阅读说明：本技术 一种基于双平面波导耦合的表面等离激元共振传感器 (Surface plasmon resonance sensor based on double-plane waveguide coupling ) 是由 贺梦冬 鲁登云 赵凯 王凯军 张新民 李建波 于 2019-10-19 设计创作，主要内容包括：一种基于双平面波导耦合的表面等离激元共振传感器,包括依次设置的棱镜、金层或者银层、第一平面介质波导和第二平面介质波导；第一平面介质波导包括依次设置的上含氟聚合物层、上二氧化锆层和传感层,第二平面介质波导包括依次设置的传感层、下二氧化锆层和下含氟聚合物层,第一平面介质波导和第二平面介质波导共用传感层,传感层内设置有待测液体或者待测气体的通道。本发明继承传统SPR传感器的样品无标记、实时动态检测等优点之外,由于Fano效应的发生而具有损耗低、成像灵敏度与Q因子高等突出优点。(A surface plasmon resonance sensor based on double-plane waveguide coupling comprises a prism, a gold layer or a silver layer, a first plane dielectric waveguide and a second plane dielectric waveguide which are sequentially arranged; the first planar dielectric waveguide comprises an upper fluorine-containing polymer layer, an upper zirconium dioxide layer and a sensing layer which are sequentially arranged, the second planar dielectric waveguide comprises a sensing layer, a lower zirconium dioxide layer and a lower fluorine-containing polymer layer which are sequentially arranged, the first planar dielectric waveguide and the second planar dielectric waveguide share the sensing layer, and a channel for liquid or gas to be detected is arranged in the sensing layer. Besides the advantages of no mark of a sample, real-time dynamic detection and the like of the traditional SPR sensor, the invention has the outstanding advantages of low loss, high imaging sensitivity, high Q factor and the like due to the Fano effect.)

1. The utility model provides a surface plasmon resonance sensor based on biplane waveguide coupling which characterized in that: the waveguide comprises a prism, a gold layer or a silver layer, a first planar dielectric waveguide and a second planar dielectric waveguide which are arranged in sequence; the first planar dielectric waveguide comprises an upper fluorine-containing polymer layer, an upper zirconium dioxide layer and a sensing layer which are sequentially arranged, the second planar dielectric waveguide comprises a sensing layer, a lower zirconium dioxide layer and a lower fluorine-containing polymer layer which are sequentially arranged, the first planar dielectric waveguide and the second planar dielectric waveguide share the sensing layer, and a channel for liquid to be detected or gas to be detected is arranged in the sensing layer.

2. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 1, wherein: the thickness of the gold layer or the silver layer is 30-100 nm.

3. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 2 wherein: the thickness of the gold layer or the silver layer is 48 nm.

4. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 1, wherein: the thickness of the upper fluorine-containing polymer layer is 500-1500nm, the thickness of the upper zirconium dioxide is 80-150nm, and the thickness of the sensing layer is 100-500 nm.

5. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 4, wherein: the thickness of going up fluoropolymer layer is 895nm, the thickness of going up the zirconium dioxide is 110nm, the thickness of sensing layer is 371 nm.

6. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 1, wherein: the thickness of the lower zirconium dioxide layer is 50-200 nm.

7. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 6 wherein: the thickness of the lower zirconium dioxide layer is 115 nm.

8. The dual planar waveguide coupling-based surface plasmon resonance sensor of claim 1, wherein: the prisms and lower fluoropolymer layer have a thickness that is more than 10 times the thickness of the upper fluoropolymer layer.

Technical Field

The invention relates to the technical field of light induction, in particular to a surface plasmon resonance sensor based on double-plane waveguide coupling.

Background

Surface Plasmon Resonance (SPR) is a collective oscillation formed by coupling of free electrons bound to a metal-dielectric interface with an electromagnetic wave. The change of the refractive index of the liquid or the gas can be monitored in real time by using the SPR-based biosensing technology. Due to the advantages of relatively accurate detection capability, non-labeling analysis, small sample demand and the like, the SPR sensing analysis can be used for analyzing and characterizing toxic gases, chemical biomolecules and living cells.

The traditional SPR sensor has the defects of high loss, low Q factor and sensitivity and the like. For example: [1] x.c. yuan, b.h.ong, y.g.tan, d.w.zhang, r.irawan, s.c.tjin, J optapurepl Opt 8(12)959 (2006); [2] G.Zheng, J.Cong, L.xu, J.Wang, Applied Physics Express 10,042202 (2017); [3] s.hayashi, d.v.nesterenko, Z Sekkat, j.phys.d: appl.phys.48,325303 (2015); [4] ruan, q.you, j.zhu, l.wu, j.guo, x.dai, y.xiang, opt.express 26(13)16884 (2018).

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the surface plasmon resonance sensor based on the coupling of the biplane waveguide, which has the outstanding advantages of low loss, high imaging sensitivity and Q factor and the like besides the advantages of no mark of a sample, real-time dynamic detection and the like of the traditional SPR sensor.

In order to solve the technical problems, the technical scheme provided by the invention is as follows: a surface plasmon resonance sensor based on double-plane waveguide coupling comprises a prism, a gold layer or a silver layer, a first plane dielectric waveguide and a second plane dielectric waveguide which are sequentially arranged; the first planar dielectric waveguide comprises an upper fluorine-containing polymer layer, an upper zirconium dioxide layer and a sensing layer which are sequentially arranged, the second planar dielectric waveguide comprises a sensing layer, a lower zirconium dioxide layer and a lower fluorine-containing polymer layer which are sequentially arranged, the first planar dielectric waveguide and the second planar dielectric waveguide share the sensing layer, and a channel for liquid to be detected or gas to be detected is arranged in the sensing layer.

In the surface plasmon resonance sensor based on the double planar waveguide coupling, preferably, the thickness of the gold layer or the silver layer is 30-100 nm.

In the surface plasmon resonance sensor based on the double planar waveguide coupling, preferably, the thickness of the gold layer or the silver layer is 48 nm.

Preferably, the thickness of the upper fluorine-containing polymer layer is 1500-.

Above-mentioned surface plasmon resonance sensor based on biplane waveguide coupling, it is preferable, go up fluoropolymer layer's thickness for 895nm, go up the thickness of zirconium dioxide and be 110nm, the thickness of sensing layer is 371 nm.

In the surface plasmon resonance sensor based on the coupling of the double planar waveguides, preferably, the thickness of the lower zirconium dioxide layer is 50-200 nm.

In the surface plasmon resonance sensor based on the biplanar waveguide coupling, the thickness of the lower zirconium dioxide layer is preferably 115 nm.

In the surface plasmon resonance sensor based on the biplanar waveguide coupling, the thickness of the prism and the lower fluoropolymer layer is preferably 10 times or more the thickness of the upper fluoropolymer layer.

In the invention, TM polarized light enters a prism, passes through a gold (Au) thin film to enter a fluorine-containing polymer (Cytop) medium, and under the condition of meeting wave vector matching, a Surface Plasmon Polariton (SPP) mode is generated at an Au-Cytop interface, and the energy of the incident light is absorbed, thereby generating SPR resonance.

SPR resonance wave vector matching condition:

wherein epsilon₁Denotes the dielectric constant of the metal,. epsilon₂Denotes the dielectric constant, k, of the fluoropolymer₀Is the light wave vector in vacuum.

The upper fluoropolymer layer, the upper zirconia layer, and the sensing layer together form a first planar dielectric waveguide (abbreviated PWG1), and the sensing layer, with the underlying lower fluoropolymer layer and lower zirconia, together form a second planar dielectric waveguide (abbreviated PWG 2). The waveguide modes formed in PWG1 and PWG2 are referred to as PWG mode 1 and PWG mode 2, respectively. When the effective refractive indices of PWG mode 1 and mode 2 are close to that of the SPP mode, the electromagnetic coupling between the PWG mode and the SPP mode is strong, and a Fano resonance valley is formed in the reflection curve, i.e., the curve in which the reflectance varies with the incident angle (s.hayashi, d.v. nesterenko, z.sekkat, applied physics Express 8,022201 (2015)). Small changes in the refractive index of the sensing layer, i.e. changes in the refractive index of the gas or liquid to be measured, cause changes in the effective refractive indices of the two PWG modes, and consequently the angular position of the Fano effect, which together with the magnitude of the change in reflectivity determines the magnitude of the imaging sensitivity (g.zheng, j.cong, l.xu, j.wang, Applied Physics Express 10,042202(2017)) (s.hayashi, d.v. nesterenko, z.sekkat, Applied Physics Express 8,022201 (2015)). Here, Fano resonances formed by PWG mode 1, PWG mode 2 and SPP mode coupling are referred to as Fano resonance 1 and Fano resonance 2, respectively. When the sensing medium is liquid, the effective refractive index of the PWG mode 1 is closer to that of the SPP mode than that of the PWG mode 2, and the coupling between the PWG mode 1 and the SPP mode is stronger than that between the PWG mode 2 and the SPP mode, so that the Fano resonance 1 is more obvious than the Fano resonance 2, and the imaging sensitivity generated by the Fano resonance 1 is higher; when the sensing medium changes to gas, the angular positions of the Fano resonance 1 and Fano resonance 2 change greatly. At this time, Fano resonance 2 is more significant than Fano resonance 1, and imaging sensitivity by Fano resonance 2 is higher. Based on the above phenomena, the Fano resonance 2 and the Fano resonance 1 can be used to monitor the refractive index changes of the gas and the liquid, respectively.

Compared with the prior art, the invention has the advantages that: (1) the invention is based on the prior mature biosensing technology and multilayer film technology, the process flow is not complicated, and the operation is simple. Compared with the traditional SPR sensor, the introduction of the dual-medium planar waveguide can increase the detection range of the refractive index of the sensing medium, and can cover the refractive index range of gas and liquid media. (2) The invention can regulate and control the sensitivity of detecting gas and liquid by controlling the thicknesses of the medium waveguide layer and the adjacent upper and lower layers, and the optimized sensor has high imaging sensitivity, high Q factor, high real-time detection speed and wide detection range of the sensing refractive index.

Drawings

Fig. 1 is a schematic structural diagram of a surface plasmon resonance sensor based on dual planar waveguide coupling according to the present invention.

FIG. 2 is a reflection spectrum of a surface plasmon resonance sensor based on bi-planar waveguide coupling in the detection of gas in example 1.

FIG. 3 is a reflection spectrum of a surface plasmon resonance sensor based on bi-planar waveguide coupling in the detection of a liquid according to example 1.

FIG. 4 is a graph of imaging sensitivity versus incident angle for a surface plasmon resonance biosensor based on biplane waveguide coupling in the detection of gas in example 1.

FIG. 5 is a graph of imaging sensitivity versus incident angle for a surface plasmon resonance biosensor based on biplane waveguide coupling in the detection of a liquid in example 1.

n_p-refractive index of SF11 prism, n₁Refractive index of-gold layer, n₂Refractive index of the upper fluoropolymer layer, n₃Refractive index of upper zirconium dioxide layer, n_s-refractive index of sensing layer, n₄Lower zirconium dioxide layer refractive index, n₅Lower refractive index of the fluoropolymer layer, d₁、 d₂、d₃、d_s、d₄The thicknesses of the gold layer, the upper fluorine-containing polymer layer, the upper zirconium dioxide layer, the sensing layer and the lower zirconium dioxide layer are respectively.

Detailed Description

In order to facilitate an understanding of the present invention, the present invention will be described more fully and in detail with reference to the preferred embodiments, but the scope of the present invention is not limited to the specific embodiments described below.

It should be particularly noted that when an element is referred to as being "fixed to, connected to or communicated with" another element, it can be directly fixed to, connected to or communicated with the other element or indirectly fixed to, connected to or communicated with the other element through other intermediate connecting components.

Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.