An apparatus for label-free analysis of molecules, including interactions and reactions of the molecules, is disclosed. The apparatus is based on detecting molecule movement under the influence of an external electric field. The apparatus is able to achieve sensitive detection of molecular binding to proteins or other molecules, and conformational changes of proteins or other molecules and biochemical reactions of the proteins or other molecules. Applications of the apparatus include screening of drug molecules, kinetic analysis of posttranslational modification of proteins, and small molecule-protein interactions.

The present invention relates to a DNA aptamer binding specifically to tuberculosis specific antigen 7.7 kDa (TB7.7), a biosensor for diagnosis of tuberculosis, comprising the same, and a method for providing information for diagnosis of tuberculosis. The present inventors found that not only does a DNA aptamer according to the present invention have specific binding potential to TB7.7 protein, but also the binding affinity is excellent. When used, the DNA aptamer of the present invention can be thus expected to exhibit greater stability than a conventional ELISA method using an antibody. Hence, the aptamer is expected to find useful applications in the development of compositions for tuberculosis diagnosis, biosensors for tuberculosis diagnosis, and information providing methods for tuberculosis diagnosis.

The present invention relates to a DNA aptamer binding specifically to tuberculosis specific antigen 7.7 kDa (TB7.7), a biosensor for diagnosis of tuberculosis, comprising the same, and a method for providing information for diagnosis of tuberculosis. The present inventors found that not only does a DNA aptamer according to the present invention have specific binding potential to TB7.7 protein, but also the binding affinity is excellent. When used, the DNA aptamer of the present invention can be thus expected to exhibit greater stability than a conventional ELISA method using an antibody. Hence, the aptamer is expected to find useful applications in the development of compositions for tuberculosis diagnosis, biosensors for tuberculosis diagnosis, and information providing methods for tuberculosis diagnosis.

Disclosed is a sensitized magnetic responsive particle including: a magnetic responsive particle having a core particle and at least one magnetic layer disposed on the core particle, the magnetic layer containing microparticles of a magnetic metal and/or an oxide thereof; and a substance that specifically interacts with an analyte, the substance being supported on the magnetic responsive particle, wherein, assuming that a volume and a weight of the core particle are respectively v.sub.c and w.sub.c, and that a volume and a weight of the magnetic responsive particle are respectively v.sub.e and w.sub.e, the magnetic material density [(w.sub.e−w.sub.c)/(v.sub.e−v.sub.c)] satisfies the following expression 1:

2.0≤(w.sub.e−w.sub.c)/(v.sub.e−v.sub.c)   Expression 1

The magnetic responsive particle has a high magnetic collection property in spite of a small particle size. When the magnetic responsive particle is used, a reagent for an immunoassay having excellent magnetic separability and capable of realizing high sensitivity can be provided.

Disclosed is a sensitized magnetic responsive particle including: a magnetic responsive particle having a core particle and at least one magnetic layer disposed on the core particle, the magnetic layer containing microparticles of a magnetic metal and/or an oxide thereof; and a substance that specifically interacts with an analyte, the substance being supported on the magnetic responsive particle, wherein, assuming that a volume and a weight of the core particle are respectively v.sub.c and w.sub.c, and that a volume and a weight of the magnetic responsive particle are respectively v.sub.e and w.sub.e, the magnetic material density [(w.sub.e−w.sub.c)/(v.sub.e−v.sub.c)] satisfies the following expression 1:

2.0≤(w.sub.e−w.sub.c)/(v.sub.e−v.sub.c)   Expression 1

The magnetic responsive particle has a high magnetic collection property in spite of a small particle size. When the magnetic responsive particle is used, a reagent for an immunoassay having excellent magnetic separability and capable of realizing high sensitivity can be provided.

Embodiments of the present disclosure provide plasmonic structures, methods of making plasmonic structures, and the like.

Embodiments of the present disclosure provide plasmonic structures, methods of making plasmonic structures, and the like.

Described is a method and device for detecting an analyte in a sample, comprising bringing a sample comprising a target analyte into contact with magnetisable particles, the particles being coated with binding molecules complementary to the target analyte, resulting in bound and unbound binder complexes, positioning the magnetisable particles, comprising both bound and unbound binder complexes, in proximity to a magnetic field sensor, changing the magnetic field sufficient to release at least a portion of the magnetisable particles, comprising both bound and unbound binder complexes, from their proximity to the magnetic field sensor, and measuring changes in a magnetic signal detected from the net movement, being either translational or rotational movement, of the magnetisable particles relative to the magnetic sensor.

An immunochromatography includes steps of mixing a specimen capable of containing an antigen and a modified particle, which is a particle modified with a substance having a specific affinity to the antigen, to obtain a mixture containing particle composite bodies; sedimenting the particle composite bodies in the mixture using a centrifuge; dissociating the sedimented particle composite bodies into the particles and the antigen by mixing the sedimented particle composite bodies with a dissociation solution, recovering an antigen-concentrated solution by sedimenting the dissociated particles using a centrifuge; neutralizing the antigen-concentrated solution using a neutralization solution; spreading particle composite bodies for labeling on an insoluble carrier having a reaction site, in a state where the particle composite bodies for labeling, which are composite bodies of the antigen in the neutralized antigen-concentrated solution and a modified particle for labeling, are formed; and capturing the particle composite bodies for labeling at the reaction site.

An immunochromatography includes steps of mixing a specimen capable of containing an antigen and a modified particle, which is a particle modified with a substance having a specific affinity to the antigen, to obtain a mixture containing particle composite bodies; sedimenting the particle composite bodies in the mixture using a centrifuge; dissociating the sedimented particle composite bodies into the particles and the antigen by mixing the sedimented particle composite bodies with a dissociation solution, recovering an antigen-concentrated solution by sedimenting the dissociated particles using a centrifuge; neutralizing the antigen-concentrated solution using a neutralization solution; spreading particle composite bodies for labeling on an insoluble carrier having a reaction site, in a state where the particle composite bodies for labeling, which are composite bodies of the antigen in the neutralized antigen-concentrated solution and a modified particle for labeling, are formed; and capturing the particle composite bodies for labeling at the reaction site.