Magnetic sensor, production method of the same, and target substance detecting apparatus and biosensor kit using the same

• US 8,092,745 B2
• Filed: 01/26/2011
• Issued: 01/10/2012
• Est. Priority Date: 04/11/2006
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ikeda, Takashi, Okano, Kazuhisa
• Primary Examiner(s): Gordon, Brian R
• Assistant Examiner(s): Sasaki, Shogo
• Application Number:
  US13/014,667
• Publication Number:
  US 20110117676A1
• Time in Patent Office: 349 Days
• Field of Search: 422/61, 422/186.01, 422/68.1, 422/83, 436/526, 436/149, 436/806
• US Class Current: 422/68.1
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01N 27/745 for detecting magnetic beads used in biochemical assays concerning the assays G01N33/54326; sensors therefor G01R33/1269; automatic analysers therefor G01N35/0098
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G01R 33/1269 of molecules labeled with magnetic beads magnetic particles for bio assay G01N33/54326
• CPC Class Codes: Y10S 436/806 Electrical property or magnetic property

Abstract

The present invention provides a magnetic sensor which detects a target substance indirectly by making a labeling substance larger than the target substance bond with the target substance contained in a sample in a detection area, and detecting the labeling substance, comprising a capture area which is relatively easy to capture the target substance, and a non-capture area which is relatively hard to capture the target substance, on a surface of a member which is comprised in a detection area, wherein the capture area is surrounded by the non-capture area. Thereby, the sensor enables to detect comparatively accurately the number and concentration of substances which cannot be directly detected, and enables to be used for detection of various target substances.

Claims

1. A method for magnetic sensing using a magnetic sensor to detect a target substance in a sample,

wherein the magnetic sensor comprises a magnetic field detecting element,

wherein the method comprises detecting the target substance in the sample indirectly by immobilizing the target substance to a surface of the magnetic field detecting element, by making a labeling substance larger than the target substance bond with the target substance immobilized on the surface of the magnetic field detecting element, and by detecting a change of magnetic field using the magnetic field detecting element, the change of magnetic field being due to the target substance being immobilized to the magnetic field detecting element and consequently the target substance being close to the magnetic filed detecting element,

wherein the labeling substance is a magnetic particle,

wherein the surface of the magnetic field detecting element to which the sample is in contact comprises a first plurality of areas each of which has a substance that specifically captures the target substance,

wherein each of the first plurality of areas is surrounded by a second area which does not have the substance that specifically captures the target substance,

wherein a distance between respective ones of the first plurality of areas is larger than a diameter of the labeling substance, and

wherein each of the first plurality of areas has a size such that only one molecule of the target substance is captured.

2. The method according to claim 1, wherein the first plurality of areas is formed as a plurality of dots.

3. The method according to claim 1, wherein each of the first plurality of areas comprises gold, and the second area comprises silicon.

4. The method according to claim 3, wherein the second area comprises either silicon nitride or silicon oxide.