Liquid purification or separation – Constituent mixture variation responsive – With membrane
Patent
1993-11-04
1995-11-21
Drodge, Joseph W.
Liquid purification or separation
Constituent mixture variation responsive
With membrane
156250, 204415, 204418, 204419, 210490, 427245, B01D 6900, G01N 2740
Patent
active
054683742
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention concerns a miniaturized sensor component for measuring concentrations of substances in liquids. The sensor component comprises a support. The support contains cavities. The cavities accommodate a membrane. The membrane is produced in situ by polymerization or by precipitation from a solution. An electric lead is either mechanically connected to or integrated into the membrane and is in contact with the membrane.
The present invention also concerns a method of manufacturing such a sensor component.
The membranes in miniaturized sensor components of the aforesaid genus are ion-selective. The sensors are employed in medicine to measure blood-electrolyte levels and in environmental engineering to determine how contaminated drinking water might be.
Manufacturing miniaturized ion-selective electrodes (ISE's) by the "wire-coating" method is known (P. Berveld, Development and Application of Chemical Sensors in Liquids, in Sensors and Sensory Systems for Advanced Robots, Berlin and Heidelberg, Springer, 1988, 403). A slender silver wire is coated with an ion-selective polymer membrane obtained from a liquid by immersing the wire in a solution for example.
Ion-selective electrodes can also be manufactured by coating a sheet of plastic instead of wire (U. Lemke & K. Cammann, Coated Film Electrodes, Fresenius Z. Anal. Chem. 335 [1989], 852-54). In their simplest form, these electrodes comprise an ion-selective polymer membrane over a thin layer of silver on the plastic.
Methods for producing such ion-selective polymer membranes are also known (Fluka Feinchemikalien Gmbh, Neu-Ulm sales literature, Selectophore Ionophores for Ion-Selective Electrodes). Such a membrane typically consists of a polyvinyl-chloride matrix containing both a softener and an electrically active substance (an ionophore) that determines what ions the membrane will allow through. The substance, dissolved in such a solvent as tetrahydrofuran, is cast into a membrane that solidifies as the solvent evaporates.
Slightly more complicated than the aforesaid sensor components are what are called thin-film electrodes (K. Cannann et al, Chemo- und Biosensoren-Grundlagen und Anwendungen, Z. Angew. Chem. 103 [1991], 519-541]. These components have a layer of silver chloride between the elemental silver and the ion-selective polymer membrane as well as a solidified layer of reference electrolytes. The reference electrolytes make it possible to establish a constant potential difference between the membrane and the silver.
The potential at the phase boundary between the solution being tested and the ion-selective membrane in such an electrode will vary with the ionic activity of the solution and hence with its concentration of ions. The variation can be compared with a reference electrode of constant potential.
Several ion-selective membranes can be combined on a common support to make a multiple sensor (European Patent Application No. 0,302,228 A2).
Using ion-selective electrodes to make biological sensor components is also known. An enzyme is established in the ion-selective membrane, at its surface, or in or on another membrane or layer of gel by adsorption, gel inclusion, covalent coupling, or cross-linking. Glucose oxidase for instance can be employed to manufacture potentiometric glucose sensors (F. Scheller & F. Schubert, Biosensoren, Berlin, Akademie-Verlag, 1989, 89 & 49-52).
The known sensor components have drawbacks. Thin-film electrodes for instance are complicated to manufacture. Coated-sheet electrodes are easier to make by casting or cementing, but each sensor component is made, and must accordingly be calibrated, separately.
SUMMARY OF THE INVENTION
The object of the present invention is accordingly to improve such sensor components for chemical and biological sensing devices to the extent that they can be manufactured simply and cost-effectively. The sensor components are by the way obtained from sheet. Their sensing capabilities are inherent in the sheet itself. The sheet is trimmed into a
REFERENCES:
patent: 2510262 (1950-06-01), Sollner et al.
patent: 3668101 (1972-06-01), Bergman
patent: 4454007 (1984-06-01), Pace
patent: 5063081 (1991-11-01), Cozzette et al.
patent: 5120504 (1992-06-01), Petro-Poy et al.
patent: 5350518 (1994-09-01), Hiti et al.
Drodge Joseph W.
Milde Jr. Karl F.
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