Magnetic nanoparticles for sample separation
AssigneeAgilent Technologies, Inc.
InventorsJeffrey Carl Braman, Natalia Novoradovskaya, David Long, Bruce Richter, Derick Lucas
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Abstract
Silica-coated magnetic nanoparticles with greater ability to remain dispersed, and methods of making and using silica-coated magnetic nanoparticles. The magnetic nanoparticles comprise a core and a coating, where the core comprises Fe3O4 or other magnetic material and the coating has a thickness of from about 1.5 nm to about 2 nm. The magnetic nanoparticles are useful for preparing nucleic acids for analysis, by separating nucleic acids from other components and by normalizing nucleic acid concentrations.
Claims4
A method of making silica-coated magnetic nanoparticles comprising:
- preparing an aqueous solution of Fe+3 and Fe+2 ions in deionized, de-oxygenated water in a Fe3+/Fe2+ molar ratio of about 2/1;
- sonicating the aqueous solution;
- adding a base to the aqueous solution to precipitate Fe3O4 nanoparticles from the aqueous solution, thereby forming a mixture comprising Fe3O4 nanoparticles in an alkaline water;
- removing substantially all the alkaline water from the Fe3O4 nanoparticles to form a concentrated mixture;
- adding a de-oxygenated alcohol to the concentrated mixture to form an aqueous alcohol mixture;
- adding a silicate solution to the aqueous alcohol mixture to form a silica coating on the Fe3O4 nanoparticles;
- and
- separating the silica-coated Fe3O4 nanoparticles from the silicate-containing aqueous alcohol mixture.
Dependencies are inferred from the claim text.