Abstract: A method and apparatus for non-invasively determining the concentration of a substance in blood, such as glucose, include a sample portion arranged for contacting an eye region of a user to obtain a tear fluid sample, a sensor in communication with the sample portion for generating a signal related to the tear substance concentration, and a processor in communication with the sensor for determining a blood substance concentration corresponding to the tear substance concentration.

Abstract: The present invention disclose a method for fabricating planar reference electrodes. Particularly, the present invention relates to the planar reference electrode comprising plate (4); electrode connection (1); electrode (3); insulating membrane (2); inner reference solution (5); junction (7 or 9); and protecting membrane (6, 8 or 9), and processes for fabrication thereof, in which the junction is composed of porous material such as cotton thread, glass fiber, cellulose nitrate, cellulose acetate, filter paper and any material that can produce capillary action; porous polymer membrane; or a capillary either directly printed on the substrate or inserted with a thin film. The planar reference electrode of the present invention exhibit stable electric potential and short activation period, and may be used in both potentiometry and voltammetry. The planar reference electrodes of the present invention can be easily miniaturized and mass produced.

Abstract: There is provided the reagent layer composition that can substantially reduce the measurement bias arising from hematocrits. The addition of fatty acid (4-20 carbons) and quaternary ammonium salt to a commonly used reagent layer composition composed of an enzyme, an electron transfer mediator, and several water soluble polymers not only reduce the hematocrit level-dependent bias but also provide very stable performance for an extended period of time. Disclosed are also various types of sub microliter sample volume electrochemical biosensors that are suitable to use with the reagent layer composition of present invention.

Abstract: Disclosed herein is a dual blood glucose meter. The dual blood glucose meter includes a meter body, a measurement strip, a variety of electronic parts and upper and lower strip receiving ports. The meter body is provided with a liquid crystal display panel on the front thereof to display measured numerical values and various pieces of pictorial information. The measurement strip is brought into contact with blood at a blood collection spot so as to measure blood glucose of the blood. The electronic parts are used to measure the blood glucose of the blood. The upper and lower strip receiving ports are formed at upper and lower ends of the meter body to receive the measurement strip, and are each electrically connected to the electric parts.

Abstract: Disclosed is a polymeric reference electrode membrane comprising (a) one selected from a porous polymer or a hydrophilic plasticizer; (b) a lipophilic polymer; and optionally an adhesion-enhancing material. A reference electrode equipped with the polymeric reference electrode membrane can be shortened the preconditioning time, and extended lifetime for storage and use owing to excellent adhesion, and showed reproducibility and good yield. So, a miniaturized multi-potentiometric sensor can be fabricated comprising a solid-state reference electrode of the present invention and a set of ion-selective electrodes, thus being useful in the potentiometric fields, including clinical, environmental, food and industrial analysis.

Abstract: A biosensor, for use in measurement of an analyte, includes a microporous membrane support, a first electrode system, a second electrode system, and a pair of insulating films. The first electrode system is formed on the surface of the microporous membrane support and the second electrode system is formed on the opposite surface of the microporous membrane support. The biosensor enables a rapid, simple, separation-free, and selective detection of the analytes. The biosensor does not require any bulky additional electrode, so that miniaturization, point-of-car testing, and disposability can be achieved.

Abstract: There is provided a microchip-based differential-type carbon dioxide gas sensor for detecting dissolved carbon dioxide levels. It functions with at least one working electrode composed of an unbuffered hydrogel membrane containing a certain amount of sodium bicarbonate and a pH-sensitive gas-permeable membrane; and a reference electrode composed of a buffered hydrogel membrane and a pH-sensitive gas-permeable membrane. The unbuffered hydrogel membrane contains carbonic anhydrase, which reduces the time period for the hydration of carbon dioxide, thereby allowing the quick measurement of the level of carbon dioxide. In addition to being significantly improved in stabilization, sensing, and recovering time periods, the differential-type carbon dioxide gas sensor can be fabricated in small sizes and quickly measure levels of carbon dioxide dissolved in sample solution.

Abstract: Disclosed is a porous membrane built-in biosensor comprising (a) at least one substrate; (b) an electrode layer patterned on the substrate, consisting of an electrode system and a circuit connector; (c) an insulator, formed on parts of the electrode layer, for electrically separating the electrode system from a circuit connector; and (d) a porous membrane via the insulator on the electrode system, wherein, when a whole blood sample is introduced to the biosensor, the whole blood sample is separated into its components during the chromatographic motion through the porous membrane so that only blood plasma can be contacted with the electrode system. The porous membrane built-in biosensor is provided with a sample inlet, which allows samples to be introduced in a constant quantity to the biosensors porous membranes without pretreatment.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

Abstract: A method and apparatus for non-invasively determining the concentration of a substance in blood, such as glucose, include a sample portion arranged for contacting an eye region of a user to obtain a tear fluid sample, a sensor in communication with the sample portion for generating a signal related to the tear substance concentration, and a processor in communication with the sensor for determining a blood substance concentration corresponding to the tear substance concentration.

Abstract: The present invention relates to a reference electrode for a potentiometric electrode system, characterized in that the junction in contact with a sample solution is enlarged and an ion-sensitive membrane containing an ion selective material as a protective membrane for the inner reference solution is employed, which comprises a substrate; a metal layer; an insoluble metal salt layer; an insulating film for insulating the metal layer from an aqueous solution; a hydrogel serving as an inner reference solution; the junction on the hydrogel contacting with a sample solution; the ion-sensitive, protective membrane formed over all surface areas of the hydrogel, except for the junction, to separate the sample solution from the inner reference solution or act as an ion-sensing membrane upon the contamination of the junction, whereby the operational abnormality caused by junction contamination may be easily checked and fast activation may be achieved.

Abstract: Disclosed is a method for fabricating biosensors, using hydrophilic polyurethane. Bio-active reagents, including enzymes, antibodies, antigens, cells and receptors, are mixed with hydrophilic polyurethane and the mixture is directly coated over a signal transducer to form a sensing film which serves as a signal detector. The method using hydrophilic polyurethane allows the simplification of the fabrication of biosensors without conducting complicated chemical reactions and washing steps, such as crosslinking. The bio-active reagent entrapped within the hydrophilic polyurethane film can retains its high activity for an extended period of time and the intrinsic potentiometric response of the underlying ion-selective polymeric membrane is not affected by the bio-active reagent immobilized polyurethane film coated on its sensing surface. Therefore, the biosensors are superior in specificity, selectivity, and stability.

Abstract: Disclosed is a method for fabricating biosensors, using hydrophilic polyurethane. Bio-active reagents, including enzymes, antibodies, antigens, cells and receptors, are mixed with hydrophilic polyurethane and the mixture is directly coated over a signal transducer to form a sensing film which serves as a signal detector. The method using hydrophilic polyurethane allows the simplification of the fabrication of biosensors without conducting complicated chemical reactions and washing steps, such as crosslinking. The bio-active reagent entrapped within the hydrophilic polyurethane film can retains its high activity for an extended period of time and the intrinsic potentiometric response of the underlying ion-selective polymeric membrane is not affected by the bio-active reagent immobilized polyurethane film coated on its sensing surface. Therefore, the biosensors are superior in specificity, selectivity, and stability.

Abstract: Disclosed is a microchip-based differential-type potentiometric oxygen gas sensor, which comprises a working electrode and a reference electrode. The working electrode is composed of a cobalt-plated electrode, a buffered hydrogel, and an ion sensitive gas permeable membrane while the reference electrode is composed of an oxygen non-sensitive silver chloride electrode and the same ion-selective gas-permeable membrane of working electrode. By taking advantage of the corrosion potential, the microchip-based oxygen gas sensor can accurately and quickly detect the content of dissolved oxygen in a sample solution. With this structure, the oxygen gas sensor is applied to a microchip-based all potentiometric multi-sensor capable of detecting two or more ions and gas species on a single chip.

Abstract: Disclosed is a polymeric reference electrode membrane comprising (a) one selected from a porous polymer or a hydrophilic plasticizer; (b) a lipophilic polymer; and optionally an adhesion-enhancing material. A reference electrode equipped with the polymeric reference electrode membrane can be shortened the preconditioning time, and extended lifetime for storage and use owing to excellent adhesion, and showed reproducibility and good yield. So, a miniaturized multi-potentiometric sensor can be fabricated comprising a solid-state reference electrode of the present invention and a set of ion-selective electrodes, thus being useful in the potentiometric fields, including clinical, environmental, food and industrial analysis.

Abstract: Disclosed is a porous membrane built-in biosensor comprising (a) at least one substrate; (b) an electrode layer patterned on the substrate, consisting of an electrode system and a circuit connector; (c) an insulator, formed on parts of the electrode layer, for electrically separating the electrode system from a circuit connector; and (d) a porous membrane via the insulator on the electrode system, wherein, when a whole blood sample is introduced to the biosensor, the whole blood sample is separated into its components during the chromatographic motion through the porous membrane so that only blood plasma can be contacted with the electrode system. The porous membrane built-in biosensor is provided with a sample inlet, which allows samples to be introduced in a constant quantity to the biosensors porous membranes without pretreatment.

Abstract: The present invention relates to chloride-selective electrodes which comprise insoluble metal salt layer and a protecting membrane formed of hydrophilic polyurethane thereon, wherein the hydrophilic polyurethane coated chloride-selective electrodes show fast activation and response time and are usefully employed to accurately measure the chloride by reducing the interference from bromide and iodide or preventing the surface of the electrode from protein adsorption.

Abstract: There is provided a microchip-based differential-type carbon dioxide gas sensor for detecting dissolved carbon dioxide levels. It functions with at least one working electrode composed of an unbuffered hydrogel membrane containing a certain amount of sodium bicarbonate and a pH-sensitive gas-permeable membrane; and a reference electrode composed of a buffered hydrogel membrane and a pH-sensitive gas-permeable membrane. The unbuffered hydrogel membrane contains carbonic anhydrase, which reduces the time period for the hydration of carbon dioxide, thereby allowing the quick measurement of the level of carbon dioxide. In addition to being significantly improved in stabilization, sensing, and recovering time periods, the differential-type carbon dioxide gas sensor can be fabricated in small sizes and quickly measure levels of carbon dioxide dissolved in sample solution.

Abstract: The present invention disclose a method for fabricating planar reference electrodes. Particularly, the present invention relates to the planar reference electrode comprising plate (4); electrode connection (1); electrode (3); insulating membrane (2); inner reference solution (5); junction (7 or 9); and protecting membrane (6, 8 or 9), and processes for fabrication thereof, in which the junction is composed of porous material such as cotton thread, glass fiber, cellulose nitrate, cellulose acetate, filter paper and any material that can produce capillary action; porous polymer membrane; or a capillary either directly printed on the substrate or inserted with a thin film. The planar reference electrode of the present invention exhibit stable electric potential and short activation period, and may be used in both potentiometry and voltammetry. The planar reference electrodes of the present invention can be easily miniaturized and mass produced.

Abstract: The present invention relates to a measuring device which comprises electrodes fabricated on porous membrane substrate in which the sample migrates chromatographically; and the method of quantifying material in the sample by using the device. The sample material for measuring can be quantified by the measuring device of this invention, which is consists pretreatment bands in the lower part of porous membrane substrate and electrodes in the upper prt of pretreatment bands, by the procedure as foolows: The sample material for measuring is chromatographically migrated in the porous membrane substrate by applying the sample on the lower part of the porous membrane substrate; and then the changes of electric signal by the material at the electrode are measured to quantify the material.