Functionalized nanoparticles and methods of use

• US 7,524,630 B2
• Filed: 04/22/2003
• Issued: 04/28/2009
• Est. Priority Date: 04/22/2002
• Status: Expired due to Fees

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Shouguang, Jin, Zhao, Xiaojun, Hilliard, Lisa Renee, Dytioco, Rovelyn Tapec, Drake, Timothy James, Tan, Weihong
• Primary Examiner(s): Chin; Christopher L
• Application Number:
  US10/421,491
• Publication Number:
  US 20040067503A1
• Time in Patent Office: 2,198 Days
• Field of Search: None
• US Class Current: 435/6.11
• CPC Class Codes: B82Y 15/00 Nanotechnology for interacting, sensing or actuating, e.g. quantum dots as markers in protein assays or molecular motors
• CPC Class Codes: C12Q 1/6816 characterised by the detection means C12Q1/6804 takes precedence
• CPC Class Codes: C12Q 2563/155 Particles of a defined size, e.g. nanoparticles
• CPC Class Codes: G01N 33/54346 Nanoparticles
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/552 Glass or silica
• CPC Class Codes: G01N 33/588 with semiconductor nanocrystal label, e.g. quantum dots

Abstract

Silica-coated nanoparticles functionalized with biologically active molecules such as antibodies and nucleotides are used to label cells, to detect and isolate nucleic acid molecules having specific nucleotide sequences, and to separate a mixture of different nucleic acid molecules.

Claims

1. A functionalized magnetic nanoparticle comprising a metal core and a silica surface, the silica surface being conjugated with at least one functional group comprising an oligonucleotide in the form of a molecular beacon, wherein the sequence of said oligonucleotide comprises a single-stranded loop structure comprising a nucleic acid sequence of interest, and a stem-forming arm structure on either side of the sequence of interest, the two stem-forming arm structures comprising bases complementary to one another that form a stem when hybridized with one another, said oligonucleotide further comprising a fluorophore attached at one end of said sequence, and a quencher attached at the other end of said sequence, wherein fluorescence emission of the fluorphore is inhibited by the quencher when the stem-forming structures are hybridized to one another in the absence of a complement of the nucleic acid sequence of interest.

2. The functionalized nanoparticle of claim 1, wherein the molecular beacon is conjugated to the silica surface by a biotin-avidin linkage.

3. The functionalized nanoparticle of claim 1, wherein the sequence of said oligonucleotide differs from the target sequence by one base.

4. A functionalized magnetic nanoparticle comprising a metal core and a silica surface, the silica surface being conjugated with at least one functional group comprising an oligonucleotide in the form of a molecular beacon, wherein the sequence of said oligonucleotide comprises a single-stranded loop structure comprising a nucleic acid sequence of interest and wherein the sequence of said oligonucleotide differs from the target sequence by one or more bases, and a stem-forming arm structure on either side of the sequence of interest, the two stem-forming arm structures comprising bases complementary to one another that form a stem when hybridized with one another, said oligonucleotide further comprising a fluorophore attached at one end of said sequence, and a quencher attached at the other end of said sequence, wherein fluorescence emission of the fluorphore is inhibited by the quencher when the stem-forming structures are hybridized to one another in the absence of a complement of the nucleic acid sequence of interest.