KR102322195B1 - Aerosol Collecting and Analyzing Device - Google Patents

Abstract

The present invention includes: a collecting part having a curved pipe part, receiving fine particles and a liquid material, and collecting liquid so as to flow the fine particles into the liquid substance by centrifugal force and inertial force in the curved pipe part; and a detection unit connected to the collection unit to receive the liquid-phase collected fine particles, and to enable analysis of the liquid-phase collected fine particles.

Description

Fine particle collection and analysis device {Aerosol Collecting and Analyzing Device}

The present invention relates to a device for collecting and analyzing fine particles, and more particularly, to a device for collecting and analyzing fine particles that enables continuous monitoring by moving particles from air to a liquid phase.

Fine particles in the air contain various chemical and biological elements, such as heavy metals and harmful microorganisms. Due to the particle size of several nanometers to several hundreds of micrometers, they can be suspended in the air for a long time and can be spread over a large area by the surrounding air currents. Because of this, it can act as an anxiety factor for health and environmental welfare. In order to prevent and manage the spread of harmful fine particles, it is necessary to develop a technology that can quickly and effectively capture and analyze them.

As an existing analysis method for fine particles, real-time analysis technology exists at the level of analyzing physical characteristics such as size and concentration of fine dust, but for detailed analysis such as chemical and biological composition within fine particles, collection and analysis of fine particles This is the level of analysis by moving and transporting expensive analysis equipment that cannot be continuously detected due to this duality, or that can be used at the laboratory level.

The microfluidic-based analysis method is a method that is actively performed in the field of bio/medical technology as a method that enables precise control of a sample, can reduce the size of a system to a very small size, and can also reduce costs. However, most microfluidic-based analysis methods are conducted in a liquid phase, and microfluidic-based analysis methods targeting gases such as air are being studied at a relatively insignificant level.

Among the samplers for liquefying fine particles, BioSampler and Impinger use a liquid-based sampling method, so it is easy to collect fine particles as well as to preserve particle properties.

However, since it is a passive system that a researcher must directly drive to operate the sampler, there is a problem in that continuous detection and measurement is impossible.

In addition, in the case of the existing liquid-based sampling technology, there was a problem that it was not suitable for use with other advanced technologies for real-time and continuous monitoring.

It is an object of the present invention to provide a microfluidic-based microparticle collection and analysis method for real-time, continuous analysis of microparticles in air.

In order to solve the above problems, the apparatus for collecting and analyzing fine particles of the present invention includes a curved pipe part, receives fine particles and a liquid material, and converts the fine particles into the liquid substance by centrifugal force and inertial force in the curved pipe part a collecting unit for collecting liquid to flow therein; and a detection unit connected to the collection unit to receive the liquid-phase collected fine particles, and to enable analysis of the liquid-phase collected fine particles.

According to an example related to the present invention, the collecting unit may include: a sample inlet through which air containing the fine particles is introduced; a liquid inlet through which the liquid material is introduced; and an air outlet for discharging the air.

Preferably, the collecting unit may further include a sheath air inlet for allowing sheath air to flow into the inside of the bent pipe unit.

According to another example related to the present invention, the outer periphery of the curved pipe portion may be treated with a super hydrophilic surface.

The liquid material may be water containing silver nanoparticles or gold nanoparticles.

According to another example related to the present invention, the apparatus for collecting and analyzing fine particles of the present invention may further include a light processing unit that enables the analysis of the fine particles by irradiating light to the fine particles of the detection unit.

The microchannel-based microparticle collection and analysis method according to the present invention moves microparticles existing in the air into a liquid through centrifugal and inertial forces in an air-liquid laminar flow formed through a curved tube in the microchannel. This enables high-concentration liquefied collection and continuous transfer of the collected liquid sample to the detection unit for real-time analysis.

In addition, the microchannel-based microparticle collection and analysis method according to the present invention can enable classification by size of the collected particles by controlling centrifugal force and inertial force, and according to the analysis method of the detection unit, additives in the injected liquid Since the injection is possible by adding it, it is possible to induce the capture of the fine particles and the pretreatment of the captured particles by the additives contained in the liquid at the same time.

In addition, the present invention is a method for collecting and analyzing fine particles based on microchannels, which enables real-time and continuous chemical and biological analysis of fine dust, greatly reduces the size, and has a large effect of cost reduction, so that public health and environmental welfare-related policies and markets.

Figure 1a is a conceptual diagram showing the apparatus for collecting and analyzing fine particles of the present invention.
Figure 1b is an enlarged view of the curved pipe portion (A portion) of the collecting portion.
1C is a conceptual diagram illustrating an example in which a laser is applied to fine particles of a detection unit (part B) by a light processing unit.
1D is a photograph showing a fiber-bonded laser.
Figure 1e is a conceptual diagram showing the flow of air, fine particles and liquid material in the device for collecting and analyzing fine particles of the present invention.
Fig. 2a is a graph showing stable air-liquid laminar flow and operating conditions in a bent tube section;
Figure 2b is a graph showing the efficiency in which fine particles in the air are collected into a liquid by centrifugal force and inertia.
Figure 3a is a graph showing the particle size distribution with respect to the particle size of the airborne bacteria when using the airborne bacteria as fine particles in the air.
Figure 3b is a transmission electron microscope picture of each type of floating bacteria in Figure 3a.
Figure 3c is a graph showing the collection efficiency of each particle size of the floating bacteria of Figure 3a.
4A is a conceptual diagram illustrating a process in which a liquid in which fine particles are collected in air in a microchannel is separated from air and stably moved to a detection unit.
Figure 4b shows that when the surface-enhanced Raman analysis is applied to the suspended staphylococcal particles collected in the liquid phase, the silver nanoparticles added as an additive to the collection liquid collect the suspended staphylococcal particles in the liquid phase and the silver nanoparticles adhere to the surface of the staphylococcus at the same time. Transmission electron micrograph showing the pre-treatment state.
Figure 5a is a graph showing the analysis results of real-time and continuous surface-enhanced Raman analysis of the sample in the detection unit when the floating bacteria are used as fine particles for collection and surface-enhanced Raman analysis is applied for the analysis.
5B is a graph showing a change in Raman analysis intensity according to a change in the concentration of Staphylococcus in the air.
5C is a graph showing the correlation between the concentration of staphylococcus in the air and the intensity of the dominant peak obtained through Raman analysis.

Hereinafter, the embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but the same or similar reference numerals are assigned to the same or similar components, and overlapping descriptions thereof will be omitted. The suffix "part" for the components used in the following description is given or mixed in consideration of only the ease of writing the specification, and does not have a meaning or role distinct from each other by itself. In addition, in describing the embodiments disclosed in the present specification, if it is determined that detailed descriptions of related known technologies may obscure the gist of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are only for easy understanding of the embodiments disclosed in the present specification, and the technical spirit disclosed herein is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , should be understood to include equivalents or substitutes.

Terms including an ordinal number, such as first, second, etc., may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

When a component is referred to as being “connected” to another component, it may be directly connected to the other component, but it should be understood that other components may exist in between.

The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as "comprises" or "have" are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

As used herein, the term “fine particles” refers to particulate matter suspended in the air, and may include heavy metals and airborne microorganisms such as bacteria, viruses, and fungi having biological properties.

The apparatus 100 for collecting and analyzing fine particles of the present invention includes a collecting unit 10 and a detecting unit 20 .

As shown in FIGS. 1A and 1B , the collecting unit 10 may have a tubular structure including a microchannel having a curved pipe part 11, and centrifugal and inertial forces are applied to the particulate matter suspended in the air in the microchannel. It is used to collect substances in a liquid state.

The liquid material improves the collection efficiency of fine particles by the surface-enhanced Riemann spectrum effect. In the present invention, the liquid material (a liquid material) may be water containing silver nanoparticles or gold nanoparticles.

The collecting unit 10 is preferably formed of a silicon-containing polymer or a photosensitive resin as a material having a fixed shape and capable of moving a sample. For example, the collection unit 10 may be formed of one of a polymer material such as polydimethylsiloxane (PDMS) or polymethylmethacrylate (PMMA).

The curved pipe part 11 can induce a streamline of a passing sample to change rapidly, so that if it is a structure capable of applying centrifugal force and inertial force to the fine particles in the air, the shape is not limited.

The bent tube portion 11, although an example of a semicircular shape is shown in FIG. 1A, is not necessarily limited to this structure, and may be formed in a mixed form of several flat surfaces and curved surfaces.

The particles collected by the collecting unit 10 are concentrated in a liquid state and are continuously transferred to the detecting unit 20 .

That is, the collecting unit 10 collects, liquefies, and concentrates fine particles that are airborne microorganisms in the air, and transfers them to the detecting unit 20 .

The collection unit 10 may include a sample inlet 13 , a liquid inlet 15 , and an air outlet 17 .

The sample inlet 13 introduces air containing fine particles into the tube inside the collecting unit 10 .

The liquid inlet 15 is a liquid material is introduced. In the present invention, various additives may be included in the liquid material according to the type of analysis method of the detection unit 20 to be described later. The additive may be silver nanoparticles, gold nanoparticles for surface-enhanced Raman analysis, quantum dots for fluorescence analysis, dye samples, dissolved samples for bioluminescence analysis, and ATP luminescent enzymes.

The air outlet 17 is configured to discharge air. 1A shows an example of the air outlet 17 provided on the upper right side of the collecting unit 10, the air flowing together with the liquid material is discharged.

The outer periphery of the curved pipe part 11 of the collecting part 10 is treated with a super hydrophilic surface to enable the formation of a stable and uniform liquid film on the outer wall of the curved pipe part 11 .

Flow rates of the air and collection liquid injected into the collection unit 10 of the apparatus 100 for collecting and analyzing fine particles may vary depending on the size of the particles to be collected in the microfluid. As an example, when targeting particles having a diameter of 1 μm, the air flow rate may be 0.3 to 0.9 L/min, and the water flow rate may be 0.5 to 3.0 mL/min.

1B is an enlarged view of the curved pipe part 11 of the collecting part 10. Referring to FIG. 1B, at the lower end of the curved pipe part 11, the liquid material 3 and the liquid material 3 in the liquid material 3 are shown. An example in which (3) and air (5) flow laminar, and fine particles (1) flow therewith is shown. The liquid material 3 flows at the lower end of the collecting unit 10 by centrifugal force. In the inside of the curved pipe part 11, the air 5 flows in the upper part of the liquid material 3 at the bottom. An example of air 5 flowing at a tangential velocity Vr and a radial velocity U is shown in FIG. 1B . The liquid material 3 also flows in the curved pipe portion 11 at tangential and radial speeds.

The fine particles in the air in the curved pipe part 11 are transferred to the liquid material and are introduced into the detection unit 20 together with the liquid material. The fine particles 1 are shown as dots in FIG. 1b , and the flow 1a of the particles is shown with dotted lines. Meanwhile, the flow line 5a of the air 5 is also shown in FIG. 1b .

The centrifugal force of air and liquid material can be controlled by adjusting the flow rate of air and liquid material in the bent pipe part 11 or by adjusting the angle of the bent pipe part 11, thereby collecting fine particles of a desired size. can

When the relative centrifugal force is increased, relatively small fine particles can be collected, and when the centrifugal force is relatively decreased, relatively large fine particles can be collected.

The collecting unit 10 may further include a sheath air inlet 19 for allowing sheath air to flow into the bent pipe unit 11 . By introducing the sheath air into the inside of the curved pipe part 11 through the sheath air inlet 19, it is possible to more activate the collection of the liquid phase of the fine particles.

The detection unit 20 is configured to perform pre-processing and spectroscopy analysis of the liquid-phase captured particles, and displays the analysis results in real time.

The detection unit 20 is connected to the collection unit 10 , and may have a tubular structure formed of a microchannel like the collection unit 10 .

The detection unit 20 may include a pre-processing unit 23 for pre-processing the liquid material provided from the collecting unit 10 .

Referring to FIG. 1A , an example in which the pre-processing unit 23 is connected to the bent pipe unit 11 of the collecting unit 10 and is bent a plurality of times is shown. As the liquid material and the fine particles pass through the pre-processing unit 23, the flow rate and pressure are controlled, so that analysis is easy.

As an example, the detection unit 20 may perform a real-time optical analysis method of fine particles through surface-enhanced Raman scattering signal analysis of suspended fine particles. In the present invention, the optical analysis method may be FT-IR analysis, fluorescence analysis or light scattering analysis.

In addition, the detection unit 20, it is also possible to perform a molecular biological analysis method, the molecular biological analysis method, ELISA (enzyme-linked immunosorbent assay, enzyme-linked immunospecific assay), PCR (polymerase chain reaction), ATP ( Adenosine triphosphate) method or QCM (Quartz crystal microbalance) may be used.

The apparatus 100 for collecting and analyzing fine particles may further include a light processing unit 30 configured to analyze the fine particles by irradiating light to the fine particles of the detection unit 20 .

The light processing unit 30 may include components for irradiating a laser to the fine particles shown in FIG. 1C .

1C is a conceptual diagram illustrating an example in which a laser is applied to the fine particles of the detection unit 20 .

The laser irradiated from the light source 30a of the fiber-coupled laser device passes through the first lens 31a and the first polarizing filter 31b, and the first lens 31a and the first polarizing filter ( After passing through 31b) of a predetermined wavelength (for example, 532 nm) or more, the laser is reflected by the dichroic mirror 33 and then passes through the objective lens 34 to arrive as fine particles.

In addition, some of the laser light reaching the fine particles is reflected from the fine particles, passes through the objective lens 34 and the dichroic mirror 33, is separated through the beam splitter 35, and then reaches the CMOS 36 .

On the other hand, some of the laser light reaching the fine particles is reflected from the fine particles, passes through the objective lens 34 and the dichroic mirror 33, is separated through the beam splitter 35, and then the second lens 37a, It passes through the second polarizing filter 37b and the fiber member 37c to reach the spectrometer 38 .

The CMOS 36 captures an image of the fine particles, and the spectrometer 38 obtains spectral information of the fine particles.

The image in the CMOS 36 and the spectral information of the spectrometer 38 are provided and stored to a PC 39 (Personal Computer), respectively, and can be analyzed.

1E is a conceptual diagram illustrating the flow of air, fine particles, and liquid material in the apparatus 100 for collecting and analyzing fine particles of the present invention.

Referring to FIG. 1E , in the apparatus 100 for collecting and analyzing fine particles, air including fine particles is introduced through the sample inlet 13 , and liquid material is introduced through the liquid inlet 15 , respectively, to the curved pipe part 11 . is brought in

In addition, sheath air is introduced into the bent pipe portion 11 through the sheath air inlet 19 .

The fine particles collected in the liquid phase inside the curved pipe unit 11 are introduced into the pre-processing unit 23 of the detection unit 20 and pre-treated, then detected and analyzed, and discharged through the sample discharge unit 25 .

On the other hand, the air inside the bent pipe portion 11 is not introduced into the detection unit 20 , but is discharged to the outside through the air outlet 17 .

In addition, the apparatus 100 for collecting and analyzing fine particles of the present invention may further include a variable control unit for controlling one or more parameters of the sample injected into the sample injection unit, and the variables include Reynolds number, Stokes. Examples are Stokes number and Dean number. The definition of each variable is as follows.

Here, ρ is the density of air, U is the velocity of the air, D _h is the hydraulic diameter, μ is the viscosity of the air, ρ _p is the density of the particles, d _p is the diameter of the particles, and R _o is the curvature of the flow path. When the above parameters of the injected sample are adjusted, particles having a size greater than or equal to a desired diameter can be collected.

In addition, the apparatus 100 for collecting and analyzing fine particles of the present invention may include a collection liquid such as distilled water or PBS buffer in order to effectively collect the fine particles collected in the microchannel in the case of a liquid injected into the collection liquid injection unit. have.

In addition, the apparatus 100 for collecting and analyzing fine particles of the present invention may include a device for measuring and analyzing bio-aerosols by being connected to the sample discharge unit 25 . For example, it is possible to measure the shape and characteristics of the captured particles in real time, including a microscope, a charge-coupled device camera (CCD camera), and the like. In addition, continuous Raman and fluorescence analysis can be used as optical methods, and it is an integrated system that can capture and detect bioaerosols in real time by linking with various in situ physicochemical analysis methods such as single cell flow cytometry and bacterial ATP-luminescence. Extensibility may be possible.

[Experimental Example 1]

Analysis of collection efficiency by particle size according to injection flow rate

In addition, as Experimental Example 1 of the present invention, an experiment was conducted using standard particles (Polystyrene Latex particles) in order to analyze the collection efficiency according to the particle size inside the fine particle collection device.

Standard particles having various sizes (Duke scientific, USA) were suspended in the air using a nebulizer (MRE CN25, BGI Corp, USA), and then to the fine particle collection device to analyze the collection efficiency according to the flow rate. A mass flow controller (FC-280S, Mykrolis Corp., Billerica, MA) was used to control the air flow rate from 0.3 to 0.9 L/min, and a syringe pump (KDS Scientific Inc., Holliston, MA, USA) for the collection liquid flow rate. was added at 0.5 to 3.0 mL/min. At this time, the particle diameter of each standard particle was 0.65, 0.80, 0.91, 1.00, 1.53, 2.10 μm.

The collection efficiency was calculated as follows. Concentrations were measured at the sample inlet 13 and the sample outlet containing air in the microchannel by using an aerodynamic particle size analyzer (Aerodynamic Particle Sizer, TSI inc.). Then, the collection efficiency (E(%)) was calculated according to Equation 2, and the results are shown in FIGS. 2A and 2B.

In this case, N ₁ is the concentration of standard particles at the sample inlet 13 including air, and N ₂ is the concentration of standard particles at the sample outlet.

As shown in FIGS. 2A and 2B , when the injection flow rate is increased, the radial movement distance with the streamline increases according to the centrifugal force, so the particle collection efficiency for the entire size range increases with the air flow rate. It can be confirmed that it is possible to selectively collect according to the particle size according to the target particle size according to the injection flow rate.

At this time, it is important to form a stable liquid film on the outer wall of the curved tube with a relatively high flow rate of air injected into the microchannel system and a low flow rate of collected liquid. This is maintained by balancing the surface tension of the liquid and the centrifugal force exerted as it passes through the curved tube by flowing the collecting liquid at a relatively small liquid flow rate when a high air flow rate is passed, and the shear force occurring at the interface between the air and the collecting liquid. way you can

[Experimental Example 2]

Analysis of collection efficiency using actual airborne bacterial particles

An experiment was conducted to analyze the collection efficiency of the fine particle collection system by injecting actual suspended bacterial particles into the fine particle collection and analysis apparatus 100 according to the present invention.

Staphylococcus epidermidis, Micrococcus luteus, Enterococcus hirae, Bacillus subtilis, Escherichia coli having the size distribution shown in FIG. 3A was used as a bio-aerosol, which was used as a nebulizer (Nebulizer, MRE CN25, BGI Corp, USA) was suspended in the air, and introduced at a flow rate of 1 L/min through the sample inlet 13 of the fine particle collecting device of the above example.

Then, the collection efficiency of the floating bacterial particles was calculated in the same manner as in [Experimental Example 1] using [Equation 2]. As a result, as shown in Fig. 3b, the maximum and minimum aerodynamic diameters were 0.55 μm and 1.3 μm, respectively. The collection efficiency curve of Staphylococcus aureus was similar to that of PSL particles of standard size. In addition, the collection efficiency was over 90% over the entire size range.

[Experimental Example 3]

Surface-enhanced Raman Scattering Analysis Using Real Airborne Bacterial Particles

An experiment was conducted to analyze the surface-enhanced Raman scattering of the microparticle detection system according to an embodiment of the present invention using actual floating bacterial particles. The number concentration of each test suspended bacterial particle was about 10 ⁸ CFU/mL, and the concentration of surface-enhanced Raman scattering nanoparticles was 1 mM. As a result of the electron microscope analysis, the nanoparticles were attached to the surface of the bacteria as shown in FIG. 4b. As a result of the surface-enhanced Raman scattering spectrum ^{, commonly distinguished peaks were observed at 732, 1322, 1440, and 1600 cm -1} , which is shown in FIG. 5a . In particular, adenine (732 cm ^-1 ), protein or lipid (1440 cm ^-1 ) peaks were detected only in Staphylococcus aureus and Enterococcus.

According to an embodiment of the present invention, for the analysis of the surface-enhanced Raman scattering results according to the concentration of the suspended bacterial particles, the concentration of the suspended bacterial particles ^{was increased from 10 3} CFU/mL to 10 ⁸ CFU/mL, and the results are shown in FIG. 5b shown in the graph. The results of surface-enhanced Raman scattering according to the concentration were prominent in the two peaks, ^{732 cm -1} and 1324 cm ^{-1 .} The quantification of the scattering intensity change at the two peak points according to the change in the concentration of suspended bacteria particles is shown in Fig. 5c. The surface-enhanced Raman scattering signal was strengthened by the number of bacterial cells in the detection amount, and the signal increased linearly as the ^{bacterial concentration increased from 10 3} CFU/mL to 10 ^{7 CFU/mL.} The peak intensity at 732 cm ^-1 was more sensitively affected by changes in bacterial concentration.

As described above, in the case of the airborne bacterial particle collection and detection system, it was possible to detect an excellent collection efficiency and quantitative surface-enhanced Raman scattering signal. In the case of the device for collecting fine particles of the present invention, if a higher concentration ratio is given in a short time, it has a similar microbial recovery rate to that of a biosampler and shows the possibility of more quantitative analysis of suspended microorganism concentration. In addition, it can be said that it is a real-time collection and detection method that can be continuously used in the field.

The fine particle collection and analysis apparatus 100 described above is not limited to the configuration and method of the embodiments described above, but all or part of each embodiment is selectively combined so that various modifications can be made. could be

It is apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the present invention. Accordingly, the above detailed description should not be construed as restrictive in all respects but as exemplary. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention.

100: Fine particle collection and analysis device
10: Collection part 11: Bend pipe part 13: Sample injection port
15: liquid inlet 17: air outlet 19: sheath air inlet
20: detection unit 23: pre-processing unit 25: sample discharge unit
30: light processing unit
30a: light source 31a: first lens 31b: first polarizing filter
33: dichroic mirror 34: objective lens 35: beam splitter
36: CMOS 37a: second lens 37b: second polarizing filter
37c: fiber member 38: spectrometer
39:PC
3: Liquid substance 1: Fine particles 5: Air

Claims (6)

a collecting part having a curved pipe part, receiving fine particles and a liquid substance, and collecting the liquid to flow the fine particles into the liquid substance by centrifugal force and inertial force in the curved pipe part; and
It is connected to the collection unit to receive the liquid-phase collected fine particles, and comprises a detection unit that enables analysis of the liquid-phase collected fine particles,
The detection unit includes a pre-processing unit for pre-processing the liquid material, and the pre-processing unit has a shape bent a plurality of times and is connected to the bent pipe unit,
The collection unit,
a sample inlet through which air containing the fine particles is introduced;
a sheath air inlet for allowing sheath air to flow into the curved pipe portion;
a liquid inlet through which the liquid material is introduced; and
It includes an air outlet for discharging the air,
The flow of liquid material, the flow of air containing fine particles, and the flow of sheath air are moved in a laminar flow within the bent pipe part,
A device for collecting and analyzing fine particles, characterized in that between the flow of the liquid material and the flow of the sheath air, a flow of air containing fine particles is located.
delete delete According to claim 1,
An apparatus for collecting and analyzing fine particles, characterized in that the outer periphery of the curved pipe part is treated with a super-hydrophilic surface.
According to claim 1,
The liquid material is an apparatus for collecting and analyzing fine particles, characterized in that water containing silver nanoparticles or gold nanoparticles.
According to claim 1,
The apparatus for collecting and analyzing fine particles, characterized in that it further comprises a light processing unit that enables analysis of the fine particles by irradiating light to the fine particles of the detection unit.

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