Sensor and detecting method

• US 20050170405A1
• Filed: 02/03/2005
• Published: 08/04/2005
• Est. Priority Date: 02/03/2004
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Utsunomiya, Norihiko
• Granted Patent: US 7,195,738 B2
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: B01L 2300/0636 Integrated biosensor, microarrays
• CPC Class Codes: B01L 2300/0645 Electrodes
• CPC Class Codes: B01L 3/508 rigid containers not provided for above
• CPC Class Codes: G01N 27/3276 being a hybridisation with immobilised receptors using a FET type sensor G01N27/4145; concerning the hybridisation C12Q1/68
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

A sensor for detecting a substance in a sample comprises composite-forming means which is comprised of a first capturing molecule and two or more electrodes, for forming on the two or more electrodes a composite comprising the first capturing molecule for specifically capturing the substance, the substance captured by the first capturing molecule and a second capturing molecule having a catalyst and being modified by the substance, current-detecting means for detecting a current flowing through at least one of the working electrodes having the catalyst thereon so as to detect a product formed when an catalytic substrate capable of acting with the catalyst is contacted with the catalyst, and substance-detecting means for determining the amount of the substance in the sample on the basis of the current value detected by the current-detecting means in a specified period of time after the catalyst has contacted with the catalytic substrate.

Claims

1. A sensor for detecting a substance in a sample comprising:

composite-forming means which is comprised of a first capturing molecule and two or more electrodes, for forming on the two or more electrodes a composite comprising the first capturing molecule for specifically capturing the substance, the substance captured by the first capturing molecule and a second capturing molecule having a catalyst and being modified by the substance;

current-detecting means for detecting a current flowing through at least one of the working electrodes having the catalyst thereon so as to detect a product formed when a catalytic substrate capable of acting with the catalyst is contacted with the catalyst; and

substance-detecting means for determining the amount of the substance in the sample on the basis of the current value detected by the current-detecting means in a specified period of time after the catalyst has contacted with the catalytic substrate.

2. The sensor according to claim 1, wherein the substance-detecting means determines the amount of the product from the current value, and then determines the amount of the substance in the sample from the amount of the product.

3. The sensor according to claim 2, wherein the specified period of time is shorter than the time necessary for the product to reach at least one of the electrodes adjacent to the electrode having the catalyst thereon which has formed the product.

4. The sensor according to claim 3 further comprising:

an electrode for detecting a crosstalk between the electrodes, wherein the specified period of time is the time necessary for the current flowing through an electrode for detecting the crosstalk to show a particular change; and

means for determining the captured amount of the substance, on the basis of the value of the detected current flowing through the electrode having the catalyst, in the period of time before the current has shown the particular change.

5. The sensor according to claim 2, wherein the first capturing molecule has a different specie on each of two or more electrodes from that of other bodies.

6. A detecting method for detecting a substance in a sample comprising the steps of:

forming on two or more electrodes a composite comprising a first capturing molecule for specifically capturing the substance, the substance captured by the first capturing molecule and a secondary capturing molecule having a catalyst and being modified by the substance;

detecting a current flowing through a working electrode having the catalyst thereon so as to detect a product formed when a catalytic substrate capable of acting with the catalyst contacts with the catalyst; and

determining the amount of the substance in the sample on the basis of the value of the current detected in a specified period of time after the catalyst has contacted with the catalytic substrate.

7. The detecting method according to claim 6, wherein the step of determining the amount of the substance in the sample comprises determining the amount of the product from the value of the current, and determining the amount of the substance in the sample from the amount of the product.