 mg Mn2FeO4 was dissolved in 10.0 mL ethanol solution under sonication. The MnFe2O4 film was prepared by drop casting about 1.0 mL MnFe2O4 suspension onto the ITO glass and maintained at 2000 rpm for 20 s. The film was dried naturally overnight. The electropolymerization of aniline onto the as-treated ITO glass or formed MnFe2O4 film was performed on an electrochemical working station VersaSTAT 4 potentiostat (Princeton Applied Research). A typical three electrode electrochemical cell was employed, in which a saturated calomel electrode (SCE) served as the reference electrode, a platinum (Pt) wire served as the counter electrode and the MnFe2O4 coated ITO glass or bare ITO glass slide with an effective area of 4.0 cm2 served as the working electrode. A long path length home-made spectroelectrochemical cell was used for optical characterizations. A typical electrochemical polymerization was performed 10 cycles scanned back and forth from 0 to +1.2 V vs. SCE at a scan rate of 50 mV/s in 0.5 M H2SO4aqueous solution containing 0.1 M aniline. Results and Discussion A fewer amount of PANI was deposited on the MnFe2O4 layer due to the increased resistance caused by the introduced MnFe2O4. The relationship between MnFe2O4 and PANI is probably caused by the π-π stacking, electrostatic interactions as well as hydrogen bonding between MnFe2O4 and the -NH group in PANI. The higher coloration efficiency and stable chronocoulometry of MnFe2O4/PANI nanocomposite further confirm the positive role of MnFe2O4 layer. Enhanced capacitance of MnFe2O4/PANI nanocomposite is probably due to the supercapacitive role of MnFe2O4 and resulted rougher morphology. Enhanced capacitances were obtained when increasing temperature in low temperature range and decreasing H2SO4concentration. Conclusion A PANI matrix embedded with MnFe2O4 particles nanocomposite film was successfully prepared by an electrodeposition of PANI monomer onto a MnFe2O4 coated ITO glass. Multi-color electrochromic phenomenon, higher coloration efficiency and faster switching response were obtained due to the major PANI and the inner interactions between the PANI matrix and the MnFe2O4 particles as well as the resulted rougher morphology. The PANI/MnFe2O4 nanocomposite film also exhibits an enhanced areal capacitance compared to that of the pristine PANI film at low scan rates due to the capacitive role of MnFe2O4. A negative role of increasing the H2SO4 concentration and a positive role of increasing temperature on the supercapacitive behaviors of both the pristine PANI and PANI/MnFe2O4 composites films was also demonstrated. Acknowledgments The financial supports from University of Tennessee Knoxville are kindly acknowledged. Figure 1. CV curves of pureMnFe2O4 film, pristine PANI film and PANI/MnFe2O4 nanocomposite film onto ITO glass in 1.0 M H2SO4 at a scan rate of 5 mV/s. Background is the TEM image of PANI/MnFe2O4nanocomposite accompanied with the color changing phenomenon.

Aerosol assisted chemical vapour deposited (AACVD) of TiO2 thin film as compact layer for dye-sensitised solar cell

Compact TiO2 has been introduced onto the surface of an indium tin oxide glass slide (ITO), using an aerosol-assisted chemical vapour deposition method. This serves as a blocking layer for a dye-sensitised solar cell (DSSC). The thickness of the compact TiO2 could be controlled by deposition time. X-ray diffraction and Raman spectroscopy analyses reveal that the compact TiO2 is made up of mixed anatase and rutile phases. The field emission scanning electron microscopy image displays a pyramidal morphology of the compact TiO2. A layer of P25 paste was then smeared onto the compact TiO2-modified ITO, using the doctor's blade method. A post-treatment procedure was applied to remove the contaminants from the prepared hybrid film, by immersing in a hydrochloric acid solution. The photoelectrochemical measurements and J–V characterisation of the hybrid film show an approximately fourfold increase in photocurrent density generation (114.22µA/cm2), and approximately 25% enhancement of DSSC conversion efficiency (4.63%), compared to the acid-treated P25 paste alone (3.68%).

Increased Proliferation and Differentiation of Pre-Osteoblasts MC3T3-E1 Cells on Nanostructured Polypyrrole Membrane Under Combined Electrical and Mechanical Stimulation

Polypyrrole (PPy), as an electrical conductive polymer, has been widely investigated in biomedical fields. In this study, PPy membrane at nanoscale was electrically deposited on indium-tin oxide glass slide with sodium p-toluenesulfonate as supporting electrolyte. Electropolymerization of PPy was performed under a constant 800 mV voltage for 10 seconds. Chemical compositions and morphology were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The results showed that the nanoscaled PPy particles distributed uniformly and the average diameter of PPy particles was 62 nm. Since bone cells can respond to both electrical and mechanical stimulation in vivo, pre-osteoblasts MC3T3-E1 cells were cultured ort nanostructured PPy membrane under the combined electrical and mechanical stimulation. The nano-PPy membrane was conducive to transferring uniform electrical stimulation and applying steady mechanical stimulation. It is suggested that the combined stimulation did not affect cells morphologies significantly. However, cell proliferation tested by MTT, alkaline phosphatase activities, and gene expression of Collagen-I indicated that combined stimulation can enhance the proliferation and differentiation of MC3T3-E1 cells more efficiently than single electrical stimulation or single mechanical stimulation. The combined stimulation through a nano-PPy membrane may provide a highly potential stimulated method in bone tissue engineering.

Microfluidic photoelectrocatalytic reactors for water purification with an integrated visible-light source

This paper reports experimental studies using the photoelectrocatalytic effect to eliminate a fundamental limit of photocatalysis - the recombination of photo-excited electrons and holes. The fabricated reactor has a planar reaction chamber (10 × 10 × 0.1 mm(3)), formed by a blank indium tin oxide glass slide, an epoxy spacer and a BiVO(4)-coated indium tin oxide glass substrate. A blue light-emitting diode panel (emission area 10 × 10 mm(2)) is mounted on the cover for uniform illumination of the reaction chamber. In the experiment, positive and negative bias potentials were applied across the reaction chamber to suppress the electron/hole recombination and to select either the hole-driven or electron-driven oxidation pathway. The negative bias always exhibits higher performance. It is observed that under -1.8 V the degradation rate is independent of the residence time, showing that the accompanying electrolysis can solve the oxygen deficiency problem. The synergistic effect of photocatalysis and electrocatalysis is observed to reach its maximum under the bias potential of ± 1.5 V. The photoelectrocatalytic microreactor shows high stability and may be scaled up for high-performance water purification.

Metallopolymers from ruthenium and iron pyrrole-containing π-extended complexes as model components for solid state solar cells

New metallopolymers were generated efficiently on Pt and ITO (indium–tin oxide) glass slides by repeated scan oxidation of Ru and Fe complexes containing pyrrolostyryl bipyridine ligands. The UV–Vis spectrum and voltammogram of Ru-based polymer films showed blue-shifts of the MLCT absorption bands and increased oxidation potentials indicating conjugation cut in the π-extended system. In contrast, formation of polypyrrole occurred in Fe-based polymers due to oxidation of pyrrole groups by the initially oxidised metal centres. The coated ITO electrodes displayed promising wide absorption domains for use in light conversion devices.

Synthesis and characterization of azo‐based methacrylate polymers with methoxy and nitro end groups for nonlinear optical applications

AbstractOne new and three already described azobased methacrylate monomers with methoxy and nitro end groups and spacer length 2 and 6 were synthesized. These monomers were copolymerized with methyl methacrylate and the monomers as well as copolymers were characterized by classical spectroscopy techniques (FTIR, NMR, and UV‐VIS), gel permeation chromatography (GPC), elemental analysis and thermal analysis (TGA and DSC). The glass transition temperature of the polymers was found to be above room temperature and thermal decomposition temperatures above 100°C. All the polymers were amorphous in nature and formed excellent homogeneous films with good optical transparency. The polymer films coated on indium tin oxide glass slides were poled and their order parameters were calculated to check the stability of oriented dipoles. Few samples were also studied for their second harmonic generation properties. Temporal stability, checked up to 120 h at room temperature, was found to be quite satisfactory. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3497–3504, 2007

Area-tunable micromirror based on electrowetting actuation of liquid-metal droplets

The authors report a micromirror device actuated by electrowetting effect. The micromirror surface is formed by a liquid-metal droplet jetted on a substrate and then topped with a parylene/Teflon coated indium tin oxide glass slide. The droplet is deformed by a voltage applied across the parylene/Teflon film. The radius of micromirror is tuned from 13μm (0V) to 88μm (90V), and the normalized area increases from 0.2 to 0.94 accordingly. The switching time ranges from 1ms for a 350μm diameter droplet to 0.2ms for a 50μm one. A 4×1 micromirror array is demonstrated and switched simultaneously.

Chemical bath deposition of tin selenide thin films

Tin selenide thin films have been deposited on indium tin oxide glass slides in alkaline medium. The method is based on simple bath deposition technique that requires less chemicals and monitoring. Uniform and well-adhered films were obtained upon required deposition period. X-ray, morphology, optical and photoelectrochemical study was carried out for the as-deposited film. The films were polycrystalline and covered the surface of the substrate completely. Photoelectrochemical test shows a p-type conduction mechanism. The band gap was found to be about 1.25 eV with direct transition.