Lipophilic Anionic Dye Research Articles

Preparation of Sodium Ion-Sensing Plates Based on a Thin Layer Liquid Membrane Containing a Neutral Ionophore and a Lipophilic Anionic Dye

A sodium ion-sensing plate was prepared as an easily-handled ion-sensing optical chemical sensor (optode) probe. The sensing plate consisted of an ion-sensing liquid thin layer containing a Na+-selective neutral ionophore (16-crown-5 derivatives) and a lipophilic anionic dye (KD-A3), which was placed on a chemically modified (octadecyl silanized) frosted glass plate that was covered with a cellulose dialysis membrane. This ion-sensing plate can easily determine Na+ ranging from 10-4 to 10-1 M by simply dipping the plate into the sample solution. The response time was ca. 80 s for 10-1 M NaCl with good reproducibility (relative standard deviation (RSD)=±1.33% for ten sequential measurements).

Active optical thin-film waveguide sensor for ion sensing

In this paper, an active PVC optical thin-film waveguide sensor is proposed which can select a specific ion and measure its concentration. The waveguide was fabricated using the plasticized poly(vinyl chloride) (PVC), bis ethyl hexyl phthalate (BEHP), lipophilic anionic dye (LAD-3), and ionophores (K23E1 for calcium, or C14DD16C5 for sodium) in which the PVC membrane plays important roles for both incident light propagation and selective ion sensing. In order to investigate the applicability of this sensor to Ca 2+ and Na + measurement, the sensor was applied to sample solutions whose CaCl 2 concentration was gradually altered. Also, we applied it to a NaCl solution. In this experiment, we found that this PVC thin-film waveguide possessed good light propagation for argon laser light at 488 nm. Also, the comparison of the experimental responses between the active waveguide sensor and a commonly utilized waveguide sensor (evanescent waveguide spectrometry), indicated that the sensitivity of the active waveguide sensor is obviously higher than that of the conventional waveguide sensor. These findings suggested that the proposed PVC waveguide ion sensor is applicable to the determination of various ions with high sensitivity.

Ion-sensitive and selective active waveguide optodes

A novel polymer waveguide (active waveguide) type optode possessing the advantages of both selective analyte determination and optical signal propagation was developed. The noteworthy concept of this active waveguide is the integration of plural functions into the planar waveguide itself, such as molecular recognition, color change, and light propagation. In order to demonstrate this concept, the analyte sensing layer is utilized as the light propagating layer. An ion-selective optode membrane consisting of a plasticized poly(vinylchloride) (PVC) membrane containing a neutral ionophore and a color changeable lipophilic anionic dye was used as the planar active waveguide sensing layer. The principle of the response of this active waveguide is based on the measurement of the output light signal intensity in which this light is propagated through the color changeable PVC membrane phase, and its intensity is decreased by interaction with the analyte ions. In this report, calcium and sodium ion-sensitive waveguides were prepared based on our developed neutral ionophores. Comparison of the experimental responses between the novel active waveguide optode and a commonly utilized conventional waveguide optode based on evanescent wave spectrometry demonstrated that the sensitivity of the active waveguide optode is obviously greater than that of the conventional waveguide optode. This concept of an active waveguide fully demonstrates the advantageous property of a planar waveguide with respect to highly sensitive and selective optical chemical sensing.

Calcium Optical Sensors Based on Lipophilic Anionic Dye and Calcium-Selective Organophosphate Ionophore or Neutral Carrier

ABSTRACT Lipophilic anionic dichlorofluorescein ester was examined as a chromophore for the development of polymeric film based optical sensors for calcium. A calcium organophosphate salt and a neutral ionophore were employed as the active component for calcium sensing. The response pH. dynamic range, detection limit and selectivities are governed by the calcium carrier as well as the membrane plasticizer. The membrane that uses the anionic chromophore and the calcium organophosphate salt responds to calcium in the range of 1.0 × 10−6 to 0.2 M at pH 7.4.

Ion sensing film optodes: disposable ion sensing probes for the determination of Na+, K+, Ca2+ and Cl− concentrations in serum

Abstract Highly selective ion sensing film optodes for the determination of four kinds of ions (Na+, K+, Ca2+, Cl−) were prepared with plasticized PVC membranes containing the respective ionophores and a newly prepared lipophilic anionic dye. The principle of the optical response of these sensing films is based on ion-pair extraction of the ion-ionophore complex and a deprotonated or protonated lipophilic anionic dye. These film optodes are for disposable use and can detect ions by simply immersing them into a glass vessel which is filled with the samples solution and determining the ion by measuring the absorbance change at the respective maximum absorption wavelength of the lipophilic anionic dyes in the visible region. The theoretical response of these films was also discussed based on the ion-extraction model. The ion selectivity of these films was sufficient for the determination of Na+, K+, Ca2+ and Cl− in diluted serum samples, and satisfactory results were obtained in serum analysis.

Japan — Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye : In ANAL. CHIM. ACTA (299/2 (179–187) 1994) H. Hisamoto, K. Watanabe, E. Nakagawa, D. Siswanta, S. BY K. Suzuki of Keio University report on “Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye”

Japan — Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye : In ANAL. CHIM. ACTA (299/2 (179–187) 1994) H. Hisamoto, K. Watanabe, E. Nakagawa, D. Siswanta, S. BY K. Suzuki of Keio University report on “Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye”

Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye

Flow-through type calcium ion selective optodes based on novel neutral ionophores and a lipophilic anionic dye were developed. The novel calcium ion selective neutral ionophores designed and synthesized were double-armed diazacrown ether compounds possessing glycolic amides as the binding arms. Cation sensing material was prepared by coating pellicular-type ODS (octadecylsilica) beads with a lipophilic organic liquid which incorporates a novel neutral calcium ionophore and a lipophilic anionic dye of the diphenyl amine type. These beads were packed in a flow-through optical cell, and the Ca 2+ measurement was performed to measure the absorbance change of the sensing beads at 516 nm. The best optode tested exhibited a good response to calcium ions in the concentration range from 10 −7 M to 10 −1 M with 0.05 M Tris-HCl of pH 7.0 as the flowing buffer solution. This optode showed excellent Ca 2+ selectivity of over 10 −4 in selectivity coefficient values ( k i,j opt.; i = primary ion (Ca 2+); j = interfering ion) against Na +, K + and Mg 2+ which are primary interferents for human serum analysis. Sensor response theory, response time, selectivity, and application to the determination of calcium ion concentration in human serum were also discussed together with experimental results.

Flow-through Type Chloride Ion Selective Optodes Based on Lipophilic Organometallic Chloride Adducts and a Lipophilic Anionic Dye

Flow-through type fiber-optic chloride ion selective optodes have been developed based on chloride adducts of lipophilic organometallic compounds, including a metal: Sn, Ge, Hg or Hf and a lipophilic anionic indicator dye of the diphenyl amine type. The pellicular-type ODS beads were coated with a lipophilic organic liquid containing the lipophilic organometallic compound as the anion-selective ionophore ligand and LAD-3 as the color changeable indicator dye. The optode system was constructed by packing these color changeable ion sensing beads in the flow-through optical cell (cell volume, 7 μl) having a quartz window attached directly to the distal end of a bifurcated optical fiber

Lithium ion selective optical fiber sensor based on a novel neutral ionophore and a lipophilic anionic dye

Lithium ion selective optical fiber sensor based on a novel neutral ionophore and a lipophilic anionic dye

Fibre-optic potassium ion sensors based on a neutral ionophore and a novel lipophilic anionic dye

A novel lipophilic anionic dye, N-2,4-dinitro-6-octyloxyphenyl-2′,4′-dinitro-6′-trifluoromethylphenylamine (LAD), was synthesized. On deprotonation at neutral Ph it forms anions and brings about a change in the absorption spectrum in the visible region. This anionic dye was incorporated into a poly(vinyl chloride) matrix membrane with dibenzo-18-crown-6 (DB18C6) or valinomycin, which are K +-selective neutral ionophores. An optical K + sensor was prepared using the polymeric membrane set 1 mm apart from the tip of a bifurcated optical fibre with a cylindrical plastic support. This sensor could detect a wide range of K + concentrations (10 −6−1 M K + for the DB18C6-based sensor, 10 −8−10 −2 M K + for the valinomycin-based sensor) at Ph 7.0 by measuring the absorbance change at 513 nm. The factors that influence the response sensitivity of the sensor are discussed theoretically.