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Publication numberUS3904373 A
Publication typeGrant
Publication dateSep 9, 1975
Filing dateOct 26, 1973
Priority dateOct 26, 1973
Publication numberUS 3904373 A, US 3904373A, US-A-3904373, US3904373 A, US3904373A
InventorsGerald Bruce Harper
Original AssigneeGerald Bruce Harper
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Indicators covalently bound to insoluble carriers
US 3904373 A
Abstract
Indicators insolubilized by covalent bonding to inorganic carriers for indicating the hydrogen ion concentration, oxidation-reduction state or specific ion concentration in liquid media. Since the indicators are insoluble they do not contaminate the solution tested, and they may be used repeatedly in different media. They replace the well known indicator test papers which consists of a substrate dyed with an indicator. Methods of making the indicators are also provided.
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United States Patent [19] Harper Sept. 9, 1975 INDICATORS COVALENTLY BOUND TO INSOLUBLE CARRIERS [21] Appl. No.: 409,876

[52] US. Cl 23/253 TP; 252/408; 260/448.2 B;

[51] Int. Cl. GOln 29/02; GOln 31/00;

GOln 33/00 [58] Field of Search 252/408; 23/253 TP; 424/7 [56] References Cited UNITED STATES PATENTS 2,626,855 1/1953 Hand 23/253 TP 2,929,829 3/1960 Morehouse 252/408 X 3,350,175 10/1967 McConnaughey ct al...... 23/253 TP OTHER PUBLlCATlONS New Method Makes Possible Nonbleeding Indicator Paper, Chem. and Engin. News, Vol. 48, No. 10, p. 38 (Mar. 9, 1970).

Surface-Produced Alignment of Liquid Crystals, Kahn, F. J., et al., Proc. of The IEEE, Vol. 61, No. 7, pp. 823-828 (July 1973).

Primary ExaminerBenjamin R. Padgett Assistant ExaminerT. S. Gron Attorney, Agent, or FirmF." Campbell Rutherford [5 7 ABSTRACT Indicators insolubilized by covalent bonding to inorganic carriers for indicating the hydrogen ion concentration, oxidation-reduction state or specific ion concentration in liquid media. Since the indicators are insoluble they do not contaminate the solution tested, and they may be used repeatedly in different media. They replace the well known indicator test papers which consists of a substrate 'dyed with an indicator. Methods of making the indicators are also provided.

17 Claims, N0 Drawings INDICATORS COVALENTLY BOUND TO INSOLUBLE CARRIERS This invention consists of a new type of indicators, which are hereinafter referred to as bound indicators.

Indicators are organic compounds which absorb visible light, which absorption(s) change in wave length and/or intensity as the composition of a solution to which the indicator may be exposed changes. Indicators are widely used to determine such parameters in solutions as hydrogen ion concentration (pH), oxidation-reduction potential or specific ion concentrations.

The term indicator", as used herein, refers to organic molecules or ions which absorb visible light and whose absorption(s) change in wave length and/or intensity as solution conditions are varied, and includes precursors, organic species which are not indicators as free species, but which when bound to inorganic carriers via silane coupling agents give a bound indicator. The term bound indicator, as used herein, refers to any complex comprising an organic species covalently coupled via a silane coupling agent to a carrier having available hydroxyl or oxide groups, which absorb visible light and which ahsorption(s) change in wave length and/or intensity as solution conditions are varied.

Conventionally, indicators have been used by dissolving the indicator chemical entity in the liquid to be tested, or by coating a carrier, such as paper, with the chemical entity and then contacting the coated carrier with the liquid to be tested.

In whatever form indicators were previously used, a quantity of the indicator was required for each test. If a liquid was being monitored for changes in pH, ion concentration or oxidation-reduction potential with an indicator, samples of the liquid to be tested had to be contacted with the appropriate indicator and the sample then had to be discarded because it has been contaminated by the indicator or, in the case of a coated paper indicator, because the paper had absorbed a component of the test liquid. Thus the amount of previ ously known indicators consumed in an active chemical laboratory, or for control purposes in a plant, could be substantial. Such use could also be costly since a typical indicator species is expensive to prepare.

My invention consists of insoluble bound indicators which are able to fulfill the various functions of soluble indicators. Bound indicators have several advantages over soluble indicators:

1. they can, in most cases, be used repeatedly 2. they are largely unsusceptible to microbial attack 3. they are insoluble and hence do not contaminate systems 4. they may be made in a form which is especially convenient for laboratory operations, e.g. glass stirring rods Bound indicators are very useful in analytical procedures in laboratories and industry and may also be used in the preparation of many foodstuffs, chemicals and pharmaceuticals. I have observed continued and apparently constant activity, as indicated by the intensity of colour changes, over a period of months, upon expo sure to various organic and aqueous assay conditions. Because of their advantages, bound indicator sintered glass rods and the like are preferable to pH papers and soluble indicators for many uses. While bound indicators may be made with either inorganic or organic carriers, the former are normally preferable for use because they are more rigid and insoluble and more resistant to microbial attack.

Bound indicators must be substantially insoluble in a solution to be useful in it. Most indicators in widespread use change colour with pH and are, in fact, used to measure the pH of solutions. Other indicators have different functions, e.g. the measurement of the oxidation-reduction potential of a system, and the detection and measurement of various ions in solution.

The silane coupling agents are molecules which are characterized by two different kinds of reactivity. These are organofunctional, and silicon-functional, so characterized that the silicon portion of the molecule has an affinity for inorganic materials, such as glass and aluminum silicate, while the organic portion of the molecule is an indicator or precursor or is tailored to combine with indicators or precursors. One function of the coupling agent then, is to provide a bond between the indicator and the carrier. The variety of possible organofunctional silanes useful in this invention is limited only by the number of organofunctional groups which bind to silicon to give a stable coupling agent, by the stability of the bonds to the carrier and to the indicator and by the available sites in the organic species which yield an active bound indicator.

Many different silane coupling agents of the general formula X,,SiR can be used, wherein X is a substituent, which may be a substituted (or unsubstituted) aryl, alkyl or lower alkyl-aryl, nitro, nitroso, diazo, cyano, isocyano, isothiocyano, carboxy, carbonyl, keto, halocarbonyl, sulfoxy, sulfonyl halide, or more complex derivatives of any of these; R is a member selected from a group comprising lower alkoxy, phenoxy and halo; and n is an integer which is l, 2 or 3, usually I. The silane coupling agent may or may not itself be an indicator. This definition includes simple silane coupling agents wherein X is simply amino, carboxyl, carbonyl, sulfliydryl or halocarbonyl.

Coupling agents include gamma-aminopropyltriethoxysilane, 2,4,6-trimethoxybenzyltriethoxysilane, N- beta-aminoethyl-gamma-aminopropyltrimethoxysilane, and N-beta-aminoethyl-(alpha-methyl-gammaaminopropyl)-dimethoxymethylsilane. While some simple silane coupling agents are commercially avail able, many others, including more complex ones, may be made by known chemical methods. For example, I have added 2,4,6-trimethoxybenzoic acid to trichlorosilane in acetonitrile, then added tri-n-propylamine to form 2,4,6trimethoxybenzyltriethoxysilane. Ethanolysis yielded the useful coupling agent 2,4,6- trimethoxybenzyltriethoxysilane. As another example, gamma-aminopropyltriethoxysilane couples to inorganic carriers giving the aminoalkylsilane derivative, which can be reacted with alkoxybenzoyl chlorides to form another complex which binds diazotized indicators or precursors. Another reaction sequence involves reacting the aminoalkylsilane derivative with pnitrobenzoyl chloride, reducing the nitro group with sodium dithionite and diazotizing with sodium nitrite: this diazonium salt attacks activated aryl rings of indicators or indicator precursors. Alternatively, an aminoalkylsilane derivative may be reacted with thiophosgene to give an isothiocyanoalkyl derivative which binds amino groups. Where the indicator or precursor or derivative contains a suitable aromatic ketone. aldehyde, acyl chloride or carboxy group it is possible to prepare silane coupling agents which are also indicators or precursors.

The carriers used can be organic, but generally, inorganic materials with available hydroxyl or oxide groups are preferred. The quantity of indicator or precursor which can be bound, and hence the colour intensity of the bound indicator. increases with increasing surface area of the carrier. Hence, a carrier such as smooth, unetched glass is an unsatisfactory carrier, as it yields a bound indicator of weak colour. The carriers must have little or no solubility in various solutions and are either weak acids or weak bases. They may also be classified in terms of chemical composition as siliceous materials, non-siliceous metal oxides, or as mixtures of the two, such as Zirconia-clad glass. Of the siliceous materials, the preferred carriers are sintered, etched or porous glass. These may be used in such forms as rods or discs. or as fragments. Glass has the advantages of being dimensionally stable, of being transparent or white in colour thus allowing colour changes to be easily judged, and it can be thoroughly cleaned to remove contaminants as, for example, by sterilization. The corrosion rate of glass varies with glass composition and solution conditions, but corrosion has remained undetectable throughout this work. Other useful siliceous inorganic carriers are silica gel, eoloidal silica (commercially available under the trade mark Cab-O-Sil), wollastonite (a naturally-occuring calcium silicate) and beatenite. Representative non-siliceous metal oxides include alumina, hydroxy apatite and nickel oxide. These inorganic carriers may be classified as in Table I.

Bound indicators may be classified under three general headings:

1. pH indicators 2. redox indicators (i.e. oxidation-reduction indicators) 3. adsorption indicators (i.e. ion detectors) of which examples of each class are listed below. Bound pH indicators can be produced using many pH indicators or functionalized derivatives of those indicators. Suitable organic species include: phenolphthalein, fluorescein, phenol red, cresol red, pararosaniline, magenta red, xylenol blue, bromocresol purple, bromophenol blue, bromothymol blue, metacresol purple, thymol blue, bromophenol blue, tetrabromophenol blue, brom-chlorphenol blue, bromocresol green, chlorphenol red, o-cresolphthalein, thymolphthalein. metanil yellow, diphenylamine, N,Ndimethylaniline, indigo blue, alizarin, alizarin yellow GG, alizarin yellow R, Congo red, methyl red, methyl orange, orange l, orange II, nile blue A. ethyl bis( 2,4-dinitrophenyl) acetate, gamma-naphtholbenzein, methyl violet 68, 2,5- dinitrophenol, p-nitrophenol, and/or the various functionalized derivatives of the above species. Even when Bound adsorption indicators can be made from organic species which include fluorescein, diiodofluorescein, dichlorofluorescein, phenosafranin, rose bengal, eosin l bluish, eosin yellowish, magneson, tartrazine, eriochrome black T and others.

The following examples illustrate typical methods of preparation of the new indicators:

EXAMPLE I indicators in the form of a stirring rod, and in the form of a powder, were prepared, starting with a heavily etched silica glass stirring rod for the former, and 1 gram of fragments of 96% silica porous glass for the latter. Both carriers were cleaned by soaking in 0.2M nitric acid at 95 C for 1 hour, rinsing several times with distilled water and then heating overnight at 650 in air.

The two samples of glass were cooled, placed in flasks and to each was added 50 millilitres of a 10% solution of gamma-aminopropytriethoxysilane. Both mixtures were refluxed overnight, cooled and washed with acetone.

The two glass products, now in the form of aminoalkylsilane derivatives, were refluxed for one hour in solutions containing 10 ml of chloroform, 100 mg of pnitrobenzoyl chloride and 50 mg of triethylamine, washed with chloroform and air-dryed. The nitro groups were reduced by refluxing in 17! aqueous sodium dithionite, giving the arylamine derivative. The amino groups were diazotized by adding 10 ml of glacial acetic acid followed by an excess (0.3 g) of sodium nitrite. The mixtures were placed under vacuum until all air and gas bubbles were removed from the glass. after which 1 g of phenolphthalein was added to each followed by placing under vacuum for a further 30 minutes. The resulting products, which in each case was phenolphthalein coupled to the silane by an azo linkage with the silane bound to the glass, were washed with water, acetone and benzene until any phenolphthalein non-covalently adsorbed on the glass was not detectably eluted. The phenolphthalein glasses when exposed to liquids of different pH concentration underwent a colour change which I observed to occur in the pH range 8.59.0; at a pH of 8.5 the glasses were pale yellow and at a pH of 9.0 were deep red-brown. These indicators retained their colour and activity indefinitely, despite exposure to strong organic and aqueous acids and bases, to various solutions and reagents, and to air.

EXAMPLE II A l g sample of porous zirconia-clad silica glass amino alkylsilane derivative (e.g. Corning Glass Works product MAO-3930) was refluxed for 1 hour in a chloroform solution containing 100 mg p-nitrobenzoyl chloride and 50 mg triethylamine, as in example I. The nitro groups on this product were again reduced with dithionite. This was followed by diazotization by 0.3 g sodium nitrite in 10 ml glacial acetic acid, under a vacuum at 0. Excess (0.5 g) N,N-dimethylaniline was added. The product was a deep-burgundy colour in solutions of pH below 4.5. turning to a pale orange-red colour at pH 4.5 to 5.5 The bound indicator retained colour and activity, despite exposure to various conditions. Presumably. the bound indicator is of the following structure:

EXAMPLE 111 A g sample of 2.4.o-trimethoxybenzoic acid and 49 g trichlorosilane were dissolved in 200 ml acetonitrilc and refluxed for 1 hour. Two equivalents of tripropylamine were added at this point and the resulting mixture was refluxed at 80-90 for 8 hours. Treatment with dry ether caused the precipitation of tripropylamine hydrochloride (95% Distillation of the filtrate gave 1 l g of 2.4.6-trimethoxybenxyltrichlorosilane boiling at 8084 (6mm). This product was dissolved in 100 ml ethanol. Five equivalents of tripropylamine were added and the mixture refluxed for 1.5 hours at 7075. The mixture was distilled yielding 2.1 g of 2.4- ,t'w-trimethoxybenzyltriethoxysilane. l g of porous glass and ml of toluene were added to this and the mixture was refluxed overnight giving a trimethoxyarylsilane glass derivative.

Fifteen g of 3-nitro-N.N-dimethylaniline was mixed with 17 g of sodium thiosulphate in 200 ml water and refluxed for 1 hour to give 3-amino-N.N- dimethylaniline. This mixture was cooled to 10 and sodium nitrite (20 g) was added slowly. 3-diaZo-N,N- dimethylanilinium chloride was collected as a filtrate and added to the trimethoxyarylsilane glass derivative and 10 ml glacial acetic acid. in an ice bath. The mix ture was evacuated for minutes to remove air and gas bubbles from the glass. The reaction product, which was again N.N-dimethylaniline bound to glass by azo linkage to the silane. was washed extensively until molecules non-covalently adsorbed on the glass were not detectably eluted. The product was a bound indicator of the structure:

52 ocn N(CH3)2 O GLASS 0 831 N=N CH3 CH3 in acidic solutions of a pH below 4.0 it was burgundy in colour and underwent a colour change to pale orange-red between pH 4.05.5. The bound indicator retained colour and activity despite exposure to various organic and aqueous solvents and to strong acids and bases. Exposure to a sodium hypoehlorite solution caused irreversible colour change to pale yellow and hence its destruction as a useful bound indicator.

EXAMPLE IV The procedure of Example 11 was used to produce. from the reduced form of methylene blue. methylene blue bound by azo linkage to zirconia-clad glass. The glass is bright blue under most solution conditions. but turns reversibly pale yellow when exposed to strong reducing conditions such as Zinc dust in dilute sulfuric acid.

M HL

EXAMPLE V 2.4.6-trimeth0xybenzoic acid was dissolved in sulfonyl chloride and refluxed over a steam bath for 1 hour to give 2,4.6-trimethoxybenzoyl chloride. To 250 mg of this was added 10 ml of pyridine and l g of aminoalkylsilane porous glass (Corning GAO-3940). This mixture was stirred at room temperature. and then refluxed 30 minutes to give a glass complex with highly activated phenyl rings. presumably of the following structure:

This glass was decanted. washed in acetone and airdryed. The nitro group of Eriochrome Black T was reduced to an amino group. the product was recrystallized from ethanol. and: l g of this indicator derivative was added to 10 ml of glacial acetic acid over an icebath and diazotized with 0.5 g sodium nitrite. Then 1 g of the glass complex was added to this mixture. The resulting orange bound indicator was washed thoroughly with water. acetone and benzene until colour was no longer eluted. This orange bound indicator turned reversibly violet in the range pH 10.0 to 12.00.

EXAMPLE VI Nickel screen. of mesh and 0.1 mm thickness. was heated overnight in a furnace at 700 in an oxygen atmosphere to oxidize the surface. thus forming a NiO coating on the screen. The screen was then cut into strips 1 inch by 4 inches. which were rolled into cylinders of approximately 0.5 inch diameter and the ends soldered to prevent ravelling.

One of these NiO coated cylinders was refluxed overnight in a 10% solution of gamma-aminopropyltricthoxysilane in toluene. This aminoalkylsilane derivative was washed in toluene and air-dryed. The screen was refluxed in 10% thiophosgene in chloroform. The isothiocyanoalkylsilane derivative was washed with chloroform and coupled to ethoxazene. The bound indicator thus created underwent a colour change from red below pH 5 to yellow above pH 5.

EXAMPLE Vll 4-carboxy-alpha-hydroxy-alpha. alpha-bis (phydroxyphenol)-l-toluenesulfonic acid was prepared by condensing phenol with 3-carboxy-l-sulfobenzoic anhydride in the presence of zinc chloride. Equimolar quantities of this phenol red derivative and tri-npropylamine were combined with 3 molar equivalents of trichlorosilane in a vigorously exothermic reaction. After refluxing for 1 hour at 55-75 and treating the mixture with tri-n-propylamine hydrochloride in pentane, and ethanolysis, the product. an indicator silane. was isolated by low pressure distillation.

This silane coupling agent, 3-carboxyphenol red triethoxysilane was then bound to l g of porous 96V: silica glass in Example I. to give methylenephenol red glass which was red at pH 7.0 and below and changed to orange-yellow at pH 8.5.

EXAMPLE Vlll A bound indicator on a glass carrier was prepared by the procedure of Example I from fluorescein instead of phenolphthalein.

EXAMPLE lX A bound indicator on a glass carrier was prepared by the procedure of Example I from xylenol blue instead of phenolphthalein.

EXAMPLE X A bound indicator on a glass carrier was prepared by the procedure of Example I from cresol red instead of phenolphthalein.

While a number ofexamples of the bound indicators of this invention and methods of preparing them have been given. such disclosure is intended for illustration only and to impose no limitation on the scope of the invention beyond those included in the appended claims.

What is claimed is:

I. An insolubilized bound indicator useful in determining parameters such as hydrogen ion concentration (p"), oxidatiomreduction potential or specific ion concentrations in solutions consisting of an organic indicator covalently coupled by means of an organofunctional silane coupling agent to an inorganic carrier having available hydroxyl or oxide groups.

2. A bound indicator as claimed in claim 1 wherein said silane coupling agent is combined with said indicator by means of an alkyl linkage.

3. A bound indicator as claimed in claim 1 wherein said silane coupling agent is combined with said indicator by means of an azo linkage.

4. A bound indicator as claimed in claim I wherein said silane coupling agent is combined with said indicator by means of a sulfonamide linkage.

5. A bound indicator as claimed in claim 1 wherein said silane coupling agent is represented by the general formula in which X represents a substituted or unsubstituted aryl. alkyl or alkyl-aryl group, the substituent(s) being selected from groups which include hydroxy, lower alkoxy. amino, lower alkylamino, lower dialkylamino, alkyl. nitro, nitroso, diazo, cyano. isocyano, isothiocyano, carboxy, carbonyl, keto, halocarbonyl, sulfoxy and halosulfonyl; R represents a group which may be lower alkoxy, aryloxy or halogen; and n is one of the integers. l, 2 and 3.

6. A bound indicator as claimed in claim 1 wherein said carrier is a glass.

7. A bound indicator as claimed in claim 1 wherein said carrier is zirconia coated glass.

8. A bound indicator as claimed in claim 1 wherein said carrier is a metal oxide.

9. A bound indicator as claimed in claim 1 wherein said carrier is nickel oxide.

10. A bound indicator as claimed in claim 1 wherein said organic indicator is an N.N-dialkylaniline.

11. A bound indicator as claimed in claim I wherein said organic indicator is selected from the group consisting of diazo. amino. carboxy and alkylsilane derivatives of N,N-dimcthylaniline.

12. A bound indicator as claimed in claim 1 wherein said organic indicator is selected from the group consisting of B-naphthol and derivatives thereof.

13. A bound indicator as claimed in claim 1 wherein said organic indicator is selected from the group consisting of triarylmethyl compounds.

14. A bound indicator as claimed in claim 1 wherein said organic indicator is phenolphthalein.

15. A bound indicator as claimed in claim 1 wherein said indicator is methylene blue.

16. A bound indicator as claimed in claim 1 wherein said organic indicator is Eriochrome Black T.

l7. A process for the preparation of the bound indicator of claim 1 which includes the steps of providing a silane which has an organofunctional group, causing the silane to react with a carrier which has available hydroxyl or oxide groups. and causing the organofunctional group of the silane to react with an indicator.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2626855 *Jun 26, 1950Jan 27, 1953Wilfred C HandSeafood spoilage indicating system
US2929829 *Oct 12, 1956Mar 22, 1960Union Carbide CorpOrganosilicon acylamino compounds and process for producing the same
US3350175 *Jul 2, 1963Oct 31, 1967Mine Safety Appliances CoColorimetric indicator device for the determination of gases
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3998591 *Sep 26, 1975Dec 21, 1976Leeds & Northrup CompanySpectrochemical analyzer using surface-bound color reagents
US3999948 *Nov 3, 1975Dec 28, 1976International Diagnostic TechnologyDiagnostic reagent holder and method
US4034073 *Mar 28, 1975Jul 5, 1977Corning Glass WorksComposite for biased solid phase radioimmunoassay of triiodothyronine and thyroxine
US4050895 *Sep 17, 1976Sep 27, 1977Monsanto Research CorporationOptical analytical device, waveguide and method
US4056609 *Jan 28, 1976Nov 1, 1977Gunn, Kirchubel & MillerArticle for diagnosis of achlorhydria
US4142783 *May 31, 1977Mar 6, 1979International Business Machines CorporationCopolymer with covalently bonded electroactive molecules
US4166804 *Oct 14, 1977Sep 4, 1979Ceskoslovenska Akademie VedPolymeric color indicators and a method of their preparation
US4203952 *Sep 8, 1977May 20, 1980The British Petroleum Company LimitedProcess for the removal of heavy metals and transition metals other than platinum from solution
US4207075 *Aug 8, 1978Jun 10, 1980Liburdy Robert PRabbit immunoglobulin-N-(3-pyrene)-maleimide conjugate for fluorescent immunoassay
US4207200 *Mar 20, 1978Jun 10, 1980Hans BunemannSoluble complex former for the affinity specific separation of macromolecular substances, its preparation and its use
US4275300 *Oct 23, 1978Jun 23, 1981Varian Associates, Inc.Fluorescent composition, a process for synthesizing the fluorescent composition, and methods of use of the fluorescent composition
US4301027 *Jul 3, 1979Nov 17, 1981Dynamit Nobel AgColorimetric analysis
US4316041 *Feb 19, 1980Feb 16, 1982Union Carbide CorporationLiquid crystal silanes
US4377555 *Jul 27, 1977Mar 22, 1983The British Petroleum Company LimitedRemoval of metal from solution
US4396528 *Jun 9, 1981Aug 2, 1983Varian Associates, Inc.Fluorescent composition, a process for synthesizing the fluorescent composition
US4496482 *Oct 22, 1981Jan 29, 1985Union Carbide CorporationLiquid crystal silanes
US4530963 *Feb 24, 1983Jul 23, 1985Devoe-Holbein International, N.V.Insoluble chelating compositions
US4560248 *Aug 9, 1982Dec 24, 1985Imperial Chemical Industries, PlcFibre optic sensor with bonded dye
US4568518 *Dec 2, 1983Feb 4, 1986Avl AgCarrier membrane, immobilized network structure containing indicator
US4585559 *Jun 28, 1984Apr 29, 1986Devoe-Holbein International, N.V.Selective removal of metals from solution
US4626416 *Jun 22, 1984Dec 2, 1986Devoe-Holbein International, N.V.Insoluble carrier with organic coordinating sites
US4626693 *Mar 31, 1983Dec 2, 1986The Regents Of The University Of CaliforniaRemote multi-position information gathering system and method
US4654197 *Oct 12, 1984Mar 31, 1987Aktiebolaget LeoBlood analysis, disposable, semipermeable membrane
US4661338 *Nov 19, 1982Apr 28, 1987Societe D'etudes Scientifiques Et Industrielles De L'ile De FranceApplying indicator to stomach wall; noting coalor chagne
US4799756 *Nov 1, 1985Jan 24, 1989The Regents Of The University Of CaliforniaRemote multi-position information gathering system and method
US4803049 *Dec 12, 1984Feb 7, 1989The Regents Of The University Of CaliforniaFiber optic, rhodamine, fluorescein dye with silane coupler; indicates ph by fluorescence intensity
US4806311 *Aug 28, 1985Feb 21, 1989Miles Inc.Multilayer immunoassay test using detectable physical properties
US4806312 *Aug 28, 1985Feb 21, 1989Miles Inc.Multilayer immunoassay test using detectable chemical properties
US4824789 *Oct 10, 1986Apr 25, 1989Cardiovascular Devices, Inc.Gas sensor
US4867919 *Jan 26, 1989Sep 19, 1989Minnesota Mining And Manufacturing CompanyMethod of making a gas sensor
US4929561 *Aug 8, 1985May 29, 1990Regents Of The University Of CaliforniaFluoroescence, signals, absorbers
US4965087 *Mar 23, 1988Oct 23, 1990Avl AgMethod of making a sensor element for fluorescence-optical measurements
US4999306 *Apr 28, 1988Mar 12, 1991Minnesota Mining And Manufacturing CompanyComposition, apparatus and method for sensing ionic components
US5006314 *Jun 13, 1988Apr 9, 1991Minnesota Mining And Manufacturing CompanyMonitoring oxygen partial pressure of blood
US5019350 *Feb 13, 1986May 28, 1991Pfizer Hospital Products, Inc.Fluorescent polymers
US5047208 *Feb 23, 1989Sep 10, 1991Medtronic, Inc.Colorimetric analysis; optical fibers
US5057431 *Sep 15, 1988Oct 15, 1991Max Planck Gesellschaft Zur Forderung Der WissenschaftenDevice for optical measuring of physical dimensions and material concentrations
US5071769 *Dec 17, 1987Dec 10, 1991Abbott LaboratoriesMethod and device for ketone measurement
US5081041 *Apr 3, 1990Jan 14, 1992Minnesota Mining And Manufacturing CompanyIonic component sensor and method for making and using same
US5081042 *Mar 20, 1990Jan 14, 1992Minnesota Mining And Manufacturing CompanyIonic component sensor and method for making and using same
US5120510 *Dec 6, 1990Jun 9, 1992Minnesota Mining And Manufacturing CompanyBlood analyzing
US5175016 *Mar 20, 1990Dec 29, 1992Minnesota Mining And Manufacturing CompanyMethod for making gas sensing element
US5182353 *Jul 24, 1990Jan 26, 1993Puritan-Bennett CorporationMethod for bonding an analyte-sensitive dye compound to an addition-cure silicone
US5219527 *Aug 28, 1991Jun 15, 1993Puritan-Bennett CorporationAnalyte-permeable matrix which supports analyte-sensitive indicator solution in a plurality of vesicles
US5266271 *May 22, 1992Nov 30, 1993Puritan-Bennett CorporationOptical fiber, dye indicator
US5284775 *Sep 21, 1992Feb 8, 1994Minnesota Mining And Manufacturing CompanyBlends of sensing component, polymer precursor amd hydroxy-alkylcellulose dispersants; detecting carbon dioxIde in blood
US5326531 *Dec 11, 1992Jul 5, 1994Puritan-Bennett CorporationCO2 sensor using a hydrophilic polyurethane matrix and process for manufacturing
US5330718 *Oct 14, 1992Jul 19, 1994Puritan-Bennett CorporationCarbon dioxide, optical fibers
US5335305 *Oct 23, 1992Aug 2, 1994Optex Biomedical, Inc.Optical sensor for fluid parameters
US5397536 *Dec 8, 1993Mar 14, 1995Riken Keiko Co., Ltd.Silane gas detecting tape
US5407829 *Jun 29, 1993Apr 18, 1995Avl Medical Instruments AgMethod for quality control of packaged organic substances and packaging material for use with this method
US5408999 *Jun 2, 1994Apr 25, 1995Optex Biomedical, Inc.Fiber-optic probe for the measurement of fluid parameters
US5462052 *Apr 27, 1993Oct 31, 1995Minnesota Mining And Manufacturing Co.Apparatus and method for use in measuring a compositional parameter of blood
US5541115 *Jun 3, 1991Jul 30, 1996Abbott LaboratoriesMethod and device employing covalently immobilized colored dyes
US5830526 *Feb 19, 1997Nov 3, 1998Fibermark, Inc.Light-activated antimicrobial and antiviral materials
US5833882 *Jun 2, 1997Nov 10, 1998Japan Pionics Co., Ltd.Detecting agent
US6777243Mar 11, 2003Aug 17, 2004Arkray Inc.Measuring detectable substance by using aqueous reaction system including formation reaction of detectable substance based on chemical reaction of analyte contained in sample; reacting in presence of layered inorganic compound
US7098038Mar 11, 2003Aug 29, 2006Arkray Inc.Method for measuring substance and testing piece
US7153696Mar 11, 2003Dec 26, 2006Arkray Inc.Method for measuring substance and testing piece
US7189576Mar 11, 2003Mar 13, 2007Arkray Inc.Using dye; colorimetric analysis; forming insoluble compound
US7835003Dec 1, 2005Nov 16, 2010Schlumberger Technology CorporationpH detection system based on the chemical immobilization of a monolayer of chromophoric indicators, in a uniform orientation, onto a transparent substrate via a two-step reaction scheme
EP0039027A1 *Apr 18, 1981Nov 4, 1981Gerhard ScharfChemical compounds, method for their preparation, means containing these compounds and their application
EP0072627A2 *Jul 20, 1982Feb 23, 1983Imperial Chemical Industries PlcFibre optic sensor with bonded dye
EP0080411A1 *Nov 18, 1982Jun 1, 1983Societe D'etudes Scientifiques Et Industrielles De L'ile-De-FranceA colour indicator for the determination of hypoacidity in the gastric mucosa, utilizing gastroscopy
EP0211534A2 *Jul 14, 1986Feb 25, 1987DeVoe-Holbein International N.V.Insoluble composition for removing mercury from a liquid medium
WO2006059097A1 *Dec 1, 2005Jun 8, 2006Schlumberger HoldingsOptical ph sensor
WO2006097481A1 *Mar 15, 2006Sep 21, 2006Ng Bam Bundesanstalt Fuer MateOptochemical sensor membrane and method for producing the same
Classifications
U.S. Classification422/425, 436/169, 436/166
International ClassificationG01N31/22
Cooperative ClassificationG01N31/22, G01N31/221
European ClassificationG01N31/22, G01N31/22B