Abstract: A biosensor, a measuring instrument for biosensor, and a method of quantifying a substrate contained in specimen liquid to reduce a measurement error by the biosensor; a biosensor, comprising at least a pair of electrodes formed on an insulation substrate; a measuring instrument, comprising a supporting part for detachably supporting the biosensor, a plurality of connection terminals electrically connected to the electrodes, and a drive power supply for applying a voltage to the electrodes through the connection terminals; wherein the biosensor is inserted into the measuring instrument, either one of the electrodes of the biosensor is connected to first and second connection terminals fined to the measuring instrument only when the biosensor is inserted into the support part of the measuring instrument in a specified direction and has an electrode structure to allow the first connection terminal to conduct with the second connection terminal when a voltage is applied by the drive power supply.

Abstract: A glucose sensor system comprising the steps of using as a sample discriminating parameter a ratio (I/?I) of a measured current value I to the time-differential value of the current value ?I, defining a discrimination function that discriminates whether a sample is blood or control fluid and uses the discriminating parameter as an independent variable, quantitating as a discriminating index a numeric value obtained by substituting a discriminating parameter value into this discrimination function, and automatically discriminating, based on this index, whether the sample is blood or a control fluid, whereby a kind of the sample can be automatically quantitated by measuring electric current when a sensor system is used for quantitating the concentration of an analysis object in the sample.

Abstract: A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltage to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction, and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.

Abstract: A method of measuring a quantity of a substrate contained in sample liquid is provided. This method can reduce measurement errors caused by a biosensor. The biosensor includes at least a pair of electrodes on an insulating board and is inserted into a measuring device which includes a supporting section for supporting detachably the biosensor, plural connecting terminals to be coupled to the respective electrodes, and a driving power supply which applies a voltage to the respective electrodes via the connecting terminals. One of the electrodes of the biosensor is connected to the first and second connecting terminals of the measuring device only when the biosensor is inserted into the measuring device in a given direction, and has a structure such that the electrode becomes conductive between the first and second connecting terminals due to a voltage application by the driving power supply.

Abstract: The present invention provides a high-performance glucose sensor having excellent storage stability and an improved response characteristic. This sensor comprises: an electrically insulating base plate; an electrode system including at least a working electrode and a counter electrode formed on the base plate; and a reaction layer containing at least pyrrolo-quinoline quinone dependent glucose dehydrogenase, formed in contact with or in the vicinity of the electrode system, and the reaction layer contains at least one kind of additive selected from the group consisting of gluconic acid and salts thereof.

Abstract: According to the standard solution and the determination method of the present invention, in a case where a voltage is applied by a drive voltage of a measurement apparatus to an electrode portion of a biosensor comprising an electrode portion including a counter electrode and a measuring electrode formed on an insulating substrate, and a reagent layer which reacts with a sample solution supplied to the electrode portion, and a current value which flows at the application is measured, thereby determining a substrate contained in the sample solution, a reducing substance is contained in the standard solution used for controlling a precision of measurement of the measurement apparatus. Therefore, when the standard solution is measured, a large change occurs in a current waveform between time t0 and t1 shown in FIG. 6 due to the reducing substance, thereby discriminating whether the analyte liquid being measured is the standard solution or the sample solution and easily identifying the kind of analyte liquid.

Abstract: In a biosensor for measuring a specific substance in a liquid sample, one or a combination of sugar alcohol, metallic salt, organic acid or organic acid salt which has at least one carboxyl group in a molecule, and organic acid or organic acid salt which has at least one carboxyl group and one amino group in a molecule, is included in a reagent layer provided on electrodes, thereby providing a highly-accurate biosensor which is excellent in stability and has high response (sensitivity, linearity) of the sensor to the substrate concentration.

Abstract: In a biosensor for measuring a specific substance in a liquid sample, one or a combination of sugar alcohol, metallic salt, organic acid or organic acid salt which has at least one carboxyl group in a molecule, and organic acid or organic acid salt which has at least one carboxyl group and one amino group in a molecule, is included in a reagent layer provided on electrodes, thereby providing a highly-accurate biosensor which is excellent in stability and has high response (sensitivity, linearity) of the sensor to the substrate concentration.

Abstract: A reaction layer 12 which reacts with a substance to be measured in a sample solution is provided on a working electrode 1, a counter electrode 2, and a third electrode 3 which are provided on an insulating substrate 7 so as to bridge the respective electrodes, the content of the substance to be measured is measured from a current value which reaction is obtained between the working electrode 1 and the counter electrode 2, and the types of sample solution is judged by a difference between oxidation current values or between oxidation current waveforms, which are obtained between the third electrode 3 and the counter electrode 2 or between the third electrode 3 and the working electrode 1, thereby automatically judging the types of sample solution.

Abstract: The invention provides a biosensor comprising a support; a conductive layer composed of a electrical conductive material such as a noble metal, for example gold or palladium, and carbon; slits parallel to and perpendicular to the side of the support; working, counter, and detecting electrodes; a spacer which covers the working, counter, and detecting electrodes on the support; a rectangular cutout in the spacer forming a specimen supply path; an inlet to the specimen supply path; a reagent layer formed by applying a reagent containing an enzyme to the working, counter, and detecting electrodes, which are exposed through the cutout in the spacer; and a cover over the spacer. The biosensor can be formed by a simple method, and provides a uniform reagent layer on the electrodes regardless of the reagent composition.

Abstract: A biosensor includes a pair of conductive lead parts formed on an insulating substrate, a working electrode and a counter electrode formed at the ends of the conductive lead parts, respectively, and a reaction layer formed so as to bridge the electrodes and react with a measurement target substance in a specimen liquid. The biosensor measures the content of the measurement target substance from an electric current value based on the reaction between the measurement target substance and the reaction layer, which current value is obtained through the pair of conductive lead parts. The reaction layer is not provided above at least one of the conductive lead parts so that the reaction layer and the conductive lead parts do not contact directly even when pin holes or cracks are generated in the electrodes.

Abstract: A biosensor for analyzing specific components in an introduced liquid sample by reaction of the liquid sample with a reagent comprises a cavity into which the liquid sample is introduced, an air hole communicating from the cavity to outside, and a water repellent part having a water repellency at 43 mN/m or less in surface free energy and provided to at least a portion around the outlet of the air hole. By the water repellent part around the air hole, the liquid sample can be prevented from flowing out through the air hole, thereby achieving a high-accuracy measurement.

Abstract: A biosensor having an electrode layer, which includes a working electrode and a counter electrode, and a reagent layer 10 are formed on an insulating support. Further, a spacer having a long and narrow cut-out portion on the reagent layer is bonded to a cover having an air hole to form a cavity that sucks blood as a liquid sample by capillary phenomenon, and a portion of side walls of the spacer and the cover, which side walls face the cavity, is subjected to a treatment for making the portion itself have hydrophilicity. Accordingly, when blood is sucked into the cavity by capillary phenomenon, the suction is promoted, and the performance of a sensor of the biosensor is improved. Further, the process of manufacturing the sensor is simplified, thereby resulting in increased productivity.

Abstract: A glucose sensor system comprising the steps of using as a sample discriminating parameter a ratio (I/&Dgr;I) of a measured current value I to the time-differential value of the current value &Dgr;I, defining a discrimination function that discriminates whether a sample is blood or control fluid and uses the discriminating parameter as an independent variable, quantitating as a discriminating index a numeric value obtained by substituting a discriminating parameter value into this discrimination function, and automatically discriminating, based on this index, whether the sample is blood or a control fluid, whereby a kind of the sample can be automatically quantitated by measuring electric current when a sensor system is used for quantitating the concentration of an analysis object in the sample.

Abstract: A glucose sensor system comprising the steps of using as a sample discriminating parameter a ratio (I/&Dgr;I) of a measured current value I to the time-differential value of the current value &Dgr;I, defining a discrimination function that discriminates whether a sample is blood or control fluid and uses the discriminating parameter as an independent variable, quantitating as a discriminating index a numeric value obtained by substituting a discriminating parameter value into this discrimination function, and automatically discriminating, based on this index, whether the sample is blood or a control fluid, whereby a kind of the sample can be automatically quantitated by measuring electric current when a sensor system is used for quantitating the concentration of an analysis object in the sample.

Abstract: A biosensor according to the present invention comprises a support 1, a conductive layer 2 composed of an electrical conductive material such as noble metal, for example gold, palladium or the like, and carbon, slits 3a and 3b parallel to the side of the support 1, slits 4a and 4b vertical to the side of the support 1, a working electrode 5, a counter electrode 6, a detecting electrode 7, a spacer 8 which covers the working electrode 5, the counter electrode 6 and the detecting electrode 7 on the support 1, a rectangular cutout part 9 forming a specimen supply path, an inlet 9a of the specimen supply path, a reagent layer 12 formed by applying a reagent including an enzyme or the like to the working electrode 5, the counter electrode 6 and the detecting electrode 7, which is exposed from the cutout part 9 of the spacer 8, and a cover 13 which covers the spacer 8, as shown in FIG. 1.

Abstract: A biosensor according to the present invention comprises a support 1, a conductive layer 2 composed of an electrical conductive material such as noble metal, for example gold, palladium or the like, and carbon, slits 3a and 3b parallel to the side of the support 1, slits 4a and 4b vertical to the side of the support 1, a working electrode 5, a counter electrode 6, a detecting electrode 7, a spacer 8 which covers the working electrode 5, the counter electrode 6 and the detecting electrode 7 on the support 1, a rectangular cutout part 9 forming a specimen supply path, an inlet 9a of the specimen supply path, a reagent layer 12 formed by applying a reagent including an enzyme or the like to the working electrode 5, the counter electrode 6 and the detecting electrode 7, which is exposed from the cutout part 9 of the spacer 8, and a cover 13 which covers the spacer 8, as shown in FIG. 1.

Abstract: The present invention provides a high performance glucose sensor which can demonstrate high stability against preservation and produces only a low blank value. The glucose sensor comprises an electrically insulating base plate, an electrode system formed on the base plate, and a reaction layer which is formed in contact with or in the vicinity of the electrode system and contains at least a glucose dehydrogenase whose coenzyme is pyrrolo-quinoline quinone, the reaction layer further containing an additive such as phthalic acid.

Abstract: An electrode layer comprising a working electrode 1 and a counter electrode 2, and a reagent layer 10 are formed on an insulating support 5 and, further, a spacer 7 having a long and narrow cut-out portion on the reagent layer 10 is bonded to a cover 6 having an air hole 9 to form a cavity 12 that sucks blood as a liquid sample by capillary phenomenon, and a portion of side walls of the spacer 7 and the cover 6, which side walls face the cavity 12, is subjected to a treatment for making the portion itself have hydrophilicity.

Abstract: The oil pan structure of the present invention comprises an oil pan separator 3, disposed within an oil pan 2, for separating a main chamber provided with a suction port disposed therewithin and a sub chamber provided with no suction port from each other, the oil pan separator 3 having a recess forming the main chamber, the main chamber communicating with the inside of an engine block 1, the recess being formed with communication holes 3c, 3d for communicating the main and sub chambers to each other. The sub chamber is formed so as to surround the main chamber as a whole, whereas the outer face of the bottom part of the oil pan separator 3 and the inner face of the bottom part of the oil pan 2 are not in contact with each other. Therefore, raising the temperature of engine oil within the main chamber earlier can lubricate the engine more effectively.