The reason why nano-world or nano-technology attracts\neveryone’s attention is because when the material is in the nanometer size, it\nexhibits many physical and chemical properties that are different from macroscopic\nand molecular levels. For example, silver blocks can be electrically\nconductive. But when it is small enough to be nanoscale, it can’t conduct\nelectricity. When copper is made of nanometer size, it becomes incapable of\nconducting heat. These new characteristics of nanomaterials have provided many\nnew opportunities for people in the world of scientific research, and have\nquickly become the focus of the scientific and technological community.\nMagnetic nanoparticles are one of the many applications of nanotechnology in\nthe biological field.<\/p>\n\n\n\n

The so-called magnetic nanoparticles refer to small\nmagnetic particles of a size suitable for measurement by nanometers, generally\nreferred to as 1 to 100 nanometers. Such magnetic particles have a very special\nmagnetic property called superparamagnetism, that is, it has strong magnetic\nresponsiveness in the applied magnetic field, and after the magnetic field is\nremoved, the magnetic properties of the magnetic particles disappear immediately,\nwhich means there is no remanence, and the particles are evenly dispersed in\nsolution again. What scientists like is this feature, which can be used to\nadsorb a certain component in a solution and then magnetically separate the\nmagnetic particles to achieve the purpose of separating the components. Of\ncourse, in order to be able to adsorb the desired substance, a specific group\nsuch as an amino group, a hydroxyl group, a carboxyl group or a thiol group\nmust be coated on the surface of the particle, and by specifically binding\nthese groups with the target molecule, and then collecting the magnetic\nparticles by magnetic force, the desired substance can be separated. <\/p>\n\n\n\n

The magnetic beads themselves are mostly inorganic\nmaterials, the most common material being magnetite, and the surface coating is\nbasically organic. According to the positional relationship between the\nmagnetic beads itself and the coating material, there are four kinds of\nstructures for distinguishing the magnetic beads, namely, a core-shell type, a\nmosaic type, a shell-core type, and a shell-core-shell type.<\/p>\n\n\n\n

\"\" — A: magnetic core-organic shell; B: magnetic particles homogeneously distributed in an organic bead; C: magnetic shell-organic core; D: organic shell-magnetic core-organic shell. <\/figcaption><\/figure><\/div>\n\n\n\n
<\/p>\n\n\n\n
Among them, the core-shell type is researched and used\nmost, whose core is the magnetic material. The polymer material is encapsulated\non the surface of the magnetic particles as a shell layer, contributing to the\nspecificity of the entire particle, and the inorganic magnetic core imparts\nsuperparamagnetism to the whole particle, contributing to the availability for\nseparation. In a well-mixed liquid environment, the polymer shell binds with\nthe target substance through its functional group, and an external magnetic\nfield controls the movement and collection of these particles, thereby finally\nachieving the purpose of separating the target substance. The tiny magnetic\nparticles are so powerful that in addition to their superparamagnetism, they\nalso possess the following characteristics:<\/p>\n\n\n\n
1. It has good surface effect. The specific surface area\nincreases sharply, the microsphere functional group density and selective\nadsorption capacity increase, the adsorption equilibrium time is greatly\nshortened, and the adsorption capacity is improved.<\/p>\n\n\n\n
2. Physicochemical properties are stable, with a certain\ndegree of biocompatibility, and will not cause significant damage to the\norganism.<\/p>\n\n\n\n
3. Particle surface modification is available. The surface\nof the magnetic particle itself can be of or be modified to have functional\ngroups (such as -OH, -COOH, -NH2, etc.), which can bind to biologically active\nsubstances (such as nucleic acids, enzymes, etc.), or can be coupled with\nspecific molecules (such as specific ligands, antibodies, antigens, etc.) to\nspecifically separate biological macromolecules.<\/p>\n\n\n\n
**The application of magnetic nanoparticles<\/strong><\/p>\n\n\n\n**
**1. Cell separation<\/p>\n\n\n\n**
Bioactive adsorbents or other ligands, such as antibodies\nand exogenous coagulations, are attached to the surface of the magnetic\nmicrospheres, and their specific binding to the target cells can be\nconveniently and quickly applied to separate the cells by the action of an\nexternal magnetic field. Magnetic microspheres also have important applications\nin the isolation, purification and detection of bacteria in microorganisms. The\nuse of immunomagnetic microspheres combined with other immunoassay methods can\nquickly, accurately and efficiently separate microorganisms in samples, greatly\nimproving the specificity of detection methods, and is of great significance\nfor food hygiene and prevention of disease transmission. For example, the\nisolation of *Staphylococcus\naureus <\/em>and Salmonella<\/em>\ncan be carried out without subsequent damage to the bacteria which can be\nfurther cultured.<\/p>\n\n\n\n*
***2. Protein separation<\/p>\n\n\n\n***
Traditional protein separation methods such as salt\nprecipitation, organic solvent precipitation, membrane chromatography and\nion-exchange chromatography, generally achieve the purpose of separating\nproteins by changing the pH, dielectric constant, temperature or ionic strength\nof the solution. The operation process is cumbersome, energy-consuming, and the\nloss of the target protein is large. The magnetic microspheres have a small\nparticle size, a large specific surface area, and a functional group on the\nsurface, so that the coupling capacity is large, and it is capable of\ncovalently binding a ligand which can be recognized and reversibly bound by the\ntarget protein. Then, the magnetic microspheres are added into the mixed\nsolution containing the target protein, after the target protein is tightly\nbound to the magnetic microspheres, it is separated by an external magnetic\nfield. The entire separation process does not require adjustment of the pH,\ntemperature, ionic strength and dielectric constant of the mixed solution,\nthereby avoiding the loss of protein during the conventional separation\nprocess. Compared with traditional separation methods, protein magnetic\nseparation technology has the advantages of being fast, high purity and high\nyield.<\/p>\n\n\n\n
***3. DNA extraction<\/p>\n\n\n\n***
Magnetic particles-based DNA extraction is widely used in\nvarious biological research. Because any DNA-related scientific research is\ninseparable from DNA extraction, and DNA extraction is the first step in all\nsubsequent studies, so the efficiency of DNA extraction and the effect directly\naffects subsequent research. Magnetic particles-based DNA extraction has the\nfollowing advantages:<\/p>\n\n\n\n
1). The operation is simple, and the whole process is only\nfour steps, that is, lysis, binding, separation and elution, without cumbersome\ncentrifugation, most of which can be completed in 40 minutes;<\/p>\n\n\n\n
***2). High efficiency. The large surface area of the magnetic\nbeads and the specific binding with the nucleic acid make the extracted nucleic\nacid high in purity and concentration;<\/p>\n\n\n\n***
***3). It\u2019s safe and non-toxic, and does not use any toxic\nreagents, such as phenol, in line with modern environmental protection\nconcepts;<\/p>\n\n\n\n***
***4). It can achieve automation, large-scale operation.<\/p>\n\n\n\n***
Traditional DNA separation techniques include precipitation and centrifugation. These purification methods are complicated, time-consuming, and low in yield, and are difficult to automate when exposed to toxic reagents. Magnetic particles-based separation technology can overcome these shortcomings well, and achieve rapid and efficient preparation of samples, which is an important direction for the development of future DNA purification methods. <\/p>\n\n\n\n
Biomagnetic beads can also be used in gene chips, luminescence detection and disease treatment, and even as contrast agents, showing an extremely broad application prospect. <\/p>\n","protected":false},"excerpt":{"rendered":"
The reason why nano-world or nano-technology attracts everyone’s attention is because when the material is in the nanometer size, it<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[4],"class_list":["post-29","post","type-post","status-publish","format-standard","hentry","category-magnetic-beads","tag-magnetic-particles"],"_links":{"self":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/29","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/comments?post=29"}],"version-history":[{"count":1,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/29\/revisions"}],"predecessor-version":[{"id":31,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/posts\/29\/revisions\/31"}],"wp:attachment":[{"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/media?parent=29"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/categories?post=29"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cd-bioparticles.com\/blog\/wp-json\/wp\/v2\/tags?post=29"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}