CN207114429U - Terahertz surface plasma resonance sensing equipment - Google Patents

Abstract

It the utility model is related to Terahertz surface plasma resonance sensing equipment, including base station, the rotation platform by motor-driven rotation is provided with base station, refractive index sensing coupled structure is provided with rotation platform, refractive index sensing coupled structure includes prism, the MgF set gradually₂Basalis, cushion, doped graphene layer, sample cell, medium by the use of graphene as excitating surface plasma polarization ripple, sample cell is set with the gateway for sample inflow and outflow, the sample flowed into sample cell directly contacts with doped graphene layer, terahertz transmitter, Terahertz receiver are provided with base station, one side of prism is connected with MgF2 basalises, terahertz transmitter, Terahertz receiver respectively positioned at prism not with MgF₂The side for two sides that basalis is connected, Terahertz receiver connection signal processing apparatus, the utility model is simple in construction, easy to operate, highly reliable, substantially increases the practicality of system detectio.

Description

Terahertz surface plasma resonance sensing equipment

Technical field

It the utility model is related to a kind of Terahertz surface plasma body resonant vibration in Terahertz plasma resonance sensing field Sensing device.

Background technology

Surface plasma is caused by the concussion of the collective of conducting medium and insulator medium interface free electron. Close coupling effect between photon and surface plasma is referred to as surface plasma body polarization, and the coupling between them will be led Cause the resonance of surface plasma（SPR）, and to the change of the media environment at conducting medium and insulator medium interface Change very sensitive, therefore SPR sensorgram technology is often employed for sensing analysis, and especially in terms of the utilization of bio-sensing, it can be with Effectively the course of reaction of biomolecule is monitored.

Graphene has perfect two dimensional crystal structure, and its lattice is the hexagon surrounded by six carbon atom, thickness For an atomic layer, about 0.34nm.By σ key connections, combination it is sp2 hydridization between carbon atom, these σ keys impart stone The extremely excellent mechanical property of black alkene and structural rigidity.The hardness of graphene is stronger than best steel 100 times, or even also to exceed Diamond.In graphene, each carbon atom has the p electronics of a non-bonding, and these p electronics can freely move in crystal It is dynamic, and movement velocity is up to the 1/300 of the light velocity, imparts the good electric conductivity of graphene.The superior performance of graphene, makes its quilt Widely apply to SPR sensorgram field.

Terahertz（THz）It is one of vibration frequency unit.THz wave frequencies section is a kind of new probably between 0.1-10THz , radiation source that have many particular advantages.Because Terahertz has penetrability and unionized to most packaging material, make It has important application in terms of lossless safety detection.In addition, the intrinsic vibration of most of macromoleculars and speed are located at Terahertz frequency range, so there is only day to obtain thick advantage for application of the Terahertz in bio-sensing field.Its unique performance is also given The fields such as broadband connections, radar, electronic countermeasure, ELECTROMAGNETIC WEAPON, astronomy, medical imaging, Non-Destructive Testing, safety inspection are brought Far-reaching influence.

The content of the invention

The purpose of this utility model is to be directed to above weak point, there is provided a kind of Terahertz surface plasma body resonant vibration passes Induction device.

Scheme is used by the utility model solves technical problem, a kind of Terahertz surface plasma resonance sensing dress Put, including base station, the rotation platform by motor-driven rotation is provided with the base station, refraction is provided with the rotation platform Rate senses coupled structure, and the refractive index sensing coupled structure includes prism, the MgF set gradually₂Basalis, cushion, Doped graphene layer, sample cell, the sample cell are set with the gateway for sample inflow and outflow, the sample flowed into sample cell Directly contacted with doped graphene layer, terahertz transmitter, Terahertz receiver, one side of prism are provided with the base station Face is connected with MgF2 basalises, terahertz transmitter, Terahertz receiver respectively positioned at prism not with MgF₂Basalis phase The side of two sides of connection, the Terahertz receiver connect signal processing apparatus.

Further, the signal processing device is set to PC.

Further, the MgF₂Basalis is adhered on prism.

Further, the cushion is the derivative NFC using poly- light base styrene in MgF₂Spin coating is carried out in substrate, Thickness is 20 nm.

Further, the doping rate of the doped graphene layer is 0.6-1.64eV.

Further, the terahertz transmitter tranmitting frequency is the Terahertz light source of 5THz, TM polarization.

Further, the MgF₂Basalis is by 5.5 μ m-thicks, MgF that refractive index is about 1.36₂Material is formed.

Further, the prism is germanium prism.

Compared with prior art, the utility model has the advantages that：Excitating surface is used as by the use of doped graphene The medium of plasma, realize that Terahertz is incident with different angle with reference to angle modulated technology, general medium wave is reflected according to Terahertz The drift of paddy position, the detection of object refractive index is realized, it is simple in construction, easy to operate, it is highly reliable, in research high sensitivity etc. There is potential engineering application value in terms of gas ions co-vibrating object index sensor, effectively overcome Otto types surface etc. Gas ions resonance coupling structure sensor-based system, in detection, the shortcomings that preparing specific small thickness analyte, substantially increase and be The practicality of system detection.

Brief description of the drawings

The utility model patent is further illustrated below in conjunction with the accompanying drawings.

Fig. 1 is the structural representation of the present apparatus；

Fig. 2 is that terahertz signal reflection is general under different graphene doped levels；

Fig. 3 is that terahertz signal reflection is general under different samples；

Fig. 4 is full width at half maximum (FWHM), quality factor and testing sample index of refraction relationship curve map；

Fig. 5 is analyte refractive index and the matched curve figure of resonance angle under different base.

In figure：

1- terahertz transmitters；2- prisms；3- rotation platforms；4- terahertz detectors；5- sample cells；6- samples；7- Doped graphene layer；8- cushions；9-MgF₂Basalis；10- signal processing apparatus.

Embodiment

The utility model is further illustrated with reference to the accompanying drawings and detailed description.

As shown in figure 1, a kind of Terahertz surface plasma resonance sensing equipment, including base station, set on the base station There is the rotation platform by motor-driven rotation, refractive index sensing coupled structure, the refractive index are provided with the rotation platform Sensing coupled structure includes prism, the MgF set gradually₂Basalis, cushion, doped graphene layer, sample cell, utilize stone The superior electronics performance of black alkene, as the medium of excitating surface plasma polarization ripple, the sample cell, which sets to use, supplies sample The gateway of inflow and outflow, the sample flowed into sample cell are directly contacted with doped graphene layer, are provided with too on the base station Hertz transmitter, Terahertz receiver, one side of prism are connected with MgF2 basalises, terahertz transmitter, Terahertz Receiver respectively positioned at prism not with MgF₂The side for two sides that basalis is connected, the Terahertz receiver connection Signal processing apparatus.

In the present embodiment, prism has spin coating the MgF of cushion₂Substrate, which connects, glues above it, then sets and mixes again Miscellaneous graphene layer, form the prism surface plasmon coupling structure of Kretschmann types.

In the present embodiment, the signal processing device is set to PC.

In the present embodiment, the MgF₂Basalis is adhered on prism.

In the present embodiment, the cushion is the derivative NFC using poly- light base styrene in MgF₂Carried out in substrate Spin coating, thickness are 20 nm.

In the present embodiment, the doping rate of the doped graphene layer is 0.6-1.64eV.

In the present embodiment, graphene is doped using making alive, and graphene is transferable to be put on cushion.

In the present embodiment, the terahertz transmitter tranmitting frequency is the Terahertz light source of 5THz, TM polarization.

In the present embodiment, the MgF₂Basalis is by 5.5 μ m-thicks, MgF that refractive index is about 1.36₂Material is formed.

In the present embodiment, the prism is germanium prism.

It is as follows using step：（1）Refractive index sensing coupled structure is positioned on rotation platform, sample is added into sample Pond, rotation platform rotation carry out the modulation of terahertz emission source incident angle；（2）Terahertz transmitter transmitting Terahertz light source is extremely Prism, Terahertz light source are incident with the incident angle more than the prism cirtical angle of total reflection from one side of prism（ ）, occur to be totally reflected and formed evanescent wave in prism bottom, when the photon energy and momentum and graphite of the TM polarised lights of incidence When the energy and momentum of surface plasma polarized wave on alkene-example interface match, it will be excited on graphene-example interface Surface plasma polarized wave, the single-frequency of incidence angles degree, TM polarization terahertz emissions source will couple with specific example reaction Into the surface plasma polarized wave propagated along graphene-example interface, total reflection is then produced, is penetrated from prism another side Go out；（3）The terahertz emission source of terahertz detector detection Rhizoma Sparganii prism modulation, by the information transmission that detection collects to PC； （3）PC is calculated under each incident angle, places the signal intensity for detecting to obtain after sample and the letter for detecting to obtain before placement sample The ratio of number intensity, this ratio is the reflectivity of this angle, finally obtains the reflectivity under incidence angles degree, forms terahertz Hereby reflectance spectrum.

In the present embodiment, when there is plasma polarization ripple to excite, in reflection is general, a trough is will appear from, it is different Sample because having different dielectric constants so that the dielectric environment of graphenic surface changes, so cause Terahertz it is anti- The position for penetrating spectrum trough is moved, and the sensing of object refractive index can be realized according to this characteristic.

The present apparatus, which innovatively utilizes, substitutes the graphene of doping traditional precious metal material, such as gold, silver, using too Hertz technology, inspires surface plasma.In the design of sensing arrangement, graphene is transferred into spin coating NFC cushions MgF₂In substrate, and substrate is then adhered directly on germanium prism, forms Kretschmann type surface plasma body resonant vibration couplings Structure is closed, to realize the detection of analyte refractive index.The structure effectively overcomes the coupling of Otto types surface plasma body resonant vibration Structure sensor-based system, in detection, the shortcomings that preparing specific small thickness analyte, substantially increase the practicality of system detectio Property.The system architecture is simple, easy to operate, highly reliable, shows through analog study, when the doped level of graphene is 1.0 EV, the accuracy of detection of the sensor-based system can be made to reach maximum；Meanwhile the sensitivity by calculating the system reached 28.5 degree/ RIU；Quality factor are in 6.84 RIU^-1And 7.43RIU^-1Between change.Further, helped using the substrate of larger refractive index Sensitivity and quality factor in the system of raising, when the ion glue for being about 1.73 using refractive index（ion-gel）During as substrate, The sensitivity of sensor-based system and quality factor have respectively reached 49.5 degree/RIU, 8.76 RIU^-1.Utilize the superior electronics of graphene Medium of the performance as excitating surface plasma is learned, with reference to Terahertz Technology, in research high sensitivity plasma resonance thing There is potential engineering application value in terms of body index sensor.

As shown in Fig. 2 double dot dash line, chain-dotted line, dotted line, dotted line and solid line, are represented when the refractive index of analyte is 1 respectively When, when graphene doped level EF is respectively 0.6-1.64eV, terahertz signal reflection is general.Illustration represents that terahertz signal is anti- Penetrate general full width at half maximum (FWHM) A and graphene doped level, i.e. fermi levelE _F Relation.From figure it will be seen that with graphite The raising of alkene doped level, terahertz signal reflect general full width at half maximum (FWHM) and taper into and tend towards stability.The detection of sensor-based system Definition of accuracy be full width at half maximum (FWHM) inverse, from illustration, it is apparent that graphene doped level E_F Half during=1.0 eV Peak overall with is minimum, i.e., accuracy of detection is maximum.So the doped level for properly increasing graphene similarly helps to the inspection of raising system Survey precision.

As shown in figure 3, double dot dash line, chain-dotted line, dotted line, dotted line, solid line, represent graphene doped level E respectively_F = 1.0 eV, analyte refractive index from 1.0 change to 1.4 when terahertz signal reflection it is general.It will be seen that surface from figure Plasma resonance angle increases with the increase of analytical refraction rate, by analyte refractive index and corresponding optimum resonance angle The scatterplot data of degree carry out linear fit and obtain the slope of matched curve, i.e. the sensitivity of sensor-based system is 28.5 degree/RIU.

As shown in figure 4, square point curve and buying curve represent respectively, graphene doped level E_F During=1.0 eV, the biography Full width at half maximum (FWHM), quality factor and the analyte refractive index of sensing system（n _a ）Relation curve；It can be seen that with treating test sample The increase of product refractive index, full width at half maximum (FWHM) first reduce and increased afterwards, i.e., systematic survey sensitivity first increases reduces afterwards, and quality factor Variation tendency is consistent with the variation tendency of system sensitivity, is similarly first to increase and reduces afterwards, in 1.0-1.4 analyte refractive index In the range of, system quality factor is in 6.84 RIU^-1And 7.43RIU^-1Between change.

As shown in figure 5, solid line, dotted line, double dot dash line, dotted line and chain-dotted line represent respectively, in graphene doped level E_F = During 1.0 eV, substrate refractive index from 1.36 change to 1.73 when, in the matched curve of different analyte refractive indexes and resonance angle, It can be seen that with the increase of substrate refractive index, the slope of the matched curve of analyte refractive index and resonance angle increases Add, i.e. the sensitivity increase of system.In substrate refractive index n_s When=1.73, its sensitivity reaches 49.5 degree/RIU.Accordingly We are calculated when analyte refractive index is 1, and quality factor corresponding to system are 8.76 RIU^-1.So using larger refraction The substrate of rate is favorably improved sensitivity and the quality factor of system.

Above-listed preferred embodiment, the purpose of this utility model, technical scheme and advantage are further described, It should be understood that and the foregoing is only preferred embodiment of the present utility model, it is all not to limit the utility model Within the spirit and principles of the utility model, any modification, equivalent substitution and improvements made etc., this practicality should be included in Within new protection domain.

Claims (8)

1. A kind of 1. Terahertz surface plasma resonance sensing equipment, it is characterised in that：Including base station, it is provided with the base station By the rotation platform of motor-driven rotation, refractive index sensing coupled structure is provided with the rotation platform, the refractive index passes Sense coupled structure includes prism, the MgF set gradually₂Basalis, cushion, doped graphene layer, sample cell, the sample Pond sets the gateway used for sample inflow and outflow, and the sample flowed into sample cell directly contacts with doped graphene layer, described Terahertz transmitter, Terahertz receiver are provided with base station, one side of prism is connected with MgF2 basalises, Terahertz Transmitter, Terahertz receiver respectively positioned at prism not with MgF₂The side for two sides that basalis is connected, it is described too Hertz receiver connection signal processing apparatus.
2. 2. Terahertz surface plasma resonance sensing equipment according to claim 1, it is characterised in that：At the signal Reason device is PC.
3. 3. Terahertz surface plasma resonance sensing equipment according to claim 2, it is characterised in that：The MgF₂Base Bottom is adhered on prism.
4. 4. Terahertz surface plasma resonance sensing equipment according to claim 3, it is characterised in that：The cushion To use the derivative NFC for gathering light base styrene in MgF₂Spin coating is carried out in substrate, thickness is 20 nm.
5. 5. Terahertz surface plasma resonance sensing equipment according to claim 4, it is characterised in that：The doping stone The doping rate of black alkene layer is 0.6-1.64eV.
6. 6. Terahertz surface plasma resonance sensing equipment according to claim 5, it is characterised in that：The Terahertz Transmitter tranmitting frequency is the Terahertz light source of 5THz, TM polarization.
7. 7. Terahertz surface plasma resonance sensing equipment according to claim 6, it is characterised in that：The MgF₂Base For bottom by 5.5 μ m-thicks, refractive index is 1.36 MgF₂Material is formed.
8. 8. Terahertz surface plasma resonance sensing equipment according to claim 7, it is characterised in that：The prism For germanium prism.