Microscope Slide Substrates Research Articles

Sol-Jel Yöntemiyle Hazırlanan Kobalt Ftalosiyanin Katkılı TiO2 Filmlerin Optik ve Yapısal Özelliklerinin İncelenmesi

Bu çalışmada, sol-jel spin kaplama yöntemi kullanılarak mikroskop cam altlıklar üzerine TiO2, TiO2/CoPc ve CoPc filmleri hazırlanmış ve CoPc katkı konsantrasyonunun filmlerin optik ve yapısal özellikleri üzerine etkisi araştırılmıştır. İnce filmlerin optik geçirgenliğini ölçmek için 300-1100 nm dalgaboyu aralığında bir spektrofotometre kullanılmıştır. Uv-Vis çalışmaları, B ve Q bandı absorpsiyon bölgelerine karşılık gelen aralıklarda artan CoPc konsantrasyonu ile filmlerin geçirgenliğinin azaldığını göstermiştir. İnce filmlerin yüzey morfolojisini karakterize etmek için taramalı elektron mikroskobu (SEM) kullanılmış ve homojen olarak kaplandıkları görülmüştür. Tavlanmış filmlerin XRD ölçümlerinde, TiO2 filmlerde anataz-brookit karışık faz görülürken TiO2/CoPc filmlerin anataz olduğu tespit edilmiştir. Filmlerin dislokasyon yoğunluğu, kristal boyutu gibi önemli parametreleri hesaplanmıştır.

TiO2/SiO2 multilayer as an antireflective and protective coating deposited by microwave assisted magnetron sputtering

AbstractIn this paper designing, preparation and characterization of multifunctional coatings based on TiO2/SiO2 has been described. TiO2 was used as a high index material, whereas SiO2 was used as a low index material. Multilayers were deposited on microscope slide substrates by microwave assisted reactive magnetron sputtering process. Multilayer design was optimized for residual reflection of about 3% in visible spectrum (450–800 nm). As a top layer, TiO2 with a fixed thickness of 10 nm as a protective film was deposited. Based on transmittance and reflectance spectra, refractive indexes of TiO2 and SiO2 single layers were calculated. Ultra high vacuum atomic force microscope was used to characterize the surface properties of TiO2/SiO2 multilayer. Surface morphology revealed densely packed structure with grains of about 30 nm in size. Prepared samples were also investigated by nanoindentation to evaluate their protective performance against external hazards. Therefore, the hardness of the thin films was measured and it was equal to 9.34 GPa. Additionally, contact angle of prepared coatings has been measured to assess the wetting properties of the multilayer surface.

Rf-sputtering deposition of nano-crystalline zirconia thin films with high transparency

Zirconia thin film was deposited on a microscope slide substrate by rf-sputtering. The surface morphology and elemental composition of the film were characterized by SEM and EDX. SEM images showed that the surface morphology of the film consists of spherical-like grains, grain agglomerates and micro voids. EDX experiments showed that the film is composed of 32.82at% Zr and 67.18at% O. The microstructure of the film was also investigated by TEM. It was found that the film has poly crystalline grains with nano-sized and different orientations. A study of lattice image for the film was done by HRTEM. The dhkl values were evaluated. Defects and lattice distortions were seen. The optical properties of the film showed that its average optical transmittance in the visible region is high (∼84%) and the values of Eg and Eu are ∼4.05eV and ∼0.446eV, respectively.

HistoFlex—a microfluidic device providing uniform flow conditions enabling highly sensitive, reproducible and quantitative in situ hybridizations

A microfluidic device (the HistoFlex) designed to perform and monitor molecular biological assays under dynamic flow conditions on microscope slide-substrates, with special emphasis on analyzing histological tissue sections, is presented. Microscope slides were reversibly sealed onto a cast polydimethylsiloxane (PDMS) insert, patterned with distribution channels and reaction chambers. Topology optimization was used to design reaction chambers with uniform flow conditions. The HistoFlex provided uniform hybridization conditions, across the reaction chamber, as determined by hybridization to microscope slides of spotted DNA microarrays when applying probe concentrations generally used in in situ hybridization (ISH) assays. The HistoFlex's novel ability in online monitoring of an in situ hybridization assay was demonstrated using direct fluorescent detection of hybridization to 18S rRNA. Tissue sections were not visually damaged during assaying, which enabled adapting a complete ISH assay for detection of microRNAs (miRNA). The effects of flow based incubations on hybridization, antibody incubation and Tyramide Signal Amplification (TSA) steps were investigated upon adapting the ISH assay for performing in the HistoFlex. The hybridization step was significantly enhanced using flow based incubations due to improved hybridization efficiency. The HistoFlex device enabled a fast miRNA ISH assay (3 hours) which provided higher hybridization signal intensity compared to using conventional techniques (5 h 40 min). We further demonstrate that the improved hybridization efficiency using the HistoFlex permits more complex assays e.g. those comprising sequential hybridization and detection of two miRNAs to be performed with significantly increased sensitivity. The HistoFlex provides a new histological analysis platform that will allow multiple and sequential assays to be performed under their individual optimum assay conditions. Images can subsequently be recorded either in combination or sequentially through the ability of the HistoFlex to monitor assays without disassembly.

Effect of composition on the properties of Te–Ge thick films deposited by co-thermal evaporation

Due to their remarkable transparency in the mid to far-infrared region, telluride films are considered for the fabrication of micro-components for infrared applications. In the framework of the Darwin mission initiated by the European Space Agency, amorphous Te xGe 100 − x (with x comprised between 73.1 and 88.5 at.%) thick films were deposited by co-thermal evaporation from tellurium and germanium elemental powders. Homogeneous films with thickness comprised between 6 and 15 μm were obtained. Specimens deposited on microscope slide substrates were used for composition, structure, thermal properties, transmission and Vicker's microhardness measurements. Films deposited on commercial As 2Se 3 bulk glass substrates were used for refractive index measurements by the M-lines method. The different measurements revealed that the replacement of Ge by Te in the Te xGe 100 − x films was responsible for a decrease in the glass transition temperature and in the stability of the glass against crystallization. Moreover a two-stage crystallization implying the presence of two crystallization peaks in the DSC curves was highlighted for x > 80 at.% Te. The increase in x was also shown to be responsible for a decrease in the Vicker's microhardness and an increase in the linear refractive index.

Effect of thickness and heat treatment on the crystallite size and dislocation density of nanostructured zinc oxide thin films

The zinc oxide thin films were deposited by the sol–gel method on the glass microscope slide substrates. The microstructure of films was determined as a function of film thickness as well as annealing temperature using X-ray line broadening technique and applying whole powder pattern modeling (WPPM). This investigation showed that the film thickness has no significant effect on the grain size, whereas the dislocation density decreases with the film thickness. On the other hand with the rise of annealing temperature the dislocation density decreases, but the crystallite size becomes larger.

Solar parameters of induced WO 3-coated glass

WO 3 films were prepared by sol–gel deposition process on Corning 2947, microscope slide substrates. The effects of irradiation on the solar parameters of WO 3 films were investigated between ∼1 and 21 kGy absorbed dose by Co-60 radioisotope. Three characteristic optical density bands explained the causes of color due to the absorption of sunlight at induced color centers of the transition elements such as W, Fe and Zr after the gamma irradiation. These bands lead to variations on the solar control in terms of shading coefficient. The absorbed dose plays a key role in the improvement of the shading coefficient dramatically, hence the solar parameters changed considerably depending on the induced color centers of the transition elements and the variations of the grains and the void sizes of the film. The results of the solar parameters of irradiated WO 3 films were compared with the unirradiated WO 3 films and uncoated corning in the solar range.

Influence of background gas pressure on copper film deposition and ion current in a hot refractory anode vacuum ARC

A 200 A Hot Refractory Anode Vacuum Arc (HRAVA) was studied. The arc was sustained between a cylindrical Cu cathode and an Mo anode spaced ∼ 10 mm apart. In the HRAVA, metallic plasma (from cathode material) expands radially. He, N 2 or Ar gas was introduced into the arc chamber through an electrically controlled valve. Films were deposited onto glass microscope slide substrates. The angular film distribution and the influence of different background gases on films deposited by the HRAVA were measured. The film thickness was measured by profilometry. The ion current was measured by a circular flat probe. It was shown that the film thickness was uniform with respect to the azimuthal angle around the electrode axis within approximately 10%. The film thickness was independent of gas pressure p, below a critical value p cr. For p > p cr, the film thickness decreased with p, eventually reaching 0. The value of p cr was less for gases with larger molecular weight—60, 10 and 5 mTorr (0.67, 1.33 and 8 Pa) for He, N 2 and Ar, respectively. The ion current to a 78 mm 2 probe in vacuo increased with time and reached a saturation value of approximately 4.5 mA after about 60 s from arc ignition. The ion flux fraction in the total deposition mass flux was estimated to be about 60% in the fully developed HRAVA ( t = 60–90 s).

The use of near-infrared spectroscopy for the cure monitoring of an ethyl cyanoacrylate adhesive

Near-IR reflectance spectroscopy has been used to study the curing of ethyl cyanoacrylate adhesive on polished dental glass and microscope slide substrates. The effects of changing the glue film thickness and the type of substrate on the curing rate have been investigated whilst maintaining a constant humidity. The FTIR spectral data has been used to calculate and plot the extents of cure versus time for various film thicknesses.

A comparison of microscope slide substrates for use in transfected cell microarrays

Transfected cell microarrays, arrays of mammalian cells expressing defined genes, offer enormous potential for the development of high-throughput cell-based detection technologies to monitor the presence of biological agents or environmental toxicants. The signals generated from these arrays are intimately linked to the efficiency of DNA uptake by the cells located on the micrometer-sized spots. However, quantitative analysis of the transfection efficiency on cellular microarrays has been limited. Further, little regard has been given to the role of the substrate in influencing the transfection efficiency of mammalian cells on transfected microarrays. In this report, we have quantified the transfection efficiency of mammalian cells on different microscope slide substrates. Using commercially available microscope slides bearing substrates that mediate cellular attachment (polystyrene, 3-aminopropylsilane, and poly- l-lysine), we have demonstrated the role of substrate hydrophobicity in determining the resulting spot size and the local DNA concentration when plasmid DNA is dispensed in a printing buffer containing gelatin and sucrose using a noncontact microarray printer. The mean spot diameter varied inversely with the substrate water contact angle ( r 2=0.970). Further, the relative local plasmid DNA concentration was a function of the mean spot diameter. The deposition of Rhodamine Red-labeled plasmid DNA revealed that, across all substrates, the average fluorescence signal within the spots varied inversely with the mean spot diameter ( r 2=0.976). The transfection efficiency of HEK 293T/17 cells varied in accord with the mean spot diameter, demonstrating that the uptake of DNA was a function of the local DNA concentration on each substrate.

A comparison of microscope slide substrates for use in transfected cell microarrays

Transfected cell microarrays, arrays of mammalian cells expressing defined genes, offer enormous potential for the development of high-throughput cell-based detection technologies to monitor the presence of biological agents or environmental toxicants. The signals generated from these arrays are intimately linked to the efficiency of DNA uptake by the cells located on the micrometer-sized spots. However, quantitative analysis of the transfection efficiency on cellular microarrays has been limited. Further, little regard has been given to the role of the substrate in influencing the transfection efficiency of mammalian cells on transfected microarrays. In this report, we have quantified the transfection efficiency of mammalian cells on different microscope slide substrates. Using commercially available microscope slides bearing substrates that mediate cellular attachment (polystyrene, 3-aminopropylsilane, and poly-l-lysine), we have demonstrated the role of substrate hydrophobicity in determining the resulting spot size and the local DNA concentration when plasmid DNA is dispensed in a printing buffer containing gelatin and sucrose using a noncontact microarray printer. The mean spot diameter varied inversely with the substrate water contact angle (r2=0.970). Further, the relative local plasmid DNA concentration was a function of the mean spot diameter. The deposition of Rhodamine Red-labeled plasmid DNA revealed that, across all substrates, the average fluorescence signal within the spots varied inversely with the mean spot diameter (r2=0.976). The transfection efficiency of HEK 293T/17 cells varied in accord with the mean spot diameter, demonstrating that the uptake of DNA was a function of the local DNA concentration on each substrate.

Analysis of Metallo‐Supramolecular Systems Using Single‐Molecule Force Spectroscopy

AbstractSingle‐molecule force spectroscopy has been used for the investigation of the rupture behavior of individual metallo‐supramolecular systems. For this purpose, a specifically designed unsymmetrical α,ω‐functionalized poly(ethylene oxide) has been employed for mono‐termination with a terpyridine ligand and subsequently for the attachment onto atomic force microscopy (AFM) tips and microscope slide substrates. Metallo‐supramolecular complexes were formed by the use of ruthenium(III)–ruthenium(II) chemistry. Vertical stretching with the AFM cantilever ruptured the coordinative bonds. The rupture force of individual bisterpyridine ruthenium(II) complexes was determined to be 95 pN at a force loading rate of 1 nN s–1. Simultaneous rupturing of multiple parallel metallo‐supramolecular bonds was also observed. Monte Carlo simulations corroborated the experimental observations. The presented results lay the basis for the application of such metallo‐supramolecular systems in advanced functional nanomaterials.

Preparation and spectroscopy of anhydrous borosilicate sols and their application to thin films

Borosilicate sols with various boron:silicon ratios were prepared from an anhydrous boric acid (H 3BO 3)–ethanol (C 2H 5OH)–tetraethyl orthosilicate (TEOS) mixture, and dip-coated onto microscope slide substrates under N 2 protection. Transparent crack-free films were obtained when the molar ratio of boric acid to TEOS was between 0.66:1 and 1.33:1. NMR ( 29Si and 11B) and IR spectroscopic techniques were used to infer the formation of borosiloxane (B–O–Si) linkages in the anhydrous sols, and their susceptibility to hydrolysis by atmospheric moisture was observed.

Improvement of thin film semiconductor conductivities using a transverse current during deposition

The effect of electrical current flow parallel to the surface of a growing semiconductor thin film on the electrical conductivity and microstructure of the deposition was investigated. The depositions were produced by filtered vacuum arc deposition. Conducting Sn-O coatings were produced using a 160 A arc on the Sn cathode, with a background O 2 pressure of 0.8 Pa, while B-doped amorphous Si depositions were produced with 20 A arcs on a B-doped Si cathode. The Sn or Si plasma was extracted through a 122 mm inner diameter annular anode and passed through a 160 mm minor diameter, 600 mm major diameter, quarter-torus magnetic filter with a 14 mT magnetic field in order to remove macroparticles. The thin films were deposited on glass microscope slide substrates held at room temperature. Prior to deposition, silver paint electrodes were applied to the substrate in the form of two parallel bands, separated by 20 mm. A potential difference of 0–36 V was applied between the electrodes during the deposition process, and the current flowing along the deposition could be monitored via a shunt resistor. Transparent Sn-O conductivity increased as a function of the applied voltage, reaching an improvement factor of 9 in comparison with films deposited without an imposed transverse current. Scanning electron microscopy examination of the coating surface revealed the presence of numerous round structures. When no current was rejected during film growth, these structures were arranged randomly on the surface, whereas the structures tended to be aligned in long strings parallel to the current field lines when a current was injected during deposition. X-ray diffraction patterns obtained with the sample aligned with the current injection direction parallel and perpedicular to the X-ray beam reveal distinct differences indicating an anisotropy in the microstructure. Preliminary experiments on B-doped Si films similarly showed an improvement by a factor of 2 in the conductivity with the imposition of a transverse potential difference of 36 V.

Study of the thermocontrolled wave division multiuse technique based on a two-mode coupling mechanism

novel tunable wave division multiuse (WDM) device has been formed on a microscope slide substrate. On the surface of the substrate is a K-ion-exchanged directional coupler with zero separation. On the top of the interaction region a Ti-film heater is placed. The operational behavior of the device is controlled by thermo-optical effect, and thus by the current through the Ti-film heater. Operational wavelengths designed for the device are 0.85 and 0.6328 μm. The measured results show that the device has predicted characteristics and thatthe design is reasonable.

Hole Formation in Gold Films

During recent experiments on Au films, a qualitative correlation between hole formation and deposition rate was observed. These early studies were concerned with films 80 to 1000A thick deposited on glass at -185°C and annealed at 170°C. In the present studies this earlier work was made quantitative. Deposition rates varying between 5 and 700 A/min were used. The effects of deposition rate on hole density for two films 300 and 700A thick were investigated.Au was evaporated from an outgassed W filament located 10 cm from a glass microscope slide substrate and a quartz crystal film thickness monitor. A shutter separating the filament from the substrate and monitor made it possible to obtain a constant evaporation rate before initiating deposition. The pressure was reduced to less than 1 x 10-6 torr prior to cooling the substrate with liquid nitrogen. The substrate was cooled in 15 minutes during which the pressure continued to drop to the mid 10-7 torr range, where deposition was begun.

Accurate Determination of Carbon-Foil Surface Densities

We have developed a method of accurate measurement of the surface densities of carbon foils prepared by vacuum evaporation, and have studied some of the properties of such foils in the range 0–70 μg/cm2. The method consists of burning a sample foil in a stream of pure oxygen, trapping the carbon dioxide thus formed, and measuring the pressure of the trapped gas in a known volume. We find that T, the optical transmittance at λ546 nm of a foil on a microscope slide substrate, indicates the foil's carbon content to within about 10% over the range 5–60 μg/cm2 and is given approximately by the relationship T=0.687 [exp(0.0911 σ) + 0.0273 exp(−0.0911 σ) −0.330 cos2π (0.089+0.055 σ)]−1, where σ=relative surface density with 1 μg/cm2 taken as unity. Such foils behave nearly as simple conducting layers having a complex refractive index 2.75+0.720i at λ546 nm. Our unbacked carbon foils have a noncarbon component with a surface density of 1.6±0.5 μg/cm2, approximately independent of foil thickness. This component may cause significant errors in other kinds of measurements of the thicknesses of foils prepared by evaporation.