A system for detecting airborne tuberculosis bacilli

Abstract

The present invention provides a system for detecting airborne tuberculosis bacilli, comprising a condensing device, a peristaltic pump, a switching valve, a microfluidic chip and a signal display device electrically connected to the microfluidic chip, which are sequentially connected through pipelines. The system for detecting airborne tuberculosis bacilli described in the present invention integrates exhaled breath collection, sample preparation, microfluidic multi-channel sampling, biological reaction and sensor detection. Through real-time signal detection and timely feedback, complex analysis schemes can be simplified and sample quantity, detection time and reagent cost can be reduced. At the same time, multiple samples can be continuously detected, thereby improving the efficiency of airborne tuberculosis detection and the portability of outdoor operation, and is expected to play a role in preliminary screening in tuberculosis hotspots.

Description

Technical Field

[0001] The invention belongs to the field of environmental monitoring, and in particular relates to a system for detecting airborne tuberculosis bacilli. Background Art

[0002] Airborne respiratory infectious diseases frequently break out and spread rapidly and widely around the world. Among them, tuberculosis has a high morbidity and mortality rate and is a chronic infectious disease mainly transmitted through the respiratory tract. To make matters worse, WHO modeling and analysis show that the COVID-19 pandemic has severely undermined public health services. It may cause 6.3 million new cases of tuberculosis worldwide between 2020 and 2025. Therefore, tuberculosis remains a public health issue that cannot be ignored.

[0003] Rapid and accurate detection is the basis of tuberculosis control. Bacteriological detection accounts for 80% of tuberculosis diagnosis. Tuberculosis is mostly transmitted from person to person through droplets or aerosols carrying Mycobacterium tuberculosis. However, Mycobacterium tuberculosis has a strong ability to resist harsh environments and can survive in the air for a long time. At present, the conventional detection methods for Mycobacterium tuberculosis mainly include culture method, imaging detection, sputum smear microscopy, tuberculin sensitivity test, serological detection and molecular diagnosis. Most of these technologies are complex, time-consuming, low in sensitivity and high in operation requirements, which limits their application outside the laboratory. In addition, the concentration of Mycobacterium tuberculosis in the air is extremely low and impurities will cause interference, making it difficult to effectively detect Mycobacterium tuberculosis.

[0004] Various sensors have been developed for use in a wide range of fields. However, their applicability in the detection of Mycobacterium tuberculosis still faces many challenges. One of the challenges is that the samples currently detected by sensors are mostly liquid samples, and it is relatively rare to directly collect air samples for detection. Another is that sensor detection mostly uses the drip method for detection, which makes the loading and handling of samples difficult to control. This method is easily disturbed by external physical factors (such as light, humidity and temperature), resulting in inaccurate measurements and poor sensing stability. Microfluidic technology integrates sample preparation, reagent operation, biological reaction and detection steps on a unique platform, which can simplify complex analysis schemes and reduce sample volume, detection time and reagent costs. In order to improve the detection efficiency of biosensors and the portability of outdoor operations, it is necessary to detect multiple samples or multiple target microorganisms at the same time to improve practicality and flexibility. Therefore, there is an urgent need for a new method for rapid detection of airborne Mycobacterium tuberculosis in this field. Summary of the invention

[0005] In view of this, the present invention aims to propose a system and method for detecting airborne tuberculosis bacteria, so as to realize gas sampling, continuously detect multiple samples at the same time, simplify complex analysis schemes and reduce sample quantity, detection time and reagent costs.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A system for detecting tuberculosis bacilli in the air comprises a condensing device, a peristaltic pump, a switching valve, a microfluidic chip and a signal display device electrically connected to the microfluidic chip, which are sequentially connected through a pipeline.

[0008] The condensation device is used to condense the exhaled breath into a liquid sample.

[0009] The peristaltic pump is used to transport the liquid sample to the microfluidic chip through the switching valve.

[0010] The microfluidic chip is used to send the detection signal to the signal display device.

[0011] Preferably, the condensation device includes an insulation box, a condensation box arranged in the insulation box, and a condensation salt solution filled between the insulation box and the condensation box, an air inlet and an air outlet are provided at both ends of the condensation box, a plurality of guide plates are staggered left and right in the condensation box, and a collection port is provided at the bottom of the condensation box.

[0012] Preferably, a guide wall for guiding the liquid sample to the collection port is provided at the bottom of the condensation box.

[0013] Preferably, the microfluidic chip comprises a shell, a sensor encapsulated in the shell, and a plurality of external circular tubes arranged on the shell, a 'M'-shaped liquid flow channel is arranged in the shell, and the external circular tubes are connected to the liquid flow channel.

[0014] Preferably, the width of the liquid flow channel is 0.5 mm.

[0015] Preferably, the sensor is a silicon nanowire field effect transistor sensor.

[0016] Preferably, a plurality of one-way valves are provided in the switching valve.

[0017] Preferably, the signal display device includes a display and a signal processing module.

[0018] A detection method using any of the above-described systems for detecting airborne tuberculosis bacteria comprises the following steps:

[0019] The gas to be tested enters the condensation device through the air inlet to obtain a liquid sample, the switching valve and the signal display device are opened, the peristaltic pump is started, and the liquid sample is introduced into the microfluidic chip.

[0020] Preferably, the flow rate of the peristaltic pump is 0.3 ml / min.

[0021] Compared with the prior art, the system and method for detecting airborne tuberculosis bacteria of the present invention have the following advantages:

[0022] (1) The system for detecting airborne tuberculosis bacteria of the present invention integrates exhaled breath collection, sample preparation, microfluidic multi-channel sampling, biological reaction and sensor detection, and provides timely feedback through real-time signal detection;

[0023] (2) The system for detecting airborne tuberculosis bacteria of the present invention can simplify complex analytical schemes and reduce sample volume, detection time, and reagent costs;

[0024] (3) The system for detecting airborne tuberculosis bacteria described in the present invention can continuously detect multiple samples at the same time, thereby improving the efficiency of airborne tuberculosis detection and the portability of outdoor operations, and is expected to play a role in preliminary screening in tuberculosis hotspots. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 This is a schematic diagram of the structure of a system for detecting airborne tuberculosis bacteria according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the normalized response for detecting simulated exhaled breath of Mycobacterium tuberculosis according to an embodiment of the present invention.

[0028] Description of reference numerals:

[0029] 1. Condensation device; 11. Condensation box; 12. Air inlet; 13. Air outlet; 14. Guide plate; 15. Guide wall; 16. Collection port; 17. Condensed salt solution; 18. Insulation box; 2. Peristaltic pump; 3. Switching valve; 31. One-way valve; 4. Microfluidic chip; 41. Shell; 42. Sensor; 43. Liquid flow channel; 44. External circular tube; 5. Signal display device. DETAILED DESCRIPTION

[0030] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods, unless otherwise specified, are all conventional methods.

[0031] The present invention will be described in detail below with reference to the embodiments and the accompanying drawings.

[0032] like Figure 1As shown, the system for detecting airborne tuberculosis bacilli of the present invention comprises a condensation device 1, a peristaltic pump 2, a switching valve 3, a microfluidic chip 4 and a signal display device 5 electrically connected to the microfluidic chip 4, which are sequentially connected through pipelines.

[0033] The condensation device 1 is used to condense the exhaled breath into a liquid sample.

[0034] The peristaltic pump 2 is used to transport the liquid sample to the microfluidic chip 4 through the switching valve 3.

[0035] The microfluidic chip 4 generates a detection signal under the action of the liquid sample and sends the detection signal to the signal display device 5 .

[0036] Preferably, the condensing device 1 comprises an insulation box 18, a condensing box 11 arranged in the insulation box 18, and a condensing salt solution 17 filled between the insulation box 18 and the condensing box 11. The condensing box 11 is provided with an air inlet 12 and an air outlet 13 at both ends. A plurality of guide plates 14 are staggered left and right in the condensing box 11. One end of the guide plate 14 is fixedly connected to the condensing box 11, and a gap for gas to pass through is left between the other end and the side wall of the condensing box 11. Since the guide plates 14 are staggered left and right, the air inlet 12 and the air outlet 13 are arranged at the ends of the condensing box 11. It is arranged that the gas moves forward along an S-shaped route in the condensation box 11, and a guide wall 15 for guiding the liquid sample to the collection port 16 is provided at the bottom of the condensation box 11. The collection port 16 is provided at the bottom of the condensation box 11. During the forward movement of the gas in the condensation box 11, the gas is cooled by the condensation salt solution 17 and condensed into a liquid sample, which adheres to the guide plate 14 or the guide wall 15, flows downward along the guide plate 14 or the guide wall 15, is collected at the bottom of the condensation box 11, and is discharged outward from the collection port 16.

[0037] The preparation steps of the microfluidic chip 4 are as follows: first, the sensor 42 is encapsulated with the shell 41 through ultraviolet curable UV glue. The shell 41 is made of PMMA plastic and is cured by ultraviolet light irradiation for 5 minutes. The sensor 42 used in this embodiment is a silicon nanowire field effect tube sensor. Then the entire liquid path system is connected, and the external circular tube 44 is connected to the liquid flow channel 43 in the shell 41. The liquid flow channel 43 is in a cross shape with a width of 0.5 mm. The end points of the external circular tube 44 and the liquid flow channel 43 are distributed in a cross shape. In this embodiment, 8 external circular tubes 44 are provided, 7 of which are liquid inlets and 1 is a liquid outlet. The liquid samples to be tested can enter from different liquid inlets in turn, and the sensor triggers the sensor to detect the liquid sample to be tested, and finally it is discharged from the liquid outlet. Multiple samples can be detected simultaneously.

[0038] When in use, the condensation device 1, the peristaltic pump 2, the switching valve 3, and the microfluidic chip 4 are connected in sequence through the pipeline. In this embodiment, the switching valve 3 is provided with a liquid inlet and 7 one-way valves 31 respectively connected to the liquid inlet, and the sample obtained by the peristaltic pump 2 can be selectively sucked into the liquid flow channel to ensure that the liquid path does not flow back. The one-way valve 31 is connected to the 7 liquid inlets on the microfluidic chip 4 in a one-to-one correspondence. The microfluidic chip 4 is connected to the signal display device 5. The signal display device 5 used in this embodiment is a Keithley2400 semiconductor parameter analyzer. In this embodiment, a tuberculosis simulant, a secretory protein of Mycobacterium tuberculosis, is used for aerosol volatilization, and the volatile gas passes through the tube The liquid enters the air inlet 12 through the channel, moves forward along the gas flow channel in the condensation device 1 until it is discharged from the air outlet 13. The volatile gas condenses into a liquid sample under the action of the condensation device 1 and is collected at the bottom of the condensation box 11. At this time, the switching valve 3 and the signal display device 5 are opened, the peristaltic pump 2 is started, and the liquid sample is injected into the microfluidic chip 4. The flow rate of the peristaltic pump is 0.3ml / min. The signal processing module in the signal display device 5 reads and processes the electrochemical signal generated by the sensor 42 and displays it on the display. During the detection process, a constant voltage of 0.5V is added between the source and drain of the sensor 42. The target current is monitored in real time during the whole process. The normalized current response result is shown in Figure 2 As shown, it is proved that the system and method for detecting airborne tuberculosis bacilli of the present invention can perform rapid detection of airborne tuberculosis bacilli.

[0039] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A system for detecting airborne tuberculosis bacilli, characterized in that: The device comprises a condensing device, a peristaltic pump, a switching valve, a microfluidic chip and a signal display device electrically connected to the microfluidic chip, which are sequentially connected through pipelines. The condensation device is used to condense the exhaled breath into a liquid sample. The peristaltic pump is used to transport the liquid sample to the microfluidic chip through the switching valve. The microfluidic chip is used to send the detection signal to the signal display device; The condensation device comprises a heat preservation box, a condensation box arranged in the heat preservation box, and a condensation salt solution filled between the heat preservation box and the condensation box, an air inlet and an air outlet are arranged at both ends of the condensation box, a plurality of guide plates are arranged in a left-right staggered manner in the condensation box, and a collection port is arranged at the bottom of the condensation box; The microfluidic chip includes a shell, a sensor encapsulated in the shell and a plurality of external circular tubes arranged on the shell. A '-shaped liquid flow channel is arranged in the shell, and the external circular tube is connected to the liquid flow channel. The sensor is a silicon nanowire field effect tube sensor.

2. The system for detecting airborne tuberculosis bacilli according to claim 1, characterized in that: A guide wall for guiding the liquid sample to the collection port is provided at the bottom of the condensation box.

3. The system for detecting airborne tuberculosis bacilli according to claim 1, characterized in that: The width of the liquid flow channel is 0.5 mm.

4. The system for detecting airborne tuberculosis bacilli according to claim 1, characterized in that: A plurality of one-way valves are arranged in the switching valve.

5. The system for detecting airborne tuberculosis bacilli according to claim 1, characterized in that: The signal display device includes a display and a signal processing module.

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