Biosensor and method of quantitative analysis using the same

Claim 1

A method of quantitative analysis of a specific compound in a liquid sample comprising supplying said liquid sample to a biosensor wherein said biosensor comprises an electrochemical means for detecting the product of a reaction of said specific compound with a biologically active material, and wherein said biologically active material is located at a position remote from the electrochemical detecting means, reading at least two electrochemical signals from the biosensor, which signals are at least a first electrochemical signal produced at the supply of the sample and generated by an electrochemically active substance present in the sample but not a product of a reaction of said specific substance with said biologically active material, and at least a second electrochemical signal generated later than said first signal by a product of a reaction of said specific compound with said biologically active material, and operating both signals, whereby the amount of said specific substance is quantitatively measured.

Claim 2

A method of quantitative analysis of a specific compound in a liquid sample comprising supplying said liquid sample to a biosensor wherein said biosensor comprises an electrochemical means for detecting the product of a reaction of said specific compound with a biologically active material, and wherein said biologically active material is located at a position remote from the electrochemical detecting means, reading at least two electrochemical signals from the biosensor, which signals are at least a first electrochemical signal produced at the supply of the sample and generated by an electrochemically active substance present in the sample but not a product of a reaction of said specific substance with said biologically active material, and at least a second electrochemical signal generated later than said first signal by a product of a reaction of said specific compound with said biologically active material, and operating both signals, whereby the amount of said specific substance is quantitatively measured.

Claim 3

A method for the quantitative analysis of a material comprising: (a) providing a biosensor comprising a measuring electrode, a mediator, and a biologically active material located at a distance from said measuring electrode; (b) supplying a liquid sample of said material, comprising the object substance to be analyzed and an interfering substance, to said biosensor; (c) reading a first electrochemical signal from said measuring electrode within a time period sufficient to allow said mediator to react with said interfering substance and the product of that reaction to reach said measuring electrode, but insufficient for a reaction product of said biologically active material and said object substance to reach said electrode; (d) reading a second electrochemical signal from said measuring electrode after a time sufficient to allow said reaction product of said biologically active material and said object substance to reach said measuring electrode; (e) determining a concentration of said interfering substance from said first electrochemical signal, and a combined concentration of said interfering substance and said reaction product from said second electrochemical signal; (f) subtracting said concentration of said interfering substance from said combined concentration of said interfering substance and said reaction product; and (g) obtaining thereby a concentration of said object substance.

Claim 4

A method for the quantitative analysis of a material comprising: (a) providing a biosensor comprising a measuring electrode, a mediator, and a biologically active material located at a distance from said measuring electrode; (b) supplying a liquid sample of said material, comprising the object substance to be analyzed and an interfering substance, to said biosensor; (c) reading a first electrochemical signal from said measuring electrode within a time period sufficient to allow said mediator to react with said interfering substance and the product of that reaction to reach said measuring electrode, but insufficient for a reaction product of said biologically active material and said object substance to reach said electrode; (d) reading a second electrochemical signal from said measuring electrode after a time sufficient to allow said reaction product of said biologically active material and said object substance to reach said measuring electrode; (e) determining a concentration of said interfering substance from said first electrochemical signal, and a combined concentration of said interfering substance and said reaction product from said second electrochemical signal; (f) subtracting said concentration of said interfering substance from said combined concentration of said interfering substance and said reaction product; and (g) obtaining thereby a concentration of said object substance.

Claim 14

A method for quantitative analysis of an analyte in a liquid sample which comprises: i) contacting said sample with an electrode having coated thereupon a mediator substance which is electrochemically active upon reaction with a contaminant substance present in said sample; ii) concurrently with step (i), contacting said sample with a composition comprising said mediator substance admixed with a biologically active substance wherein said biologically active substance specifically reacts with said analyte to produce an intermediate product moiety that is electrochemically reactive with said mediator; iii) measuring a first electrical current at said electrode, at a first time, which results from the electrochemical reaction of said contaminant with said mediator; iv) measuring a second electrical current at said electrode, at a second time later than said first time, which results from the electrochemical reaction of said intermediate product moiety with said mediator and also from the reaction of said contaminant with said mediator; v) subtracting the current measured in step (iii) from the current measured in step (iv) to obtain a corrected current resulting only from the intermediate product moiety with said mediator; and vi) comparing the corrected current obtained in step (v) to a calibration curve relating corrected current to analyte concentration to obtain a quantitative value of the analyte concentration.

Claim 15

A method for quantitative analysis of an analyte in a liquid sample which comprises: i) contacting said sample with an electrode having coated thereupon a mediator substance which is electrochemically active upon reaction with a contaminant substance present in said sample; ii) concurrently with step (i), contacting said sample with a composition comprising said mediator substance admixed with a biologically active substance wherein said biologically active substance specifically reacts with said analyte to produce an intermediate product moiety that is electrochemically reactive with said mediator; iii) measuring a first electrical current at said electrode, at a first time, which results from the electrochemical reaction of said contaminant with said mediator; iv) measuring a second electrical current at said electrode, at a second time later than said first time, which results from the electrochemical reaction of said intermediate product moiety with said mediator and also from the reaction of said contaminant with said mediator; v) subtracting the current measured in step (iii) from the current measured in step (iv) to obtain a corrected current resulting only from the intermediate product moiety with said mediator; and vi) comparing the corrected current obtained in step (v) to a calibration curve relating corrected current to analyte concentration to obtain a quantitative value of the analyte concentration.