Development of Tetrahydrofuran/Water Optical Waveguide and Its Application to the Observation of Extraction Behavior of 1-Anilino-8-naphtalene Sulfonate at the Tetrahydrofuran/Water Interface.

A stable two-phase sheath flow using tetrahydrofuran (THF) for an inner flow and water for an outer flow was formed in a glass capillary, and worked as a stable liquid-core/liquid-cladding optical waveguide (THF/water LLW). Although THF and water were miscible with any ratio, the length of the stable THF/water LLW at 0.9 - 2.

Surface plasmon field-enhanced fluorescence spectroscopy apparatus with a convergent optical system for point-of-care testing.

Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) is a promising methodology for point-of-care (POC) testing. The SPFS devices that have been reported are equipped with an angle rotating stage to adjust the surface plasmon resonance (SPR) angle. In a clinical setting, however, the SPR angle determination is a tedious and time-consuming process.

Effect of dielectric spacer thickness on signal intensity of surface plasmon field-enhanced fluorescence spectroscopy.

Surface plasmon field-enhanced fluorescence spectroscopy (SPFS) combines enhanced field platform and fluorescence detection. Its advantages are the strong intensity of the electromagnetic field and the high signal/noise (S/N) ratio due to the localized evanescent field at the water/metal interface. However, the energy transfer from the fluorophore to the metal surface diminishes the fluorescence intensity, and this reduces the sensitivity.

Flow injection spectrophotometric determination of sub-mg dm(-3) silver(I) in a strongly acidic solution containing concentrated copper(II) using a pyridylazo reagent.

A novel spectrophotometric flow injection method for determination of silver(I) in a strongly acidic solution containing concentrated copper(II) was developed using a coloring ligand, 4-(3,5-dibromo-2-pyridylazo)-N-ethyl-N-(3-sulfopropyl)aniline (3,5-diBr-PAESA). The method was first investigated by batch method. The interference from copper(II) chelate could be eliminated by the masking effect of EDTA.

Surface plasmon resonance and surface plasmon field-enhanced fluorescence spectroscopy for sensitive detection of tumor markers.

Surface plasmon resonance (SPR), which provides real-time, in situ analysis of dynamic surface events, is a valuable tool for studying interactions between biomolecules. In the clinical diagnosis of tumor markers in human blood, SPR is applied to detect the formation of a sandwich-type immune complex composed of a primary antibody immobilized on a sensor surface, the tumor marker, and a secondary antibody. However, the SPR signal is quite low due to the minute amounts (ng-pg/mL) of most tumor markers in blood.

Slab optical waveguide high-acidity sensor based on an absorbance change of protoporphyrin IX.

A sensitive and fast-responsive evanescent wave absorption sensor has been constructed for pH measurements in highly acidic ranges. This sensor is based on a pH-dependent color change of protoporphyrin IX (PPIX). For the sensitive detection, a visible attenuated total reflection spectrometer with a slab optical waveguide (SOWG) was laboratory-made, and the guiding layer surface was modified with a PPIX-immobilized acrylamide-based thin membrane.

Liquid core waveguide spectrophotometry for the sensitive determination of nitrite in river water samples.

A flow injection analysis system was built with a liquid core waveguide spectrophotometric detector using an 80 cm Teflon AF-1600 capillary tube (2,2-bistrifluoromethyl-4,5-difluoro-1,3-dioxole/tetrafluoroethylene). The system was applied to determine nitrite ion in river water samples. The lower limit of detection for nitrite was 2.

Characteristics of a liquid/liquid optical waveguide using sheath flow and its application to detect molecules at a liquid/liquid interface.

The formation conditions and characteristics of a liquid/liquid optical waveguide (LLW) were studied using a two-phase sheath flow, where the inner organic phase flow acted as the core and the outer aqueous flow acted as the clad. In immiscible solvent systems, i.e.

Liquid/liquid optical waveguides using sheath flow as a new tool for liquid/liquid interfacial measurements.

A liquid/liquid optical waveguide was constructed using a sheath flow. Since the refractive index of an organic solvent is generally higher than that of water (nD = 1.33), light introduced into the inner organic flow should proceed with total multi-reflection within the inner flow, so that the inner part of the sheath flow acts as the core of an optical waveguide.