Photoelectric Cells of Merocyanine Langmuir-Blodgett Films Utilizing Surface Plasmon Excitations

2001 ◽  
Vol 708 ◽  
Author(s):  
Keizo Kato ◽  
Futoshi Takahashi ◽  
Kazunari Shinbo ◽  
Futao Kaneko ◽  
Takashi Wakamatsu
Keyword(s):  
Thin Films ◽  
Surface Plasmon ◽  
Short Circuit ◽  
Schottky Diodes ◽  
Attenuated Total Reflection ◽  
Dielectric Constants ◽  
Type I ◽  
Type Ii ◽  
Lb Films ◽  
Langmuir Blodgett

ABSTRACTShort-circuit photocurrents (ISC) due to surface plasmon (SP) excitations have been investigated for the photoelectric cells using Langmuir-Blodgett (LB) films of merocyanine (MC) dye. The MC dye exhibits p-type conduction, and the Schottky and Ohmic contacts are obtained at the interfaces between MC LB films and Al thin films and between MC LB films and Ag thin films, respectively. Since the Schottky diodes show the photoelectric effects, the Schottky photoelectric cells have been constructed. The cells with two kinds of structures, that is, prism/Al/MC/Ag (type I) and prism/MgF2/Al/MC/Ag (type II), have been prepared. In the attenuated total reflection (ATR) method, the types I and II have the Kretschmann and both the Kretschmann and Otto configurations, respectively. SP has been resonantly excited at the interface between Ag and air for the type I and at the interfaces between MgF2 and Al between Ag and air for the type II. The ATR and the ISC properties have been simultaneously measured as a function of the incident angles of the laser beams. The peaks of the ISC have corresponded to the resonant angles of the ATR curves. The electric fields and optical absorptions in the cells have been also calculated using the dielectric constants and the film thicknesses obtained from the ATR measurements. The calculated absorptions in the MC layers as a function of the incident angles have corresponded to the results of ISC. It has been estimated that the ISC for both types I and II could be enhanced by the excitations of SP in the ATR configurations.

Emission Light Properties from Ag/Rhodamine-B LB Films Due to Surface Plasmon Excitations in the Kretschmann and Reverse Configurations

2000 ◽  
Vol 660 ◽  
Author(s):  
T. Nakano ◽  
H. Kobayashi ◽  
K. Shinbo ◽  
K. Kato ◽  
F. Kaneko ◽  
...  
Keyword(s):  
Surface Plasmon ◽  
Rhodamine B ◽  
Emission Angle ◽  
Attenuated Total Reflection ◽  
Peak Wavelength ◽  
Resonant Condition ◽  
Lb Films ◽  
Langmuir Blodgett ◽  
Kretschmann Configuration ◽  
Emission Light

ABSTRACTEmission light from Ag/ Rhodamine-B (RB) Langmuir-Blodgett (LB) films due to surface plasmon (SP) excitations has been investigated using the Kretschmann configuration of the attenuated total reflection (ATR) method and the reverse irradiation of laser beam from air to the samples. The conventional photoluminescence (PL) of the RB LB films showed a broad spectrum and the peak wavelength was about 600 nm. In the reverse irradiation, emission light was observed through the prism, and the intensities and the spectra strongly depended upon the emission angle where the light was observed. The wavelengths of the emission light became shorter as the emission angles increased. The relation between the wavelength and the emission angle agreed with the resonant condition of excitations of SPs in the Kretschmann configuration of ATR method. It was concluded that the emission light was caused by excitations of multiple SPs at the Ag/RB LB films.

NANOSTRUCTURED LB FILMS AND EMISSION LIGHT DUE TO MULTIPLE SURFACE PLASMON EXCITATIONS IN THE KRETSCHMANN CONFIGURATION

2002 ◽  
Vol 01 (05n06) ◽  
pp. 409-414
Author(s):  
FUTAO KANEKO ◽  
MITSURU TERAKADO ◽  
TOSHIHARU SATO ◽  
HIROTSUGI HATAKEYAMA ◽  
WATARU SAITO ◽  
...  
Keyword(s):  
Laser Beam ◽  
Surface Plasmon ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Dye Molecules ◽  
Lb Films ◽  
Langmuir Blodgett ◽  
Kretschmann Configuration ◽  
Direct Irradiation ◽  
Emission Light

Surface plasmon (SP) excitations have been investigated in the attenuated total reflection (ATR) Kretschmann configuration of prism/metal/Langmuir–Blodgett (LB) films containing dyes. The emission light through the prism was observed using direct irradiation of a laser beam from air to the LB films, i.e., reverse irradiation. The emission intensities depend on the emission angles through the prism, nanostructure of metal and LB films, dye molecules, separation between metal and dye molecules, interactions of dye molecules, etc. The spectra is strongly depended on the emission angles, and the emission light was caused by multiple SP excitations. Nanostructured devices of LB films using SP excitations are described.

Enhancement of Photoelectric Effect in Organic Dye Thin Film Cells by Surface Plasmon Excitation

2003 ◽  
Vol 796 ◽  
Author(s):  
Keizo Kato ◽  
Masaru Hirano ◽  
Kazunari Shinbo ◽  
Futao Kaneko ◽  
Takashi Wakamatsu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Surface Plasmon ◽  
Short Circuit ◽  
Photoelectric Effect ◽  
Film Structure ◽  
Organic Dye ◽  
Attenuated Total Reflection ◽  
Kretschmann Configuration ◽  
Photoelectric Properties

ABSTRACTPhotoelectric properties have been investigated for the organic dye thin film cells utilizing surface plasmon (SP) excitation. The cells fabricated in this work had a prism/Al thin film/copper phtalocyanine (CuPc) thin film/Ag thin film structure, which was the Kretschmann configuration in the attenuated total reflection (ATR) method. Since the CuPc thin film exhibits p-type conduction, the Schottky and Ohmic contacts can be obtained at the interfaces between the CuPc and Al thin films and between the CuPc and Ag thin films, respectively, and the cells used in this work show photoelectric properties. The ATR and short-circuit photocurrent properties have been simultaneously measured as a function of the incident angles of the laser beams. The experimental and calculated results of the ATR and short-circuit photocurrent properties and the optical absorptions of the organic dye layers were discussed. It was found that the photoelectric effect in the organic dye thin film cells the Kretschmann configuration in the ATR method was enhanced by the SP excitation.

scholarly journals Surface plasmon enhanced energy transfer between type I CdSe/ZnS and type II CdSe/ZnTe quantum dots

2010 ◽  
Vol 96 (7) ◽  
pp. 071906 ◽  
Author(s):  
C. H. Wang ◽  
C. W. Chen ◽  
Y. T. Chen ◽  
C. M. Wei ◽  
Y. F. Chen ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Energy Transfer ◽  
Surface Plasmon ◽  
Type I ◽  
Type Ii

Corticosterone's metabolite is an agonist for Na+ transport stimulation in A6 cells

1988 ◽  
Vol 255 (4) ◽  
pp. F736-F748 ◽  
Author(s):  
R. L. Duncan ◽  
W. M. Grogan ◽  
L. B. Kramer ◽  
C. O. Watlington
Keyword(s):  
Binding Sites ◽  
Short Circuit ◽  
Type I ◽  
Type Ii ◽  
Na Transport ◽  
Single Class ◽  
Apparent Dissociation Constant ◽  
Lower Affinity ◽  
A6 Cells ◽  
Nuclear Binding

This study tests the hypothesis, in A6 epithelia, that 1) corticosterone stimulates active Na+ transport (short-circuit current, Isc) by an additional receptor mechanism to the type I (mineralocorticoid) and type II (glucocorticoid) mechanisms shared with aldosterone (Aldo) and 2) that the agonist may be 6 beta-OH-corticosterone made in the effector cell. The dose-response relationship of corticosterone at 24 h resolves into two components, by curve fitting, with a 50% effective concentration (EC50) for 10% of maximum Isc stimulation of 2 X 10(-9) M and an EC50 for the other 90% of 3 X 10(-7) M. The EC50 of the smaller component correlates with the apparent dissociation constant (K'd) of corticosterone for high affinity (type II) nuclear binding sites shared with Aldo. In unlabeled analogue competition studies Aldo and corticosterone displaced nuclear binding equally below 10(-8) M [3H]corticosterone, indicating only shared sites. However, nonshared saturable sites (displaced by corticosterone but not by Aldo) were found at [3H]-corticosterone concentrations above 10(-8) M. Concentration-binding curves performed with [3H]corticosterone, in presence of 1,000 X Aldo to displace shared sites, revealed a single class of binding sites with a half-maximal saturation of 2 X 10(-7) M, which is quite similar to the EC50 of the lower affinity component of Isc stimulation by corticosterone at 24 h. Reversed phase high-pressure liquid chromatography of nuclear extracts indicates that the saturable component of bound [3H] was 6 beta-OH-[3H]corticosterone derived from [3H]corticosterone. Thus, A6 cells metabolize corticosterone to 6 beta-OH-corticosterone, which in turn occupies lower-affinity receptors not shared with Aldo or corticosterone, to mediate most of the active Na+ transport stimulation by corticosterone.

Rheo-Optical Study of Polymers by Using Time-Resolved Soft-Pulse Compression Attenuated Total Reflection Step-Scan Fourier Transform Infrared Spectroscopy

2009 ◽  
Vol 63 (11) ◽  
pp. 1204-1210 ◽  
Author(s):  
Yuji Nishikawa ◽  
Tatsuhiko Nakano ◽  
Isao Noda
Keyword(s):  
Fourier Transform ◽  
Pulse Compression ◽  
Dynamic Compression ◽  
Pulse Frequency ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Type I ◽  
Type Ii ◽  
Time Resolved ◽  
2D Ir

A time-resolved soft-pulse dynamic compression attenuated total reflection (ATR) step-scan Fourier transform rheo-optical system has been developed. This system was used to observe different viscoelastic properties of polyethyleneterephthalate (PET) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHx). Resonance features were observed in the dynamic compression ATR spectrum of PHBHx with 625 Hz soft-pulse frequency. In contrast, the dynamic compression ATR spectrum of PET showed no resonance features. The resonance feature of PHBHx was found at 1723 cm−1, which corresponds to the structural or morphological reorganization of a less ordered (Type II) crystalline form under compressive perturbation. The time-resolved evolution of infrared (IR) spectra was effectively analyzed by conventional generalized two-dimensional (2D) correlation analysis. The 2D-IR results indicate that the dynamic response of the well-ordered Type I crystalline state (1289 and 1261 cm−1) is faster than that of the Type II (1723, 1277, and 1228 cm−1). The present method shows promise for characterizing a wide variety of viscoelastic materials, including polymer alloys, blends, composites, and copolymers, and semicrystalline polymers.

scholarly journals UTP regulation of ion transport in alveolar epithelial cells involves distinct mechanisms

2009 ◽  
Vol 297 (3) ◽  
pp. L439-L454 ◽  
Author(s):  
Chuanxiu Yang ◽  
Lijing Su ◽  
Yang Wang ◽  
Lin Liu
Keyword(s):  
Ion Transport ◽  
Short Circuit ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Channel Blockers ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Type I Cells ◽  
I Cells

UTP is known to regulate alveolar fluid clearance. However, the relative contribution of alveolar type I cells and type II cells to this process is unknown. In this study, we investigated the effects of UTP on ion transport in type I-like cell (AEC I) and type II-like cell (AEC II) monolayers. Luminal treatment of cell monolayers with UTP increased short-circuit current ( Isc) of AEC II but decreased Isc of AEC I. The Cl− channel blockers NPPB and DIDS inhibited the UTP-induced changes in Isc (Δ Isc) in both types of cells. Amiloride, an inhibitor of epithelial Na+ channels (ENaC), abolished the UTP-induced Δ Isc in AEC I, but not in AEC II. The general blocker of K+ channels, BaCl2, eliminated the UTP-induced Δ Isc in AEC II, but not in AEC I. The intermediate conductance (IKCa) blocker, clofilium, also blocked the UTP effect in AEC II. The signal transduction pathways mediated by UTP were the same in AEC I and AEC II. Furthermore, UTP increased Cl− secretion in AEC II and Cl− absorption in AEC I. Our results suggest that UTP induces opposite changes in Isc in AEC I and AEC II, likely due to the reversed Cl− flux and different contributions of ENaC and IKCa. Our results further imply a new concept that type II cells contribute to UTP-induced fluid secretion and type I cells contribute to UTP-induced fluid absorption in alveoli.

Modulation of bioelectric properties across alveolar type II cells by substratum

1989 ◽  
Vol 257 (4) ◽  
pp. C678-C688 ◽  
Author(s):  
G. R. Cott
Keyword(s):  
Cell Morphology ◽  
Short Circuit ◽  
Alveolar Type ◽  
Type I ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Capacitance Effects ◽  
Short Circuit Currents ◽  
Cells Cultured

Rat alveolar type II cells were cultured on collagen-coated filters (CCF) and human amnionic basement membrane (ABM) to determine the effect of culture substratum on the development of monolayer bioelectric properties. Monolayers cultured on both substrata rapidly developed bioelectric properties with similar time courses, monolayer capacitance values (approximately 1 muF/cm2), current-voltage relationships, and responses to stimulants and inhibitors of active ion transport. Increasing seeding densities tended to increase monolayer bioelectric properties regardless of culture substratum. Monolayers cultured on ABM had higher resistance values (491 vs. 291 omega.cm2) and lower short-circuit currents (2.85 vs. 4.51 muA/cm2) than monolayers with similar cell densities cultured on CCF. These differences in monolayer bioelectric properties were not due to differences in substratum resistance or capacitance effects. The relationships between monolayer bioelectric properties were also affected by the culture substratum. In additional experiments, cells cultured on contracted gels formed monolayers with high short-circuit currents (9.25 muA/cm2). Cell morphology varied depending on the culture substratum, with cells cultured on contracted gels appearing the most cuboidal, whereas the flattest and most attenuated cells were those cultured on ABM. On the basis of these observations, we conclude that culture substratum significantly affects the development of bioelectric properties across alveolar type II cell monolayers. In vivo the bioelectric properties across the alveolar epithelium may also vary with changes in cellular substratum or cell density (e.g., after acute lung injury) and possibly with cell morphology (e.g., alveolar type I vs. alveolar type II cells).

scholarly journals Characterization of PKA isoforms and kinase-dependent activation of chloride secretion in T84 cells

1998 ◽  
Vol 275 (2) ◽  
pp. C562-C570 ◽  
Author(s):  
A. K. Singh ◽  
K. Taskén ◽  
W. Walker ◽  
R. A. Frizzell ◽  
S. C. Watkins ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Chloride Secretion ◽  
Immunogold Electron Microscopy ◽  
Apical Plasma Membrane ◽  
Epithelial Cell Line ◽  
Type I ◽  
Type Ii ◽  
T84 Cells

Chloride exit across the apical membranes of secretory epithelial cells is acutely regulated by the cAMP-mediated second messenger cascade. To better understand the regulation of transepithelial chloride secretion, we have characterized the complement of cAMP-dependent protein kinase (PKA) isoforms present in the human colonic epithelial cell line T84. Our results show that both type I and type II PKA are present in T84 cells. Immunoprecipitation of 8-azido-[32P]cAMP-labeled cell lysates revealed that the major regulatory subunits of PKA were RIα and RIIα. In addition, immunogold electron microscopy showed that RIIα labeling was found on membranes of the trans Golgi network and on apical plasma membrane. In contrast, RIα was randomly distributed throughout the cytoplasm, with no discernible membrane association. Northern blot analysis of T84 RNA revealed that Cα was the predominantly expressed catalytic subunit. Short-circuit current measurements were performed in the presence of combinations of site-selective cAMP analog pairs to preferentially activate either PKA type I or PKA type II in intact T84 cell monolayers. Maximal levels of chloride secretion (∼100 μA/cm2) were observed for both type I and type II PKA-selective analog pairs. Subsequent addition of forskolin was unable to further increase chloride secretion. Thus activation of either type I or type II PKA is able to maximally stimulate chloride secretion in T84 colonic epithelial cells.

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