US 2019/0154580 A1 · OPTICAL DETECTION METHOD AND OPTICAL DETECTION DEVICE

Abstract

A problem is to provide an optical detection method that enables sensitive and quick detection of a micro target substance in a near field and such a device. As means for solving the problem, an optical detection method for a target substance detects light, such as fluorescence, as an optical signal from a conjugate comprising the target substance on a surface of a sensing plate in a near field, wherein the conjugate comprises at least the target substance bonding with a magnetic particle. The method comprises: detecting the target substance by measuring a decrease in the optical signal generated by applying a first magnetic field to move the conjugate in the direction parallel to or away from the surface, etc. An optical detection device comprises a liquid holding part comprising a sensing plate that can form a near field on a surface with light irradiated from a side of a rear face under a condition of total reflection, the liquid holding part being capable of holding a liquid sample comprising a target substance and a magnetic particle that forms a conjugate with the target substance on the surface of the sensing plate, a light irradiation unit, a light detection unit, and a magnetic field application unit configured to apply a magnetic field to move the conjugate in the direction parallel to or away from the surface, etc.

Claims15

Dependent claims

An optical detection method for a target substance that detects fluorescence or scattered light as an optical signal from a conjugate comprising the target substance on a surface of a sensing plate in a near field, comprising:

detecting the target substance by measuring a decrease in or a movement of the optical signal due to a conjugate moving step,
wherein the conjugate comprises at least the target substance bonding with a magnetic particle, and
the conjugate moving step is implemented by any one of the steps of:
a first conjugate moving step of applying a first magnetic field such that the conjugate moves in a direction parallel to the surface or away from the surface or such that orientation of the conjugate changes;
and a second conjugate moving step of drawing the conjugate on the surface by applying a second magnetic field from a magnetic field application unit disposed on a side of a rear face of the sensing plate, and moving the magnetic field application unit in a direction having a vector component parallel to an in-plane direction of the surface of the sensing plate while applying the second magnetic field so as to move the conjugate in accordance with the movement of the magnetic field application unit or change the orientation of the conjugate.

2 more elements

An optical detection device comprising:

a liquid holding part comprising a sensing plate that can form a near field on a surface with light irradiated from a side of a rear face under a condition of total reflection, the liquid holding part being capable of holding a liquid sample comprising a target substance and a magnetic particle that forms a conjugate with the target substance on the surface of the sensing plate;
a light irradiation unit configured to irradiate light from the side of the rear face of the sensing plate under the condition of total reflection;
a light detection unit disposed on a side of the surface of the sensing plate, the light detection unit being configured to detect fluorescence or scattered light emitted from the conjugate at a detection region on the surface and in the near field;
and
a magnetic field application unit comprising any one of a first magnetic field application unit configured to apply a first magnetic field such that the conjugate moves in a direction parallel to the surface or away from the surface or such that orientation of the conjugate changes, and a second magnetic field application unit disposed on the side of the rear face of the sensing plate, the second magnetic field application unit being configured to be capable of drawing the conjugate in the sample that is introduced on the surface of the sensing plate toward the surface of the sensing plate by applying a magnetic field, and move the conjugate in a direction having a vector component parallel to an in-plane direction of the surface of the sensing plate or change orientation of the conjugate while applying the magnetic field.

2 more elements

Dependencies are inferred from the claim text.

Optical detection method and optical detection device

Life of this patent

Optical detection method and optical detection device

Life of this patent

Abstract

Claims15