An optical system and detection method for intrinsic fluorescence detection of bioaerosols

Abstract

The invention discloses an optical system and a detection method for intrinsic fluorescence detection of bioaerosols. The optical system comprises: a red light path system, which is provided with a red light laser, a quarter wave plate, a red light negative meniscus lens, a red light double convex lens, a birefringent crystal, a red light cylindrical mirror, a dichroic mirror and a window in sequence, and a pinhole aperture is provided on the window; an ultraviolet light path system, which comprises an ultraviolet laser, an ultraviolet light splitter, an ultraviolet light reflector and an ultraviolet light cylindrical mirror connected in series in sequence, and the ultraviolet light cylindrical mirror and the dichroic mirror are connected in series; a detection cavity is provided with bioaerosol to be detected, and the front of the detection cavity is connected with the window; an extinction lens system is provided at the rear of the detection cavity; a scattering receiving device is provided at one side of the detection cavity; and a fluorescence receiving optical path system is provided at the other side of the detection cavity opposite to the scattering receiving device, and the bioaerosol particles are irradiated by double optical paths to respectively divide the particle size of the bioaerosol particles and detect the intrinsic fluorescence of the bioaerosol particles.

Description

Technical Field

[0001] The present invention relates to the technical field of ultraviolet laser induced fluorescence detection of biological intrinsic fluorescence and the technical field of aerodynamic particle size measurement of bioaerosols, and in particular to an optical system and a detection method for detecting intrinsic fluorescence of bioaerosols. Background Art

[0002] Bioaerosol refers to a multiphase system consisting of the atmosphere and biological particles suspended in it. The particle size range of biological particles is 10 -3 ~10 2 μm, including microorganisms such as bacteria, fungi, viruses, pollen and spores. The composition and concentration of bioaerosols directly affect environmental quality and human health. Therefore, the research on bioaerosol detection technology is of great significance. Bioaerosol detection technology based on optical measurement has the advantages of rapidity, non-destructiveness and sensitivity. This technology generally detects and analyzes the shape, size and intrinsic fluorescence of aerosol particles based on optical principles, so as to pre-judge their biological properties.

[0003] Intrinsic fluorescence refers to the unique fluorescence emitted by organic molecules such as amino acids (tyrosine, tryptophan, etc.), nicotinamide adenine dinucleotide (NADH) and riboflavin contained in biological substances under the excitation of light of a specific wavelength. Intrinsic fluorescence is one of the important bases for distinguishing biological properties. At the same time, due to the different proportions of various organic molecules in different microorganisms, the absorption and emission spectra exhibited are also quite different. By detecting the spectral intensity of different intrinsic fluorescence bands and using calibration and analysis methods to obtain the relative content of various organic molecules, the pre-classification of bioaerosol types can be achieved.

[0004] Amino acids exist in almost all living organisms, including viruses. By detecting and analyzing them, biological particles in aerosols can be detected more accurately. The absorption peak wavelength of amino acids is below 300nm, the emission peak is between 300 and 420nm, and the Stokes shift is relatively small, so the signal-to-noise ratio of the fluorescence detection system is relatively high. Domestic related studies have pointed out that under specific experimental conditions, the fluorescence efficiency is higher when 365nm excitation light induces tryptophan and NADH, while the fluorescence efficiency is not high when 280nm excitation light induces NADH. Therefore, for this phenomenon, it is particularly important to select a specific wavelength of ultraviolet excitation light so that it can cover more of the excitation light wavelength of biological substances, so as to obtain the intrinsic fluorescence spectra of different biological substance aerosol particles at the same excitation wavelength, and to distinguish the similarities and differences of the intrinsic fluorescence of different biological substances. Summary of the invention

[0005] In order to study the fluorescence spectra of intrinsic fluorescence induced by the same ultraviolet excitation light in different biological substances and to distinguish different biological substances, the present invention provides an optical system and detection method for detecting intrinsic fluorescence of bioaerosols, which uses dual light paths to illuminate bioaerosol particles to respectively divide the particle size of bioaerosol particles and detect the intrinsic fluorescence of bioaerosol particles.

[0006] To achieve the above object, the present invention provides an optical system for detecting intrinsic fluorescence of bioaerosols, comprising:

[0007] A red light path system, which is provided with: a red light laser, a quarter wave plate, a red light negative meniscus lens, a red light biconvex lens, a birefringent crystal, a red light cylindrical mirror, a dichroic mirror and a window in sequence, wherein the window is provided with a pinhole aperture;

[0008] An ultraviolet light path system, comprising: an ultraviolet laser connected in series with an ultraviolet beam splitter, an ultraviolet reflector connected in series with the ultraviolet beam splitter, an ultraviolet cylindrical mirror connected in series with the ultraviolet reflector, and the ultraviolet cylindrical mirror connected in series with the dichroic mirror, so that the ultraviolet light is transmitted to the window through the dichroic mirror;

[0009] A detection cavity, in which the bioaerosol to be detected is built, the front of the detection cavity is connected to the window, and is used to simultaneously receive the excitation light of the red light path system and the ultraviolet light path system;

[0010] A de-glare lens system, arranged at the rear of the detection cavity, for eliminating the red light spot and the ultraviolet light spot after detection;

[0011] A scattering receiving device, disposed on a side of the detection cavity, for receiving scattering information generated by bioaerosol under the irradiation of red light spot and ultraviolet laser to detect particle size;

[0012] A fluorescence receiving optical path system is arranged on another side of the detection cavity opposite to the side on which the scattering receiving device is arranged, and is used to receive the light signal of the intrinsic fluorescence of the bioaerosol particles.

[0013] In one embodiment of the present invention, the red laser is a red laser light source with a single wavelength, and the ultraviolet laser is a 266nm ultraviolet laser light source with a single wavelength.

[0014] In one embodiment of the present invention, the ultraviolet light path system further includes a green light extinction plate, which is arranged above the ultraviolet light splitter and is used to absorb the stray light of 532 nm mixed in the 266 nm laser.

[0015] In one embodiment of the present invention, the red light optical path system is connected in parallel with the ultraviolet light path system, and the dichroic mirror is a rotatable dichroic mirror, which is used to make the light spot in the ultraviolet light path system below the light spot in the red light path system by adjusting the angle of the dichroic mirror.

[0016] In one embodiment of the present invention, the light spot of the red light path includes two red light spots, namely an o-light spot and an e-light spot.

[0017] In one embodiment of the present invention, the quarter wave plate is a rotatable quarter wave plate, which is used to change the phase between the o-light spot and the e-light spot by rotating the quarter wave plate.

[0018] In one embodiment of the present invention, the birefringent crystal is a rotatable birefringent crystal, which is used to adjust the distance between the two red light spots by rotating the birefringent crystal to change the angle between the crystal axis of the birefringent crystal and the incident light spot.

[0019] In one embodiment of the present invention, the scattering receiving device is an avalanche photodiode, which is used to convert the received optical signals of different amplitudes into electrical signals to statistically calculate the particle size information spectrum corresponding to different particle sizes.

[0020] In one embodiment of the present invention, the fluorescence receiving optical path system includes:

[0021] a first aspherical condenser lens;

[0022] a short-wave interference filter connected to the first aspheric condensing lens and used for filtering out scattered light of red light incidental to the fluorescence;

[0023] A second aspherical condenser lens connected to the short-wave interference filter;

[0024] a long wave pass filter, connected to the second aspherical condenser lens, for filtering out scattered light of 266 nm ultraviolet light;

[0025] an aperture stop, disposed at the focus of the second aspherical condenser lens, for filtering out interference of stray light and cavity background on intrinsic fluorescence reception of bioaerosol particles;

[0026] A photomultiplier tube is connected to the aperture diaphragm and is used to convert the captured light signal into an electrical signal.

[0027] To achieve the above object, the present invention provides a detection method for bioaerosol intrinsic fluorescence detection, which comprises the following steps:

[0028] The bioaerosol to be detected is placed in the detection cavity, and the red light laser and the ultraviolet laser are started, so that the red light enters the detection cavity through the red light optical path system, and the ultraviolet light enters the detection cavity through the ultraviolet light optical path system;

[0029] Rotate the 1 / 4 wave plate to adjust the phase between the o-light spot and the e-light spot in the red light, and rotate the birefringent crystal to adjust the distance between the center points of the o-light spot and the e-light spot in the red light;

[0030] Adjust the angle of the dichroic mirror so that the ultraviolet light spot entering the detection cavity is below the two red light spots;

[0031] The particle size information of bioaerosol particles is statistically analyzed through the scattered information received by the avalanche photodiode to form a particle size information map corresponding to different particle sizes;

[0032] The received intrinsic fluorescence is converted into an electrical signal by a photomultiplier tube to obtain an intrinsic fluorescence curve of the intrinsic fluorescence of the bioaerosol particles.

[0033] Compared with the prior art, the advantages of the present invention are at least:

[0034] (1) By measuring the bioaerosol particle size based on the red light path, the particle size can be calculated based on the flight time of bioaerosol particles of different sizes between the double red light spots. The intrinsic fluorescence induced by the 266nm laser for bioaerosol particles of different sizes is statistically analyzed one by one, which is convenient for finding patterns.

[0035] (2) By connecting the red light optical path system and the ultraviolet intrinsic fluorescence excitation system in parallel, the triggering laser frequency of the ultraviolet 266nm laser can be realized through the detected bioaerosol particles, avoiding excessive false triggering, and ensuring that one particle is excited when one particle is detected, basically achieving a one-to-one correspondence between the intrinsic fluorescence spectrum of the biological particles and the particle size.

[0036] (3) The collection of bioaerosol intrinsic fluorescence data is achieved through the fluorescence collection optical path, and the photoelectric signal conversion is performed using a photomultiplier tube (PMT), which can clearly reflect the most original situation of bioaerosol intrinsic fluorescence and provide strong basic data for studying the intrinsic fluorescence excitation of different biological substances by 266nm excitation light. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0038] Figure 1 This is a structural diagram of an optical system according to an embodiment of the present invention;

[0039] Figure 2 Schematic diagram of the optical path of the red light optical path system in one embodiment of the present invention;

[0040] Figure 3 FIG. 4 is a schematic diagram of the optical path of the ultraviolet light system in one embodiment of the present invention.

[0041] Explanation of the accompanying drawings: 1-red laser; 2-1 / 4 wave plate; 3-red negative meniscus lens; 4-red biconvex lens; 5-birefringent crystal; 6-red cylindrical mirror; 7-dichroic mirror; 8-window; 9-pinhole diaphragm; 10-detection cavity; 11-extinction lens system; 12-ultraviolet laser; 13-green extinction plate; 14-ultraviolet spectroscope; 15-ultraviolet cylindrical mirror; 16-ultraviolet reflector; 17-avalanche photodiode; 18-first aspheric condensing lens; 19-short-wave interference filter; 20-second aspheric condensing lens; 21-long-wave filter; 22-aperture diaphragm; 23-photomultiplier tube. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] Embodiment 1

[0044] Figure 1 FIG. 1 is a structural diagram of an optical system according to an embodiment of the present invention. Figure 1 As shown, the present invention provides an optical system for detecting intrinsic fluorescence of bioaerosols, comprising:

[0045] A red light optical path system is provided with: a red light laser (1), a quarter wave plate (2), a red light negative meniscus lens (3), a red light biconvex lens (4), a birefringent crystal (5), a red light cylindrical mirror (6), a dichroic mirror (7) and a window (8), wherein a pinhole aperture (9) is provided on the window (8);

[0046] An ultraviolet light path system comprises: an ultraviolet laser (12) connected in series with an ultraviolet beam splitter (14), an ultraviolet reflector (16) connected in series with the ultraviolet beam splitter (14), an ultraviolet cylindrical mirror (15) connected in series with the ultraviolet reflector (16), and the ultraviolet cylindrical mirror (15) connected in series with a dichroic mirror (7), so as to transmit the ultraviolet light to the window (8) through the dichroic mirror (7);

[0047] In this embodiment, the ultraviolet light path system further includes a green light extinction plate (13), which is arranged above the ultraviolet light splitter (14) and is used to absorb 532nm stray light mixed in the 266nm laser.

[0048] a detection cavity (10) containing the bioaerosol to be detected, the front of which is connected to the window (8) and is used to simultaneously receive the excitation light from the red light path system and the ultraviolet light path system;

[0049] A light-extinguishing lens system (11), arranged at the rear of the detection cavity (10), for eliminating the red light spot after detection;

[0050] a scattering receiving device, arranged on a side of the detection cavity (10), for receiving scattering information generated by bioaerosol under the irradiation of red light spot and ultraviolet laser to detect particle size;

[0051] In this embodiment, the scattering receiving device is an avalanche photodiode (APD) (17), which is used to convert the received light signals of different amplitudes into electrical signals, and provide a particle size information spectrum corresponding to different particle sizes through statistics of a subsequent processing circuit. The processing circuit subsequently connected to the avalanche photodiode (APD) (17) is a prior art and will not be described in detail here. An aerodynamic particle size algorithm is used for the particle size measurement and analysis of bioaerosol particles.

[0052] A fluorescence receiving optical path system is arranged on another side of the detection cavity (10), the side where the fluorescence receiving optical path system is arranged being opposite to the side where the scattering receiving device is arranged, and is used to receive the optical signal of the intrinsic fluorescence of the bioaerosol particles.

[0053] In this embodiment, the fluorescence receiving optical path system includes:

[0054] a first aspherical condensing lens (18);

[0055] A short-wave interference filter (19) connected to the first aspheric condensing lens (18) for filtering out scattered light of red light incidental to the fluorescence;

[0056] a second aspherical condenser lens (20) connected to the short-wave interference filter (19);

[0057] a long-wave pass filter (21), connected to the second aspherical condenser lens (20), and used for filtering out scattered light of 266nm ultraviolet light;

[0058] an aperture stop (22), arranged at the focus of the second aspherical condenser lens (20), for filtering out interference of stray light and cavity background on intrinsic fluorescence reception of bioaerosol particles;

[0059] A photomultiplier tube (PMT) (23) is connected to the aperture diaphragm (22) and is used to convert the captured light signal into an electrical signal, and then form a corresponding curve of the intrinsic spectrum of the tested substance after the electrical signal is processed by a subsequent processing circuit. The subsequent processing circuit connected to the photomultiplier tube (PMT) (23) is a prior art and will not be described in detail here.

[0060] In this embodiment, the red laser (1) is a red laser light source with a single wavelength, and the ultraviolet laser (12) is a 266nm ultraviolet laser light source with a single wavelength.

[0061] In this embodiment, the red light path system is connected in parallel with the ultraviolet light path system, the dichroic mirror (7) is a rotatable dichroic mirror, and the red light path system and the ultraviolet light path system adjust the angle of the dichroic mirror (7) so that the light spot of the ultraviolet light path is below the light spot of the red light path.

[0062] In this embodiment, the light spot of the red light optical path system includes two red light spots, namely an o-light spot and an e-light spot.

[0063] In this embodiment, the quarter wave plate (2) is a rotatable quarter wave plate, and the phase between the o-light spot and the e-light spot can be changed by rotating the quarter wave plate (2), thereby changing the energy intensity distribution of the two red light spots at the position of the detection cavity (10). Rotating the quarter wave plate can make the aerosol particles passing through the two red light spots be exposed to the same light beam intensity, and then the aerodynamic particle size of the bioaerosol particles can be measured and measured.

[0064] In this embodiment, the birefringent crystal (5) is a rotatable birefringent crystal, and specifically, the angle between the crystal axis of the birefringent crystal (5) and the incident light spot can be changed by rotating the birefringent crystal (5), thereby adjusting the distance between the two red light spots.

[0065] In this embodiment, the bioaerosol to be detected in the detection cavity (10) includes at least different substances such as tryptophan, tyrosine, riboflavin, and NADH.

[0066] Embodiment 2

[0067] Figure 2 FIG. 1 is a schematic diagram of the optical path of the red light optical path system in one embodiment of the present invention. Figure 2 As shown, in the red light path system of this embodiment, the red light laser (1) is a single-wavelength red light laser light source, and the red light laser (1) is connected in series with a quarter wave plate (2), a red light negative meniscus lens (3), a red light biconvex lens (4), a birefringent crystal (5), and a red light cylindrical mirror (6). The red light laser (1) emits red light, and the phase between the o-light spot and the e-light spot in the red light passing through the quarter wave plate (2) can be controlled by rotating the quarter wave plate (2), so that the energy of the two polarized lights transmitted through the quarter wave plate (2) can be adjusted. The light spot is then shaped by the red light negative meniscus lens (3) and the red light biconvex lens (4) and then irradiated onto the birefringent crystal (5). Due to the different refractive indices of the o-light spot and the e-light spot in the light in the birefringent crystal (5), the light spot is located in the birefringent crystal (5). 5) After projection, two circular light spots are formed, wherein the two light spots are distributed one above the other, and the distance between the center points of the two light spots can be controlled by rotating the birefringent crystal (5) (i.e., the size of the controllable distance is related to the thickness of the birefringent crystal). After the two light spots pass through the subsequent red light cylindrical mirror (6), the two circular light spots can be stretched into two thin linear light spots, and then the two light spots pass through the dichroic mirror (7) and the window plate (8) to reach the detection cavity (10), and finally the red light is eliminated by the extinction lens system (11). Among them, a small hole diaphragm (9) is also arranged on the window (8).

[0068] Figure 3 FIG. 1 is a schematic diagram of the optical path of the ultraviolet light path system in one embodiment of the present invention. Figure 3As shown, in the ultraviolet light path system of this embodiment, the ultraviolet laser (12) is a 266nm ultraviolet laser light source with a single wavelength. The ultraviolet laser (12) emits 266nm ultraviolet light. Since the ultraviolet laser is a solid laser, the laser emitted from the light outlet along with the 266nm laser contains part of the 532nm green light component. The 266nm laser is then purified by the ultraviolet light spectroscope (14). The 532nm green light after the splitting by the ultraviolet light spectroscope (14) is absorbed by the green light extinction sheet (13). The purified 266nm laser transmitted through the ultraviolet light spectroscope (14) is The laser is then reflected by the ultraviolet light reflecting mirror (16) so that the 266nm laser is irradiated onto the ultraviolet light cylindrical mirror (15). After the 266nm ultraviolet light passes through the ultraviolet light cylindrical mirror (15), the light spot can be stretched into a beam of horizontal line light spots, and then the light spots are respectively transmitted backwards through the dichroic mirror (7) together with the red light spots in the red light path. At this time, the position of the line light spot of the 266nm ultraviolet light on the dichroic mirror (7) should be slightly higher than the position of the upper line light spot of the double line light spots of the red light on the dichroic mirror (7). The ultraviolet light spot and the red light spot respectively pass through the window (8) and reach the position of the detection cavity (10).

[0069] Please combine Figure 1 In this case, the red light path system and the ultraviolet light path system are connected in parallel, and the ultraviolet light spot can be placed below the red light double-line spot by adjusting the angle of the dichroic mirror (7).

[0070] An avalanche photodiode (APD) (17) is arranged on one side of the detection cavity (10). When the bioaerosol in the detection cavity (10) is irradiated by a red light spot and an ultraviolet 266nm laser, the avalanche photodiode (APD) (17) receives scattered information. The information can be input into an existing processing circuit to count the particle size information of the bioaerosol particles, thereby forming a particle size information spectrum corresponding to different particle sizes.

[0071] The fluorescence receiving optical path system is arranged on the other side of the detection cavity (10) opposite to the surface where the scattering receiving device is placed. The bioaerosol particles will generate fluorescence under the induction of 266nm ultraviolet light. The generated fluorescence can form approximately parallel light after passing through the first aspheric condensing lens (18) in the fluorescence receiving optical path system. A short-wave interference filter (19) is added to the propagation path of the parallel light to remove the scattered light of the red light in the red light optical path system attached to the fluorescence. After passing through the short-wave interference filter (19), the fluorescence is transmitted through the second aspheric condensing lens (20) and the light spot is focused. After the second aspheric condensing lens (20), a long-wave filter (21) is added to the second aspheric condensing lens (20). 1), thereby blocking the scattered light of 266nm ultraviolet light from affecting the reception of intrinsic fluorescence of bioaerosol particles, and then finding the focus of the fluorescence after passing through the second aspheric condensing lens (20), and placing an aperture diaphragm (22) at the focus to filter out the interference of stray light and cavity background on the reception of intrinsic fluorescence of bioaerosol particles, and finally the shaped intrinsic fluorescence of bioaerosol particles is received by a photomultiplier tube (PMT) (23), and the intrinsic fluorescence is converted into a photoelectric signal by the photomultiplier tube (PMT) (23), and finally input into the existing processing circuit, and can form an intrinsic fluorescence curve of the intrinsic fluorescence of bioaerosol particles after detailed calculation and processing.

[0072] In this embodiment, 266nm ultraviolet laser of the same wavelength is used to induce different substances (such as tryptophan, tyrosine, riboflavin, NADH, etc.) to produce intrinsic fluorescence, and the intrinsic fluorescence spectra of different substances under 266nm ultraviolet light excitation can be obtained.

[0073] Embodiment 3

[0074] This embodiment provides a detection method for bioaerosol intrinsic fluorescence detection, which includes the following steps:

[0075] The bioaerosol to be detected is placed in the detection cavity, and the red light laser and the ultraviolet laser are started, so that the red light enters the detection cavity through the red light optical path system, and the ultraviolet light enters the detection cavity through the ultraviolet light optical path system;

[0076] Rotate the 1 / 4 wave plate to adjust the phase between the o-light spot and the e-light spot in the red light, thereby adjusting the energy of the two polarized lights; rotate the birefringent crystal to adjust the distance between the center points of the o-light spot and the e-light spot in the red light;

[0077] Adjust the angle of the dichroic mirror so that the ultraviolet light spot entering the detection cavity is below the two red light spots;

[0078] The particle size information of the bioaerosol particles is statistically obtained through the scattered information received by the avalanche photodiode (APD) to form a particle size information spectrum corresponding to different particle sizes (realized by a processing circuit connected to the avalanche photodiode, which can adopt existing technology and will not be described in detail here);

[0079] The photomultiplier tube (PMT) converts the received intrinsic fluorescence into an electrical signal to obtain an intrinsic fluorescence curve of the intrinsic fluorescence of the bioaerosol particles.

[0080] The advantages of the present invention are at least:

[0081] (1) By measuring the bioaerosol particle size based on the red light path, the particle size can be calculated based on the flight time of bioaerosol particles of different sizes between the double red light spots. The intrinsic fluorescence induced by the 266nm laser for bioaerosol particles of different sizes is statistically analyzed one by one, which is convenient for finding patterns.

[0082] (2) By connecting the red light optical path system and the ultraviolet intrinsic fluorescence excitation system in parallel, the triggering laser frequency of the ultraviolet 266nm laser can be realized through the detected bioaerosol particles, avoiding excessive false triggering, and ensuring that one particle is excited when one particle is detected, basically achieving a one-to-one correspondence between the intrinsic fluorescence spectrum of the biological particles and the particle size.

[0083] (3) The collection of bioaerosol intrinsic fluorescence data is achieved through the fluorescence collection optical path, and the photoelectric signal conversion is performed using a photomultiplier tube (PMT), which can clearly reflect the most original situation of bioaerosol intrinsic fluorescence and provide strong basic data for studying the intrinsic fluorescence excitation of different biological substances by 266nm excitation light.

[0084] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0085] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from the embodiment. The modules in the above embodiment can be combined into one module, or can be further divided into multiple sub-modules.

[0086] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An optical system for detecting intrinsic fluorescence of bioaerosols, characterized in that: include: A red light path system, which is provided with: a red light laser, a quarter wave plate, a red light negative meniscus lens, a red light biconvex lens, a birefringent crystal, a red light cylindrical mirror, a dichroic mirror and a window in sequence, wherein the window is provided with a pinhole aperture; the red light laser is a single wavelength red light laser light source, the light spot of the red light path includes two beams of red light spots, namely an o-light spot and an e-light spot, the quarter wave plate is a rotatable quarter wave plate, which is used to change the phase between the o-light spot and the e-light spot by rotating the quarter wave plate; the birefringent crystal is a rotatable birefringent crystal, which is used to change the angle between the crystal axis of the birefringent crystal and the incident light spot by rotating the birefringent crystal to adjust the spacing between the two beams of red light spots; An ultraviolet light path system, comprising: an ultraviolet laser connected in series with an ultraviolet beam splitter, an ultraviolet reflector connected in series with the ultraviolet beam splitter, an ultraviolet cylindrical mirror connected in series with the ultraviolet reflector, and the ultraviolet cylindrical mirror connected in series with the dichroic mirror, so as to transmit ultraviolet light to the window through the dichroic mirror, wherein the ultraviolet laser is a 266nm ultraviolet laser light source with a single wavelength, and the ultraviolet light path system also includes a green light extinction plate, which is arranged above the ultraviolet beam splitter and is used to absorb 532nm stray light mixed in the 266nm laser; A detection cavity, in which the bioaerosol to be detected is built, the front of the detection cavity is connected to the window, and is used to simultaneously receive the excitation light of the red light path system and the ultraviolet light path system; A de-glare lens system, arranged at the rear of the detection cavity, for eliminating the red light spot and the ultraviolet light spot after detection; A scattering receiving device, disposed on a side of the detection cavity, for receiving scattering information generated by bioaerosol under the irradiation of red light spot and ultraviolet laser to detect particle size; A fluorescence receiving optical path system, arranged on the other side of the detection cavity opposite to the surface on which the scattering receiving device is arranged, for receiving the light signal of the intrinsic fluorescence of the bioaerosol particles; Wherein, the dichroic mirror is a rotatable dichroic mirror, which is used to make the light spot in the ultraviolet light path system below the light spot in the red light path system by adjusting the angle of the dichroic mirror.

2. The optical system according to claim 1, characterized in that The red light optical path system is connected in parallel with the ultraviolet light optical path system.

3. The optical system according to claim 1, characterized in that The scattering receiving device is an avalanche photodiode, which is used to convert the received light signals of different amplitudes into electrical signals to statistically calculate the particle size information spectrum corresponding to different particle sizes.

4. The optical system according to claim 1, characterized in that The fluorescence receiving optical path system comprises: a first aspherical condenser lens; a short-wave interference filter connected to the first aspheric condensing lens and used for filtering out scattered light of red light incidental to the fluorescence; A second aspherical condenser lens connected to the short-wave interference filter; a long wave pass filter, connected to the second aspherical condenser lens, for filtering out scattered light of 266 nm ultraviolet light; an aperture stop, disposed at the focus of the second aspherical condenser lens, for filtering out interference of stray light and cavity background on intrinsic fluorescence reception of bioaerosol particles; A photomultiplier tube is connected to the aperture diaphragm and is used to convert the captured light signal into an electrical signal.

5. A detection method for intrinsic fluorescence detection of bioaerosols, which is implemented by the optical system according to any one of claims 1 to 4, characterized in that: It includes the following steps: The bioaerosol to be detected is placed in the detection cavity, and the red light laser and the ultraviolet laser are started, so that the red light enters the detection cavity through the red light optical path system, and the ultraviolet light enters the detection cavity through the ultraviolet light optical path system; Rotate the 1 / 4 wave plate to adjust the phase between the o-light spot and the e-light spot in the red light, and rotate the birefringent crystal to adjust the distance between the center points of the o-light spot and the e-light spot in the red light; Adjust the angle of the dichroic mirror so that the ultraviolet light spot entering the detection cavity is below the two red light spots; The particle size information of bioaerosol particles is statistically analyzed through the scattered information received by the avalanche photodiode to form a particle size information map corresponding to different particle sizes; The received intrinsic fluorescence is converted into an electrical signal by a photomultiplier tube to obtain an intrinsic fluorescence curve of the intrinsic fluorescence of the bioaerosol particles.

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