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Electropolymerization of carboxylated conducting polymer/carbon nanotubes (CNTs) composites thin films has been studied by in situ electrochemical-surface plasmon resonance (EC-SPR) spectroscopy. Two derivatives of benzothiophene, thianaphthene-2-carboxylic acid and benzothiophene-2-propionic acid, composited with CNTs were electropolymerized in an acetonitrile with the potential range between 0 and 1.2 V at scan rate of 20 mV/s. The obtained films were characterized by in situ EC-SPR spectroscopy, UV-vis absorption spectroscopy, and atomic force microscopy. It was found that CNTs can improve properties of polymer/CNT composites films. Moreover, the obtained thianaphthene-2-carboxylic acid film can be further used for construction of immunosensor for detection of human IgG.

Poly(2–aminobenzylamine)/single wall carbon nanotube (P2ABA/SWNTS) thin films were fabricated for the detection of UA by using electrochemical surface plasmon resonance spectroscopy (EC–SPR) technique. The suspension of 0.01% wt of carboxylated SWNTSs was assembled on the polymer film because of the electrostatic and van der Waals interactions between the ‒COOH and ‒NH2. The P2ABA/SWNTS thin film formation on gold electrode was studied by EC–SPR technique. In this work, uric acid was detected by EC–SPR in PBS buffer comparing with the interference response with ascorbic acid. EC–SPR uric acid sensor using P2ABA/SWNTS thin film can be applied for the detection of uric acid in urine.

The functionalized pyrrole copolymers were fabricated by electropolymerization of pyrrole (Py) and functionalized pyrrole monomers, pyrrole-3-carboxylic acid (P3C) and 4-(3-pyrrole) butyric acid (PBA). The electrochemical behavior and doping/dedoping properties of the obtained copolymer thin films were investigated by cyclic voltammetry (CV) in neutral phosphate-buffered saline (PBS) solution. Moreover, the functionalized pyrrole copolymer films were characterized by UV-vis absorption spectroscopy and atomic force microscopy (AFM). The obtained copolymer thin films showed good stability and electroactivity in neutral PBS solution. The presented functionalized pyrrole copolymer thin films may possess potential applications to study in various systems of the biosensors.

Key Clinical Message Exostosis in external auditory canal is common among surfers. Common symptoms are decreased hearing or loss of hearing, ear infection, and/or plugging sensation. Repeated exposure to cold water is a key clinical history to suspect this condition. Based on symptoms and existence of infection, surgical removal of the exostosis is recommended.

Key Clinical Message Catheter‐related bloodstream infection can be detected with CT. Although it is not mandatory for its diagnosis, it is strong evidence as a cause of fever if detected incidentally.

In this study, we demonstrate a long-range surface plasmon resonance (LR-SPR) biosensor for the detection of whole cell by captured antigens A and B on the surface of red blood cells (RBCs) as a model. The LR-SPR sensor chip consists of high-refractive index glass, a Cytop film layer, and a thin gold (Au) film, which makes the evanescent field intensity and the penetration depth longer than conventional SPR. Therefore, the LR-SPR biosensor has improved capability for detecting large analytes, such as RBCs. The antibodies specific to blood group A and group B (Anti-A and Anti-B) are covalently immobilized on a grafting self-assembled monolayer (SAM)/Au surface on the biosensor. For blood typing, RBC samples can be detected by the LR-SPR biosensor through a change in the refractive index. We determined that the results of blood typing using the LR-SPR biosensor are consistent with the results obtained from the agglutination test. We obtained the lowest detection limits of 1.58 × 105 cells/ml for RBC-A and 3.83 × 105 cells/ml for RBC-B, indicating that the LR-SPR chip has a higher sensitivity than conventional SPR biosensors (3.3 × 108 cells/ml). The surface of the biosensor can be efficiently regenerated using 20 mM NaOH. In summary, as the LR-SPR technique is sensitive and has a simple experimental setup, it can easily be applied for ABO blood group typing.

Normal.dotm 0 0 1 234 1268 HIIT 23 5 1643 12.1 0 false 18 pt 18 pt 0 0 false false false Transcripts of conversations are a valuable research resource in social sciences and can be used to make inferences about subjects’ behaviour and intentions. Large-scale communications records can be coded and analysed statistically for generalisable results. Virtual environments are a good place to gather communications records, because they exhibit a wide variety of subject behaviours. However, compared to traditional channels such as forums and chat rooms, virtual environments can be more challenging to obtain data from. In this article, we describe three approaches to collecting user-to-user communications data from virtual environments: requesting back-end records from the operator of the environment, recruiting “data donors” among the users, and setting up researchers’ own “listening posts”. The data collection approaches are evaluated empirically in Uncharted Waters Online , a Japanese massively-multiplayer game. Avatar gender ratio is used as a diagnostic variable to compare the representativeness of the resulting data sets. Both data donors and listening posts yielded data with a gender ratio that corresponds to the back-end records, but the back-end gender ratios differed significantly between two different servers. We conclude that all three approaches can be statistically viable: the choice of method depends more on desired sampling scope and on practical factors such as resources and timetable; but when defining a sampling frame, it cannot be assumed that one server is necessarily representative of the whole platform.

In this study, urchin-like gold nanoparticles (UL-AuNPs) are used in the fabrication of organic thin-film solar cells (OSCs). UL-AuNPs, which have gold nanothorns on their surface, enhance light accumulation by acting as light-trapping materials. This is due to the enhanced electric field and light scattering attributed to the nanothorns on the surface of the nanoparticles. UL-AuNPs were incorporated into a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) thin-film layer of organic thin-film solar cells (OSCs). UV-vis spectra, atomic force microscopy (AFM) images, current density versus voltage properties, and the impedance spectra of the fabricated devices were recorded at various concentrations of UL-AuNPs. We found that the efficiency of the OSCs with UL-AuNPs was not only higher than that of a reference cell without nanoparticles but also higher than that of OSCs with spherical AuNPs. Finite-difference time-domain (FDTD) simulation indicated that the electric field around the UL-AuNPs increased due to the presence of nanothorns.

Kimura's disease (KD) is a rare lymphoproliferative inflammatory disorder, typically presenting as firm, painless or pruritic single or multiple subcutaneous lesions in the head and neck, especially in the parotid and submandibular regions. We herein report a case of a 39-year-old Japanese man presenting with a typical cephalocervical KD lesion around the salivary glands with a rare association with a distant subcutaneous mass at the hip. We also emphasize the radiologically and clinically important features in the differential diagnosis and management. To the best of our knowledge, this case is the first report of KD manifesting with a typical cephalocervical lesion and an atypical subcutaneous hip mass lesion.

Because digital games are interactive media, it is expected that digital games have various effects on players. In this paper, the previous studies on digital game effects are reviewed based on Cultivation Theory. Cultivation Theory is often used in television studies and to use it in digital game studies, the need for content analysis and improvement of measurement is addressed as problems. Content analyses of digital games are discussed concerning the problems addressed. Finally, the study conducts a content analysis to look at the positive contents that are often overlooked in previous studies. Cultivation Theory in digital game studies in comparison with television studies is discussed. This study suggests that more content analyses are needed to have an in-depth discussion on associating Cultivation Theory to digital game effects.

A 47-year-old man was referred to our hospital due to symptoms of trismus and exacerbation of palmoplantar pustulosis. He had been presenting, for 20 years, with refractory and recurrent mandibular osteomyelitis accompanied by palmoplantar pustulosis and anterior chest pain—symptomatic treatment and surgery had been given at each presentation. When the mandibular lesion got worse this time, he also had anterior chest pain. He had experienced similar episodes before this event. MRI (STIR: short tau inversion recovery) showed high signal intensity in the right ramus of the mandible, with perilesional soft tissue swelling …

An otherwise-healthy 82-year-old woman presented to the emergency department with abdominal pain gradually migrating to the right and vomiting. Her body temperature was 37.2°C, abdominal examination showed tenderness in the right lower abdomen, and her WBC was 8,400/μL no plasma levels of enzymes were elevated. She was thin (body mass index 20.4 kg/m2 ) with scoliosis. Non-enhanced Computed Tomography (CT) revealed a massively swollen gallbladder with high dense (Figure 1) and contrast enhanced CT demonstrated poorly-enhanced edematous wall thickening (Figure 2), with twisted pedicle detached from the liver, suggesting gallbladder torsion. Emergent cholecystectomy was performed, revealing a 270° counterclockwise torsion of the gallbladder. Gallbladder torsion is more prevalent in thin elderly females with spinal deformation [1]. Characteristic contrast enhanced CT findings are poorly-enhanced and thickened gallbladder wall, pericholecystic fluid, and twisted pedicle (whirl sign) [2]. Contrast enhanced CT can help establish the preoperative diagnosis of gallbladder torsion in cases involving elderly females complaining abdominal pain.

Imprinted solution-processible gold nanoparticle (AuNP) grating films were fabricated for use as a grating-coupled surface plasmon resonance (SPR) excitation substrate. The imprinted AuNP grating pattern, which consists of a 1.72 μm grating pitch, was fabricated on flat glass substrates by imprinting AuNP on silicon grating templates. In this study, the SPR measurements were carried out on an SPR device in the grating-coupling configuration with a He–Ne laser ( λ = 632.8 nm) as the excitation source, and multimode surface plasmon excitations were observed upon irradiation with white light. SPR excitation of our substrate was observed at the incident angle of 47.1°. For SPR measurements using white light irradiation, multimode surface plasmon excitation resulting from several diffraction orders was observed in the wavelength region of 500–850 nm. The surface plasmon dispersion branches were calculated to obtain the diffraction order in this region. SPR excitation of the imprinted AuNP grating substrate was further studied by fabrication of a layer-by-layer ultrathin film of iron containing bis(terpyridine) polymer (Fe(II)-BTP) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). A shift of the SPR excitation spectrum was observed when the ultrathin film was deposited on the imprinted AuNP grating surface. Thus, this substrate should be a useful SPR substrate in a variety of applications such as photoelectric conversions and sensors.

A non-contact gear mechanism is important for the non-contact transmission of a torque and a motion. In this paper, a magnetic gear system without contact which requires no lubricant oil is proposed. The driving gear consists of some iron discs with gear teeth whose shape is an involute curve. The discs of the follower gear are inserted in the gaps between the discs of the driving gear, and the attractive forces between the discs generate the torque transmission. Using the magnetic gear system, a magnetically connected planetary gear device is developed. Moreover we measure and study the slip torque as static property, and the step-out torque as dynamic property due to implication of rotational speed.

Surface plasmon resonance (SPR)-enhanced optical transmission is actively controlled by an electrochromism of conducting polymer thin fi lms. Polyaniline and poly(3,4-ethylenedioxythiophene) thin fi lms are deposited on a thin gold grating surface. SPR-enhanced optical transmission is demonstrated by irradiating white light on the conducting polymer thin fi lm‐gold grating surface and detecting the transmitted light from the back side. The transmission SPR system is combined with an electrochemical setup to manipulate the resonance. The wavelength of the sharp peak in the transmission light spectra is tuned by electrochemical doping/dedoping of the conducting polymer thin fi lms. The present study of controllable SPR-enhanced optical transmission should provide novel active plasmonic devices such as active bandpass fi lters or biosensors.

We developed a novel technique for increasing the sensitivity of transmission surface plasmon resonance (T-SPR) signals. T-SPR spectroscopy was performed by irradiating, with white light, a gold grating substrate whose surface was nanostructured by growing gold nanoparticles (AuNPs). AuNPs were grown directly on the substrate surface by alcohol reduction and their growth was observed at various stages by UV–visible spectroscopy and standard Kretschmann-type SPR spectroscopy. For comparison, normal gold film with smooth surface was examined under similar condition. The T-SPR results show a possibility of hybrid excitation of both localized and propagating surface plasmon. Significantly, T-SPR spectra of the gold grating substrate obtained during AuNP growth show stronger and narrower peaks in the range 650–800 nm. The maximum T-SPR excitation was at an incident angle of 35°. A layer-by-layer system of 5,10,15,20-tetrakis (1-methyl-4-pyridinio)porphyrin tetra(p-toluenesulfonate) molecules and sodium copper chlorophyllin molecules was used to verify the enhancement of the developed system. We believe that the AuNPs/Au grating for T-SPR devices will provide enhanced signals for detecting nanometer order materials and for high-sensitive sensor applications.

Optical near-field excitations were investigated on the basis of molecular alignment control of liquid crystals (LCs) on an optically rewritable nanostructure of photoreactive molecular thin films. Twisted nematic (TN) cells of LC molecules were constructed utilizing ITO substrates with 260 nm gratings of an azobenzene molecular thin film, fabricated using standing evanescent waves. The polarization changes of light transmitted through the TN cells, which were due to the alignment changes of LC molecules locally rubbed by the azobenzene nanogratings, were observed. Furthermore, we demonstrated local plasmon excitation of Au nanowires deposited on the azobenzene nanogratings using oblique vacuum evaporation, a phenomenon that produced strong anti-optical absorption spectra. The modulation of the local plasmon resonance in metallic nanowires decorated with LC molecules was confirmed.

Key Clinical Message If there is no pain in the temporal artery, the diagnosis of giant cell arteritis (GCA) may be delayed and blindness may occur. Therefore, FDG‐PET/CT is important as a modality for diagnosis of GCA. When GCA is suspected and F‐18 FDG‐PET/CT is performed, it is worthwhile to pay attention to shoulder and hip joints as polymyalgia rheumatica commonly presents with GCA.

Key Clinical Message It is important for the dentists to make accurate diagnosis and appropriate treatment of odontogenic cutaneous fistula. Although large facial skin lesions may bring up malignancy on top of the differential list, careful evaluation including physical observation, imaging, and pathology can rule out malignancies.

Key Clinical Message Although rare, Eagle syndrome should be always considered in the differential diagnosis in patients with chronic orofacial pain refractory to conventional treatments. Treatment is surgery and exeresis of the styloid process via a transoral or cervical approach depending on clinical and radiological features.

PurposeResearch on prosocial behaviour shows that help‐giving differs between the sexes. Gender role theory posits that males specialise in material aid, while females specialize in emotional support. Today, people increasingly help and support each other via online environments. The purpose of this study is to examine whether the genders of avatars used in online interactions influence help‐giving behaviour in similar ways as physical sex does in face‐to‐face situations.Design/methodology/approachAn empirical study was conducted using a unique observational data set from a Japanese massively‐multiplayer online game. Instances of help‐giving were identified from conversation logs, coded, and analysed statistically to discover differences between male and female avatars and different help types.FindingsAvatar gender is found to influence help‐giving in ways that deviate from expected gender roles: female avatars are more likely than males to provide assistance in the form of material support and labour, and no more likely than males to provide emotional support. Female avatars are more likely to give help to male avatars than other females. The results are explained using behavioural confirmation and self‐perception theory.Research limitations/implicationsPhysical sex was not controlled for, but most players were male. The study should be repeated in other environments.Practical implicationsThe results suggest that designers can prime users towards prosocial behaviours by tuning the available line‐up of avatars.Originality/valueThe research question and use of observational data are novel. The study is valuable to online educators, companies seeking to reduce customer support costs through peer help, and policymakers dealing with ICTs and societal change.

In this study, we demonstrate the fabrication of grating-coupled surface plasmon resonance (SPR) enhanced organic thin-film photovoltaic cells and their improved photocurrent properties. The cell consists of a grating substrate/silver/P3HT:PCBM/PEDOT:PSS structure. Blu-ray disk recordable substrates are used as the diffraction grating substrates on which silver films are deposited by vacuum evaporation. P3HT:PCBM films are spin-coated on silver/grating substrates. Low conductivity PEDOT:PSS/PDADMAC layer-by-layer ultrathin films deposited on P3HT:PCBM films act as the hole transport layer, whereas high conductivity PEDOT:PSS films deposited by spin-coating act as the anode. SPR excitations are observed in the fabricated cells upon irradiation with white light. Up to a 2-fold increase in the short-circuit photocurrent is observed when the surface plasmon (SP) is excited on the silver gratings as compared to that without SP excitation. The finite-difference time-domain simulation indicates that the electric field in the P3HT:PCBM layer can be increased using the grating-coupled SP technique.

In this review, we introduce a variety of surface sensitive techniques for the study of organic thin films, and applications to organic devices. These studies include surface plasmon emission light, organic thin film transistors, combination of quartz crystal microbalance and optical waveguide spectroscopy, evaluation of alignment of liquid crystal molecules at surfaces, and biosensor applications.

In this Article, we present a novel method to detect adrenaline on poly(3-aminobenzylamine) (PABA) ultrathin films by electrochemical-surface plasmon resonance (EC-SPR) spectroscopy. We prepared a PABA film, which specifically reacts with adrenaline, on a gold electrode by electropolymerization of 3-aminobenzylamine. The specific reaction of benzylamine within the PABA structure with adrenaline was studied by XPS, UV-vis spectroscopy, and EC-SPR techniques. Adrenaline was detected in real time by EC-SPR spectroscopy, which provides simultaneous monitoring of both optical SPR reflectivity and electrochemical current responses upon injecting adrenaline into the PABA thin film. The number of changes in both current and SPR reflectivity on the injection of adrenaline exhibited the linear relation to the concentration, and the detection limit was 100 pM. The responses were distinctive to those for uric acid and ascorbic acid, which are major interferences of adrenaline.

The in situ electrochemical and dielectric film properties of monomer co-electropolymerization with a CPN precursor was investigated. A polysiloxane/polythiophene precursor was electropolymerized with thiophene monomer at different composition ratios using cyclic voltammetry. This was investigated in situ by EC-SPR spectroscopy and EC-SPFELS. The characteristic oscillations corresponded to distinct transitions in film deposition. The resonance coupling of the SPR decreased with higher thiophene monomer content. Increasing the amount of thiophene monomer increased the RMS roughness of the film as observed by AFM, which corresponded to an increase in scattered light intensity with EC-SPFELS.

The self-assembled monolayer formation of a series of thiophene dendron thiols with different generations and alkyl chain lengths onto gold surfaces is studied. Average film thicknesses and dielectric constants were calculated from SPR using a two-subphase differential method. The in situ adsorption of the thiophene dendron thiols was monitored by SPR kinetics measurements and fitted using an empirical three-step model. Electrochemical redox molecular probing experiments provided additional insight into surface coverage, which showed different abilities to block electron transfer at the monolayer/electrode interfaces. The surface coverage of the films was also estimated by QCM measurements and supported by static WCA measurements.

In this paper, we demonstrate photocurrent generation from nanostructured layer-by-layer (LbL) ultrathin films consisting of chromophores and single-walled carbon nanotubes (SWNT). We fabricated 5,10,15,20-tetrakis(1-methyl-4-pyridinio)porphyrin tetr (p-toluenesulfonate) (TMPyP)-SWNT/sodium copper chlorophyllin (SCC)-SWNT LbL film from noncovalently adsorbed composites. SWNT were dissolved in water-soluble cationic TMPyP and anionic SCC, and the resulting solutions were used for electrostatic LbL multilayer fabrication. The solubility of SWNT in water was studied by UV−vis absorption spectroscopy. The composites were highly dispersed owing to the π−π interactions. The fluorescence spectroscopy measurements showed efficient quenching of TMPyP and SCC fluorescence, which was due to the interaction with SWNT. In situ surface plasmon resonance spectroscopy during the LbL multilayer fabrication indicated a stepwise increase in reflectivity, implying the successive formation of nanostructured hybrid ultrathin f...

In this work, we report an electrochemical surface plasmon resonance/waveguide (EC-SPR/waveguide) glucose biosensor that could detect enzymatic reactions in a conducting polymer/glucose oxidase (GO(x)) multilayer thin film. In order to achieve a controlled enzyme electrode and waveguide mode, GO(x) (negatively charged) was immobilized with a water-soluble, conducting N-alkylaminated polypyrrole (positively charged) using the layer-by-layer (LbL) electrostatic self-assembly technique. The electrochemical and optical signals were simultaneously obtained from the composite LbL enzyme electrode upon the addition of glucose as mediated by the electroactivity and electrochromic property of the polypyrrole layers. Signal enhancement in EC-SPR detection is obtained by monitoring the doping-dedoping events on the polypyrrole. The real-time optical signal could be distinguished between the change in the dielectric constant of the enzyme layer and other nonenzymatic reaction events such as adsorption of glucose and the change of the refractive index of the solution. This was possible by correlation of both the SPR mode and the m = 0 and 1 modes of the waveguide in an SPR/waveguide spectroscopy experiment.

An electrochemically controlled surface plasmon resonance (SPR) immunosensor based on carboxylated polyaniline was constructed for detecting human immunoglobulin G (IgG) without using further labeled molecules. The carboxylated polyaniline, poly(3-aminobenzoic acid) (PABA), was prepared by electropolymerization of its monomer, 3-aminobenzoic acid (ABA), on a gold-coated high-refractive-index glass slide that was also used as a working electrode for the electrochemical system. The kinetic properties during electropolymerization were monitored in situ with electrochemical-surface plasmon resonance (EC-SPR) spectroscopy. The obtained PABA film, which was used to construct the immunosensor, showed electroactivity in neutral phosphate-buffered saline solution. The carboxylic acid surface of the PABA film was then activated to immobilize anti-human IgG. Finally, the immunosensor electrode was used to probe the binding reaction of anti-human/human IgG with various concentrations of human IgG at different constant applied potentials. The immobilization and binding reaction processes were controlled and also studied in situ by EC-SPR spectroscopy. The binding process at different applied potentials was studied and fitted using the Freundlich model. The surface morphology of the films after the immobilization of anti-human IgG was studied by atomic force microscopy.

In this study, we report on evaluation of liquid crystal (LC) cells using simultaneous surface plasmon resonance (SPR) and optical waveguide spectroscopy (OWS) technique in attenuated total reflection configuration. This technique allows for in-situ monitoring of alignment property of LC molecules adjacent to the surface and the bulk in the LC cell simultaneously. An increase of the hysteresis both for near the surface and whole cell was observed in SPR/OWS kinetic properties as the number of voltage cycling increased. The LC alignment properties after applying a DC voltage were also measured to study the effect of impurity residual ions in LC cells.

Organic field-effect transistors (OFETs) were fabricated using poly(3-hexyl thiophene) (P3HT), and the effects of inserted Lewis-acid thin layers on electrical properties were investigated. The OFETs have active layers of P3HT and vanadium pentoxide (V2O5) as a Lewis-acid layer. Larger drain currents were observed for the OFET with the V2O5 layer than that without the layer. The calculated field-effect mobility of the fabricated OFET was 1.4 × 10−2 cm2/(Vs), where as that of the OFET without the V2O5 layer was 6.2 × 10−3 cm2/(Vs). It was thought that charge transfer (CT) complex which was formed at the interface between P3HT and V2O5 layer was dissociated by gate voltage, and the generated holes seem to contribute to drain current and the apparent high mobility.

In this report, we demonstrate a convenient method of fabricating single-walled carbon nanotubes/organic semiconductor hybrid ultrathin multilayers using a layer-by-layer self-assembly approach. Single-walled carbon nanotubes were solubilized by water-soluble cationic alcian blue pyridine variant and anionic copper phthalocyanine-3,4′,4″,4′″-tetrasulfonic acid tetrasodium salt, which were then utilized for electrostatic layer-by-layer multilayer fabrication. The solubilization ability of single-walled carbon nanotubes was studied in water by UV–vis absorption spectroscopy. The composites were highly dispersed owing to the π–π interactions. In situ surface plasmon resonance spectroscopy during the layer-by-layer multilayer fabrication indicated a stepwise increase in reflectivity, indicating the successive formation of nanostructured hybrid ultrathin films. Cyclic voltammetry revealed that the electroactivity of the hybrid film was enhanced by the incorporation of single-walled nanotubes.

An electrochemically synthesized graphene oxide (GO)/poly(3,4-ethylenedioxythiophene) (PEDOT)/poly(styrene sulfonate) (PSS) thin film-based electrochemical surface plasmon resonance (EC-SPR) sensor chip was developed and employed for the detection of human immunoglobulin G (IgG). GO introduced the carboxylic group on the film surface, which also allowed electrochemical control, for the immobilization of the anti-IgG antibody via covalent bonding through amide coupling reaction. The SPR sensitivity of the detection was improved under the control by applying an electrochemical potential, by which the sensitivity was increased by the increment in applied potential. Among the open-circuit and different applied potentials in the range of −1.0 to 0.50 V, the EC-SPR immunosensor at an applied potential of 0.50 V exhibited the highest sensitivity of 6.08 × 10−3 mL µg−1 cm−2 and linearity in the human IgG concentration range of 1.0 to 10 µg mL−1 with a relatively low detection limit of 0.35 µg mL−1. The proposed sensor chip is promising for immunosensing at the physiological level.

In this study, we report on the evaluation of tilt angles of liquid crystal (LC) molecules near the surface of SiO2 alignment layers and in the whole cell when constant voltages are applied. A LC molecule, 4-cyano-4'n-pentylbiphenyl, was used in this study. The LC cell consisted of Au (50nm) / SiO2 (30nm) /LC (3 μm)/ SiO2 (30nm) / Au (100nm) system. SiO2 alignment layers were obliquely evaporated on both Au surfaces. Surface plasmon resonance and guided waveguide excitation modes in attenuated total reflection configuration were used to monitor the alignment property of LC molecules adjacent to the surface and the bulk in the LC cell. In the ATR angular scan properties, the theoretical fittings agreed well with the experimental data on the assumption of simplified 5 LC layers model. The profile of the tilt angles from the surface to inside the cells was obtained by the theoretical fitting. In comparison with the internal bulk region, LC molecules near the surface required higher voltages to change their tilt angles toward vertical direction. As demonstrated in this report, this technique should provide the useful information to understand the interfacial phenomena for LC displays.

A new Mach-Zehnder type optical-interferometer utilizing evanescent wave illuminations of a reflected beam at a prism surface was constructed to evaluate photoreactive molecular thin films on a prism surface. Refractive index changes of the films due to photoisomerization of azo molecules on the prism caused by an irradiation beam were observed from phase changes between an incident beam and the reflected one at the prism surface. Real-time measurements were also demonstrated using the interferometer microscopy, exhibiting two dimensional distributions of the refractive indices in the molecular films partially excited by the focused irradiation laser beam.

In this study, attenuated total reflection (ATR) utilizing surface plasmon (SP) excitation and SP emission lights were observed for the adsorption of polystyrene (PS) spheres and a water-soluble polymer. The PS spheres contained fluorescent dyes and exhibited red fluorescence. The ATR properties indicated film deposition with increasing number of adsorption cycles. The SP emission light induced by the fluorescent dye in the spheres was also measured, and an increase in the peak intensity, as well as an angle shift, was observed. Furthermore, the SP emission light spectra were investigated at various emission angles. The dispersion relation obtained from the SP emission light almost corresponded to that obtained from the ATR curves.

Developing highly selective and sensitive chemical sensors is a challenge with respect to new materials for chemical recognition. In this study, a new conjugated polymer network precursor, hexahomotriazacalix[3]arene−carbazole has been synthesized and electrochemically cross-linked to form ultrathin films using cyclic voltammetry. The incorporation of hexahomotriazacalix[3]arene moiety as a neutral cation-binding receptor into a conjugated polycarbazole network facilitates high selectivity and sensitivity for Zn2+. The ultrathin films were characterized spectroscopically using UV−vis absorption and fluorescence spectroscopy. Surface morphology properties were examined by atomic force microscopy. Electrochemical deposition parameters and sensor transduction was studied by an electrochemical quartz crystal microbalance, surface plasmon resonance spectroscopy, and open-circuit potentiometry techniques. The results indicate that the high selectivity and sensitivity for Zn2+ compared to those of other cations ...

Carbazole containing ligand dendrons are designed based on second generation polybenzyl ether dendrons (2GPO). This is subsequently used for directly synthesizing and capping CdSe nanoparticles in contrast to ligand exchange for introducing functionality. The stable hybrid CdSe-2GPO quantum dot nanoparticles have characteristic energy-transfer properties from the donor carbazole peripheral groups to the acceptor CdSe nanoparticles, i.e., overlap of the fluorescence of the carbazole with the absorbance of the CdSe nanoparticle resulting in an enhanced fluorescence with concentration through Forster resonance energy transfer (FRET). However, electropolymerization of the peripheral electroactive carbazole units result in a red-shift in absorbance and quenching in fluorescence. This is attributed to a reversed molecular orbital energy order with respect to the electropolymerized carbazole dendron and CdSe nanoparticle. The hole-transfer results in fluoresence quenching and charge transfer between the CdSe nanoparticles and the polycarbazole peripheral units. The photoelectric alteration may yet provide for an interesting electro-optical or sensing device application based on electrochemical properties of the hybrid material.

In this study, thin films of poly(vinyl alcohol) (PVA) mixed with 100 nm polystyrene (PS) microspheres were prepared, and changes in attenuated total reflection (ATR) utilizing surface plasmon (SP) excitation due to the adsorption of humidity were investigated. The PS microspheres contained luminescent dyes, and SP emission light due to these dyes was observed. The sample configuration was prism/Ag film (50 nm)/PVA film with sphere. ATR dip and SP emission peak angles shifted with the adsorption and desorption of humidity, and SP emission light intensity changed markedly. Furthermore, kinetic curves were plotted and humidity adsorption responses were repeatedly observed. Finally, the dispersion relations of SPs were obtained from ATR and SP emission light properties.

The preparation and properties of an electrochemically crosslinked Au nanoparticle/polyvinylcarbazole (PVK)/polyfluorene (PFC) nanocomposite film is described. Blends of the blue-light emitting PFC, PVK, and the 11-(9H-carbazol-9-yl)-undecane-1-thiol-capped Au nanoparticles (CBZ-S-Au) were prepared as thin films by spin-coating and subsequent crosslinking by cyclic voltammetry (CV). The electrochemical properties are then evaluated on the basis of the redox behavior (reversibility) and electron-transport properties of the films. They are further characterized by UV-vis spectroscopy, photoluminescence spectroscopy, and atomic force microscopy (AFM). The large differences in photoluminescence properties of the CBZ-S-Au/PFCVK crosslinked copolymer composite film compared to the PFCVK polymer alone result in an efficient energy-transfer system, in which the excimer peak is almost totally quenched. This indicates a compatible match between the absorbance of the Au plasmons and the emission of the excimer energy trap from PF polymers. Furthermore, electrochemical crosslinking enhances this match both by shifting the absorbance to greater overlap and decreasing the Forster distance between the Au nanoparticle and the PFCVK polymer chains.

Vapor treatments using several organic solvents were carried out for vacuum-evaporated magnesium phthalocyanine (MgPc) thin films. The UV–vis absorption spectra, surface morphologies, and X-ray diffraction patterns were markedly altered by the treatments and depend on the vapor. Furthermore, Au top-contact organic field-effect transistors (OFETs) were fabricated using MgPc films with and without the vapor treatments. The FET with N-methylpyrrolidone treatment did not work, but that with dichloromethane vapor treatment showed a large improvement in the on/off ratio and field-effect mobilities. Ethanol vapor treatment (5 min) also improved the FET characteristics, but long-term treatment (60 min) induced poor performance.

Investigations on optical and dielectric properties of hybrid ultrathin layer-by-layer (LbL) films of gold nanoparticles (AuNPs) and polyelectrolytes under different pH conditions resulted in surface plasmon resonance (SPR) signal enhancement under attenuated total reflection (ATR) spectroscopy conditions. Theoretical considerations on the basis of the Maxwell−Garnett theory were made to compare with experimental results. LbL films with different layer architectures were fabricated from AuNPs and two polyelectrolytes: poly(allylamine hydrochloride) (PAH) and poly(styrene sulfonate) (PSS) on Au and Ag thin film substrates for ATR. UV−vis spectroscopy and SPR spectroscopy were applied to study LbL film growth and monitor SPR shift upon pH switching. The (PAH/AuNPs)x multilayers showed an interesting dual-responsive SPR change as a function of pH and distance between AuNP layers and metal film. The addition of (PAH/PSS)y layers was found to act as an effective cushion to enhance this SPR response due to the...