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CN-121978781-A - Fe3O4Asymmetric self-assembly structure and method of@Au nano particles and light response composite tuning structure

CN121978781ACN 121978781 ACN121978781 ACN 121978781ACN-121978781-A

Abstract

The invention discloses an asymmetric self-assembly structure and method of Fe 3 O 4 @Au nano particles and a light response composite tuning structure, wherein Fe 3 O 4 @Au nano particles are used as basic construction units to form a swastika shape, the self-assembly structure is non-coincident with mirror images of the swastika shape, the self-assembly structure consists of two mutually orthogonal parts, the two parts share one Fe 3 O 4 @Au nano particle, each part comprises two structure arms and one structure main shaft, each structure arm and each structure main shaft consist of a plurality of Fe 3 O 4 @Au nano particles, the two structure arms are perpendicular to the structure main shaft to form a right-angle Z shape, and the two structure arms share one Fe 3 O 4 @Au nano particle with the structure main shaft respectively.

Inventors

  • Shui Xinxiao
  • SUN JIAJIA
  • SHI ZONGQIAN
  • DU WANYI
  • XIN SHUMIN
  • WANG RUICHEN

Assignees

  • 西安交通大学

Dates

Publication Date
20260505
Application Date
20260128

Claims (10)

  1. 1. The Fe 3 O 4 @Au nanoparticle asymmetric self-assembly structure is characterized in that the self-assembly structure takes Fe 3 O 4 @Au nanoparticles as basic construction units to form a swastika shape, and the self-assembly structure and a mirror image thereof cannot be overlapped; The self-assembled structure is composed of two mutually orthogonal parts, the two parts share one Fe 3 O 4 @Au nanoparticle, each part comprises two structural arms and one structural main shaft, each structural arm and each structural main shaft are composed of a plurality of Fe 3 O 4 @Au nanoparticles, the two structural arms are perpendicular to the structural main shaft to form a right-angle Z shape, and the two structural arms and the structural main shaft share one Fe 3 O 4 @Au nanoparticle respectively.
  2. 2. The Fe 3 O 4 @au nanoparticle asymmetric self-assembled structure according to claim 1, wherein the Fe 3 O 4 @au nanoparticle is core of Fe 3 O 4 , shell of Au, and the diameter of the Fe 3 O 4 @au nanoparticle is smaller than the wavelength of incident light, which is incident light of a light response test process.
  3. 3. The asymmetric self-assembled structure of Fe 3 O 4 @ Au nanoparticles according to claim 1, wherein the distance between adjacent Fe 3 O 4 @ Au nanoparticles in the self-assembled structure is not less than 2nm.
  4. 4. A self-assembly method of an asymmetric self-assembly structure of Fe 3 O 4 @ Au nanoparticles as claimed in any one of claims 1 to 3, comprising the steps of: Firstly, a silicon wafer is used as a bottom substrate, a swastika-shaped soft magnetic array is processed on the silicon wafer, an Au film with preset thickness is plated around the swastika-shaped soft magnetic array to form a soft magnetic mold, the soft magnetic array is made of permalloy, the thickness of the Au film is higher than that of the swastika-shaped soft magnetic array, and a groove which has the same shape as the swastika-shaped soft magnetic array and has the depth equivalent to the diameter of Fe 3 O 4 @Au nano particles is formed above the swastika-shaped soft magnetic array; And secondly, loading a micro-fluid channel on the soft magnetic mold, wherein the micro-fluid channel is Fe 3 O 4 @Au nano particle suspension, and simultaneously, using a permanent magnet to provide an external bias magnetic field to guide Fe 3 O 4 @Au nano particles to complete the assembly of the swastika-shaped structure.
  5. 5. The method for self-assembly of an asymmetric self-assembly structure of Fe 3 O 4 @ Au nanoparticles according to claim 4, wherein in the second step, the velocity v in =1 mm/s of the Fe 3 O 4 @ Au nanoparticle suspension at the entrance of the microfluidic channel is set.
  6. 6. The self-assembly method of an asymmetric self-assembly structure of Fe 3 O 4 @au nanoparticles according to claim 4, wherein in the second step, the magnetic induction intensity of the external bias magnetic field B bias =500 mT.
  7. 7. The method of claim 4, further comprising a third step of raising the speed of the Fe 3 O 4 @au nanoparticle suspension to v in =0.3 m/s after the completion of the assembly to remove stray particles deposited near the grooves.
  8. 8. The optical response composite tuning structure is based on the Fe 3 O 4 @Au nanoparticle asymmetric self-assembly structure as claimed in any one of claims 1 to 3, and is characterized by comprising a target substrate and the Fe 3 O 4 @Au nanoparticle asymmetric self-assembly structure arranged on the target substrate.
  9. 9. The light responsive composite tuning structure of claim 8, wherein the target substrate is glass, a metal back plate, or a flexible film.
  10. 10. The light response composite tuning structure according to claim 8, wherein flexible regulation and control of the light response of the asymmetric self-assembled structure of the 'swastika' -shaped Fe 3 O 4 @Au nanoparticle is achieved by controlling the type of the target substrate, the core or shell size of the Fe 3 O 4 @Au nanoparticle, the compactness of the Fe 3 O 4 @Au nanoparticle, the polarization direction of an external incident light field and the surrounding medium environment.

Description

Fe 3O4 @Au nanoparticle asymmetric self-assembly structure and method and light response composite tuning structure Technical Field The invention relates to the technical field of functional nano materials, in particular to an asymmetric self-assembly structure and method of Fe 3O4 @Au nano particles and a light response composite tuning structure. Background Magnetic plasmonic nanoparticles, such as Fe 3O4 @Au core-shell structures, are favored in the field of nanomaterials due to their unique bifunctional integration characteristics. The Fe 3O4 core imparts its excellent magnetic response properties enabling it to be precisely manipulated by external magnetic fields, while the Au shell provides excellent Localized Surface Plasmon Resonance (LSPR) properties, good biocompatibility and chemical properties that facilitate surface functionalization. Compared with single-component nanoparticles, such as pure magnetic nanoparticles or pure gold nanoparticles, the gold magnetic core-shell structure has higher stability, controllability and versatility, so that the gold magnetic core-shell structure has great application potential in the fields of targeted drug delivery, magnetic Resonance Imaging (MRI) enhancement, tumor hyperthermia, catalysis, surface Enhanced Raman Scattering (SERS) detection and the like. By orderly assembling and precisely regulating and controlling the Fe 3O4 @Au nano particles, the self-assembled structure can obtain some superior properties exceeding the nano particles, and can show the characteristics which are not possessed by the conventional materials in the fields of magnetism, electricity, light and the like. In addition, under the irradiation of external incident light, the asymmetric self-assembled structure can restrict light energy in a very small space by breaking the geometric limitation of the traditional symmetric structure, and extremely strong local electromagnetic field is generated in the gaps of the nano particles. Based on strong electromagnetic coupling action between nano particles and incident light, the asymmetric self-assembled structure can show unique, flexible and adjustable optical response and magnetic response, and has quite considerable application prospect in the aspects of developing novel optical devices and functional metamaterials. The prior researches show that the symmetrical assembly structure can generate specific optical spectral lines, but has the obvious limitations that firstly, the optical response mode is generally single and mainly comes from electric dipole resonance hybridization, high-order quadrupole or magnetic dipole resonance is difficult to excite, and secondly, the resonance wave band is concentrated and difficult to respond to the complicated requirements, so that the application of the symmetrical assembly structure in the front-edge fields of high-precision biosensing and the like is greatly limited. Disclosure of Invention The invention aims to provide an asymmetric self-assembly structure and method of Fe 3O4 @Au nano particles and a light response composite tuning structure, so as to solve the problems of high symmetry, single light response mode and insufficient tuning capability of the conventional assembly structure. In order to achieve the above purpose, the invention adopts the following technical scheme: The Fe 3O4 @Au nanoparticle asymmetric self-assembly structure takes Fe 3O4 @Au nanoparticles as a basic construction unit to form a swastika shape, and the self-assembly structure and a mirror image thereof cannot be overlapped; The self-assembled structure is composed of two mutually orthogonal parts, the two parts share one Fe 3O4 @Au nanoparticle, each part comprises two structural arms and one structural main shaft, each structural arm and each structural main shaft are composed of a plurality of Fe 3O4 @Au nanoparticles, the two structural arms are perpendicular to the structural main shaft to form a right-angle Z shape, and the two structural arms and the structural main shaft share one Fe 3O4 @Au nanoparticle respectively. Further, the Fe 3O4 @Au nanoparticle takes Fe 3O4 as a core and takes Au as a shell, and the diameter of the Fe 3O4 @Au nanoparticle is smaller than the wavelength of incident light, wherein the incident light is the incident light in the light response test process. Further, in the self-assembled structure, the distance between adjacent Fe 3O4 @Au nano particles is not less than 2nm. The self-assembly method of the Fe 3O4 @Au nanoparticle asymmetric self-assembly structure comprises the following steps: Firstly, a silicon wafer is used as a bottom substrate, a swastika-shaped soft magnetic array is processed on the silicon wafer, an Au film with preset thickness is plated around the swastika-shaped soft magnetic array to form a soft magnetic mold, the soft magnetic array is made of permalloy, the thickness of the Au film is higher than that of the swastika-shaped soft magnetic array, and a gr