CN105118541B - Tunable capturing and screening method of linear polarization planar optical waves for particle located above chalcogenide substrate - Google Patents

Abstract

The invention provides a method for tunable trapping and screening of particles located above a chalcogenide substrate by a linearly polarized plane light wave. By placing the particles above a chalcogenide substrate plate, the symmetry of the Poynting vector around the particles is broken. distribution, so that the total Poynting vector on the particle is not zero, resulting in a non-gradient optical force; then, by changing the lattice structure of the chalcogenide substrate plate, changing the direction and magnitude of the total Poynting vector on the particle, Then change the direction and size of the non-gradient optical force of the total Poynting vector acting on the particle to regulate the trajectory of the particle in the incident light field, so as to perform tunable capture and screening of nanometer-sized molecules attached to the surface of the particle Technical solutions. Among them, the lattice structure of the chalcogenide substrate plate can be changed by means of light, electricity, heating and pressure.

Description

Tunable Trapping of Microparticles Over Chalcogenide Substrates by Linearly Polarized Plane Lightwaves and filter method

technical field

The invention relates to a method for tunable trapping and screening of particles above a chalcogenide substrate by linearly polarized plane light waves, which can be applied to the fields of biology, medicine, nanometer manipulation and the like.

Background technique

Optical trapping and screening of tiny objects has always been a research hotspot in the field of optics. Optical gradient force plays an important role in various optical trapping technologies, such as optical tweezers and optical bundling through optical gradient force. However, optical gradient forces have the disadvantages of complex devices, non-tunable devices, and difficulty in trapping and screening nanometer-sized molecules. In 2008, Ward, T.J. et al proposed that the optical gradient force generated by circularly polarized light can capture and separate chiral molecules with nanometer size. However, the circularly polarized incident light still needs to be generated by complex equipment, which is not conducive to the practical application of the system; and the nano-sized molecules captured and separated must have a chiral structure, thus limiting the scope of its target. Therefore, the present invention proposes to cover the surface of the particle above the chalcogenide substrate plate with nano-sized molecules, so that it can generate non-gradient optical force around the particle under the irradiation of the linearly polarized plane light wave; The characteristics of light field, electric field, temperature field, and pressure field change, and the size and direction of the non-gradient optical force on the particles above the chalcogenide substrate plate are tuned, so as to realize the capture and capture of nanometer-sized molecules attached to the particle surface Screening where nanoscale molecules can be achiral.

Contents of the invention

The purpose of the present invention is to overcome the complexity of the incident light source (that is, the incident light must be circularly polarized or elliptically polarized) and the limitation of the screening object (that is, the nanoscale molecule must have chiral structure), the gradient optical force generated by circularly polarized or elliptically polarized light is not tunable, and it is difficult to capture nano-sized achiral molecules, etc., and provide a system with simple system, convenient operation, ultra-sensitive, ultra-fast, The non-gradient optical force generated by linearly polarized plane light waves, which has the advantages of active tuning, traps and screens achiral nanometer-sized molecules above the chalcogenide substrate plate, which can be used in the fields of biology, medicine, and nanomanipulation.

The technical scheme that the present invention solves the problem adopts as follows:

A method for tunable trapping and screening of particles by linearly polarized plane light waves placed above a chalcogenide substrate plate that disrupts the glass print around the particle Symmetric distribution of Ting vectors, so that the total Poynting vector on the particle is not zero, resulting in non-gradient optical force; by changing the chalcogenide lattice structure of the chalcogenide substrate plate, changing the distribution of the total Poynting vector on the particle , and then change the direction and magnitude of the non-gradient optical force of the total Poynting vector acting on the particle to adjust the trajectory of the particle in the incident light field, so as to perform tunable capture and screening of nanometer-sized molecules attached to the surface of the particle , wherein the particles are placed above the chalcogenide substrate plate, the particle material can be medium or metal, the length, width and height of the chalcogenide substrate are from 10 nanometers to 10 meters, and the distance between the particles and the surface of the chalcogenide substrate plate The distance is l (l>0); the shape of the particle can be a curved surface geometry such as a sphere, a cylinder, a cone, or a polyhedron such as a prism, a cube, and a cuboid, and the volume is between 1 cubic nanometer and 1000 cubic microns.

According to the incident light according to claim 1, the incident light is a linearly polarized plane wave; the direction of the incident light is parallel to the chalcogenide substrate plate, the frequency range is 0.3 microns to 20 microns, and the power range is 0.1mW/μm ² to 10mW/μm ² .

The light source of the incident light adopts a wavelength-tunable laser, a semiconductor continuous or quasi-continuous laser, or a light emitting diode.

The surface is attached with particles of nanometer size molecules, the particle material can be metal or medium, wherein the metal can be Al, Ag, Au, Cu, Ni, Pt, etc., and the medium can be semiconductor materials such as Si, SiO ₂ , GaAs , InP, Al ₂ O ₃ , etc. or polymers.

For the chalcogenide substrate plate, the chalcogenides can be GeTe, Ge ₂ Sb ₂ Te ₅ , Ge ₁ Sb ₂ Te ₄ , Ge ₂ Sb ₂ Te ₄ , Ge ₃ Sb ₄ Te ₈ , Ge ₁₅ Sb ₈₅ , Ag ₅ In ₆ Sb ₅₉ Te ₃₀ .

Said particles with nano-sized molecules attached to the surface, the nano-sized molecules may have achiral structure or chiral structure, such as antigens, antibodies, enzymes, hormones, amines, peptides, amino acids, vitamins and the like.

As for the chalcogenide substrate flat plate, the chalcogenide is realized through material growth processes, including magnetron sputtering, electron beam evaporation, chemical vapor deposition of metal organic compounds, vapor phase epitaxy growth, molecular beam epitaxy and the like.

The chalcogenide substrate plate can change the crystal lattice structure of the chalcogenide by means of light, electricity, heating and pressure.

The system of the invention consists of a light source, a microscope and an optical force display. Before the test, place the chalcogenide substrate plate at the bottom of the sample pool filled with water or oil, then place the particles with nanometer-sized molecules on the surface in the sample pool filled with water or oil, and place the chalcogenide substrate at the same time. Above the substrate plate, a linearly polarized plane wave light source enters from the side wall of the sample cell to irradiate the particles. Since the chalcogenide substrate plate destroys the symmetrical distribution of the Poynting vector around the particle, the total Poynting vector on the particle is not Zero, resulting in a non-gradient optical force; by changing the lattice structure of the chalcogenide, changing the distribution of the total Poynting vector on the particle surface above the chalcogenide substrate plate, and then changing the non-gradient force of the total Poynting vector acting on the particle The direction and magnitude of the optical force are used to control the trajectory of the particles in the incident light field, so that the nano-sized molecules attached to the surface of the particles can be tunably captured and screened. Microscopes can be used to observe the trajectory of particles with nanometer-sized molecules attached to their surfaces under the action of incident light. The microscope can be an ordinary fluorescence vertical or upright microscope.

The system can realize tunable trapping and screening of objects with nanometer-sized achiral structures through simple linearly polarized plane light waves. It overcomes the complexity of the incident light source (that is, the incident light must be circularly polarized or elliptically polarized), the limitation of the screening object (that is, the nanoscale molecule must have chirality), The gradient optical force generated by circularly polarized or elliptically polarized light is not tunable, and it is difficult to capture nanometer-sized molecules. It has the advantages of simple system, convenient operation, ultra-sensitivity, ultra-fast, active tuning, etc. It can be used in biology, medicine and nanomanipulation and other fields.

Description of drawings

Figure 1 is a schematic diagram of particles with nanometer-sized molecules attached to their surfaces.

Fig. 2 is a schematic diagram of the process of trapping and screening microparticles with nanometer-sized molecules on the surface above a chalcogenide substrate plate by non-gradient optical force generated by linearly polarized light.

3 is a schematic diagram of a test system for trapping and screening microparticles with nanometer-sized molecules on the surface above a chalcogenide substrate plate by non-gradient optical force generated by linearly polarized light.

In the figure: 1 particle, 2 nanometer size molecule, 3 chalcogenide substrate plate, 4 light source, 5 microscope, 6 optical force display, 7 sample cell, 8 temperature controller, 9 CCD camera, 10 monitor, 11 computer, 12 video recorders.

detailed description

In order to make the content of the technical solution of the present invention clearer, the specific implementation manners of the present invention will be described in detail below in combination with the technical solution and the accompanying drawings. The material growth techniques include: magnetron sputtering, electron beam evaporation, chemical vapor deposition of metal-organic compounds, vapor phase epitaxy, and molecular beam epitaxy.

Example 1

First, particles 1 are produced through a material growth process, as shown in Fig. 1(a). The geometric shape and size of particles can be determined by finite time domain difference method, finite element method and other algorithms.

Secondly, nanometer-sized molecules 2 are attached to the outer surface of the particle 1, as shown in FIG. 1(b).

Then, the particles 1 with nanometer-sized molecules 2 attached to the surface are placed above the surface of the chalcogenide substrate plate 3 with a distance of l (l>0). When the incident light is a linearly polarized plane wave and the chalcogenide substrate plate 3 is non- In the crystalline state, the Poynting vectors around the particles 1 above the chalcogenide substrate plate 3 are distributed asymmetrically, that is, the total Poynting vectors on the particles 1 are not zero, resulting in a right-front direction along the incident light direction. The non-gradient optical force makes the particle 1 move along the right front of the incident light direction, and then drives the nano-sized molecules 2 attached to the surface of the particle 1 to move along the right front of the incident light direction, as shown in Figure 2(a).

Afterwards, the amorphous state of the chalcogenide substrate plate 3 is converted into a crystalline state by means of light, electricity, heating, and pressure, etc., so that the direction and size of the total Poynting vector on the surface of the particle 1 are changed, resulting in a The non-gradient optical force with the direction pointing to the left front makes the particle 1 drive the nanometer-sized molecules 2 attached to its surface to move along the left front of the incident light direction, as shown in Figure 2(b).

Finally, the chalcogenide substrate plate 3 is changed from a crystalline state to an amorphous state by means of cooling, lighting, etc. At this time, the non-gradient optical force on the particle 1 is changed back to the non-gradient optical force pointing to the right and forward along the incident light direction. force, the particle 1 drives the nanometer-sized molecule 2 to move along the right front of the incident light direction, as shown in Figure 2(c).

In this way, by changing the lattice structure of chalcogenides in the chalcogenide substrate plate 3, we control the trajectory of the particles 1 in the incident light field, and finally realize the tunable capture of the nanometer-sized molecules 2 attached to the surface of the particles 1 and filter.

The system of the present invention is mainly composed of a light source 4 , a microscope 5 and an optical force display 6 . Before the test, the chalcogenide substrate plate 3 is placed at the bottom of the sample pool 7 filled with water or oil, and then the particles 1 with nanometer-sized molecules 2 attached to the surface are placed in the sample pool 7 and placed on the chalcogenide liner. Bottom plate 3 tops. The light source 4 generates a linearly polarized plane wave that enters from the side wall of the sample cell 7 and irradiates the particle 1 horizontally, so as to capture and manipulate the particle 1 attached to the surface of the nanometer-sized molecule 2 . The microscope 5 can be used to observe the trajectory of the microparticles 1 attached to the nanometer-sized molecules 2 on the microsurface under the action of incident light. The non-gradient optical force produced by the linearly polarized plane wave attached to the surface of the particle 1 with nanometer-sized molecules 2 is measured by the optical force display 6 . The system of the present invention also includes temperature controller 8, CCD camera 9, monitor 10, computer 11, and video recorder 12 etc. (shown in accompanying drawing 3) simultaneously. The CCD camera 9 is used for real-time monitoring of the particles 1 with nanometer-sized molecules 2 attached to the surface irradiated by the linearly polarized plane wave, and the obtained video signal is displayed on the monitor. Video recorder 12 may be used to record images. The sample cell 7 is connected to a temperature controller 8 , and the lattice structure of the chalcogenide in the chalcogenide substrate plate 3 changes with the temperature of the sample cell 7 . The computer 11 can store the field of view information collected by the microscope 5 .

The above are the technical principles and specific examples of the application of the present invention. The equivalent transformation done according to the concept of the present invention, as long as the scheme used does not exceed the spirit covered by the description and drawings, shall be included in the present invention. Within the scope, it is hereby explained.

Claims (8)

1. method of a kind of plane of linear polarization light wave to the tunable capture and screening of the microgranule above the chalkogenide substrate, its It is characterised by, microgranule is placed in above chalkogenide substrate flat board, and the chalkogenide substrate flat board destroys the glass around microgranule Print booth vector is symmetrical, makes the total Poynting vector on microgranule be not zero, and produces non-gradient optical force；By changing chalcogenide The chalkogenide lattice structure of thing substrate flat board, changes the total Poynting vector distribution on microgranule, and then changes total Poynting vector Amount acts on the direction of the non-gradient optical force on microgranule and size, regulates and controls movement locus of the microgranule in incident field, from And the nanometer-size molecular to being attached to microparticle surfaces carries out tunable capture and screening, wherein, microgranule is placed in chalkogenide lining Above base plate, microparticle material is medium or metal, the length of chalkogenide substrate at 10 nanometers to 10 meters, microgranule and sulfur The distance of race's compound substrate planar surface is l, l> 0；The profile of microgranule is surface geometry body or polyhedron, and volume is at 1 cube Nanometer is to 1000 cu μ ms.

2. method according to claim 1, it is characterised in that incident illumination is plane of linear polarization ripple；Incident light beam strikes direction Parallel to chalkogenide substrate flat board, frequency range is 0.3 micron ~ 20 microns, and power bracket is 0.1 mW/ μm²~10mW/μm²。

3. method according to claim 1 and 2, it is characterised in that the light source of described incident illumination adopts tunable wave length Laser instrument, quasiconductor be continuous or quasi-continuous lasing or light emitting diode.

4. method according to claim 3, it is characterised in that microparticle material is metal or medium, wherein, metal be Al, Ag, Au, Cu, Ni or Pt, medium are Si, SiO₂、GaAs、InP、Al₂O₃In one kind or polymer.

5. method according to claim 4, it is characterised in that chalkogenide is GeTe, Ge₂Sb₂Te₅、 Ge₁Sb₂Te₄、 Ge₂Sb₂Te₄、Ge₃Sb₄Te₈、Ge₁₅Sb₈₅Or Ag₅In₆Sb₅₉Te₃₀。

6. the method according to claim 1 or 2 or 4 or 5, it is characterised in that nanometer-size molecular has achirality structure Or chiral structure.

7. the method according to claim 1 or 2 or 4 or 5, it is characterised in that described chalkogenide substrate flat board, sulfur family Compound realized by Material growth technique, including magnetron sputtering, electron beam evaporation, metallo-organic compound chemical gaseous phase deposition, Vapor phase epitaxial growth or molecular beam epitaxy.

8. the method according to claim 1 or 2 or 4 or 5, it is characterised in that described chalkogenide substrate flat board, passes through The lattice structure of illumination, energization, heating and pressurizing altered chalkogenide.