Passive expiration VOCs collection device and method for lung cancer detection

Abstract

The invention provides a passive expiration VOCs collection device and method for lung cancer detection, the device comprises a constant volume collection cavity and a nano-composite adsorption cylinder, the constant volume collection cavity is used for enriching tail-section alveolar gas in a single expiration process, the side wall of one end of the constant volume collection cavity is connected with a gas collection pipe capable of being communicated with a mouth-holding type connector, and the nano-composite adsorption cylinder is connected with the side wall of the other end of the constant volume collection cavity. One end of the constant-volume collecting cavity is provided with a manual propeller capable of pushing a gas sample in the constant-volume collecting cavity to pass through the nano-composite adsorption barrel, the other end of the constant-volume collecting cavity is communicated with an upstream port of the nano-composite adsorption barrel through a gas conveying pipe, a downstream port of the nano-composite adsorption barrel is communicated with a gas outlet pipe, and the gas conveying pipe and the gas outlet pipe are connected with switch valves; a super-hydrophobic nanofiber moisture-resistant layer, a hydrophobic MOF-carbon aerogel main trapping layer and a polar Zr-MOF enhancement layer are sequentially filled in the nano composite adsorption barrel from upstream to downstream. The invention establishes a collection device and method which are free of pump and electricity, simple and convenient to operate, capable of efficiently and selectively enriching trace lung cancer related VOCs and capable of ensuring good repeatability.

Description

Technical Field

[0001] This invention relates to the field of biological sample pretreatment and medical testing technology, specifically to a passive exhaled VOCs collection device and method for lung cancer detection. Background Technology

[0002] Lung cancer is one of the leading causes of cancer-related morbidity and mortality worldwide, and early screening and diagnosis are crucial for improving patient survival rates. While low-dose computed tomography (CT) scans, a commonly used early screening method, can effectively detect lung nodules, they suffer from high false-positive rates, radiation exposure, and high costs. Therefore, developing a non-invasive, convenient, and efficient early lung cancer screening technology has become an urgent clinical need.

[0003] Exhaled breath testing is a promising new non-invasive diagnostic technology. Human exhaled breath contains hundreds of volatile organic compounds (VOCs), among which the spectra of certain specific VOCs (such as alkanes and benzene derivatives) are closely related to the metabolic activity of lung cancer cells and are potential biomarkers for lung cancer. However, the concentration of VOCs in exhaled breath is extremely low (typically at the ppb-ppt level) and easily affected by ambient air pollution. Therefore, efficient and stable collection and enrichment of VOC samples are crucial for accurate analysis.

[0004] Currently, technologies for collecting exhaled VOCs are mainly divided into two categories: active sampling technology and preliminary passive sampling technology.

[0005] Active sampling techniques include directly collecting whole gas using Tedlar® gas bags or connecting adsorption tubes (such as Tenax TA) to an active sampling pump. While these methods offer large sample volumes, they have significant drawbacks: they require expensive external equipment such as pumps and flow meters, are cumbersome to operate, are unsuitable for large-scale community screening or home monitoring, and some sampling bags release substances that can interfere with test results.

[0006] Preliminary passive sampling techniques have been developed, with some designs attempting to use simple adsorbent tubes open at both ends, relying on gas diffusion for sampling. However, these techniques generally suffer from low adsorption efficiency and poor repeatability. Traditional adsorbents (such as activated carbon) are limited by high humidity interference, insufficient coverage of polar / nonpolar component spectra, and dead space gas dilution. Furthermore, existing technologies have failed to leverage the high specific surface area and tunable surface chemistry of advanced nanomaterials to achieve efficient and selective capture of trace lung cancer biomarkers, VOCs.

[0007] In summary, there is an urgent need for a VOCs collection solution that can overcome the above shortcomings. To achieve low-cost, simple, and efficient clinical / community applications, it is necessary to establish a structure that does not require external power and uses nanomaterials as the core to achieve broad-spectrum and selective capture of lung cancer-specific VOCs, while also ensuring transport and storage stability. Summary of the Invention

[0008] To address the technical problems existing in current lung cancer exhaled gas collection devices, this invention provides a passive exhaled VOCs collection device for lung cancer detection. It achieves efficient dehumidification and enrichment of exhaled gas through multiple layers of nanomaterials, and selects and enriches specific VOCs by adjusting the number of nanomaterial layers.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] A passive exhaled VOCs collection device for lung cancer detection includes a constant-volume collection chamber and a nanocomposite adsorption cylinder. The constant-volume collection chamber is used to enrich terminal alveolar gas during a single exhalation. One end of the constant-volume collection chamber is connected to a gas collection tube that can communicate with a mouthpiece interface. One end of the constant-volume collection chamber is equipped with a manual pusher that can push the gas sample in the chamber through the nanocomposite adsorption cylinder. The other end of the constant-volume collection chamber is connected to the upstream port of the nanocomposite adsorption cylinder through a gas delivery tube. The downstream port of the nanocomposite adsorption cylinder is connected to an outlet tube. Switch valves are connected to the gas delivery tube and the outlet tube. The nanocomposite adsorption cylinder is filled from upstream to downstream with a superhydrophobic nanofiber moisture-proof layer, a hydrophobic MOF@carbon aerogel main trapping layer, and a polar-affinity Zr-MOF reinforcing layer.

[0011] Furthermore, the nanocomposite adsorption tube is further filled with an aldehyde in-situ derivatization layer and a sulfur-containing selective layer after the polar-affinity Zr-MOF reinforcing layer.

[0012] Furthermore, the manual pusher includes a piston block that is sealed to the inner wall of the constant volume collection chamber, and a piston rod is fixedly connected to the outer end of the piston block.

[0013] Furthermore, the superhydrophobic nanofiber moisture-proof layer is made of ePTFE or PVDF-HFP electrospun nanofiber membrane / felt with a mass of 10-200 mg.

[0014] Furthermore, the hydrophobic MOF@carbon aerogel main trapping layer consists of a hydrophobic MOF loaded on a graphene / carbon nanotube aerogel scaffold with a mass of 50-300 mg. The mass ratio of the MOF to the aerogel scaffold is (0.5-2):1, and the specific surface area is ≥600 m². 2 ·g -1 .

[0015] Furthermore, the polar-affinity Zr-MOF reinforcement layer uses UiO-66-NH2, UiO-66-OH or MOF-808 moisture-resistant Zr-MOF and has a mass of 50-300 mg.

[0016] Furthermore, the aldehyde in-situ derivatization layer uses DNPH@mesoporous silica or amination MOF with a mass of 20-150 mg and a DNPH loading of 0.5-5 wt%.

[0017] Furthermore, the sulfur-containing selective layer is made of Ag nanoparticle modified activated carbon fiber or Ag-MOF composite material with a mass of 10-150 mg and an Ag loading of 0.1-5 wt%.

[0018] The present invention also provides a passive exhaled VOCs collection method for lung cancer detection, wherein the method employs the aforementioned passive exhaled VOCs collection device for lung cancer detection, and the method includes the following steps:

[0019] S1. Connect the gas collection tube to the mouth-held interface, so that the subject can take a deep breath and enrich the terminal alveolar gas with the fixed-volume collection chamber.

[0020] S2. The gas sample in the constant volume collection chamber is pushed through the nanocomposite adsorption tube in one go within 3-5 seconds by the manual pusher, so that non-polar and polar VOCs are captured in the hydrophobic MOF@carbon aerogel main trapping layer and the polar-loving Zr-MOF reinforcing layer, respectively, and aldehydes are in-situ derivatized in the optional aldehyde in-situ derivatization layer.

[0021] S3. Close the switch valves at both ends of the upstream and downstream of the nanocomposite adsorption tube. The sampled nanocomposite adsorption tube can be directly connected to a thermal desorption instrument for thermal desorption, or solvent desorption analysis can be performed using an organic solvent.

[0022] Furthermore, the temperature of the thermal desorption is 40-320℃, the time is 0.5-15 min, and the volume of the organic solvent is 0.2-2.0 mL.

[0023] Compared with existing technologies, the passive exhaled VOCs collection device and method for lung cancer detection provided by this invention have the following advantages:

[0024] (1) Minimalist structure: No pump or electricity required. The device only uses a fixed-volume collection chamber and manual propulsion to enrich the gas in the terminal alveoli. The device does not contain electronic components, which greatly reduces the cost and makes it easy to operate. It can efficiently and selectively enrich trace amounts of lung cancer-related VOCs (benzene, toluene, ethylbenzene, styrene, isoprene, acetone, 2-butanone, n-propanol, hexanal / nonanal / decanal and dimethyl sulfide) and ensure good repeatability. It is suitable for screening and follow-up scenarios of lung cancer in primary care and community.

[0025] (2) Moisture-resistant broad spectrum: The superhydrophobic nanofiber moisture-resistant layer is moisture-resistant + hydrophobic MOF@carbon aerogel main trapping layer / polar-loving Zr-MOF reinforcing layer targets both non-polar and polar spectra. When necessary, the aldehyde in-situ derivatization layer stabilizes aldehydes, and the sulfur-containing selective layer enhances sulfur content, thus achieving efficient trapping and stable preservation of lung cancer-related non-polar and polar VOCs even under high humidity conditions;

[0026] (3) Low resistance and high capacity are combined: Aerogel stents provide interconnected macroporous channels, which reduce pressure drop while increasing the equivalent filling volume;

[0027] (4) Transportation friendly: The double-ended switching valve provides instant sealing, and the in-situ derivatization layer of aldehydes enhances storage stability;

[0028] (5) Mass production at low cost: general processes such as electrospinning / coating / impregnation-in-situ growth are suitable for roll-to-roll and injection molding scale-up. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the passive exhaled VOCs collection device for lung cancer detection provided by the present invention.

[0030] In the figure, 1 is the constant volume collection chamber; 11 is the gas collection tube; 2 is the nanocomposite adsorption tube; 21 is the superhydrophobic nanofiber moisture-proof layer; 22 is the hydrophobic MOF@carbon aerogel main trapping layer; 23 is the polar-loving Zr-MOF reinforcing layer; 24 is the aldehyde in-situ derivatization layer; 25 is the sulfur-containing selective layer; 3 is the gas delivery pipe; 4 is the gas outlet pipe; 5 is the switch valve; 6 is the piston block; 7 is the piston rod; and 100 is the mouth-type interface. Detailed Implementation

[0031] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0032] Please refer to Figure 1As shown, this invention provides a passive exhaled VOCs collection device for lung cancer detection, comprising a constant-volume collection chamber 1 and a nanocomposite adsorption cylinder 2. The effective volume of the constant-volume collection chamber 1 can be specifically designed to be 100-180 mL. The constant-volume collection chamber 1 is used to enrich the alveolar gas in the terminal pulmonary tract during a single exhalation. One end of the constant-volume collection chamber 1 is connected to a flexible gas collection tube 11 that can communicate with an existing mouthpiece interface 100. One end of the constant-volume collection chamber 1 is equipped with a manual pusher that can push the gas sample in the chamber through the nanocomposite adsorption cylinder. The other end of the constant-volume collection chamber 1 is connected to the upstream port of the nanocomposite adsorption cylinder 2 through a gas delivery tube 3 (such as a Luer connector / threaded interface for quick connection). During collection, the subject takes a steady, deep exhalation. Because the volume of the constant-volume collection chamber 1 is smaller than the total exhalation volume, the gas in the initial dead space is naturally discharged to the outside, and the chamber is enriched with exhaled gas. The alveolar gas at the end of the gas phase is rich in VOCs. After collection, the gas sample in the constant-volume collection chamber 1 is pushed through the downstream nanocomposite adsorption cylinder 2 in one go using a manual pusher. The nanocomposite adsorption cylinder 2 is a tubular sealed structure (such as a glass tube or stainless steel tube). The inner diameter of the nanocomposite adsorption cylinder 2 can be designed to be 2-6 mm, and the length can be designed to be 30-120 mm. The downstream port of the nanocomposite adsorption cylinder 2 is connected to the gas outlet pipe 4. The gas supply pipe 3 and the gas outlet pipe 4 are connected to the switch valve 5. The nanocomposite adsorption cylinder is filled from upstream to downstream with a superhydrophobic nanofiber moisture-proof layer 21, a hydrophobic MOF@carbon aerogel main trapping layer 22, and a polar-loving Zr-MOF reinforcing layer 23. The total filling amount of the nanocomposite adsorption cylinder 2 is 100-800 mg, and the linear gas resistance is ≤1.0 kPa@10 L·min. -1 .

[0033] For a specific implementation method, please refer to Figure 1 As shown, the nanocomposite adsorption tube 2 is further filled with an aldehyde in-situ derivatization layer 24 and a sulfur-containing selective layer 25 after the polar-loving Zr-MOF reinforcing layer 23. The aldehyde in-situ derivatization layer 24 is used for the stable derivatization and preservation of carbon compounds such as hexanal / nonanal / decanoal, and the sulfur-containing selective layer 25 is used for coordination-enhanced capture of sulfur-containing VOCs such as dimethyl sulfide.

[0034] In a specific implementation, a sealing film is affixed to the gap between the valve stem and the valve seat of the switching valve 5. Thus, after closing the switching valves 5 at both ends of the nanocomposite adsorption cylinder 2, the gap between the valve stem and the valve seat can be further sealed by the sealing film to achieve complete and immediate sealing after sampling.

[0035] For a specific implementation method, please refer to Figure 1As shown, the manual pusher includes a piston block 6 that is sealed to the inner wall of the constant volume collection chamber 1. A piston rod 7 is fixedly connected to the outer end of the piston block 6. The sampling personnel can hold the piston rod 7 and push the piston block 6 to slide in the constant volume collection chamber 1, thereby pushing the gas sample in the constant volume collection chamber 1 through the nanocomposite adsorption tube 2 in one go.

[0036] In a specific embodiment, the superhydrophobic nanofiber moisture-proof layer 21 is made of ePTFE or PVDF-HFP electrospun nanofiber membrane / mat with a mass of 10-200 mg. The surface of the ePTFE or PVDF-HFP electrospun nanofiber membrane / mat is fluorosilaneized, and the static water contact angle is ≥150°. It is used to suppress water flow and trap aerosols, with a pressure drop ≤1 kPa@10 L·min. -1 .

[0037] In a specific embodiment, the hydrophobic MOF@carbon aerogel main trapping layer 22 uses hydrophobic MOFs such as ZIF-8 or ZIF-71 loaded on a graphene / carbon nanotube aerogel scaffold with a mass of 50-300 mg. The mass ratio of the MOF to the aerogel scaffold is (0.5-2):1, and the specific surface area is ≥600 m². 2 ·g -1 It is used for the efficient capture of nonpolar VOCs such as aromatic hydrocarbons, alkanes, and isoprene.

[0038] In a specific embodiment, the polar-loving Zr-MOF reinforcing layer 23 uses similar moisture-resistant Zr-MOFs such as UiO-66-NH2, UiO-66-OH, or MOF-808, with a mass of 50-300 mg, to enhance the selective adsorption of polar VOCs such as acetone, 2-butanone, and n-propanol, and the recovery rate of acetone or 2-butanone is ≥30% under relative humidity ≥80%.

[0039] In a specific embodiment, the aldehyde in-situ derivatization layer 24 uses DNPH@mesoporous silica or amination MOF with a mass of 20-150 mg and a DNPH loading of 0.5-5 wt%, and is used to stably derivatize carbon compounds such as hexanal / nonanal / decanal into corresponding hydrazone stabilizers for preservation.

[0040] In a specific embodiment, the sulfur-containing selective layer 25 is made of Ag nanoparticle-modified activated carbon fiber or Ag-MOF composite material with a mass of 10-150 mg and an Ag loading of 0.1-5 wt%, which is used to enhance the adsorption of dimethyl sulfide and achieve coordination-enhanced capture of sulfur-containing VOCs such as dimethyl sulfide.

[0041] As a specific implementation, the materials and manufacturing key points involved in this device include: electrospinning or ePTFE stretching of the superhydrophobic nanofiber moisture-resistant layer 21, with surface fluorosilaneization; in-situ growth or impregnation-crystallization of the hydrophobic MOF@carbon aerogel main trapping layer 22 and the polarophilic Zr-MOF reinforcing layer 23 on the graphene / carbon nanotube aerogel scaffold to ensure MOF crystallinity and adhesion; DNPH in the aldehyde in-situ derivatization layer 24 is covalently / electrostatically loaded onto mesoporous SiO2 or amination Zr-MOF; inertization of the inner wall of the cylinder by glass or 316L stainless steel; and end-sintered filter fixing with a packing density controlled at 0.2–0.6 g·cm³. -3 To balance pressure drop and capacity.

[0042] The present invention also provides a passive exhaled VOCs collection method for lung cancer detection, wherein the method employs the aforementioned passive exhaled VOCs collection device for lung cancer detection, and the method includes the following steps:

[0043] S1. Connect the gas collection tube 11 to the existing mouth-type interface, so that the subject can take a deep breath and enrich the terminal alveolar gas with the fixed-volume collection chamber 1.

[0044] S2. The gas sample in the constant volume collection chamber 1 is pushed through the nanocomposite adsorption tube 2 in one go within 3-5 seconds by the manual pusher, so that non-polar and polar VOCs are captured in the hydrophobic MOF@carbon aerogel main trapping layer 22 and the polar-loving Zr-MOF reinforcing layer 23 respectively, and aldehydes are in situ derivatized in the optional aldehyde in situ derivatization layer 24.

[0045] S3. Close the switch valves 5 at both ends of the nanocomposite adsorption cylinder 2. The sampled nanocomposite adsorption cylinder 5 can be directly connected to a thermal desorption instrument for thermal desorption, or solvent desorption coupled with GC-MS or HPLC analysis can be performed using organic solvents. This is suitable for lung cancer screening and follow-up scenarios.

[0046] In a specific embodiment, the temperature of the thermal desorption is 40-320℃, the time is 0.5-15min, and the volume of the organic solvent is 0.2-2.0mL.

[0047] To better understand the passive exhaled VOCs collection device and method for lung cancer detection provided by the present invention, the following will be described in detail with reference to specific embodiments.

[0048] Example 1: Community screening, solvent desorption

[0049] (1) Fixed volume collection chamber: effective volume 150mL, silanized glass chamber, equipped with existing oral interface;

[0050] (2) Nanocomposite adsorption tube: superhydrophobic nanofiber moisture-proof layer 21 ePTFE electrospun nanofiber membrane 50mg, hydrophobic MOF@carbon aerogel main trapping layer 22 ZIF-8@graphene aerogel scaffold 150mg, polar-affinity Zr-MOF reinforcing layer 23 UiO-66-NH2 120mg;

[0051] (3) Sampling: The subject takes a deep breath and then exhales slowly to complete a one-time collection; the gas sample is pushed through the nanocomposite adsorption tube in 3-5 seconds using a manual pusher;

[0052] (4) Desorption: 0.8 mL of acetonitrile was sonicated for 5 min, and 1 µL of the sample was injected into GC-MS;

[0053] (5) Indicators: Quantitative analysis of benzene / toluene / ethylbenzene / styrene, isoprene, acetone, 2-butanone, n-propanol, and hexanal.

[0054] Compared with existing preliminary passive sampling techniques, this embodiment employs a superhydrophobic nanofiber anti-humidity layer 21 and a hydrophobic MOF@carbon aerogel main trapping layer 22 / polar-loving Zr-MOF reinforcing layer 23 to collect lung cancer-related nonpolar and polar VOCs under high humidity conditions, targeting both nonpolar and polar spectra. Furthermore, it utilizes the high specific surface area and tunable surface chemistry of advanced nanomaterials (referring to 21 layers of ePTFE electrospun nanofiber membrane, 22 layers of ZIF-8@graphene aerogel scaffold, and 23 layers of UiO-66-NH2) to achieve efficient and selective capture of trace lung cancer biomarkers VOCs.

[0055] Example 2: Outpatient follow-up, thermal desorption

[0056] (1) Fixed volume collection chamber: effective volume 100mL, silanized glass chamber, equipped with existing oral interface;

[0057] (2) Nanocomposite adsorption tube: superhydrophobic nanofiber moisture-proof layer 21 PVDF-HFP electrospun nanofiber membrane 100mg, hydrophobic MOF@carbon aerogel main trapping layer 22 ZIF-71@carbon nanotube aerogel scaffold 200mg, polar-loving Zr-MOF reinforcing layer 23 MOF-808 100mg, aldehyde in-situ derivatization layer 24 DNPH@mesoporous silica 60mg, sulfur-containing selective layer 25 Ag nanoparticle modified activated carbon fiber (Ag-NP) 40mg;

[0058] (3) Sampling: The subject takes a deep breath and then exhales slowly to complete a one-time collection; the gas sample is pushed through the nanocomposite adsorption tube in 3-5 seconds using a manual pusher. After sampling, the double-ended valve of the nanocomposite adsorption tube is tightened and transported under cold storage for ≤24 hours.

[0059] (4) Thermal desorption: temperature 40→280℃, time 10min, introduced into GC-MS / MS, quantified using hydrazine derivative channels;

[0060] (5) Indicators: Dimethyl sulfide is co-captured with aromatic hydrocarbons / alcohols and ketones to avoid the influence of water vapor.

[0061] Example 3: Outpatient follow-up, thermal desorption

[0062] (1) Fixed volume collection chamber: effective volume 300mL, silanized glass chamber, equipped with existing oral interface;

[0063] (2) Nanocomposite adsorption tube: superhydrophobic nanofiber moisture-proof layer 21 PVDF-HFP electrospun nanofiber felt 150mg, hydrophobic MOF@carbon aerogel main trapping layer 22 ZIF-71@carbon nanotube aerogel scaffold 250mg, polar-loving Zr-MOF reinforcing layer 23 UiO-66-OH 200mg, aldehyde in-situ derivatization layer 24 DNPH@amined MOF 100mg, sulfur-containing selective layer 25 Ag-MOF composite material 100mg;

[0064] (3) Sampling: The subject takes a deep breath and then exhales slowly to complete a one-time collection; the gas sample is pushed through the nanocomposite adsorption tube in 3-5 seconds using a manual pusher. After sampling, the double-ended valve of the nanocomposite adsorption tube is tightened and transported under cold storage for ≤24 hours.

[0065] (4) Thermal desorption: temperature 40→280℃, time 10min, introduced into GC-MS / MS, quantified using hydrazine derivative channels;

[0066] (5) Indicators: Dimethyl sulfide is co-captured with aromatic hydrocarbons / alcohols and ketones to avoid the influence of water vapor.

[0067] Compared with existing preliminary passive sampling techniques, Examples 2 and 3 employ a superhydrophobic nanofiber anti-humidity layer 21, an anti-humidity + hydrophobic MOF@carbon aerogel main trapping layer 22 / polar-loving Zr-MOF reinforcing layer 23 to collect lung cancer-related nonpolar and polar VOCs under high humidity conditions, targeting both nonpolar and polar spectra. Furthermore, advanced nanomaterials (referring to 21-layer PVDF-HFP electrospun nanofiber membrane / mat, 22-layer ZIF-71@carbon nanotube aerogel scaffold, and 23-layer MOF-808 / UiO-66-OH) with high specific surface area and tunable surface chemistry are used to achieve efficient and selective capture of trace lung cancer biomarkers, VOCs. Meanwhile, Examples 2 and 3 also added 24 layers of DNPH@mesoporous silica / DNPH@amined MOF and 25 layers of Ag nanoparticle modified activated carbon fiber / Ag-MOF composite material. The aldehyde in-situ derivatization layer 24 is used to increase the recovery rate or stability of aldehydes (such as hexanal / nonanal / decanal), and the sulfur-containing selective layer 25 is used to increase the recovery rate of dimethyl sulfide, so as to maintain recovery under high humidity conditions and avoid the influence of water vapor. In the thermal desorption (TD) spectrum, the interference of water peaks is much smaller than that of traditional adsorption tubes.

[0068] Compared with existing technologies, the passive exhaled VOCs collection device and method for lung cancer detection provided by this invention have the following advantages:

[0069] (1) Minimalist structure: No pump or electricity required. The device only uses a fixed-volume collection chamber and manual propulsion to enrich the gas in the terminal alveoli. The device does not contain electronic components, which greatly reduces the cost and makes it easy to operate. It can efficiently and selectively enrich trace amounts of lung cancer-related VOCs (benzene, toluene, ethylbenzene, styrene, isoprene, acetone, 2-butanone, n-propanol, hexanal / nonanal / decanal and dimethyl sulfide) and ensure good repeatability. It is suitable for screening and follow-up scenarios of lung cancer in primary care and community.

[0070] (2) Moisture-resistant broad spectrum: The superhydrophobic nanofiber moisture-resistant layer is moisture-resistant + hydrophobic MOF@carbon aerogel main trapping layer / polar-loving Zr-MOF reinforcing layer targets both non-polar and polar spectra. When necessary, the aldehyde in-situ derivatization layer stabilizes aldehydes, and the sulfur-containing selective layer enhances sulfur content, thus achieving efficient trapping and stable preservation of lung cancer-related non-polar and polar VOCs even under high humidity conditions;

[0071] (3) Low resistance and high capacity are combined: Aerogel stents provide interconnected macroporous channels, which reduce pressure drop while increasing the equivalent filling volume;

[0072] (4) Transportation friendly: The double-ended switching valve provides instant sealing, and the in-situ derivatization layer of aldehydes enhances storage stability;

[0073] (5) Mass production at low cost: general processes such as electrospinning / coating / impregnation-in-situ growth are suitable for roll-to-roll and injection molding scale-up.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A passive exhaled VOCs collection device for lung cancer detection, characterized in that, The device comprises a constant-volume collection cavity and a nanocomposite adsorption cartridge. The constant-volume collection cavity is used to enrich end-stage alveolar air during a single exhalation. One end of the constant-volume collection cavity is connected with a gas collection tube that can communicate with a mouthpiece. The other end of the constant-volume collection cavity is provided with a manual pusher that can push the gas sample in the cavity through the nanocomposite adsorption cartridge. The other end of the constant-volume collection cavity is connected with a gas delivery tube that communicates with the upstream port of the nanocomposite adsorption cartridge. The downstream port of the nanocomposite adsorption cartridge is connected with a gas outlet tube. The gas delivery tube and the gas outlet tube are connected with on-off valves. The nanocomposite adsorption cartridge is filled with, from upstream to downstream, a super-hydrophobic nanofiber moisture-resistant layer, a hydrophobic MOF@carbon aerogel main trapping layer, and a polar Zr-MOF enhancement layer.

2. The passive exhaled VOCs collection device for lung cancer detection according to claim 1, wherein, The nanocomposite adsorption cartridge is further filled, from downstream to upstream, with an aldehyde in-situ derivatization layer and a sulfur-containing selective layer.

3. The passive exhaled breath VOCs collection device for lung cancer detection according to claim 1 or 2, characterized in that, The manual pusher comprises a piston block that is in sealing engagement with the inner wall of the constant-volume collection cavity. The outer end of the piston block is fixedly connected with a piston rod.

4. The passive exhaled VOCs collection device for lung cancer detection according to claim 1 or 2, wherein, The super-hydrophobic nanofiber moisture-resistant layer is made of ePTFE or PVDF-HFP electrospun nanofiber membrane / felt and has a mass of 10-200 mg.

5. The passive exhaled breath VOCs collection device for lung cancer detection according to claim 1 or 2, wherein, The hydrophobic MOF@carbon aerogel main trapping layer adopts a hydrophobic MOF loaded on a graphene / carbon nanotube aerogel support and has a mass of 50-300 mg, the mass ratio of the MOF to the aerogel support is (0.5-2):1, and the specific surface area is greater than or equal to 600 m 2 ·g -1 .

6. The passive breath exhaled VOCs collection device for lung cancer detection according to claim 1 or 2, wherein, The polar Zr-MOF enhancement layer is made of UiO-66-NH2, UiO-66-OH, or MOF-808 moisture-resistant Zr-MOF and has a mass of 50-300 mg.

7. The passive exhaled VOCs collection device for lung cancer detection according to claim 2, wherein, The aldehyde in-situ derivatization layer is made of DNPH@mesoporous silica or aminated MOF and has a mass of 20-150 mg and a DNPH loading of 0.5-5 wt%.

8. The passive exhaled VOCs collection device for lung cancer detection according to claim 2, wherein, The sulfur-containing selective layer is made of Ag nanoparticle modified activated carbon fiber or Ag-MOF composite material and has a mass of 10-150 mg and an Ag loading of 0.1-5 wt%.

9. A passive exhaled VOCs collection method for lung cancer detection, characterized in that, The method uses the passive exhalation VOCs collection device for lung cancer detection according to any one of claims 1-8. The method comprises the following steps: S1. The gas collection tube is connected with the mouthpiece, and the subject performs a deep breath and enriches the end-stage alveolar air in the constant-volume collection cavity. S2. The gas sample in the constant-volume collection cavity is pushed through the nanocomposite adsorption cartridge by the manual pusher within 3-5 s, so that the non-polar and polar VOCs are trapped in the hydrophobic MOF@carbon aerogel main trapping layer and the polar Zr-MOF enhancement layer, respectively, and the aldehydes are in-situ derivatized in the optional aldehyde in-situ derivatization layer. S3. The on-off valves at the upstream and downstream ends of the nanocomposite adsorption cartridge are closed. The nanocomposite adsorption cartridge after sampling can be directly connected with a thermal desorption instrument for thermal desorption or organic solvent desorption analysis.

10. The passive exhaled VOCs collection method for lung cancer detection according to claim 9, wherein, The temperature for thermal desorption is 40-320℃, and the time is 0.5-15 min. The volume of the organic solvent is 0.2-2.0 mL.

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