All-dielectric optical flow control virus sorting chip system and virus sorting method based on optical flow control technology

Abstract

The invention relates to an all-dielectric optofluidic virus sorting chip system and a virus sorting method based on an optofluidic technology. The full-dielectric optofluidic virus sorting chip system is composed of a micro-fluidic chip and a laser regulation and control module, the micro-fluidic chip is of a multi-layer bonding structure and comprises a substrate layer (1), a lossless high-refraction layer (2), a super-surface layer (3), a micro-channel layer (4) and a Quartz quartz layer (5) which are sequentially arranged from bottom to top, and two PDMS rectangular blocks (6) are arranged on the Quartz quartz layer (5) at intervals; the laser regulation and control module is arranged above the micro-fluidic chip and is used for providing accurate light field excitation for the micro-fluidic chip. According to the full-dielectric optofluidic virus sorting chip system provided by the invention, laser is bound by virtue of the BIC theory, the single virus capture control efficiency of the chip is higher than 95% under the high flux of 5 mu L / h, quantitative purification, fluorescent antibody adaptation and window period sorting assistance can be realized, single virus research is further promoted, the flux is large, and the universality is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the fields of biomedical and high-performance photonic devices, and in particular to a full-dielectric optofluidic virus sorting chip system and a virus sorting method based on the optofluidic technology. BACKGROUND

[0002] The global spread of viruses (such as the novel coronavirus SARS-CoV-2, influenza virus, etc.) highlights the urgent need for high-sensitivity and high-specificity detection technology. Although the polymerase chain reaction (PCR) technology is still the "gold standard" for clinical diagnosis, the PCR method uses reverse transcription plus real-time polymerase chain reaction (RT-PCR) to amplify the nucleic acid of the pathogen, while detecting the amplification product in real time by using a fluorescent probe. The PCR method has the characteristics of strong specificity and high accuracy, and is mature in technology and widely used by society. For example, patent CN112159868A provides a novel coronavirus fluorescent qRT-PCR rapid detection system, which optimizes the primer probe targeting the novel coronavirus ORF1ab gene, N gene, and the enzyme mixture (reverse transcriptase, DNA polymerase, and UNG enzyme) of the amplification system, the concentration of magnesium ions, etc., to realize the optimization of the amplification system and the amplification program, thereby shortening the amplification time to within 30 minutes, greatly shortening the detection time, while ensuring the sensitivity, specificity, repeatability, and accuracy of the novel coronavirus detection. Patent CN107058622A provides a kit for combined detection of respiratory pathogens by multiplex fluorescent PCR, which contains six components: reaction liquid A, reaction liquid B, reaction liquid C, enzyme mixture, positive control, and negative control, which contains 11 common respiratory pathogen detections (influenza A virus universal type, influenza B virus, respiratory syncytial virus, human parainfluenza virus 1 / 2 / 3 type, adenovirus, mycoplasma pneumoniae, chlamydia pneumoniae, legionella pneumophila, streptococcus pneumoniae, haemophilus influenzae, and group A streptococcus), which are amplified by three reaction buffers, each containing four fluorescence channels, which can detect 90% of the pathogen infections in clinical practice. However, the PCR method has relatively high requirements for operators and equipment, and the detection time is usually several hours. Most importantly, the fluorescent quantitative PCR method can only detect the minimum virus concentration corresponding to the cycle number (Ct value) at which the fluorescence reaches the pre-set threshold value. If the virus concentration is less than the threshold value, it cannot be detected, and the amount of virus contained in the window period patient is usually small, resulting in false negatives. Therefore, there is an urgent need for a technology that can rapidly capture and isolate any single virus in the body fluid in the early stage of novel coronavirus infection.

[0003] At present, there is no simple and effective method and structure that can realize single virus sorting and manipulation in a short time. SUMMARY

[0004] The application aims to overcome the defects of the prior art, and provides a full-dielectric optical flow control virus sorting chip system and a virus sorting method based on optical flow control technology.

[0005] The application can achieve the above-mentioned purposes. The application provides a full-dielectric optical flow control virus sorting chip system, which is composed of a microfluidic chip and a laser control module.

[0006] The base interface is arranged on both sides of the lossless high-refraction layer, the cooperative interface is arranged on both sides of the metasurface layer, the microchannel layer and the Quartz layer, and the extension interface is arranged on the PDMS rectangle. The nano-cavity array is affected by the laser control module, the quasi-BIC mode of the nano-cavity is excited, the optical gradient force is generated, and the virus in the fluid to be sorted is sorted when flowing through the nano-cavity array.

[0007] Further, the laser control module provides precise optical field excitation for the microfluidic chip, which is the key to exciting the BIC mode and generating enhanced optical force. -2 The laser wavelength of the laser control module is 532 nm, which is consistent with the resonant wavelength of the nano-cavity array, so as to ensure the excitation of the quasi-BIC point. The adjustable range of the laser power of the laser control module is 10-100 mW, and the equivalent laser intensity is approximately 1 mW·μm The spot size of the laser control module is 10-12 μm, covering multiple nano-cavities to realize large-range optical field confinement. The laser control module can realize the directional transmission and positioning of a single virus through the precise movement (accuracy ≤1 μm) and real-time adjustment of the power of the supporting laser.

[0008] Further, the fluid interface is a hole with a diameter of 1-2 mm.

[0009] Further, the substrate layer has a cuboid structure with a thickness of 700-800 μm and is made of Si.

[0010] Further, the lossless high-refractive layer is lossless high-refractive silicon dioxide or elemental silicon with a thickness of 1-5 μm, and the thickness of the lossless high-refractive layer is preferably 2 μm; the lossless high-refractive layer serves as an intermediate medium layer to improve the light field constraint capability.

[0011] Further, the material of the metasurface layer is Si3N4, TiO2 or ZnO, and preferably Si3N4. The thickness of the metasurface layer is sub-100 nm (preferably 100 nm), and the metasurface layer serves as a core functional layer to excite BIC modes through a nano-cavity array to generate enhanced optical forces for virus capture. The metasurface layer has a circular nano-cavity array arranged in the middle region, the nano-cavity diameter is 80-150 nm (preferably 110 nm), the nano-cavity arrangement period is 334 nm, and the reflectivity is >99% at a working wavelength of 532 nm.

[0012] Further, the thickness of the micro-channel layer is ≤1 μm; the micro-channel layer preferably has a thickness of 1 μm, and is used to construct a micro-fluid channel to guide the precise transmission of the virus sample above the metasurface layer. The micro-channel arranged on the micro-channel layer is prepared by spin-coating PDMS and then laser engraving ablation, the channel width is 20-30 μm, and preferably 20 μm, and the bonding with the metasurface layer has no leakage.

[0013] Further, the Quartz layer has a cuboid structure, is used to cover and protect the underlying structure, has high optical transparency, and does not affect the laser incidence and fluorescence signal reading; the light transmission wavelength band of the Quartz layer covers 240-1100 nm, and is suitable for 532 nm laser and fluorescence sorting.

[0014] Further, the PDMS rectangular block is used for top fixation and fluid passage extension to ensure the sealing of the chip interface with the external hose, one small hole is drilled on each surface of the two PDMS rectangular blocks, and the holes correspond to the holes of the lossless high-refractive layer for fixing the hose.

[0015] The technical scheme 2 of the application provides a virus sorting method based on optical flow control technology, which comprises the following steps: S1. Sample pretreatment The virus sample to be sorted is taken, filtered through a 0.22 μm filter membrane to remove impurity particles, diluted with physiological saline (preferably at a ratio of 1:1) to obtain a virus sample solution, and used as a fluid to be sorted; The virus sample to be sorted is taken from, for example, saliva, blood diluent, dairy product virus extraction liquid, etc. The concentration of the virus sample solution is 10 2 -10 6 CFU / mL. S2. Device parameter initialization Fluid parameter setting: inject the fluid to be sorted obtained by S1 into the fluid interface on one side of the microfluidic chip, and control the flow rate and flux of the fluid to be sorted in the microchannel of the microchannel layer through an external micropump; the flow rate is generally about 100 pm / s, and the corresponding flux is stabilized at 5 pL / h, matching the light field binding range of the nanocavity array of the super surface layer, to avoid the virus flowing out without being captured due to too fast flow rate; when other size chips are selected, the flux can be changed by changing the flow rate; Laser parameter setting: turn on the laser control module (532 nm), select the power mode according to the sorting requirement, set the single virus sorting mode to 10-80 mW, and set the large amount of virus purification sorting mode to 80-100 mW, and the laser spot is aligned with the nanocavity array region of the chip super surface layer (to ensure that the light field covers the nanocavity and excites the enhanced optical force); S3. Virus precise sorting operation Virus capture: when the fluid to be sorted flows through the super surface layer, the quasi-BIC mode of the nanocavity array is excited by the laser to generate an optical gradient force, and the virus is captured in the nanocavity; Directional movement sorting: the laser position is finely adjusted (accuracy ≤1 pm) through the laser control module to drive the captured virus to move along the PDMS microchannel direction, at this time, the virus is sorted into the nanocavity array (virus collection area, which corresponds to the transparent observation area below the Quartz layer, facilitating subsequent sorting) arranged on the chip; after a period of capture, the laser is turned off, and the impurities not captured flow out of the chip with the fluid; the laser is turned on again to maintain the virus capture state, and the separation and purification of the virus and impurities are completed.

[0016] In some specific embodiments, when the virus sample concentration is >10 5 CFU / mL, the laser power is increased to 80-100 mW to expand the light field coverage range (such as covering ≥100 nanocavities), so that a large amount of viruses are simultaneously captured in the nanocavity array; after 10 minutes of capture, the laser is turned off for 10 seconds, and the impurities not captured flow out of the chip with the fluid; the laser is turned on again (50 mW) to maintain the virus capture state, and the separation and purification of the virus and impurities are completed.

[0017] Further, the application provides a virus detection method, which adds a virus detection reagent to the fluid to be detected on the basis of the above sorting, and judges the virus sorting result through the reagent reaction result.

[0018] For example, when a fluorescent dye is used, the higher the concentration of the sorted virus, the higher the fluorescence in the chip.

[0019] The technical scheme 3 of the application provides a full-dielectric optical flow control virus sorting chip system and application of a virus sorting method based on optical flow control technology, and the application includes sorting and detection of single viruses in a window period, screening of virus inhibitors, single virus mechanism research or virus sample purification.

[0020] Compared with the prior art, the application has the following beneficial effects: The application binds a laser beam in a nano-cavity by creatively designing a full-dielectric non-absorbing two-dimensional nano-cavity array and applying a continuous domain bound state (BIC) theory to form a large-range discrete bound field. The technology can exert enhanced optical force on fast-moving viruses in a micro-channel to achieve efficient capture of the viruses. The developed chip can realize multifunctional precise capture and manipulation of any single virus under a high-throughput condition of 5 microliters / hour, and the capture efficiency is more than 95%, and the chip also has quantification and purification functions. By optimizing the stability of the viruses in the micro-flow field and the contact efficiency of the viruses and the flow field, it is ensured that the captured viruses can be fully combined with the subsequently introduced fluorescent dyeing antibodies, thereby laying a foundation for sorting and detecting single viruses in a window period. Compared with existing virus sorting and detection technologies, the application has the advantages of large sorting and detection throughput and strong universality. In addition, the technology can also promote the development of single virus analysis methods, including virus inhibitor screening, single virus mechanism research, and drug testing and other application fields. 1. A new full-dielectric nano-cavity array can concentrate light in a hole array with a diameter of about 100 nanometers. The light is not absorbed, and the damage to biological samples caused by temperature rise can be avoided.

[0021] 2. An integrated optical flow control chip system has a channel smaller than 1 micrometer, and can achieve 99% virus capture.

[0022] 3. Efficient multifunctional manipulation of single viruses and a large number of viruses.

[0023] 4. Fluorescent antibody sorting and detection of viruses with single virus precision, and the sorting and detection time is less than 2 hours. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The optical flow control chip structure (a) and the schematic diagram of capturing viruses (b) of the virus sorting method of the new optical flow control technology of the embodiment of the application are shown in FIGS. Figure 1 Figure 1 Figure 2 The flow chart of the method of the application is shown in FIG. Figure 3 The band diagram (a) and the quality factor (b) of the single-layer superstructure structure of the embodiment of the application are shown in FIG. Figure 3 Figure 3 Figure 3 ​​​​C is the optical force of four bands; the inset is the electric field diagram of four different modes; Figure 4 Parameter scanning of the small hole radius in the photonic crystal plate of the embodiment of the application; Figure 5 The reflectivity spectrum of the single-layer super-structured surface structure of the embodiment of the application, respectively, in water (a) and in air (b); Figure 5 Figure 5 The reflectivity spectrum of the single-layer super-structured surface structure of the embodiment of the application, respectively, in water (a) and in air (b); Figure 6 The fabricated super-structured surface result map (a) and the chip physical map (b) of the embodiment of the application; Figure 6 Figure 6 The fabricated super-structured surface result map (a) and the chip physical map (b) of the embodiment of the application; Figure 7 The relationship between the temperature increment and the laser intensity (a) and the temperature distribution of the captured virus under the duration (b) of the embodiment of the application; Figure 7 Figure 7 The SEM image of the chip after capturing the virus (a) and the image of the captured virus under laser irradiation (b) of the embodiment of the application; Figure 8 The SEM image of the chip after capturing the virus (a) and the image of the captured virus under laser irradiation (b) of the embodiment of the application; Figure 8 Figure 8 The SEM image of the chip after capturing the virus (a) and the image of the captured virus under laser irradiation (b) of the embodiment of the application; Figure 9 The SEM image of the chip after capturing the virus (a) and the image of the captured virus under laser irradiation (b) of the embodiment of the application; Figure 9 Figure 9 The SEM image of the chip after capturing the virus (a) and the image of the captured virus under laser irradiation (b) of the embodiment of the application; Figure 10 The fluorescence antibody inspection graph of viruses of different concentrations (the higher the virus concentration, the brighter the fluorescence). DETAILED DESCRIPTION

[0025] The application will be described in detail below with reference to the drawings and specific embodiments. The embodiments are implemented on the premise of the technical solution of the application, and detailed implementation methods and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0026] Example 1: A full-dielectric optical flow control virus sorting chip system In view of the limitations of the current virus sorting technology mentioned in the background art, such as limited single virus sorting capability, long sorting time, and high requirements for equipment and personnel; and in view of the limitations of the current optical tweezer manipulation technology in manipulating small biological particles such as viruses and exosomes, such as low capture efficiency and flux, single function, and obvious chip light absorption heating phenomenon, a new full-dielectric optical flow control virus sorting chip system is proposed to accurately manipulate single and large amounts of viruses at high flux. ​​​​​

[0027] The embodiment first provides a full-dielectric optical microfluidic virus sorting chip system, which comprises a microfluidic chip and a laser control module. Figure 1 The structure diagram of the microfluidic chip and the virus capture diagram are shown.

[0028] Figure 1 The structure diagram of the microfluidic chip shown in a is shown as follows: the microfluidic chip is a multi-layer bonding structure, comprising, from bottom to top, a substrate layer 1, a lossless high-refraction layer 2, a Si3N4 super surface layer 3, a microchannel layer 4, a Quartz layer 5, and two PDMS rectangular blocks 6.

[0029] The substrate layer 1 has a thickness of 730 μm and is made of silicon (Si), in the form of a rectangular block, serving as the base of the whole chip and providing structural support. The lossless high-refraction layer 2 has a thickness of 2 μm and is made of high-refraction silica (SiO2), in the form of a rectangular block; the surface thereof is machined with two holes by a 1.5 mm diameter acoustic wave drill, for inserting and fixing a hose, serving as the interface for fluid to enter or exit the chip. The Si3N4 super surface layer 3 is a lossless silicon nitride (Si3N4) dielectric layer with a thickness of 100 nm, in the form of a rectangular block; the middle area thereof is arranged with an array of nanometer resonant cavities (nanocavities for short) with a diameter of 110 nm, which is the key structure for realizing the core functions of the chip (such as optical control, particle capture, etc.). The microchannel layer 4 is a polydimethylsiloxane (PDMS) layer with a thickness of 1 μm; it is prepared by spin-coating PDMS on the surface of SiO2 and using laser engraving to ablate the microchannel pattern, thereby preparing a microchannel pattern bonded with the Si3N4 super surface, for guiding the transmission of fluid in the chip; the fluid in the microchannel adopts low-refraction material H2O. The Quartz layer 5 is in the form of a rectangular block, serving to cover and protect the underlying structure; at the same time, due to the optical transparency of quartz, it can meet the needs of optical sorting or control. The two PDMS rectangular blocks 6 are bonded on the top of the chip; the surface of each rectangular block is also drilled with two small holes, corresponding to the holes on the lossless high-refraction layer 2, for fixing or connecting external hoses, to ensure the integrity of the fluid passage. The layers are integrated by bonding and other means to form a complete microfluidic system. The two hoses in the figure are respectively for fluid inlet and outlet, and the fluid contains substances to be sorted. The full-dielectric optical microfluidic virus sorting chip system further comprises a laser control module, which provides precise optical field excitation for the microfluidic chip.

[0030] Figure 1 b shows that, under the irradiation of a large-size Gaussian light beam (wavelength: 532 nm; diameter: 10-12 μm), the Si3N4 nanocavity array (on the Si3N4 super surface layer 3) with a diameter of 110 nm excites the trap mode in the dielectric nanocavity and captures viruses.

[0031] Example 2: A virus sorting method based on optofluidic technology Based on the above-mentioned all-dielectric optofluidic virus sorting chip system, this embodiment provides a virus sorting method based on optofluidic technology. Through the design optimization of the nano-resonant cavity, the study of the dynamics of virus particles in optofluidic technology, and the design of the optofluidic chip and control platform, multifunctional virus control is achieved.

[0032] This virus sorting method (belonging to optical tweezers manipulation technology) can generate optical force that is tens to hundreds of times stronger than other resonant modes, thereby successfully capturing a single virus at a certain speed (greater than 100 micrometers / second) with a capture efficiency of more than 95%. It enables multifunctional manipulation of a single virus at a high throughput (5 microliters / hour), including capture, transmission and localization; as well as the isolation and purification of a large number of viruses in a nanocavity.

[0033] Specifically, such as Figure 2 As shown, the virus sorting method includes the following steps: S1. Design and optimization of all-dielectric nanocavity arrays: Based on the operating wavelength of the microfluidic chip, the period and aspect ratio of the nanocavity array unit structure are scanned to design a high-reflectivity all-dielectric nanocavity array; the intrinsic modes in the nanocavity array are analyzed to find the quasi-BIC point with a quality factor much larger than that of traditional structures.

[0034] In step S1, the metasurface layer 3 is a non-destructive dielectric material Si3N4, the nanocavity array unit structure is a Si3N4 circular nanocavity, and the single-layer metasurface structure has a reflectivity greater than 99% at the working wavelength.

[0035] S2. Dynamics of virus particles in a two-dimensional potential well and optofluidic system: By calculating the force on each virus particle at a specific depth in a two-dimensional light field, the minimum capture size of the virus particle is analyzed; at the same time, the stability of the virus in the flow field is analyzed to determine the stability of the particle and the effect of material exchange with the flow field.

[0036] Based on the (532nm-550nm) working wavelength band of the surface structure of the metasurface layer 3, a two-dimensional nanocavity array of a high-reflectivity three-layer composite structure (substrate layer 1, lossless high-refractive-index layer 2, Si3N4 metasurface layer 3) was constructed. The nanocavity processed in step S2 has a size similar to that of the virus, between 80 and 150 nanometers, and a thickness equal to that of the silicon nitride layer, which is less than 100 nanometers.

[0037] S3, Precise and Multifunctional Control of High-Throughput Virus Orders: By regulating the laser energy and position, any single virus is moved to any position for accurate positioning; meanwhile, when the virus concentration is high, the laser energy and range are increased, a large number of viruses in the microchannel are captured within a certain time, and the single virus is isolated into a single hole, so that the virus is purified.

[0038] At a higher flux (5 microliters / hour), any single virus in the microchannel is captured, and the capture efficiency is more than 95%.

[0039] The virus flow rate in the resonant cavity in step S3 can be more than 100 microns / second.

[0040] The present embodiment is mainly based on the following technical principles: The BIC mode usually relies on the interference cancellation of two optical modes, which has certain similarity with the principle of the ring dipole. Research on the BIC mode in the nano structure helps to explore the nature of the interaction between light and matter, and has great potential application in the fields of nano laser, nonlinear optics, sensing and quantum optics. The present application analyzes the intrinsic mode in the nano cavity array, finds out the perfect BIC point with almost infinite quality factor and the quasi-BIC point with much larger quality factor than the traditional structure. The optical force in the perfect BIC point and the quasi-BIC point is calculated by the Minkowski stress tensor method, and the point with the most suitable optical force greatly enhanced is found out, which provides theoretical support for optical manipulation at a higher flux.

[0041] Exploring the capture stability of single virus in the optical potential well and the faster flow field is the premise of realizing high-efficiency manipulation. The virus in the microchannel will not only be affected by the optical potential well, but also by the high-speed fluid force, so the required capture optical force is much larger than that in static state. Therefore, the optical force and the fluid force acting on the particle need to be superimposed, and the capture stability under the combined force is analyzed. When the particle is captured into a single nano cavity, the contact efficiency of the particle and the fluid without optical force and the stability of the particle in the hole need to be analyzed. This requires simulation of the flow field near the particle and the dynamics of the particle under the restriction of the flow field and the hole.

[0042] Example 3 Verification of chip system and virus sorting method The present embodiment also verifies the above-mentioned all-dielectric optical flow control virus sorting chip system and the virus sorting method based on the optical flow control technology, and realizes the virus sorting of the new optical flow control technology.

[0043] Figure 3 The mode field analysis of the single-layer super surface structure and the optical force are shown. The radius of the circular hole structure is 87 nm, the height is 100 nm, the period of the super surface (super structured surface) is 334 nm, and the reflectivity of the super structured surface is 1 at a wavelength of 532 nm. Figure 3Table a (where 1, 2, 3, and 4 represent different modes, and the electric field plots for different modes are shown in several insets) displays the simulated band structure of the TE polarization field when the aperture radius and period are 87 nm and 334 nm, respectively. Modes 3 and 4 have a quality factor as high as 10 at point Γ. 9 However, compared to other modes, the optical power of both modes is very small because the light is completely confined within the cavity, leakage is negligible, and it hinders the interaction between light and particles. The mass factor of Mode 1 is <10. 3 However, it possesses the largest quality factor ( Figure 3 (b) This is because a perfect BIC mode can trap light without leakage, while mode 1 achieves a balance between light trapping and leakage, thus enabling a strong optical gradient force ( Figure 3 (c) An optical potential well for virus capture can be created in a nanocavity. Mode 2 (at point Γ) exhibits the least optical attraction to the aperture, which is due to the deflection of light waves from the aperture.

[0044] Figure 4 This paper demonstrates a parameter scan of the aperture radius in a photonic crystal plate, first scanning the aperture period from 330 to 350 nm. Simulation results show that the calculated quasi-BIC is around 564 THz (approximately 532 nm) when the aperture period is 334 nm and 343 nm. This closely matches the desired incident light wavelength. Combined with the parameter scan results for the aperture depth, this embodiment finally determines the aperture period to be 334 nm and the depth to be 100 nm.

[0045] Figure 5 This invention demonstrates the design of a high-reflectivity all-dielectric nanocavity array after scanning the period and aspect ratio of the unit structure. Figure 5 As can be seen in Figure a, at 563.9 Hz (532 nm), the metasurface structure of this invention exhibits a reflectivity of up to 99% underwater. However, no obvious resonance peak is observed in air. Figure 5 (b) This shows that we can achieve our design goal of high reflectivity by adjusting the period or the aspect ratio of the unit structure.

[0046] Figure 6 Figure a shows a silicon nitride metasurface structure fabricated using photolithography. The packaging of PDMS optofluidic chips typically involves bonding PDMS to glass. Furthermore, to facilitate subsequent insertion into the conduit, the PDMS must be drilled. Finally, the conduit is inserted to complete the optofluidic chip fabrication. Optofluidic chip samples are shown below. Figure 6 As shown in Figure b, the channel width of the optofluidic chip is approximately 20 μm, and the thickness between the channels is approximately 1 μm.

[0047] Figure 7 In the middle 'a', it is indicated that when 1 mW·μm-2 The temperature change can be negligible (<0.05°C) when the laser intensity is irradiated, Figure 7 In the b, it is shown that the morphology and activity of the virus in the nanocavity remain stable as time goes on. Therefore, the all-dielectric nanocavity array of the present application can manipulate the virus without heating the virus and changing the activity of the virus.

[0048] Figure 8 In the a, it is shown that the SEM imaging results of the adenovirus in the all-dielectric nanocavity array. The particles at the bottom show dark features due to the light field attenuation, and the particles close to the upper surface of the hole wall show bright features due to the scattering enhancement. It is worth noting that when the particle size matches the cavity, the phenomenon of single-hole capturing a single particle is dominant, which is due to the disturbance effect of the captured particles on the local light field. This disturbance can significantly weaken the light force in the adjacent area, resulting in a decrease in the overall capture efficiency of the nanocavity array. Figure 8 In the b, it is shown that by using high laser power (60-100 mW, equivalent laser intensity ≈1 mW·μm -2 ) to continuously irradiate the nanocavity array, directional enrichment of hundreds to thousands of virus particles can be achieved. As the laser power increases, the number of local points with strong optical gradient force in the nanocavity array increases significantly, thereby realizing large-scale virus capture. When the laser power reaches 100 mW, dozens of adenoviruses can be successfully captured in the light spot area.

[0049] Figure 9 It is shown that the probability of virus entering the nanocavity ( P 捕获 ) depends on the capture time. In principle, the longer the capture time, the higher the probability of the virus being captured in the nanocavity. However, in some cases, the virus is not captured in the nanocavity for a long time. Therefore, the capture probability also depends on the speed of light beam movement when the virus is transported. Figure 9 In the a. Figure 9 In the b, it is shown that when the capture time is longer than 20 s (the laser beam remains stationary) and the laser power is greater than 80 mW, the adenovirus capture rate is >95%.

[0050] Figure 10 It is shown that after the virus surface is modified with fluorescent molecules, by adding LED light that excites the fluorescent molecules in the light path, the fluorescent molecules emit excitation fluorescence. By observing the intensity of the fluorescent light on the camera, the concentration of virus molecules in the current chip can be distinguished. The more the number of viruses, the stronger the observed fluorescent signal.

[0051] The structural parameters of the superstructure surface in the present application are not limited to this. For different design wavelengths, the period / radius of the unit structure can be reasonably adjusted according to the design wavelength.

[0052] The preferred embodiments of the present application have been described above in detail. It should be understood that modifications and variations to the preferred embodiments could be made by those skilled in the art in light of the teachings above without departing from the spirit of the present application. It is therefore to be understood that what is desired to be protected by letters patent is defined by the scope of the claims below and that on the basis of the teachings of the present application, obvious modifications and equivalents can be adopted by those skilled in the art in their possession of the teachings of the present application without departing from the spirit and scope of the application.

Claims

1. A total dielectric photonic fluidic virus sorting chip system, characterized in that, It is composed of a microfluidic chip and a laser control module, the microfluidic chip is a multi-layer bonded structure, including a substrate layer (1), a lossless high refractive layer (2), a metasurface layer (3), a microchannel layer (4) and a Quartz quartz layer (5) arranged in turn from bottom to top, two PDMS rectangles (6) are arranged on the Quartz quartz layer (5) with a certain interval; the middle region of the metasurface layer (3) is arranged with a circular nanocavity array as a virus collection area; the microfluidic channel is arranged on the microchannel layer (4); the nanocavity array is connected with the microfluidic channel; the laser control module is arranged above the microfluidic chip to provide precise optical field excitation for the microfluidic chip; The lossless high refractive layer (2) is provided with a basic interface on both sides, the metasurface layer (3), the microchannel layer (4) and the Quartz quartz layer (5) are provided with a cooperative interface on both sides, and the PDMS rectangle (6) is provided with an extension interface on each side; the basic interface, the cooperative interface and the extension interface jointly form a fluid interface, and the fluid interfaces on both sides are respectively inserted into a hose for the inlet and outlet of the fluid to be sorted; The nanocavity array is affected by the laser control module, the quasi-BIC mode of the nanocavity is excited, the optical gradient force is generated, and the virus in the fluid to be sorted is sorted when flowing through the nanocavity array due to the optical gradient force.

2. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The laser wavelength of the laser regulation module is 532 nm, the adjustable range of laser power is 10-100 mW, and the equivalent laser intensity is 1 mW·μm -2 ; the fluid interface is a hole with a diameter of 1-2 mm.

3. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The substrate layer (1) is a cuboid structure with a thickness of 700-800μm, and the material is Si, which provides structural support as a base.

4. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The lossless high refractive layer (2) is a lossless high refractive silicon dioxide or elemental silicon with a thickness of 1-5μm, which serves as an intermediate medium layer.

5. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The material of the metasurface layer (3) is selected from any one of Si3N4, TiO2 or ZnO, and the thickness of the metasurface layer (3) is sub-100 nm; the nanocavity diameter is 80-150 nm, and the nanocavity arrangement period is 334 nm.

6. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The thickness of the microchannel layer (4) is ≤1μm; the microchannel on the microchannel layer (4) is prepared by laser ablation after spin coating PDMS, and the channel width is 20-30μm.

7. The all-dielectric optical fluidic virus sorting chip system of claim 1, wherein, The Quartz quartz layer (5) is a cuboid structure, which is used to cover and protect the lower layer structure, has high optical transparency, and the light transmission band covers 240-1100nm.

8. The all-dielectric optical fluidic virus sorting chip system according to any one of claims 1-7, wherein, The thickness of the substrate layer (1) is 730μm, the thickness of the lossless high refractive layer (2) is 2μm, the material of the metasurface layer (3) is Si3N4, the thickness of the metasurface layer (3) is sub-100 nm, the nanocavity diameter is 110 nm, the nanocavity arrangement period is 334 nm, the thickness of the microchannel layer (4) is 1μm, and the microchannel width on the microchannel layer (4) is 20μm.

9. A method for virus sorting based on optofluidic technology, characterized in that, The virus sorting method is not for the purpose of disease diagnosis and treatment, comprising the following steps: S1. Sample pretreatment Take the virus sample to be sorted, filter out impurity particles through a 0.22μm filter membrane, dilute with physiological saline to obtain a virus sample solution as a fluid to be sorted; The concentration of virus in the virus sample liquid ranges from 10 2 -10 6 CFU / mL; S2. Device parameter initialization Fluid parameter setting: inject the fluid to be sorted obtained by S1 into the fluid interface on one side of the microfluidic chip, and control the flow rate and flux of the fluid to be sorted in the microchannel of the microchannel layer (4) through an external micropump; Laser parameter setting: turn on the laser control module, select the power mode according to the sorting requirement, set the single virus sorting mode to 10-80 mW, and set the large amount of virus purification sorting mode to 80-100 mW, and align the laser spot to the nanocavity array region of the super surface layer (3) of the chip; S3. Virus precise sorting operation Virus capture: when the fluid to be sorted flows through the super surface layer (3), the quasi-BIC mode of the nanocavity array is excited by laser to generate optical gradient force, and the virus is captured in the nanocavity; Directional movement sorting: adjust the laser position through the laser control module, drive the captured virus to move along the PDMS microchannel direction, at this time, the virus is sorted into the nanocavity array arranged on the chip; after a period of capture, the laser is turned off, and the impurities not captured flow out of the chip with the fluid; the laser is turned on again, and the virus capture state is maintained, and the separation and purification of the virus and the impurities are completed.

10. Use of a full dielectric optofluidic virus sorting chip system according to claim 1 or a method for virus sorting based on optofluidics according to claim 9, characterized in that, The virus sorting method is not for the purpose of disease diagnosis and treatment, and the application includes: window period single virus sorting, virus inhibitor screening, single virus mechanism research or virus sample purification.

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