Method and equipment for acquiring circular deviation scattered emission image and circular deviation scattered emission spectrum

Abstract

The invention relates to the technical field of chiral sample spectrum detection, and particularly provides a method and equipment for obtaining a circular deviation disperse emission image and a circular deviation disperse emission spectrum.The method comprises the following steps that exciting light is converged and then emitted into a sample with a plurality of chiral particles, and scattered light emitted by all the chiral particles in the sample is collected; emitting the scattered light into an imaging device, and gradually screening the target wavelength of the scattered light entering the imaging device; and receiving the scattered light through an imaging device, and generating a circular aberration scattering image corresponding to each target wavelength. And on the basis of the mapping relation between the light intensity difference value and the wavelength in the circular diffractive scattering image, obtaining the circular diffractive scattering spectrum of each chiral particle. According to the method and the equipment for acquiring the circular deviation scattered emission image and the circular deviation scattered emission spectrum, provided by the invention, the efficiency of acquiring the circular deviation scattered emission spectrum of a plurality of particles is improved, and the flux of circular deviation scattered emission spectrum detection can be greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of chiral sample spectrum detection, and in particular to a method and device for obtaining circular differential scattering images and circular differential scattering spectra. Background Art

[0002] Chirality, the property of an object where its mirror image cannot overlap with its own, is widespread in nature, making identification of an object's chirality crucial. Chiral structures exhibit distinct optical responses to circularly polarized light, exhibiting different refractive indices and extinction coefficients, or optical activities, for left- and right-handed circularly polarized light. This difference in extinction coefficients leads to circular dichroism, or the differential absorption of left- and right-handed circularly polarized light by the chiral individual being measured.

[0003] Single-particle circular differential scattering (CDSS) spectroscopy is a method for testing the optical activity of individual chiral nanoparticles. It relies primarily on traditional dark-field microscopy, using unpolarized light to excite the nanoparticles. A quarter-wavelength phase delay and a linear polarizer are sequentially added to the excitation light path between the excitation light and the condenser. These delays detect the left-handed and right-handed circularly polarized components of the light scattered by the nanoparticles, respectively. The CDSS spectrum of the single particle is then calculated by calculating their difference. This method can only detect a single nanoparticle or a few nanoparticles at a time. Detecting a large number of nanoparticles requires readjustment of the experimental setup, severely limiting its efficiency. Summary of the Invention

[0004] The present invention provides a method and device for obtaining a circular differential scattering image and a circular differential scattering spectrum, which at least solves the problem of low efficiency in obtaining circular differential scattering spectra of multiple particles.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A first aspect of the present invention provides a method for obtaining a circular differential scattering image, comprising the following steps: converging excitation light and injecting it into a sample having multiple chiral particles, and collecting scattered light emitted by each chiral particle in the sample; injecting the scattered light into an imaging device, and gradually screening the target wavelengths of the scattered light entering the imaging device; receiving the scattered light through the imaging device, and generating a circular differential scattering image corresponding to each of the target wavelengths.

[0007] Preferably, the excitation light is converged and then irradiated onto a sample having multiple chiral particles, and the scattered light emitted by each chiral particle in the sample is collected, including: emitting excitation light through a white light source; converging the excitation light and irradiating the sample having multiple chiral particles; and collecting the scattered light emitted by each chiral particle in the sample.

[0008] Preferably, the scattered light is emitted into an imaging device, and the target wavelength of the scattered light entering the imaging device is gradually screened, including: the scattered light is sequentially emitted into a phase delay device and a liquid crystal tunable filter, the polarization characteristics of the scattered light are adjusted, and the scattered light of the target wavelength is screened; the target wavelength allowed to pass through by the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength are gradually adjusted to obtain linearly polarized light corresponding to multiple target wavelengths after filtering by the liquid crystal tunable filter; wherein the linearly polarized light has a left-handed circularly polarized component or a right-handed circularly polarized component; and the linearly polarized light is emitted into the imaging device.

[0009] Preferably, the target wavelength allowed to pass through the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength are gradually adjusted to obtain linearly polarized light of multiple target wavelengths, including: setting the wavelength parameters of the liquid crystal tunable filter based on the characteristic absorption peaks in the circular dichroism spectrum of each chiral particle; wherein the wavelength parameters include: a target wavelength range and a step size; based on the wavelength parameters, gradually adjusting the wavelength allowed to pass through the liquid crystal tunable filter and adjusting the phase delay amount of the phase delay device, so that after passing through the liquid crystal tunable filter, linearly polarized light of multiple target wavelengths is obtained.

[0010] Preferably, the excitation light is converged and then injected into a sample having multiple chiral particles, and the scattered light emitted by each chiral particle in the sample is collected, including: emitting excitation light through a polarization modulated light source; sequentially injecting the excitation light into a liquid crystal tunable filter and a phase delay device to adjust the polarization characteristics of the excitation light and screen the excitation light of the target wavelength; and converging the excitation light and then injecting it into a sample having multiple chiral particles, and collecting the scattered light emitted by each chiral particle in the sample.

[0011] Preferably, the scattered light is emitted into an imaging device, and the target wavelength of the scattered light entering the imaging device is gradually screened, including: gradually adjusting the target wavelength allowed to pass through the liquid crystal tunable filter, and the phase delay amount of the phase delay device corresponding to each wavelength, to obtain excitation light with circular polarization characteristics of multiple target wavelengths; wherein the circular polarization characteristics include: left-handed circular polarization characteristics and right-handed circular polarization characteristics; and the scattered light generated after the excitation light irradiates each chiral particle of the sample is emitted into the imaging device.

[0012] Preferably, the scattered light is received by an imaging device, and a circular differential scattering image corresponding to each of the target wavelengths is generated, including: receiving the scattered light by an imaging device, and taking multiple shots at set time intervals to generate a left-handed circularly polarized scattering image and a right-handed circularly polarized scattering image corresponding to each of the target wavelengths; subtracting the light intensity of each pixel point in the left-handed circularly polarized scattering image from the light intensity of each pixel point in the right-handed circularly polarized scattering image corresponding to the target wavelength to obtain a light intensity difference value of each pixel point at each target wavelength; and generating a circular differential scattering image corresponding to each of the target wavelengths based on each of the light intensity differences.

[0013] In second aspect, the present invention provides a method for obtaining a circular differential scattering spectrum, comprising the following steps: obtaining a circular differential scattering image of each chiral particle in the sample by the above method for obtaining a circular differential scattering image; and obtaining a circular differential scattering spectrum of each chiral particle based on the mapping relationship between the light intensity difference and the wavelength in the circular differential scattering image.

[0014] In a third aspect, the present invention provides a device for obtaining a circular differential scattering image, and a method for obtaining a circular differential scattering image using any one of claims 1 to 7, comprising: an illumination system for emitting and converging excitation light; a stage, arranged on one side of the illumination system, for placing a sample having multiple chiral particles to be tested, and placing the sample within the irradiation range of the excitation light; an objective lens, arranged on a side of the stage away from the illumination system, for receiving scattered light generated by the sample when receiving irradiation with the excitation light; a phase delay device, arranged between the illumination system and the stage, or on a side of the objective lens away from the stage, for converting the polarization characteristics of the excitation light or the scattered light; a liquid crystal tunable filter, arranged on a side of the phase delay device away from the illumination system; an imaging device, arranged on a side of the objective lens away from the stage, or on a side of the liquid crystal tunable filter away from the phase delay device, for generating a circular differential scattering image of each chiral particle.

[0015] Preferably, the phase delay device and the optical axis of the liquid crystal tunable filter form an angle of 45 degrees; the phase delay amount of the phase delay device is plus or minus one quarter of the corresponding wavelength.

[0016] The above technical solution of the present invention has the following beneficial effects compared with the prior art:

[0017] Embodiments of the present invention provide a method and apparatus for acquiring circular differential scattering images and circular differential scattering spectra. By gradually screening the target wavelengths of scattered light emitted by each chiral particle in a sample and receiving the scattered light through an imaging device, circular differential scattering images corresponding to each target wavelength are generated. These methods can meet the requirements for detecting the circular differential scattering of each chiral particle in the sample. By analyzing each circular differential scattering image, the circular differential scattering spectrum of each chiral particle can be obtained, allowing for parallel detection of the circular differential scattering spectra of each chiral particle in the sample. This improves the efficiency of acquiring circular differential scattering spectra of multiple particles, significantly increasing the throughput of circular differential scattering spectral detection and addressing the low efficiency of acquiring circular differential scattering spectra of multiple particles in related technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without inventive effort.

[0019] Figure 1 The figure is a flow chart of a method for obtaining a circular differential scattering image according to an embodiment of the present invention.

[0020] Figure 2 This is the optical dark-field scattering image of chiral helical gold nanorods at 600 nm.

[0021] Figure 3 This is a circular differential scattering image obtained using the method for obtaining a circular differential scattering image according to an embodiment of the present invention.

[0022] Figure 4 This is a transmission electron microscopy image of a chiral helical gold nanorod sample.

[0023] Figure 5 This is a schematic diagram of the circular differential scattering spectrum of six nanoparticles in a chiral helical gold nanorod tested using the method for obtaining circular differential scattering spectrum created by the present invention.

[0024] Figure 6 Schematic diagram of the circular differential scattering spectrum of chiral helical gold nanorods based on finite element simulation.

[0025] Figure 7 It is a structural schematic diagram of a device for obtaining circular differential scattering spectrum according to another embodiment of the present invention.

[0026] Reference numerals in the figures:

[0027] 1. White light source; 2. Dark-field condenser; 3. Two-dimensional translation sample stage; 4. Objective lens; 5. Phase delay device; 6. Liquid crystal tunable filter; 7. Imaging device. DETAILED DESCRIPTION

[0028] The following describes embodiments of the present invention in more detail with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention.

[0029] The circular differential scattering method in the related art usually places a linear polarizer and a quarter-wave plate in the excitation light path between the excitation light and the condenser. After the excitation light is reflected by the dark-field condenser, the phase delay of the s- and p-components reflected by the reflector is different, resulting in non-circularly polarized excitation light. When the excitation light and the condenser are misaligned to produce anisotropic excitation, the artifact of circular differential scattering will significantly affect the measurement results.

[0030] Furthermore, when detecting a large number of chiral particles, the circular differential light scattering method used in related technologies causes interference or superposition of scattered light from different particles on the detector, making it difficult to distinguish the contribution of a single particle. Therefore, this method is generally only suitable for detecting single particles using circular differential light scattering spectroscopy. Detecting a large number of nanoparticles requires multiple adjustments to the experimental setup, resulting in reduced detection efficiency.

[0031] like Figure 1 As shown, in order to improve the efficiency of obtaining circular differential scattering spectra of multiple particles, an embodiment of the present invention provides a method for obtaining a circular differential scattering image, comprising the following steps:

[0032] Step S1, focusing the excitation light and injecting it into a sample having multiple chiral particles, and collecting the scattered light emitted by each chiral particle in the sample;

[0033] Step S2, injecting the scattered light into the imaging device, and gradually screening the target wavelength of the scattered light entering the imaging device;

[0034] Step S3: receiving scattered light through an imaging device to generate a circular differential scattering image corresponding to each target wavelength.

[0035] Specifically, in step S1, the chiral particles include: helical polymers, chiral nanoparticles, colloidal particles with a helical morphology, etc. In an embodiment of the present invention, the sample having multiple chiral particles is preferably chiral helical gold nanorods.

[0036] The imaging device is a device with a two-dimensionally arranged pixel array. It receives scattered light of multiple target wavelengths through the imaging device to achieve physical separation of the scattering signals of particles with different chirality on the image plane. Finally, the circular differential scattering (CDS) microscopic image of each chiral particle is obtained by calculating the difference between the left-handed and right-handed signals.

[0037] The method for acquiring circular differential scattering images provided by the present invention gradually screens for target wavelengths of scattered light emitted by each chiral particle in a sample and generates circular differential scattering images corresponding to each target wavelength using an imaging device. This method can meet the detection requirements of circular differential scattering from each chiral particle in a sample. By analyzing each circular differential scattering image, the circular differential scattering spectrum of each chiral particle can be obtained, allowing for parallel detection of the circular differential scattering spectra of each chiral particle in the sample. This significantly increases the throughput and efficiency of circular differential scattering spectroscopy detection, and can address the low detection efficiency of circular differential scattering spectroscopy detection methods in related technologies.

[0038] Furthermore, in step S2, there are two implementation methods for gradually screening the target wavelength of the scattered light entering the program device. One is: setting the phase delay device and the liquid crystal tunable filter in the detection light path; the other is: setting the phase delay device and the liquid crystal tunable filter in the excitation light path.

[0039] Among them, the detection light path is the scattered light path generated by each chiral particle in the sample after receiving the excitation light, and is located between the sample and the imaging device; while the excitation light path is the excitation light path emitted by the light source, and is located between the light source and the sample.

[0040] In a preferred embodiment of the present invention, a phase delay device and a liquid crystal tunable filter are arranged in the excitation light path. In this embodiment, step S1 includes:

[0041] Step S11 (a), emitting excitation light through a polarization modulated light source;

[0042] Step S12 (a), injecting the excitation light into the liquid crystal tunable filter and the phase delay device in sequence, adjusting the polarization characteristics of the excitation light and screening the excitation light of the target wavelength;

[0043] In step S13 (a), the excitation light is converged and then emitted into a sample having multiple chiral particles, and scattered light emitted by each chiral particle in the sample is collected.

[0044] Specifically, a liquid crystal tunable filter can be used to select the target wavelength of the excitation light. A phase delay device can then precisely modulate the polarization state of the excitation light, converting the linearly polarized light emitted by the liquid crystal tunable filter into left-handed circularly polarized light and right-handed circularly polarized light. The left-handed circularly polarized light and right-handed circularly polarized light are then irradiated onto individual particles in the sample, causing them to emit scattered light.

[0045] Furthermore, in step S1, before converging the excitation light and irradiating the sample having the plurality of chiral particles, the method includes:

[0046] Step S01, placing a sample to be tested having multiple chiral particles on a two-dimensional translation sample stage;

[0047] Step S02, adjusting the position of the sample by two-dimensionally translating the sample stage so that the sample is within the field of view of the objective lens;

[0048] The two-dimensional translation sample stage is placed between the dark field condenser and the objective lens, allowing natural light to pass through.

[0049] The dark-field condenser excites the sample only from a large angle, which is conducive to obtaining the scattering signal of each chiral particle in the sample and performing circular differential scattering imaging.

[0050] Furthermore, the two-dimensional translation sample stage is arranged parallel to the condenser, including an x-axis moving mechanism and a y-axis moving mechanism. The sample is moved in the length direction of the two-dimensional translation sample stage through the x-axis moving mechanism, and the sample is moved in the width direction of the two-dimensional translation sample stage through the y-axis moving mechanism, so that the sample can be placed within the field of view of the objective lens, so that the sample can be observed through the objective lens and circular differential scattering detection can be performed on the sample.

[0051] Furthermore, step S2 includes:

[0052] Step S21(a), gradually adjusting the target wavelengths allowed to pass through the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength, to obtain excitation light with circular polarization characteristics at multiple target wavelengths; wherein the circular polarization characteristics include left-handed circular polarization characteristics and right-handed circular polarization characteristics;

[0053] In step S22 (a), scattered light generated after the excitation light irradiates each chiral particle of the sample is emitted into an imaging device.

[0054] In the embodiment of the present invention, the target wavelength of the excitation light is screened, thereby achieving the effect of screening the target wavelength of the scattered light, so that scattered light with multiple target wavelengths enters the imaging device for imaging.

[0055] Furthermore, step S3 includes:

[0056] Step S31, receiving scattered light by an imaging device and taking multiple shots at set time intervals to generate left-handed circularly polarized scattered light images and right-handed circularly polarized scattered light images corresponding to respective target wavelengths;

[0057] Step S32, subtracting the light intensity of each pixel in the left-handed circularly polarized scattering image from the light intensity of each pixel in the right-handed circularly polarized scattering image corresponding to the target wavelength to obtain the light intensity difference of each pixel at each target wavelength;

[0058] Step S33 : generating a circular differential scattering image corresponding to each target wavelength based on each light intensity difference.

[0059] The imaging device is a camera with a two-dimensional array of pixels, such as a CMOS camera or an EMCCD camera.

[0060] Specifically, the imaging device captures both left-handed and right-handed circularly polarized scattering images of all chiral particles at the target wavelength each time it takes a shot. By capturing multiple shots, both left-handed and right-handed circularly polarized scattering images of each chiral particle in the sample can be obtained.

[0061] The above implementation modulates the polarization properties of light within the excitation optical path. Research and analysis of the present invention's embodiments revealed that this approach results in different phase delays for the s- and p-components of the excitation light after reflection from the dark-field condenser. This results in non-circularly polarized excitation light. Furthermore, when the excitation light and the condenser are misaligned, resulting in anisotropic excitation, circular differential scattering artifacts can significantly affect measurement results. Therefore, an alternative implementation is proposed, placing the phase delay device and liquid crystal tunable filter within the detection optical path.

[0062] In another preferred embodiment of the present invention, a phase delay device and a liquid crystal tunable filter are arranged in the excitation light path. Compared with the previous embodiment, the difference between this embodiment and the previous embodiment is that:

[0063] In the embodiment of the present invention, step S1 includes:

[0064] Step S11 (b), emitting excitation light through a white light source;

[0065] Step S12 (b), focusing the excitation light and irradiating it onto the sample having multiple chiral particles;

[0066] Step S13 (b), collecting scattered light emitted by each chiral particle in the sample.

[0067] Wherein, the white light source includes a halogen lamp or an LED white light lamp.

[0068] In step S11 (b), since the excitation light is generated by a white light source and is directly irradiated on the sample after convergence, the sample is excited by non-polarized light and is not affected by the mirror reflection in the dark field condenser. This fundamentally avoids the adverse effects of light scattering artifacts on the detection limit, and can more accurately analyze the polarization state of the scattered light, reducing the error caused by inaccurate polarization state analysis, thereby effectively lowering the detection limit.

[0069] Furthermore, step S2 includes:

[0070] Step S21(b), sequentially injecting the scattered light into a phase delay device and a liquid crystal tunable filter, adjusting the polarization characteristics of the scattered light and screening the scattered light of the target wavelength; wherein the optical axes of the phase delay device and the liquid crystal tunable filter form an angle of 45 degrees;

[0071] Step S22(b) gradually adjusts the target wavelengths allowed to pass through the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength, thereby obtaining linearly polarized light corresponding to the plurality of target wavelengths after being filtered by the liquid crystal tunable filter; wherein the linearly polarized light has a left-handed circularly polarized component or a right-handed circularly polarized component;

[0072] Step S23 (b): injecting the linearly polarized light into the imaging device.

[0073] Specifically, in step S21(a), the phase delay device and the optical axis of the liquid crystal tunable filter are angled at 45 degrees, achieving optimal polarization control and spectral selection, which plays a key role in improving the sensitivity and accuracy of chiral signal detection. By combining the phase delay device with the linear polarization detection function of the tunable filter, the left-handed and right-handed circularly polarized light components in the scattered light can be accurately detected. For example, by switching the delay amount to positive or negative quarter wavelengths, right-handed and left-handed circularly polarized light components can be detected.

[0074] Then, the scattered light modulated by the phase delay device enters the liquid crystal tunable filter. The liquid crystal tunable filter can screen the wavelength of the linearly polarized light allowed to pass through, so that the linearly polarized light at one wavelength enters the imaging device for imaging to meet the imaging requirements of the imaging device.

[0075] By adjusting the wavelength allowed to pass through the liquid crystal tunable filter and the phase delay amount corresponding to each wavelength of the phase delay device, the detection needs of chiral particles of different wavelengths in the sample can be met, thereby obtaining linearly polarized light of multiple target wavelengths, which can improve detection efficiency and perform parallel detection of a large number of chiral particles.

[0076] In the embodiment of the present invention, the right / left circularly polarized light components of the scattered light are first obtained, and then the target wavelength of the linearly polarized light is screened, thereby achieving the effect of screening the target wavelength of the scattered light.

[0077] Furthermore, step S22(b) includes:

[0078] Step S221 (b), setting wavelength parameters of the liquid crystal tunable filter based on characteristic absorption peaks in the circular dichroism spectrum of each chiral particle; wherein the wavelength parameters include: a target wavelength range and a step size;

[0079] Step S222 (b) gradually adjusts the wavelength allowed to pass through the liquid crystal tunable filter based on the wavelength parameter, and adjusts the phase delay amount of the phase delay device, so that linearly polarized light of multiple target wavelengths is obtained after passing through the liquid crystal tunable filter.

[0080] The wavelength parameters of the liquid crystal tunable filter include: target wavelength range and step size. For example, the wavelength range is 500–700 nm, and the step size is 10 nm. That is, the wavelength is increased by 10 nm each time the adjustment is made, and the linearly polarized light is screened once.

[0081] The remaining steps are the same as those in the previous embodiment.

[0082] In the embodiment of the present invention, since the phase delay device and the liquid crystal tunable laser are arranged in the detection light path, and the excitation light is generated by a white light source and directly irradiated on the sample after convergence, the sample is excited by non-polarized light and is not affected by the mirror reflection in the dark field condenser. This fundamentally avoids the adverse effects of light scattering artifacts on the detection limit, and can more accurately analyze the polarization state of the scattered light, reducing the error caused by inaccurate polarization state analysis, thereby effectively lowering the detection limit.

[0083] Another embodiment of the present invention provides a method for obtaining a circular differential scattering spectrum, comprising the following steps:

[0084] Obtaining a circular differential scattering image of each chiral particle in the sample by the method for obtaining a circular differential scattering image in the above embodiment;

[0085] Based on the mapping relationship between the light intensity difference and wavelength in the circular differential scattering image, the circular differential scattering spectrum of each chiral particle is obtained.

[0086] Specifically, each circular differential scattering image is analyzed, and the intensity difference of the same chiral particle is aligned according to the wavelength sequence.

[0087] By integrating the light intensity difference signal of each pixel within the ROI (Region of Interest) of each chiral particle in the image, the mapping relationship between the light intensity difference and the wavelength can be obtained, and the circular differential scattering spectrum of the corresponding chiral particle can be generated.

[0088] The method for obtaining a circular differential scattering spectrum in an embodiment of the present invention obtains a circular differential scattering spectrum based on an acquired circular differential scattering image. Since each circular differential scattering image contains circular differential scattering information of multiple chiral particles, that is, light intensity differences, the circular differential spectra of a large number of chiral particles can be detected in parallel by extracting the circular differential scattering information of each circular differential scattering image, thereby greatly improving the detection throughput of the circular differential scattering spectrum and improving the detection efficiency.

[0089] like Figure 2 As shown in FIG, the present invention uses chiral helical gold nanorods as test samples and selects dark field images of the test samples collected by a CMOS camera at 600 nm. Figure 4 As shown in the transmission electron microscopy image of the test sample, the chiral helical structure of the test sample can be clearly observed. Figure 3 As shown, a circular differential scattering image is obtained by selecting a test sample and using the method for obtaining a circular differential scattering image according to an embodiment of the present invention.

[0090] like Figure 5 The results are shown in Figure 1, which show the test results of circular differential scattering spectrum when the phase delay device and liquid crystal tunable laser are placed in the detection light path. Figure 2 Six nanoparticles in the field of view. The test spectrum shows obvious chiral optical response signals. Figure 6 The results are in good agreement with the circular differential scattering spectrum calculated based on the finite element method simulation, which further proves that the high-throughput circular differential scattering spectrum detection system in the present invention has reliable performance.

[0091] Another inventive embodiment of the present invention provides a device for obtaining a circular differential scattering image, using the method for parallel detection of circular differential scattering spectra of multiple particles of any of the aforementioned embodiments, the device includes: an illumination system, a storage table, an objective lens 4, a phase delay device 5, a liquid crystal tunable filter 6 and an imaging device 7.

[0092] The illumination system is used to emit and focus the excitation light.

[0093] The storage table is arranged on one side of the lighting system and is used to place the sample with multiple chiral particles to be tested and to place the sample within the irradiation range of the excitation light.

[0094] The objective lens 4 is arranged on a side of the stage away from the illumination system, and is used to receive scattered light generated by the sample when it is irradiated by the excitation light.

[0095] The phase delay device 5 is arranged between the illumination system and the stage, or on the side of the objective lens away from the stage, and is used to convert the polarization characteristics of the excitation light or scattered light;

[0096] The liquid crystal tunable filter 6 is arranged on a side of the phase delay device 5 away from the illumination system;

[0097] The imaging device 7 is arranged on a side of the objective lens away from the stage, or on a side of the liquid crystal tunable filter away from the phase delay device, for generating a circular differential scattering image of each chiral particle.

[0098] Specifically, when the phase delay device 5 and the liquid crystal tunable filter 6 are in the excitation light path, the phase delay device 5 is arranged between the illumination system and the stage, and the imaging device 7 is arranged on the side of the objective lens 4 away from the stage.

[0099] like Figure 7 As shown, when the phase delay device 5 and the liquid crystal tunable filter 6 are in the detection light path, the phase delay device 5 is arranged on the side of the objective lens 4 away from the storage table, and the imaging device 7 is arranged on the side of the liquid crystal tunable filter 6 away from the phase delay device 5.

[0100] The phase delay device 5 and the liquid crystal tunable filter 6 are placed in the detection light path. Compared with the excitation light path,

[0101] In a preferred but non-limiting embodiment of the present invention, when the phase delay device 5 and the liquid crystal tunable filter 6 are in the excitation light path, the illumination system includes: a polarization modulated light source and a dark field condenser 2 .

[0102] The polarization modulated light source is used to emit excitation light, and the excitation light has polarization.

[0103] At this time, the dark field condenser 2 is arranged between the polarization modulated light source and the phase delay device to focus the excitation light.

[0104] When the phase delay device 5 and the liquid crystal tunable filter 6 are in the detection light path, the illumination system includes: a white light source 1 and a dark field condenser 2. The white light source is used to emit natural light.

[0105] At this point, a dark-field condenser 2 is placed between the white-light source and the stage, focusing natural light and illuminating it onto the sample. Exciting the sample only from large angles through the dark-field condenser 2 facilitates obtaining the scattered signals of individual chiral particles in the sample and performing circular differential scattering imaging.

[0106] Furthermore, the stage is a two-dimensional translation sample stage 3; the two-dimensional translation sample stage 3 includes: an x-axis moving mechanism and a y-axis moving mechanism, which are used to adjust the position of the sample on the x-axis and y-axis of the two-dimensional translation sample stage so that the sample is within the field of view of the objective lens.

[0107] Furthermore, the 45-degree angle between the optical axes of the phase delay device 5 and the liquid crystal tunable filter 6 enables optimal polarization control and spectral selection, playing a key role in improving the sensitivity and accuracy of chiral signal detection. The phase delay of the phase delay device is plus or minus one-quarter of the corresponding wavelength.

[0108] Furthermore, the imaging device 7 is a camera with a two-dimensional array of pixels, and the central axis of the camera is collinear with the central axis of the liquid crystal tunable filter.

[0109] Specifically, the optical performance of liquid crystal tunable filters (LCTFs), such as center wavelength, transmittance, and bandwidth, typically depends on the collimation and angle of the incident light. By aligning the camera's central axis with the LCTF's central axis, we ensure that light passes perpendicularly through the filter, avoiding wavelength shift or transmittance loss caused by oblique incidence.

[0110] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, they should be understood as "one or more".

[0111] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and corresponding operation entrances shall be provided for users to choose to authorize or refuse.

[0112] The various steps described in the method implementation methods provided by the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0113] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments are referenced to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0114] The above-described embodiments merely represent several implementation methods of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of protection. It should be noted that a person of ordinary skill in the art would be able to make various modifications and improvements without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A method for obtaining a circular differential scattering image, characterized in that: The following steps are involved: The excitation light is focused and injected into a sample containing multiple chiral particles, and the scattered light emitted by each chiral particle in the sample is collected; injecting the scattered light into an imaging device, and gradually screening target wavelengths of the scattered light entering the imaging device; The scattered light is received by an imaging device to generate a circular differential scattering image corresponding to each of the target wavelengths.

2. The method for obtaining a circular differential scattering image according to claim 1, wherein: The excitation light is focused and injected into a sample with multiple chiral particles, and the scattered light emitted by each chiral particle in the sample is collected, including: emitting excitation light through a white light source; Converging the excitation light and irradiating it onto a sample having a plurality of chiral particles; The scattered light emitted by each chiral particle in the sample is collected.

3. The method for obtaining a circular differential scattering image according to claim 2, wherein: The scattered light is emitted into an imaging device, and the target wavelength of the scattered light entering the imaging device is gradually screened, comprising: injecting the scattered light into a phase delay device and a liquid crystal tunable filter in sequence, adjusting the polarization characteristics of the scattered light and screening the scattered light of the target wavelength; Gradually adjusting the target wavelength allowed to pass by the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength, thereby obtaining linearly polarized light corresponding to multiple target wavelengths after filtering by the liquid crystal tunable filter; wherein the linearly polarized light has a left-handed circularly polarized component or a right-handed circularly polarized component; The linearly polarized light is incident upon an imaging device.

4. The method for obtaining a circular differential scattering image according to claim 3, wherein: Gradually adjusting the target wavelength allowed to pass by the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength to obtain linearly polarized light of multiple target wavelengths, including: Based on the characteristic absorption peaks in the circular dichroism spectrum of each chiral particle, wavelength parameters of the liquid crystal tunable filter are set; wherein the wavelength parameters include: a target wavelength range and a step size; Based on the wavelength parameters, the wavelength allowed to pass through the liquid crystal tunable filter is gradually adjusted, and the phase delay amount of the phase delay device is adjusted. After passing through the liquid crystal tunable filter, linearly polarized light of multiple target wavelengths is obtained.

5. The method for obtaining a circular differential scattering image according to claim 1, wherein: The excitation light is focused and injected into a sample with multiple chiral particles, and the scattered light emitted by each chiral particle in the sample is collected, including: emitting excitation light through a polarization-modulated light source; injecting the excitation light into a liquid crystal tunable filter and a phase delay device in sequence, adjusting the polarization characteristics of the excitation light and screening the excitation light of the target wavelength; The excitation light is converged and then emitted into a sample having multiple chiral particles, and scattered light emitted by each chiral particle in the sample is collected.

6. The method for obtaining a circular differential scattering image according to claim 5, characterized in that: The scattered light is emitted into an imaging device, and the target wavelength of the scattered light entering the imaging device is gradually screened, comprising: Gradually adjusting the target wavelength allowed to pass by the liquid crystal tunable filter and the phase delay amount of the phase delay device corresponding to each wavelength to obtain excitation light with circular polarization characteristics of multiple target wavelengths; wherein the circular polarization characteristics include: left-handed circular polarization characteristics and right-handed circular polarization characteristics; The scattered light generated after the excitation light irradiates each chiral particle of the sample is emitted into an imaging device.

7. The method for obtaining a circular differential scattering image according to claim 1, wherein: Receiving the scattered light by an imaging device and generating a circular differential scattering image corresponding to each of the target wavelengths, including: The scattered light is received by an imaging device, and multiple shots are taken at set time intervals to generate left-handed circularly polarized scattered light images and right-handed circularly polarized scattered light images corresponding to the target wavelengths; Subtracting the light intensity of each pixel point in the left-handed circularly polarized scattering image from the light intensity of each pixel point in the right-handed circularly polarized scattering image corresponding to the target wavelength to obtain the light intensity difference of each pixel point at each target wavelength; A circular differential scattering image corresponding to each of the target wavelengths is generated based on each of the light intensity differences.

8. A method for obtaining a circular differential scattering spectrum, characterized in that: The following steps are involved: Obtaining a circular differential scattering image of each chiral particle in the sample by the method for obtaining a circular differential scattering image according to any one of claims 1 to 7; Based on the mapping relationship between the light intensity difference and the wavelength in the circular differential scattering image, the circular differential scattering spectrum of each of the chiral particles is obtained.

9. A device for acquiring a circular differential scattering image, using the method for acquiring a circular differential scattering image according to any one of claims 1 to 7, characterized in that: include: an illumination system for emitting and converging excitation light; A storage platform is provided on one side of the illumination system and is used to place a sample having multiple chiral particles to be measured and to place the sample within the irradiation range of the excitation light; an objective lens, disposed on a side of the stage away from the illumination system, for receiving scattered light generated by the sample when the sample is irradiated by the excitation light; A phase delay device is provided between the illumination system and the stage, or on the side of the objective lens away from the stage, for converting the polarization characteristics of the excitation light or the scattered light; a liquid crystal tunable filter, disposed on a side of the phase delay device away from the illumination system; The imaging device is arranged on the side of the objective lens away from the object platform, or on the side of the liquid crystal tunable filter away from the phase delay device, and is used to generate a circular differential scattering image of each chiral particle.

10. The device for acquiring circular differential scattering images according to claim 9, characterized in that: The phase delay device and the optical axis of the liquid crystal tunable filter form an angle of 45 degrees; The phase delay amount of the phase delay device is plus or minus one quarter of the corresponding wavelength.

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