Graphene metasurface structure for microparticle delivery and sorting and applications

Abstract

The application provides a graphene supersurface structure for particle transmission and sorting, which comprises an electronic gel layer, a graphene periodic circular ring array layer and a dielectric protection layer arranged in sequence; a gate region is arranged on the electronic gel layer, and a metal gate is arranged in the gate region; the graphene periodic circular ring array layer comprises multiple groups of graphene circular ring units arranged in sequence, each group of graphene circular ring units comprises a third circular ring, a second circular ring and a first circular ring with diameters increasing in sequence; the first circular ring, the second circular ring and the third circular ring have the same inner diameter. The single-layer graphene is arranged into circular rings with different sizes to form multiple groups of graphene circular ring units, and each group of graphene circular ring units is arranged into a periodic array, the graphene is adjusted to have a Fermi level to sequentially excite hot spots of graphene circular rings with different sizes, the frequency of incident laser does not need to be adjusted in the process of transmitting particles, and the complexity of supersurface optical tweezers application is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical tweezers, and more particularly to a graphene metasurface structure for particle delivery and sorting and application thereof. BACKGROUND

[0002] Plasmonic optical tweezers have been widely developed in the fields of biology and medicine due to their non-contact manipulation of microparticles, which avoids damage to microparticles caused by traditional mechanical methods. By confining light on the surface of a structure, i.e. in the evanescent field range, plasmonic optical tweezers successfully capture sub-micron particles and solve the problem of the diffraction limit of early optical tweezers. Further, after stable capture of microparticles, people began to study how to transport microparticles. Han Xue et al. used a plasmonic tweezer based on a gold ring hole array to capture 1-μm polystyrene microparticles. Shi Yuzhi et al. used a silicon nanowire waveguide array to capture 200-500-nm microparticles. Lu Changgui et al. used a plasmonic gold antenna array as a conveyor belt to transport microparticles by changing the resonance wavelength. Although metal plasmonic optical tweezers can stably capture and transport sub-micron microparticles, they are not perfect. First, metals lack real-time tunability. Once the structure shape is determined, the excitation wavelength and polarization direction of the incident light source are also determined. In order to transport microparticles, the wavelength of the light source has to be changed at any time, which undoubtedly increases the application cost. Second, under the condition that the incident light power is constant, the gradient force of the light field on a small microparticle is smaller than that on a large microparticle. The common solution is to increase the power of the incident light source, but the metal structure absorbs a lot of joule heat generated by the incident light. On the one hand, the captured microparticles may be damaged due to the high-power incident light, and on the other hand, thermal convection and thermophoresis caused by temperature rise will also affect the stable capture of microparticles. Therefore, new materials are needed to overcome the shortcomings of metal plasmonic optical tweezers.

[0003] In recent decades, graphene has been developed as a tunable and highly thermally conductive material. Graphene materials have been shown to excite plasmonic resonance in different spectral regions, thereby achieving stable capture of microparticles. Existing graphene plasmonic structures include circular holes, coaxial hole arrays with nanogaps, and grooves, but the existing graphene plasmonic structures still have defects. They require high incident light sources, the frequency of the incident light source needs to be constantly adjusted, and the excitation light polarization is strictly limited, which complicates the application of the metasurface optical tweezer. SUMMARY

[0004] The graphene super surface structure for particle delivery and sorting and the application thereof have the advantages that the graphene is arranged into a periodic circular ring array, the graphene super surface structure for particle delivery and sorting is independent of the polarization direction of a light source, the frequency of incident laser light does not need to be adjusted in the process of transmitting particles, and the complexity of the application of the super surface optical tweezers is reduced.

[0005] To achieve the above object, the application adopts the following technical scheme:

[0006] The graphene super surface structure for particle delivery and sorting comprises an electronic gel layer, a graphene periodic circular ring array layer and a dielectric protection layer arranged in sequence.

[0007] The electronic gel layer is provided with a gate region, and the gate region is provided with a metal gate.

[0008] The graphene periodic circular ring array layer comprises a plurality of groups of graphene circular ring units arranged in sequence, and each group of graphene circular ring units comprises a third circular ring, a second circular ring and a first circular ring arranged in sequence and having diameters of outer rings increasing in sequence.

[0009] The first circular ring, the second circular ring and the third circular ring have the same inner ring diameter.

[0010] Further, the inner ring diameters of the first circular ring, the second circular ring and the third circular ring are 100-1000 nm, and the first circular ring, the second circular ring and the third circular ring are single-layer graphene, and the thicknesses of the first circular ring, the second circular ring and the third circular ring are all 1 nm.

[0011] In the above technical scheme, the single-layer graphene is arranged into circular rings of different sizes to form a plurality of groups of graphene circular ring units, and each group of graphene circular ring units is arranged into a periodic array, the graphene super surface structure for particle delivery and sorting is independent of the polarization direction of an incident light source, the frequency of incident laser light does not need to be adjusted in the process of transmitting particles, and different sizes of graphene circular rings can be sequentially excited only by changing the voltage of the metal gate in a certain time sequence under monochromatic excitation light, so that particles are directionally transmitted along a hot spot path, the operation is simple, and the complexity of the application of the super surface optical tweezers is reduced.

[0012] Further, the outer ring diameter of the first circular ring is 410-3200 nm, the outer ring diameter of the second circular ring is 370-3100 nm, and the outer ring diameter of the third circular ring is 330-3000 nm.

[0013] In the above technical scheme, the inner ring diameters of the first circular ring, the second circular ring and the third circular ring are the same, and the outer ring diameters of the three are different, so that different sizes of graphene circular rings can be sequentially excited when the voltage is applied to adjust the Fermi energy level of the graphene, and particles are directionally transmitted along a hot spot path.

[0014] Further, the distance between the first circular ring, the second circular ring and the third circular ring is 55-65nm.

[0015] Further, the thickness of the electron gel layer is 200nm-5um, and the thickness of the dielectric protective layer is 2-5nm.

[0016] The application also provides a graphene super surface structure for particle delivery and sorting, and a method for particle delivery and sorting using the graphene super surface structure.

[0017] S1: applying a voltage to the metal gate on the electron gel layer to adjust the Fermi energy level of graphene, and turning on a terahertz frequency laser light source to irradiate the graphene super surface structure;

[0018] S2: the third circular ring, the second circular ring and the first circular ring correspond to a Fermi energy level, and under the excitation of the corresponding terahertz waveband laser light source, when the corresponding graphene circular ring is adjusted to the corresponding Fermi energy level, the corresponding graphene circular ring is excited to a hot spot;

[0019] S3: the gradient force generated by the strong electric field region, also called hot spot, formed by the graphene surface, is used to capture and separate the particles.

[0020] Further, the Fermi energy level corresponding to the third circular ring is 0.40eV, the Fermi energy level corresponding to the second circular ring is 0.45eV, and the Fermi energy level corresponding to the first circular ring is 0.50eV.

[0021] Further, the frequency of the terahertz waveband laser light source is 9um-12um.

[0022] In the above technical solution, the unique Dirac plasmon in graphene can adjust the carrier concentration of graphene by applying a gate voltage, that is, the change of the Fermi energy level of graphene can be controlled, so that the position of the captured particles can be changed, and the stable transmission of the particles can be realized; in addition, the excitation light source of the graphene super surface is in the terahertz waveband, the photon energy in the terahertz spectral region is relatively low, and the graphene has good thermal conductivity and less thermal damage to biological molecules.

[0023] Further, because the size or refractive index of the particles is different, the gradient force received by the particles is different, which can be clearly known from the formula

[0024] Further, in step S3, after the graphene circular ring is excited to a hot spot, the gradient force received by the particles to be captured in the x direction of the graphene super surface structure satisfies the following expression: ​

[0025]

[0026]

[0027] F dr = gamma * v

[0028]

[0029] Wherein, F op is optical gradient force, F br is Brownian force, R is Gaussian random number, K B is Boltzmann constant, F dr is viscous force, d is diameter, gamma is viscous coefficient positively related to particle radius, it is assumed that the force acting on the particle in a very short time remains unchanged, take Delta t=0.1 mu s, Delta x is the displacement of the particle in a time interval.

[0030] In the technical scheme, the gradient force in the x direction, i.e., the moving direction of the particle, reaches the order of PN, and the depth of the trapping potential well also exceeds 1K b T threshold value, so that the present application can stably capture and transport particles.

[0031] Further, different particles will cause different forces due to the difference in radius and refractive index, and then the speed of moving on different size graphene rings is also inconsistent, and the separation time of particles with different refractive indexes satisfies the following expression:

[0032]

[0033]

[0034] The present application uses the speed difference of particles with different refractive indexes in transmission, uses statistical method to verify the feasibility of particle sorting, regards the Brownian motion of particles as Gaussian distribution with variance 2Dt, designs the graphene ring array as three different specifications of rings as a period, obtains the separation time, and then obtains the separation period, so that it is known that different particles are basically separated after moving a distance.

[0035] Further, the material of the electronic gel layer is silicon dioxide, and the refractive index is 1.45.

[0036] Compared with the prior art, the beneficial effects of the technical scheme of the present application are:

[0037] 1. The application provides a graphene super surface structure and application for particle delivery and sorting, the super surface structure comprises a graphene periodic circular ring array layer, the graphene circular ring surface plasmon resonance is excited by linearly polarized light excitation, hot spots are excited with graphene circular rings of different sizes, and the medium ball is attracted and moved due to the gradient force; because the gradient force intensity of different refractive index particles is different, the speed of different particles moving above the graphene circular ring periodic structure of the application will be inconsistent, and the separation of different particles can be easily completed by using the different speeds of different particles during movement; compared with the near-field optical tweezers based on noble metals, the frequency or polarization direction of the incident laser needs to be continuously adjusted for particle transmission, the graphene circular ring near-field optical tweezers of the application is adjusted by adjusting the Fermi level of graphene to excite hot spots of graphene circular rings of different sizes, the frequency of the incident laser does not need to be adjusted, and the circular ring structure also makes it independent of the polarization direction of the light source.

[0038] 2. The metal-based super surface optical tweezers need to adjust the polarization or wavelength of the light source to realize switching of the plasmonic resonance when capturing and transmitting particles; in the existing graphene strip-based capture and transmission scheme, the excitation light polarization is also strictly limited; the graphene circular ring structure of the application is not sensitive to the excitation light polarization, and only the timing of the applied voltage needs to be set in operation, so as to realize switching of the hot spots and transmission of the particles.

[0039] 3. The application uses super surface optical tweezers to capture and transmit particles, the size of the particles can be as small as nanometers, solves the problem that the traditional optical tweezers are difficult to capture nanometer particles due to the influence of the diffraction limit, and the super surface optical tweezers can simultaneously capture a large number of particles and perform synchronous control.

[0040] 4. The heat conduction effect of graphene is much better than that of metal, which effectively reduces thermophoresis and thermal convection in a small space such as a microfluidic chip, and increases the reliability of operation, the graphene super surface structure of the application has good application prospect in the field of microfluidic chips due to the transmission and screening capabilities. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 It is a schematic diagram of the super surface structure of the application;

[0042] Figure 2 It is an analysis diagram of the graphene circular ring at three Fermi levels of 0.4 eV, 0.45 eV and 0.5 eV in Example 2 (wherein (a) is the transmission spectrum at three Fermi levels, (b) is the light field distribution diagram at three Fermi levels, and (c) is the fitting curve of the resonance wavelength with the Fermi level change);

[0043] Figure 3 It is a trend diagram of the force of the particle with the X-axis coordinate change and a potential energy distribution diagram in Example 2.

[0044] Figure 4 Fig. 6 is a diagram of the particle position distribution statistics at different Fermi energy levels in Example 2;

[0045] Figure 5 Fig. 7 is a diagram of the particle position distribution statistics at different time points when the switching frequency is 0.4 s in Example 2.

[0046] Wherein: 1-dielectric protective layer, 2-graphene periodic circular ring array layer, 3-electron gel layer, 4-metal gate, 21-first circular ring, 22-second circular ring, 23-third circular ring. DETAILED DESCRIPTION

[0047] The application will be further described below in conjunction with specific embodiments. The accompanying drawings are only used for exemplary illustration, and the representations are only schematic diagrams, not physical drawings, and should not be understood as limiting the patent; in order to better illustrate the embodiments of the application, some components of the drawings may be omitted, enlarged or reduced, and do not represent the actual product size; for those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0048] The same or similar reference numerals in the drawings of the embodiments of the application correspond to the same or similar components; in the description of the application, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the positional relationship described in the drawings is only used for exemplary illustration, and should not be understood as limiting the patent, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0049] Example 1

[0050] As shown in Figure 1 A graphene super surface structure for particle delivery and sorting, comprising an electron gel layer 3, a graphene periodic circular ring array layer 2 and a dielectric protective layer 1 arranged in sequence; a gate region is arranged on the electron gel layer 3, and a metal gate 4 is arranged in the gate region; the graphene periodic circular ring array layer 2 comprises a plurality of groups of graphene circular ring units arranged in sequence, each group of graphene circular ring units comprises a third circular ring 23, a second circular ring 22 and a first circular ring 21 arranged in sequence and having diameters increasing in sequence; the first circular ring 21, the second circular ring 22 and the third circular ring 23 have the same inner diameter.

[0051] Further, the outer ring diameter of the first circular ring 21 is 410-3200 nm, the outer ring diameter of the second circular ring 22 is 370-3100 nm, and the outer ring diameter of the third circular ring 23 is 330-3000 nm; the inner ring diameter of the first circular ring 21, the second circular ring 22 and the third circular ring 23 is 100-1000 nm, and the first circular ring 21, the second circular ring 22 and the third circular ring 23 are all single-layer graphene, and the thickness of each is 1 nm.

[0052] Further, the distance between the first circular ring 21, the second circular ring 22 and the third circular ring 23 is 55-65 nm.

[0053] In the embodiment, the graphene super surface structure for particle delivery and sorting performs particle delivery and sorting, specifically including the following steps:

[0054] S1: Apply voltage to the metal gate 4 on the electron gel layer 3 to adjust the Fermi energy level of the graphene, and turn on the terahertz frequency laser light source to irradiate the graphene super surface structure;

[0055] S2: The third circular ring 23, the second circular ring 22 and the first circular ring 21 each correspond to a Fermi energy level, and under the excitation of the corresponding terahertz waveband laser light source, when the corresponding graphene circular ring is adjusted to the corresponding Fermi energy level, the corresponding graphene circular ring is excited to a hot spot;

[0056] S3: The gradient force generated by the strong electric field region, also called hot spot, formed by the graphene surface captures and separates the particles to be captured and separated.

[0057] In the above method, the thickness of the electron gel layer 3 is 200 nm-5 um, and the thickness of the dielectric protection layer 1 is 2-5 nm;

[0058] The Fermi energy level corresponding to the third circular ring 23 is 0.40 eV, the Fermi energy level corresponding to the second circular ring 22 is 0.45 eV, and the Fermi energy level corresponding to the first circular ring 21 is 0.50 eV;

[0059] The frequency of the terahertz waveband laser light source is 9-12 um.

[0060] Embodiment 2

[0061] Based on embodiment 1, as Figures 1-5As shown, the embodiment provides a graphene super surface structure for particle delivery and sorting, a plurality of graphene ring units composed of a first ring 21, a second ring 22 and a third ring 23 are placed on an electronic gel layer 3 made of silica to form a graphene periodic ring array layer 2, and a 5nm thick dielectric protective layer 1 is covered on the graphene periodic ring array layer 2 to protect the graphene periodic ring array layer 2 from the liquid environment; a gate region is also provided on the electronic gel layer 3, and a metal gate 4 is provided in the gate region; the refractive index of the electronic gel layer 3 and the dielectric protective layer 1 is set to 1.45.

[0062] In the embodiment, the inner ring diameter of the first ring 21, the second ring 22 and the third ring 23 is 100nm, the outer ring diameter of the first ring 21 is 410nm, the outer ring diameter of the second ring 22 is 370nm, and the outer ring diameter of the third ring 23 is 330nm; the distance between every two adjacent rings is 55nm.

[0063] The particle delivery and sorting is carried out by using the above-mentioned graphene super surface structure for particle delivery and sorting, and the operation is carried out according to the following method:

[0064] S1: Apply voltage to the metal gate 4 on the electronic gel layer 3 to adjust the Fermi level of graphene, the corresponding Fermi level of the third ring 23 is 0.40ev, the corresponding Fermi level of the second ring 22 is 0.45ev, and the corresponding Fermi level of the first ring 21 is 0.50ev, and a terahertz waveband laser light source with a frequency of 9.8um is irradiated on the graphene super surface structure;

[0065] S2: When the third ring 23, the second ring 22 and the first ring 21 are adjusted to the corresponding Fermi level respectively, the corresponding graphene ring is excited to a hot spot under the excitation of the above-mentioned terahertz waveband laser light source;

[0066] S3: The gradient force generated by the strong electric field region formed by the graphene surface, also called hot spot, is used to capture and separate the particles.

[0067] In step S3, when the graphene ring is excited to a hot spot, the gradient force received by the particles to be captured in the x direction of the graphene super surface structure satisfies the following expression:

[0068]

[0069]

[0070] F dr =γv

[0071]

[0072] where F op is the optical gradient force, F br is the Brownian force, R is a Gaussian random number, K B is the Boltzmann constant, F dr is the viscous force, d is the diameter, γ is the viscous coefficient which is positively correlated with the radius of the particle, it is assumed that the force acting on the particle remains unchanged in a very short time, Δt = 0.1 μs, and Δχ is the displacement of the particle in a time interval.

[0073] Through calculation and analysis, the gradient force in the x direction, i.e. the moving direction of the particle, reaches the order of PN, and the depth of the trapping potential well also exceeds 1K b T, which is a criterion for stable trapping for those skilled in the art, proves that the graphene super surface structure of the application can stably trap and transport particles.

[0074] In this embodiment, the entire structure is above a liquid environment, and particles with three refractive indexes of 1.47, 1.59 and 1.70, respectively, can be transported and separated, and the diameter is 0.8 microns.

[0075] In this embodiment, the graphene material adopts the Falkovsky model, which is defined as:

[0076]

[0077]

[0078] where ε r = 2.5 is the background relative dielectric constant, μ c is the Fermi level, is the reduced Planck constant, the Fermi velocity v f = 1 × 10 6 m / s, the carrier mobility μ = 10000 cm 2 / v / s, Δ = 1 nm is the thickness of the graphene set, and τ is the relaxation time.

[0079] For the graphene super surface structure in this embodiment, under the irradiation of a plane wave light source with vertical incidence, the graphene ring generates a dipole resonance, and a local enhanced light field, referred to as a hot spot, is formed on the inside of the ring. As shown in Figure 2 (a) respectively shows the resonant wavelengths corresponding to the third ring 23, the second ring 22 and the first ring 21 when the Fermi level is 0.4 eV, 0.45 eV and 0.5 eV, respectively. It can be seen that when the Fermi level increases, the resonant wavelength corresponding to the graphene ring will increase synchronously, and basically in a linear relationship (as shown in Figure 2(c) shown). Thus, when the excitation wavelength is set to 9.8um, the Fermi energy level is 0.4eV, the third ring 23 with the smallest outer diameter reaches resonance and forms a hot spot in its inner ring; when the Fermi energy level increases to 0.45eV, the second ring 22 forms a hot spot; when the Fermi energy level further increases to 0.5eV, the first ring 21 with the largest outer diameter forms a hot spot. The corresponding changes in the optical field are shown in Figure 2 (b) shown.

[0080] Figure 3 (a), (b), (c) respectively show the force acting on the particle as a function of the x coordinate when each ring reaches resonance, and the center of the X axis in each figure corresponds to the position of the resonant ring. The force acting on the particle in the X direction is always directed towards the center of the graphene ring in the resonant state, indicating that the particle will be pushed towards the center of the graphene ring under the action of the optical gradient force. The force in the Z direction Fz is always negative, indicating that the particle is always limited to the surface of the conveyor belt during movement. Integrating Fx along the positive X axis can obtain the potential energy distribution of the particle in this direction, and the results are shown in Figure 3 (d) shown. When the Fermi energy level changes from 0.4eV to 0.45eV and then to 0.5eV, three potential well positions appear in turn, and the potential well depth gradually increases, which also corresponds to the three graphene ring structures that reach the resonant state, further indicating the movement trend of the particle.

[0081] From the above analysis, it can be seen that under the irradiation of monochromatic excitation light, the sequential excitation of graphene rings of different sizes can be realized by changing the gate voltage in a certain time sequence, so that the particles are directionally transferred along the hot spot excitation path.

[0082] In the liquid environment in this embodiment, the particles are not only affected by the optical force, but also by the Brownian motion and the viscous drag of the liquid. The dynamic characteristics of the particle during movement are calculated by the formula Considering the influence of thermal effects in operation, the power of the light source is set to 0.6mw / um 2 in the simulation, and the switching time of the Fermi energy level is 0.1s. The movement of the particles when the Fermi energy level is switched for the first four times is shown in Figure 4 Obviously, most of the particles can stably move between graphene rings at different positions as the Fermi energy level is switched.

[0083] In addition to stably capturing and transporting microparticles, the present application takes into account that the refractive index of microparticles will affect the size of optical force, causing differences in their moving speed. Taking three kinds of medium beads with refractive index of 1.47, 1.59 and 1.70 as an illustration, under the incident light intensity of 0.6 mw / um^2 and the switching interval of 0.4 s, the average moving speed of the three kinds of microparticles is calculated to be 0.278 um / s, 0.839 um / s and 1.074 um / s respectively according to the Langevin equation. Considering that the speed of microparticles with refractive index of 1.47 is much lower than the other two kinds of microparticles, they will be pulled apart by a distance in a short time, that is, the separation of the two kinds of microparticles with higher moving speed is mainly concerned, and their separation time is calculated to be 201.57 s, about 168 complete motion cycles. As shown in Figure 4 the end of the 168th motion cycle, the two kinds of microparticles with refractive index of 1.59 and 1.70 are basically separated, and the microparticle with the lowest moving speed lags behind obviously.

[0084] In summary, the graphene super surface structure of the present application can be used for microparticle transfer and sorting, and can automatically screen different kinds of microparticles, reducing the complexity of the application of super surface optical tweezers.

[0085] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A graphene supersurface structure for microparticle delivery and sorting, characterized by: The graphene super surface structure comprises, in sequence, an electronic gel layer (3), a graphene periodic circular ring array layer (2), and a dielectric protection layer (1). The electronic gel layer (3) is provided with a gate region, and the gate region is provided with a metal gate (4). The graphene periodic circular ring array layer (2) comprises a plurality of groups of graphene circular ring units arranged in sequence, and each group of graphene circular ring units comprises, in sequence, a third circular ring (23), a second circular ring (22), and a first circular ring (21) arranged in sequence and having diameters increasing in sequence. The first circular ring (21), the second circular ring (22), and the third circular ring (23) have the same inner diameter.

2. The graphene supersurface structure for microparticle delivery and sorting of claim 1, wherein: The outer diameter of the first circular ring (21) is 410-3200 nm, the outer diameter of the second circular ring (22) is 370-3100 nm, and the outer diameter of the third circular ring (23) is 330-3000 nm.

3. The graphene supersurface structure for microparticle delivery and sorting of claim 1, wherein: The inner diameters of the first circular ring (21), the second circular ring (22), and the third circular ring (23) are all 100-1000 nm, and the first circular ring (21), the second circular ring (22), and the third circular ring (23) are all single-layer graphene, each having a thickness of 1 nm.

4. The graphene supersurface structure for microparticle delivery and sorting of claim 3, wherein: The distance between the first circular ring (21), the second circular ring (22), and the third circular ring (23) is 55-65 nm.

5. The graphene supersurface structure for microparticle delivery and sorting of claim 1, wherein: The thickness of the electronic gel layer (3) is 200 nm-5 um, and the thickness of the dielectric protection layer (1) is 2-5 nm.

6. Use of a graphene supersurface structure for microparticle delivery and sorting according to any one of claims 1 to 5 in a method for microparticle delivery and sorting, characterized in that: The method for particle delivery and sorting adopts the graphene super surface structure for particle delivery and sorting, and specifically comprises the following steps: S1: A voltage is applied to the metal gate (4) on the electronic gel layer (3) to adjust the Fermi energy level of graphene, and a terahertz frequency laser light source is irradiated on the graphene super surface structure; S2: The third circular ring (23), the second circular ring (22), and the first circular ring (21) correspond to different Fermi energy levels, and under the excitation of the corresponding terahertz waveband laser light source, when the corresponding graphene circular ring is adjusted to the corresponding Fermi energy level, the corresponding graphene circular ring is excited to generate a hot spot; S3: The gradient force generated by the strong electric field region, also called the hot spot, formed by the graphene surface is used to capture and separate the particles.

7. Use according to claim 6, characterized in that: The Fermi energy level corresponding to the third circular ring (23) is 0.40 eV, the Fermi energy level corresponding to the second circular ring (22) is 0.45 eV, and the Fermi energy level corresponding to the first circular ring (21) is 0.50 eV.

8. Use according to claim 6, characterized in that: The frequency of the terahertz waveband laser light source is 9-12 um.

9. Use according to claim 6, characterized in that: In step S3, when the graphene circular ring is excited to generate a hot spot, the gradient force acting on the particles to be captured in the x direction of the graphene super surface structure satisfies the following expression: F dr = γv where F op is the optical gradient force, F br is the Brownian force, R is a Gaussian random number, K B is the Boltzmann constant, F dr is the viscous force, d is the diameter, γ is the viscous coefficient which is proportional to the radius of the particle, it is assumed that the force acting on the particle remains constant in a very short time, Δt = 0.1 μs, Δχ is the displacement of the particle in a time interval.

10. The use according to claim 6, characterized in that: The material of the electronic gel layer (3) is silicon dioxide, and the refractive index is 1.45.

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