Quartz Glass Slides Research Articles

Chiral nematic composite coatings as a visual detection platform for formic acid with anti-water interference

Formic acid is an important industrial chemical but is toxic and corrosive. To benefit its qualified use and to avoid corrosion or injury from touching, rapid, portable and sensitive on-site sensing of formic acid is thus of considerable importance. Here, a photonic crystal coating sensor for formic acid visual detection is fabricated through the mild co-assembly of both biomass-based cellulose nanocrystals (CNCs) and hydroxypropyl-β-cyclodextrin (HPCD) on a quartz glass slide. Further surface modification by hexadecyltrimethoxysilane (HTDMS) with low surface energy significantly overcomes the inherent water intolerance of the CNC-HPCD composite while maintaining its chiral nematic structure. The resulting hydrophobic CNC-HPCD (H-CNC) sensing slide shows a distinct and rapid structural color change after formic acid stimulation, realizing the formic acid detection by naked eye. By virtue of its stable and repeatable water resistance, the H-CNC sensing slide enables the specific colorimetric detection of formic acid in water-containing environments for qualitative and even quantitative purposes. This study suggests that H-CNC has the potential to act as a high-performance sensing platform that is useful for the colorimetric detection of formic acid in some industrial products.

An overview on spray pyrolysis deposition of metal oxide thin films

This work provided an overview on the synthesis of metal oxide thin films on different types of substrates (soda lime glass, fluorine-doped tin oxide glass, silica glass, stainless steel, quartz, silicon and microscopic glass slide) using spray pyrolysis method. The fundamentals, advantages and limitations of this method have been described. Experimental results indicated that the properties of films were strongly depending on the specific process parameters (nozzle type, distance between nozzle and substrate, solvent type, solution flow rate, precursor concentration, compressed air pressure, spray time and substrate temperature). It was noted that deposition temperature could control the surface chemical composition based on the experimental results. The presence of amorphous or polycrystalline structure could be observed for the films prepared at different deposition times as indicated in XRD studies. The obtained films indicated excellent absorption coefficient value (104 to 105 cm-1) and high transmittance value (more than 82 %) in the visible and infrared portion.

Syntheses and properties of copper hydroxide nanosheets and controlled deposition

In this study, we synthesized copper hydroxide nanosheet and investigated its electrochemical property and how to deposit it with a uniform amount. The precursor of the nanosheet was a layered copper hydroxide synthesized by the ion exchange of dodecylbenzene sulfonate (DBS) with acetate in Cu2(OH)3(CH3COO)⋅H2O. The nanosheet was prepared by delamination of the layered copper hydroxide by dispersion in 1-butanol. Atomic force microscopy (AFM) images of the nanosheets showed lateral dimensions of ca. 2 [Formula: see text]m with the height of ca. 4.5 nm. Cyclic voltammogram of the nanosheet in basic solution showed two cathodic peaks and two anodic peaks similar to the copper oxide electrode. To deposit the nanosheet, a quartz glass slide was dipped in the dispersion of the nanosheet in 1-butanol and dried after washing. This procedure was repeated and the ultraviolet (UV) and visible (Vis) light absorption spectrum of the slide was measured. The absorbance of the slide increased in direct proportion to the number of times of the dip-and-dry procedure. Thus, we confirmed that a controlled amount of nanosheet was deposited on the quartz glass.

Study on lead ion wastewater treatment of self-assembled film

The cetyl-trimethyl ammonium bromide (CTAB) and glycine betaine self-assembly formed film on the quartz glass and glass slides were prepared, respectively. The microstructure of self-assembled film was observed by the optical microscope and SEM. It was found that the self-assembled film of CTAB on quartz glass slide exhibits good film-forming effect, and the best processes of self-assembled film are that the quartz glass slide immersed in 30 mmol/L CTAB for 180 min at 40°C and pH 8. The adsorption property was evaluated through UV spectrophotometer. The removal ratio of lead ions in wastewater is up to 80%.

Reactive ion etching-assisted surface-enhanced Raman scattering measurements on the single nanoparticle level

Single-nanoparticle surface-enhanced Raman scattering (SERS) measurement is of essential importance for both fundamental research and practical applications. In this work, we develop a class of single-particle SERS approaches, i.e., reactive ion etching (RIE)-assisted SERS measurements correlated with scanning electron microscopy (SEM) strategy (RIE/SERS/SEM), enabling precise and high-resolution identification of single gold nanoparticle (AuNP) in facile and reliable manners. By using AuNP-coated silicon wafer and quartz glass slide as models, we further employ the developed RIE/SERS/SEM method for interrogating the relationship between SERS substrates and enhancement factor (EF) on the single particle level. Together with theoretical calculation using an established finite-difference-time-domain (FDTD) method, we demonstrate silicon wafer as superior SERS substrates, facilitating improvement of EF values.

The effects of post-thermal annealing on the optical parameters of indium-doped ZnO thin films

Indium-doped ZnO thin films are deposited on quartz glass slides by RF magnetron sputtering at ambient temperature. The as-deposited films are annealed at different temperatures from 400 °C to 800 °C in air for 1 h. Transmittance spectra are used to determine the optical parameters and the thicknesses of the films before and after annealing using a nonlinear programming method, and the effects of the annealing temperatures on the optical parameters and the thickness are investigated. The optical band gap is determined from the absorption coefficient. The calculated results show that the film thickness and optical parameters both increase first and then decrease with increasing annealing temperature from 400 °C to 800 °C. The band gap of the as-deposited ZnO:In thin film is 3.28 eV, and it decreases to 3.17 eV after annealing at 400 °C. Then the band gap increases from 3.17 eV to 3.23 eV with increasing annealing temperature from 400 °C to 800 °C.

Effect of In-doping on the Optical Constants of ZnO Thin Films

Abstract Highly transparent and conductive Indium-doped ZnO (ZnO:In) thin films with different In content were deposited on quartz glass slides by RF magnetron sputtering at room temperature. The thickness and the optical constants of the films were obtained by the Swanepoel method, and the effects of In concentration on the optical constants were investigated. Calculated results show that both the refractive index and optical band gap first increase then decreases with In concentration increasing in the visible region, and the variation of both ɛr and ɛi with wavelength follows the same trend as that of refractive index and extinction coefficient, respectively.

A Novel Technique for Preparation of the Fluorescence Sensor Based on Covalent Immobilization of 1-Aminopyrene

A novel technique to covalently immobilize indicator dyes with terminal amino groups for preparing optical sensors is investigated. Au nanoparticles are used as bridges and carriers for anchoring indicator dyes on the surface of a quartz glass slide. 1-Aminopyrene (AP) was employed as an example of indicator dyes and covalently immobilized onto the outmost surface of the glass slide. First, the glass slide was functionalized by (3-mercaptopropyl) trimethoxysilane (MPS) to form a thiol-terminated self-assembled monolayer, where Au nanoparticles were strongly anchored via covalent link. Then, 16-mercaptohexadecanoic acid (MHDA) was self-assembled to bring carboxylic groups onto the surfaces of Au nanoparticles. A further activation by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) converted the carboxylic group into succinimide ester. Finally, the active succinimide ester was reacted with 1-aminopyrene (AP). Thus, AP was covalently immobilized to the glass slide and an AP-immobilized sensor was obtained. The resulting sensor was used to determine rutin based on fluorescence quenching. It showed a linear response toward rutin (R) from 5.0 × 10-7 to 6.0 × 10-4 mol L-1 with a detection limit of 2.0× 10-7 mol L-1. This AP-immobilized sensor has very satisfactory reproducibility, reversibility, rapid response and no dye-leaching.

Protein photoimmobilizations on the surface of quartz glass simply mediated by benzophenone

In this paper, photoinduced protein immobilizations on quartz glass slides utilizing benzophenone as photoinitiator without any photoactive group derivatizations involved were developed. Three different methods mediated by benzophenone were investigated, including protein photo-attachment onto untreated glass surface, protein attachment onto glass surface by reacting with pre-photografted maleic anhydride, and protein photo-attachment onto alkylamino silane functionalized glass surface, respectively. Protein immobilizations were characterized by fluorescence microscopy and atomic force microscopy. The preservation of biological activity after protein photo-attachments was confirmed by immunoassays. Area-defined protein immobilization was also primarily investigated. Comparative studies demonstrated that in respect of immobilization density, coverage homogeneities and photo-localization, protein photocoupling to amino-terminated quartz glass surfaces remarkably outperformed other photoinduced methods, as well as one kind of 3-(triethoxysilyl) propyl isocyanate chemical protein immobilization. The feasibility of this protein photo-immobilization on silicon-based materials is promising for widespread application because of its simplicity and effectiveness.

Modeling, simulation and fabrication of coated structures using the dip coating technique

Using the dip coating technique, we fabricate erbia-coated quartz fibers and glass slides. Further we present a thin film model of the dip coating technique applied to the glass slides. The model includes evaporation of the solvent and a bulk reaction term to simulate the creation of the erbium oxide that forms the coating. Evolution equations for the solvent and coating thicknesses are developed and solved numerically. We study how the solvent evaporation rate, the bulk reaction rate, the dynamic viscosity, the angle of the inclined substrate, the characteristic depth of the solution thickness, the initial profile of the solution thickness, and the length of substrate affect the coating thickness. The model is calibrated using the experimental results to provide a tool for predicting the coating thickness.

Photocatalytic initiation of electroless deposition

We report a one-step photocatalytically initiated electroless deposition (PIED) process that allows for the photogeneration of robust, coherent, conducting metal layers on semiconductor-sensitised insulator surfaces. The PIED process involves two steps, performed simultaneously in the same metal precursor solution: (i) Metal nanoparticles are formed at the surface of the semiconductor by photocatalytic reduction of an appropriate metal precursor. (ii) The nanoparticles then serve as nucleation centres for an autocatalytic electroless deposition process, growing and coalescing to form a continuous metal layer. Layers of various metals including Ag and Pd have been generated by PIED on mesoporous TiO 2 (m-TiO 2) coated quartz glass slides and PVDF membranes. Deposition occurs only onto areas of the substrate both sensitised with TiO 2 and irradiated with ultra-band gap energy light. The morphology of the resultant layer is dependent upon the nucleation density occurring during the primary photocatalytic stage of PIED. PIED provides a cheaper, environmentally cleaner and more controllable option than traditional techniques of plating onto dielectric surfaces.

Novel fluorescence sensor based on covalent immobilization of 3-amino-9-ethylcarbazole via electrostatically assembled gold nanoparticle layer

A novel technique of immobilizing indicator dyes by electrostatic adsorption and covalent bonding to fabricate optical sensors was developed. 3-Amino-9-ethylcarbazole (AEC) was attached to the outmost surface of quartz glass slide via aminosilanizing the slide, crosslinking chitosan, adsorbing Au nanoparticle, self-assembling HS(CH2)11OH, and coupling AEC. Thus, an AEC-immobilized optical sensor was obtained. The sensor exhibits a wide linear response range from 7.0×10−7 to 1.0×10−4 mol/L and a correlation coefficient of 0.995 9 for the detection of 2-nitrophenol. The detection limit and response time of the sensor are 1.0×10−7 mol/L and less than 10 s, respectively. The fluorescence intensity of the used sensor can be restored to the blank value by simply rinsing with blank buffer. A very effective matrix for immobilizing indicator dye is provided by the proposed technique, which is adaptable to other indicator dyes with amino groups besides AEC.

A novel fluorescence sensor based on covalent immobilization of 3-amino-9-ethylcarbazole by using silver nanoparticles as bridges and carriers

A novel technique of covalent immobilization of indicator dyes in the preparation of fluorescence sensors is developed. Silver nanoparticles are used as bridges and carriers for anchoring indicator dyes. 3-amino-9-ethylcarbazole (AEC) was employed as an example of indicator dyes with terminal amino groups and covalently immobilized onto the outmost surface of a quartz glass slide. First, the glass slide was functionalized by (3-mercaptopropyl) trimethoxysilane (MPS) to form a thiol-terminated self-assembled monolayer, where silver nanoparticles were strongly bound to the surface through covalent bonding. Then, 16-mercaptohexadecanoic acid (MHDA) was self-assembled to bring carboxylic groups onto the surface of silver nanoparticles. A further activation by using 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) converted the carboxylic groups into succinimide esters. Finally, the active succinimide esters on the surface of silver nanoparticles were reacted with AEC. Thus, AEC was covalently bound to the glass slide and an AEC-immobilized sensor was obtained. The sensor exhibited very satisfactory reproducibility and reversibility, rapid response and no dye-leaching. Rutin can quench the fluorescence intensity of the sensor and be measured by using the sensor. The linear response of the sensor to rutin covers the range from 2.0 × 10 −6 to 1.5 × 10 −4 mol L −1 with a detection limit of 8.0 × 10 −7 mol L −1. The proposed technique may be feasible to the covalent immobilization of other dyes with primary amino groups.

Optical constants of transparent ZnO films by RF magnetron sputtering

The transparent ZnO films were deposited on quartz glass slides by RF magnetron sputtering and then the films are annealed at 500, 700, 900 °C for 60 min in pure O2. The optical transmission spectra for the as-grown and annealed ZnO films have been measured over the 300 nm to 700 nm spectral region. The optical constants and thickness of the films have been determined using a nonlinear programming method suggested by Birgin et al. The optical band gap has been determined from the absorption coefficient. The optical quality of ZnO films is improved by annealing.

An optical sensor based on covalent immobilization of 1-aminopyrene using Au nanoparticles as bridges and carriers

A novel technique of covalent immobilization of indicator dyes for the preparation of optical sensors is investigated. Au nanoparticles are used as bridges and carriers for anchoring indicator dyes on the surfaces of quartz glass slides (the substrates). 1-Aminopyrene was covalently attached to the outmost surface of the substrates via silanization, attachment of Au particles, self-assembly of HS-(CH 2) 11-OH, and coupling of 1-aminopyrene using cyanuric chloride. Thus, an aminopyrene-immobilized optical sensor was prepared and employed for determining picric acid. This sensor shows practically no dye-leaching, rapid response, high selectivity, good reproducibility and reversibility. The linear response to picric acid covers the range of 9.55 × 10 −7 to 1.91 × 10 −4 mol l −1 with a detection limit of 7.8 × 10 −7 mol l −1. The covalent immobilization of 1-aminopyrene is an example of the proposed methodology which could be readily adaptable to other indicator dyes with primary amino groups.

Layer-by-layer self-assembled multilayer films of carbon nanotubes and platinum nanoparticles with polyelectrolyte for the fabrication of biosensors

Platinum nanoparticle-doped chitosan (CHIT) solution can be easily prepared by treating the CHIT solution with aqueous H 2PtCl 6 solution followed by chemical reduction of Pt(IV) with NaBH 4. Multiwalled carbon nanotubes (MWCNT) are then dispersed in the nanoparticle-doped solution. The resulting Pt-CNT-CHIT material brings new capabilities for electrochemical devices by using the synergistic action of Pt nanaoparticles and CNT. Positively charged Pt-CNT-CHIT solution and negatively charged poly(sodium- p-styrenesulfonate) salt (PSS) have been employed to fabricate stable ultrathin multilayer films on gold electrode and quartz glass slides in a layer-by-layer fashion. Cyclic voltammetric and UV–vis adsorption spectroscopy confirms the consecutive growth of the multilayer films. The modified gold electrode allows low-potential detection of hydrogen peroxide with high sensitivity and fast response time. With the immobilization of cholesterol oxidase onto the electrode surface using glutaric dialdehyde, a biosensor that responds sensitively to cholesterol has been constructed. In pH 6.98 phosphate buffer, almost interference free determination of cholesterol has been realized at 0.1 V vs. SCE with a linear range from 0.01 to 3 mM and response time<30 s. With the immobilization of another cholesterol esterase enzyme layer, the biosensor was used to determine total cholesterol in serum samples with satisfactory results.

Low-temperature preparation of photocatalytic [formula omitted] thin films from anatase sols

Anatase TiO2 sols were synthesized under mild conditions (i.e. 75°C and ambient pressure) by hydrolysis of titanium- n-butoxide in abundant acidic aqueous solution and subsequent reflux to enhance crystallization. The influences of various acidities on crystallinity, morphology, and size of the obtained TiO2 sol particles were investigated. At room temperature and in ambient atmosphere, crystalline TiO2 thin films were deposited on quartz glass slides from the as-prepared TiO2 sol by a dip-coating method. TiO2 films on substrates could be thickened by means of consecutive dip-coating processes. The photocatalytic activities of the TiO2 thin films were assessed by the degradation of X-3B in aqueous solution under aerated conditions. The preparation process of photocatalytic TiO2 thin films was quite simple and a low-temperature route.

Growth and anisotropic properties of highly oriented films of quasi-one-dimensional platinum compounds

The semiconductors [Pt(NH 2dmoc) 4][PtCl 4], where dmoc denotes ( S)-3,7-dimethyloctyl, and [Pt(NH 2eh) 4][PtCl 4], where eh is ( R)-2-ethylhexyl, are soluble quasi-one-dimensional compounds with a backbone of linearly arranged platinum atoms. Uniaxially oriented films of those metal complexes of approximately 0.1 μm thickness were deposited from solution on quartz glass slides covered with a friction-deposited orientation layer of approximately 40 nm poly(tetrafluoroethylene) (PTFE). UV/vis spectra recorded with polarized light as well as electron diffraction patterns of [Pt(NH 2dmoc) 4][PtCl 4] indicated that the films were highly ordered, the platinum arrays oriented parallel to the orientation direction of the PTFE molecules. As a consequence, the films exhibited a pronounced anisotropy, among other characteristics, in the electric conductivity, which is of potential use in electronic devices.

A "Smart" Ultrathin Photochromic Layer

We present evidence of persistent dichroism in a monolayer which consists of azosilane molecules self-assembled on a quartz glass slide. This dichroism is shown to depend on the irradiation time. Furthermore, it could be both written and erased by irradiation with light of an appropriate wavelength. In addition, the sign of this dichroism can be inverted by choosing the appropriate polarization of the irradiating light, thus exhibiting a smart communication between the photochromic layer and the light polarization.

Spatially resolved UV-VIS characterization of radiation-induced color centers in poly(styrene) and poly(vinyltoluene)

Polystyrene (PS) and polyvinyltoluene (PVT) are in common use as base materials for plastic scintillators. Uv-vis spectroscopy was performed on irradiated disks of PS and PVT and the damage and recovery of these disks were monitored over time. By mounting the disks between quartz glass slides air diffusion was limited to two dimensions, and when the slides were mounted on a micrometer stage assembly, a one dimensional diffusion profile was measured. It was discovered that the absorbances of PS and PVT at certain wavelengths increases for several hours after the irradiation has ended when high dose rates of 6 Mrad/hour are used. It was also found that the visibly sharp annealing boundary that penetrates into the irradiated polymers consistently measured 0.03 inches wide for PS for all wavelengths between 375 and 470 nm and that therefore the oxygen induced bleaching of color centers proceeds at the same rate for all color centers in this wavelength range. A simple self-diffusion model was fit to the boundary velocity data. The self-diffusion coefficients (D 0) were calculated for PS and PVT: D 0( PS) = 1.3 × 10 −8 cm 2/ sec and D 0( PVT) = 1.7 × 10 −7 cm 2/ sec.