阅读说明：本技术 一种基于spr的纳米半球体结构阵列的荧光增强装置 (SPR-based fluorescence enhancement device of nano-hemispherical structure array ) 是由 吕江涛 常明会 梁彤 李润 谷琼婵 于 2021-07-29 设计创作，主要内容包括：本发明的一种基于SPR的纳米半球体结构阵列的荧光增强装置,包括自下而上依次设置的玻璃衬底、金属膜、半球体阵列结构、透光介质层和荧光层；半球体阵列结构由多个金属纳米半球体阵列设置构成,金属纳米半球体的阵列周期为60-600纳米,金属纳米半球体的半径为30-200纳米。该装置利用金属的表面等离子体共振,增强荧光物质的自发辐射率和荧光强度,通过调节金属纳米半球体的大小和阵列周期调制荧光的增强程度,解决了现有荧光物质的荧光信号弱的问题。(The invention relates to a fluorescence enhancement device of a nano-hemispheroid structure array based on SPR, which comprises a glass substrate, a metal film, a hemispheroid array structure, a light-transmitting medium layer and a fluorescent layer which are sequentially arranged from bottom to top; the hemisphere array structure is formed by arranging a plurality of metal nanometer hemispheroids, the array period of the metal nanometer hemispheroids is 60-600 nanometers, and the radius of the metal nanometer hemispheroids is 30-200 nanometers. The device utilizes the surface plasma resonance of metal to enhance the spontaneous radiance and the fluorescence intensity of fluorescent substances, and solves the problem of weak fluorescence signals of the existing fluorescent substances by adjusting the size of the metal nano-hemispheroids and the enhancement degree of array period modulation fluorescence.)

1. A fluorescence enhancement device of a nanometer hemispheroid structure array based on SPR is characterized by comprising a glass substrate, a metal film, a hemispheroid array structure, a light-transmitting medium layer and a fluorescent layer which are arranged from bottom to top in sequence; the hemisphere array structure is formed by arranging a plurality of metal nanometer hemispheroids, the array period of the metal nanometer hemispheroids is 60-600 nanometers, and the radius of the metal nanometer hemispheroids is 30-200 nanometers.

2. The fluorescence enhanced device of SPR-based nano-hemispheres array of claim 1 wherein the glass substrate is the basic carrier of the device and is made of isotropic and low dispersion optical glass.

3. The fluorescence enhancing apparatus of nano-hemispheres array based on SPR according to claim 1, wherein the metal film is a gold film or a silver film with a thickness of 50 to 100 nm.

4. The fluorescence enhancing apparatus of nano-hemispheres array based on SPR of claim 1, wherein the metal nano-hemispheres are solid hemispheres and the metal nano-material is gold, silver or aluminum material.

5. The fluorescence enhancing apparatus of nano hemispheroid structure array based on SPR of claim 1, wherein the light transmitting medium layer is made of silicon dioxide or polymethyl methacrylate and is evaporated on the hemispheroid array structure.

6. The fluorescence enhancing apparatus of nano-hemispheres array based on SPR of claim 1, wherein the fluorescent layer is an organic fluorescent dye layer spin coated on the transparent dielectric layer.

Technical Field

The invention belongs to the technical field of nano photoelectron, and relates to a fluorescence enhancement device of a nano hemispherical structure array based on SPR (surface plasmon resonance).

Background

Metal Surface Plasmon Resonance (SPR) is a physical optical phenomenon in which light is irradiated at a metal-dielectric interface to excite collective oscillation of electrons on the metal surface. The metal surface plasma resonance device can realize local field enhancement of an optical field near the structure, enhance the spontaneous radiance of fluorescent molecules and enhance fluorescent signals. The fluorescence enhancement technology can be applied to the fields of food safety detection, environmental pollution, light source manufacturing and the like.

The nano metal enhanced fluorescence can be explained from two processes, one is that the nano metal structure can enhance the local electric field of exciting light, so that the excitation rate of fluorescence of fluorescent molecules is enhanced; and secondly, the nano metal structure can improve the quantum yield of the fluorescent molecules.

In the existing fluorescence enhancement technology, some Metal Organic Framework (MOF) structures are generated through chemical reaction, and the nanometer metal particle clusters on the surfaces of the MOF structures can enhance fluorescence to a certain extent, but the enhancement effect is not good, the preparation flow of chemical materials is complex, and the chemical reaction time is long; some of them have a special structure obtained by ion beam etching to enhance fluorescence, but the preparation process is troublesome and is limited in mass production.

Disclosure of Invention

In order to solve the above technical problems, it is an object of the present invention to provide a fluorescence enhancing apparatus of a nano-hemispheroid structure array based on SPR, which enhances a fluorescence signal of a fluorescent substance based on surface plasmon resonance, and can adjust the degree of fluorescence enhancement by adjusting the size of a metal nano-hemispheroid and the period of the array.

The invention provides a fluorescence enhancement device of a nano-hemispheroid structure array based on SPR, which comprises a glass substrate, a metal film, a hemispheroid array structure, a light-transmitting medium layer and a fluorescent layer which are sequentially arranged from bottom to top; the hemisphere array structure is formed by arranging a plurality of metal nanometer hemispheroids, the array period of the metal nanometer hemispheroids is 60-600 nanometers, and the radius of the metal nanometer hemispheroids is 30-200 nanometers.

In the fluorescence enhancement device of the nano-hemispherical structure array based on SPR, the glass substrate is used as a basic carrier of the device and is made of isotropic and low-dispersion optical glass.

In the fluorescence enhancement device of the SPR-based nano-hemispheroid structure array, the metal film is a gold film or a silver film, and the thickness of the metal film is 50-100 nanometers.

In the fluorescence enhancement device of the SPR-based nano-hemisphere structure array, the metal nano-hemisphere is of a solid hemisphere structure, and the metal nano material is gold, silver or aluminum material.

In the fluorescence enhancement device of the nano-hemispheroid structure array based on SPR, the light-transmitting medium layer is made of silicon dioxide or polymethyl methacrylate and is evaporated on the hemispheroid array structure.

In the fluorescence enhancement device of the nano-hemispheroid structure array based on SPR, the fluorescent layer is an organic fluorescent dye layer and is spin-coated on the light-transmitting medium layer.

The fluorescence enhancement device of the nano-hemispheroid structure array based on SPR of the invention has the following beneficial effects:

1. the single metal nano-hemisphere can excite local plasma resonance and is mutually coupled with surface plasma resonance excited by a periodic hemisphere array structure, so that the field enhancement factor can be greatly improved.

2. The enhancement degree and the enhancement peak value of the fluorescence can be adjusted by adjusting the size and the array period of the metal nano-hemispheres, and the metal nano-hemispheres have certain directional adjustment capability.

3. The device has simple structure and simple preparation process, only needs to adopt a nano imprinting technology and a film evaporation process, is easy to produce in large scale and is convenient to apply.

Drawings

FIG. 1 is a schematic structural diagram of a fluorescence enhancement device of the SPR-based nano-hemispheroid structure array of the invention;

FIG. 2 is a schematic of fluorescence enhancement at different wavelengths;

FIG. 3 is a graph showing the effect of dipole-to-metal nano-hemisphere surface distance on fluorescence enhancement.

Detailed Description

As shown in FIG. 1, the fluorescence enhancing device of the nano-hemispheroid structure array based on SPR of the invention comprises a glass substrate 1, a metal film 2, a hemispheroid array structure, a light-transmitting medium layer 4 and a fluorescent layer 5 which are arranged from bottom to top in sequence. The hemisphere array structure is formed by arranging a plurality of metal nano hemispheroids 3 in an array mode, the array period of each metal nano hemisphere 3 is 60-600 nanometers, and the radius of each metal nano hemisphere 3 is 30-200 nanometers. In order to more intuitively show the structure of the fluorescence enhancement device, fig. 1 is a half-section schematic diagram, a hemisphere array structure is fully distributed on the whole metal film 2, a transparent medium layer 4 completely covers the hemisphere array structure and fills gaps among the metal nano hemispheroids 3, and a fluorescent layer 5 completely covers the transparent medium layer 4.

The glass substrate 1 is a basic carrier of the device and is made of isotropic and low-dispersion optical glass.

The metal film 2 is a gold film or a silver film, and the thickness is 50-100 nanometers.

The metal nano-hemispheroid 3 is of a solid hemispheroid structure, and the metal nano-material is gold, silver or aluminum material.

The light-transmitting medium layer 4 is made of silicon dioxide or polymethyl methacrylate and is evaporated on the hemispherical array structure.

The fluorescent layer 5 is an organic fluorescent dye layer and is spin-coated on the light-transmitting medium layer 4.

The fluorescence enhancement device of the nano-hemispherical structure array based on SPR is prepared by the following method, and specifically comprises the following steps:

1) spin-coating an organic film on a glass slide, and stamping the organic film by using a prepared template to form a hemispherical hole array structure;

2) evaporating metal on the hemisphere hole array structure to obtain a combination of the hemisphere array structure and the organic film;

3) a layer of metal film 2 is vapor-plated on a glass substrate 1;

4) an organic film is spin-coated on the metal film 2;

5) attaching the assembly prepared in steps 1) and 2) to the organic film of step 4);

6) cleaning with organic solution to remove the organic film and retain the hemispheroid array structure;

7) an optical light-transmitting medium layer is vapor-plated on the hemispheroid array structure;

8) and (3) spin-coating a fluorescent solution on the transparent medium layer to obtain a fluorescent layer, so as to prepare the fluorescence enhancement device.

The fluorescence enhancement under a single hemisphere structure was simulated by software. The model uses a monochromatic point dipole to simulate fluorescent molecules emitting fluorescence, and it can be seen from fig. 2 that the fluorescence enhancement of the dipole is enhanced by about 30 times at a wavelength of 650 nm. It can be seen in fig. 3 that the fluorescence is enhanced by about 30 times at a dipole distance of 9 nm from the surface of the metal nano-hemisphere. A large number of simulation verifications prove that the single hemisphere structure has a good fluorescence enhancement effect, the enhancement degree and the enhancement peak value of the fluorescence can be adjusted by adjusting the size of the metal nano hemisphere, and when the metal nano hemisphere array structure is expanded, the local plasma resonance excited by the single hemisphere is mutually coupled with the surface plasma resonance excited by the periodic hemisphere array structure, so that the field enhancement factor can be greatly improved, and the fluorescence enhancement effect is better. Through a large number of simulation verifications, the enhancement degree and the enhancement peak value of the fluorescence can be adjusted by adjusting the size and the array period of the metal nano hemispheroid, and the metal nano hemispheroid has certain directional adjustment capability.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the scope of the present invention, which is defined by the appended claims.