Particle having magnetic material incorporated therein, process for producing the same, particle for immunoassay and method of immunoassay
It is an object of the present invention to provide magnetic substance-encapsulated particles which have uniform magnetism, high dispersion stability and a narrow particle size distribution, a method of producing the same, particles for immunoassay formed by using the magnetic substance-encapsulated particles and a method of immunoassay in which the magnetic substance-encapsulated particles or the particles for immunoassay are used. The present invention relates to a magnetic substance-encapsulated particle, which comprises an organic polymer material and a magnetic substance having an average particle size of 1 to 30 nm, the magnetic substance being contained within a particle in a state of being dispersed.
1. A magnetic substance-encapsulated particle,
which comprises an organic polymer material and a magnetic substance, wherein the magnetic substance has an average particle size of 1 to 30 nm, the magnetic substance being dispersed and encapsulated within the organic polymer material of said particle; wherein said organic polymer material comprises a monomer not having a hydrophilic group for forming a core of said particle and a monomer having a hydrophilic group for forming a shell of said particle and forming a particle having dispersion stability in water; and
wherein an absolute deviation of a component ratio between a carbon element comprising the organic polymer material and a metal element comprising the magnetic substance is 0.27 or less,
wherein the monomer not having a hydrophilic group comprises a monomer having a glycidyl group and a styrenic monomer and wherein the monomer having a hydrophilic group is polyethylene glycol (meth)acrylate represented by the following general formula (1) or a compound represented by the following general formula (2):
CH 2 ═CR—COO—(CH 2 —CH 2 —O) n —H (1)
in the formula, R represents H or CH 3 , and n represents an integer of 1 to 20,
in the formula, X represents H or SO 3 − NH 4 + , and n represents an integer of 3 to 30.
2. The magnetic substance-encapsulated particle according to claim 1 ,
wherein the magnetic substance is formed by oxidization of a metal ion within a particle in a polymerization process of forming the magnetic substance-encapsulated particle.
3. The magnetic substance-encapsulated particle according to claim 2 , wherein the metal ion is an iron ion.
4. The magnetic substance-encapsulated particle according to claim 1 ,
wherein the proportion of a monomer unit derived from the styrenic monomer in the organic polymer material is 5 to 90% by weight.
5. The magnetic substance-encapsulated particle according to claim 1 , wherein the organic polymer material is crosslinked.
6. The magnetic substance-encapsulated particle according to claim 1 , which has at least a functional group selected from the group consisting of a carboxyl group, a hydroxyl group, an epoxy group, an amino group, a triethylammonium group, a dimethylamino group and a sulfonic acid group at the surface of the particle.
7. The magnetic substance-encapsulated particle according to claim 1 , wherein an average particle size is 0.05 to 1 μm.
8. The magnetic substance-encapsulated particle according to claim 1 , wherein a content of the magnetic substance is 0.1 to 50% by weight.
9. The magnetic substance-encapsulated particle according to claim 1 , wherein an average particle size of the magnetic substance is 2 to 10 nm.
10. The magnetic substance-encapsulated particle according to claim 1 , wherein a linker having a functional group capable of forming a covalent bond with an antigen or an antibody binds to a particle surface.
11. The magnetic substance-encapsulated particle according to claim 10 ,
wherein the functional group capable of forming a covalent bond with an antigen or an antibody is an epoxy group.
12. The magnetic substance-encapsulated particle according to claim 10 , wherein the linker is polyethylene glycol diglycidyl ether.