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US-12618777-B2 - Raman-active nanoparticle for surface-enhanced Raman scattering and method of producing the same

US12618777B2US 12618777 B2US12618777 B2US 12618777B2US-12618777-B2

Abstract

Provided is a Raman-active nanoparticle including: a spherical plasmonic metal core; a plasmonic metal shell having surface irregularities; and a self-assembled monolayer which binds to each of the core and the shell, is positioned between the core and the shell, and includes a Raman reporter satisfying the following Chemical Formula 1: NO 2 —Ar—SH  (Chemical Formula 1) wherein Ar is a (C6-C12) arylene group.

Inventors

  • Eun-Ah YOU
  • Jae-Eul SHIM
  • Tae Geol Lee

Assignees

  • KOREA RESEARCH INSTITUTE OF STANDARDS AND SCIENCE

Dates

Publication Date
20260505
Application Date
20220419
Priority Date
20210421

Claims (16)

  1. 1 . A Raman-active nanoparticle comprising: a spherical plasmonic metal core; a plasmonic metal shell having surface irregularities having a uniform size in an entire area of a surface of the plasmonic metal shell; and a self-assembled monolayer which binds to each of the core and the shell, is positioned between the core and the shell, and includes a Raman reporter satisfying the following Chemical Formula 1: NO 2 —Ar—SH [Chemical Formula 1] wherein Ar is a (C6-C12) arylene group, and wherein the plasmonic metal shell includes plasmonic metal fine particles having an average size of 0.1D to 0.8D, based on a diameter (D) of the metal core, and has surface irregularities having a uniform size in the entire area of the surface of the plasmonic metal shell due to the plasmonic metal fine particles.
  2. 2 . The Raman-active nanoparticle of claim 1 , wherein the Raman reporter satisfies the following Chemical Formula 2:
  3. 3 . The Raman-active nanoparticle of claim 2 , wherein a surface-enhanced Raman scattering signal in Raman mapping is detected in 60% or more of the Raman-active nanoparticles among all Raman-active nanoparticles.
  4. 4 . The Raman-active nanoparticle of claim 2 , wherein the plasmonic metal shell includes plasmonic metal fine particles having an average size of 0.3D to 0.8D, based on a diameter (D) of the metal core, and has surface irregularities having a uniform size in the entire area of the surface of the plasmonic metal shell due to the plasmonic metal fine particles.
  5. 5 . The Raman-active nanoparticle of claim 4 , wherein in the plasmonic metal shell, an inner shape of the shell in contact with the self-assembled monolayer is spherical.
  6. 6 . The Raman-active nanoparticle of claim 4 , wherein the plasmonic metal core has an average diameter of 20 to 100 nm.
  7. 7 . The Raman-active nanoparticle of claim 4 , wherein the self-assembled monolayer has a thickness of 0.5 to 2.0 nm.
  8. 8 . The Raman-active nanoparticle of claim 1 , wherein the plasmonic metal core and the plasmonic metal shell are independently of each other one or more metals selected from gold, silver, platinum, palladium, nickel, aluminum, and copper.
  9. 9 . The Raman-active nanoparticle of claim 8 , wherein the plasmonic metal core and the plasmonic metal shell are the same metal.
  10. 10 . The Raman-active nanoparticle of claim 1 , further comprising: a receptor which is fixed to the plasmonic metal shell and binds to the analyte.
  11. 11 . A method of producing the Raman-active nanoparticle of claim 1 , the method comprising: a) forming the self-assembled monolayer including the Raman reporter satisfying the following Chemical Formula 1 on the spherical plasmonic metal core; and b) using a reaction solution in which a buffer solution, the metal core on which the self-assembled monolayer is formed, and the plasmonic metal precursor are mixed, to form a plasmonic metal shell which surrounds the metal core on which the self-assembled monolayer is formed and has surface irregularities having a uniform size in the entire area of the surface of the plasmonic metal shell: NO 2 —Ar—SH [Chemical Formula 1] wherein Ar is a (C6-C12) arylene group.
  12. 12 . The method of claim 11 , wherein the Raman reporter satisfies the following Chemical Formula 2:
  13. 13 . The method of claim 11 , wherein a mole ratio obtained by dividing the number of moles of a buffer in the buffer solution by the number of moles of the plasmonic metal precursor is 10 to 100.
  14. 14 . The method of claim 11 , wherein a molar concentration of the buffer in the buffer solution is 10 to 200 mM.
  15. 15 . The method of claim 11 , wherein the plasmonic metal core has a diameter of 20 to 100 nm.
  16. 16 . The method of claim 11 , further comprising: after b), c) fixing a receptor which binds to the analyte to the plasmonic metal shell.

Description

TECHNICAL FIELD The following disclosure relates to a Raman-active nanoparticle for surface-enhanced Raman scattering and a method of producing the same, and more particularly, to a Raman-active nanoparticle which allows detection at a monomolecular level and may be mass-produced by a simple process, and a method of producing the same. BACKGROUND Surface-enhanced Raman spectroscopy originated from surface plasmon resonance (SPR) which is collective oscillations of free electrons on the surface of a metal nanostructure uses a phenomenon that Raman scattering intensity rapidly increases by 106 to 108 times or more when molecules are adsorbed on the surface of the metal nanostructure of gold, silver, and the like. The surface-enhanced Raman spectroscopy directly provides information about the oscillation state of molecules or a molecular structure, and is recognized as a powerful analysis method for ultra-sensitive chemical, biological, and biochemical analysis. The surface-enhanced Raman spectroscopy fused with nanotechnology, which is currently developing at a very rapid pace, is particularly greatly expected to be critically used as a biomedical sensor. As an example, currently, a study for carrying out the initial diagnosis of various diseases including Alzheimer's disease or diabetes together with high-sensitivity DNA analysis, using surface-enhanced Raman spectroscopy is actively in progress. However, though surface-enhanced Raman spectroscopy has high selectivity, high informativity, and high sensitivity, signal enhancement changes very sensitively depending on the size or type of a gap or a junction between plasmon metals, a distance between a hot spot and a Raman signal generation source, and the like, and thus, reliability and reproducibility of measurement are deteriorated. Thus, the present inventors improved the reproducibility of measurement by developing a Raman-active particle having a core-shell structure using a previously known Raman reporter, as disclosed in Korean Patent Laid-Open Publication No. 10-2021-0028984. However, since there are disadvantages of not only limitations in terms of the intensity of Raman signal enhancement and the reproducibility of measurement but also non-reproducibility of the shape of Raman-active particles produced under the same conditions, there is a need to develop a Raman-active particle which has a high degree of sensitivity to allow detection at a single molecule level, allows detection with improved reliability and reproducibility, and has excellent reproducibility when produced under the same conditions, in order to be used in the field of bioscience such as early diagnosis of diseases. RELATED ART DOCUMENTS Patent Documents Korean Patent Laid-Open Publication No. 10-2021-0028984 SUMMARY Technical Problem An embodiment of the present invention is directed to providing a Raman-active nanoparticle which has strictly defined hot spots, represents uniform Raman activity based on one nanoparticle, and simultaneously represents uniform Raman activity between particles, thereby allowing reproducible and reliable detection. Another embodiment of the present invention is directed to providing a Raman-active nanoparticle having extremely good sensitivity to allow detection at a monomolecular level. Another embodiment of the present invention is directed to providing a Raman-active nanoparticle having biocompatibility to be suitable as biosensing such as disease detection. Another embodiment of the present invention is directed to providing a method of producing a Raman-active nanoparticle which has excellent reproducibility of the shape when produced under the same conditions to allow reproducible and reliable detection and has extremely good sensitivity. Still another embodiment of the present invention is directed to providing a method of producing a Raman-active nanoparticle having very good commerciality so that the particles may be mass-produced at room temperature within a short time by a simple method. Technical Solution In one general aspect, a Raman-active nanoparticle includes: a spherical plasmonic metal core; a plasmonic metal shell having surface irregularities; and a self-assembled monolayer which binds to each of the core and the shell, is positioned between the core and the shell, and includes a Raman reporter satisfying the following Chemical Formula 1: NO2—Ar—SH  (Chemical Formula 1) wherein Ar is a (C6-C12) arylene group. In the Raman-active nanoparticle according to an exemplary embodiment of the present invention, the Raman reporter may satisfy the following Chemical Formula 2: In the Raman-active nanoparticle according to an exemplary embodiment of the present invention, the plasmonic metal shell may include plasmonic metal fine particles having an average size of 0.3D to 1D, based on a diameter (D) of the metal core, and may have surface irregularities due to the plasmonic metal fine particles. In the Raman-active nanoparticle according to a