CN112940927A

CN112940927A - System and method for detecting air tubercle bacillus

Info

Publication number: CN112940927A
Application number: CN202110390800.9A
Authority: CN
Inventors: 王灿; 马金标; 杜漫漫
Original assignee: Tianjin University
Current assignee: Tianjin University
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2021-06-11

Abstract

The invention provides a system and a method for detecting air tubercle bacillus, which comprises a condensing device, a peristaltic pump, a switching valve, a micro-fluidic chip and a signal display device electrically connected with the micro-fluidic chip which are sequentially communicated through a pipeline.

Description

System and method for detecting air tubercle bacillus

Technical Field

The invention belongs to the field of environmental monitoring, and particularly relates to a system and a method for detecting air tubercle bacillus.

Background

Airborne respiratory infections frequently occur and are rapidly and widely spread worldwide. Among them, tuberculosis has a high morbidity and mortality rate, and is a chronic infectious disease mainly transmitted through the respiratory tract. China is one of three countries with the highest burden in the world, 83.3 thousands of new tuberculosis cases exist in 2019, and 33,000 tuberculosis deaths occur. And 360 million tuberculosis patients are missed by the sanitation system every year. Worse yet, the modeling and analysis of the world health organization indicates that the pandemic of new coronary pneumonia seriously undermines public health services. During the period of 2020 to 2025, it may cause 630 million new cases of tuberculosis worldwide. Therefore, tuberculosis remains a not negligible public health problem.

Rapid and accurate detection is the basis for tuberculosis control. Bacteriological tests account for 80% of tuberculosis diagnoses. Tuberculosis is mostly transmitted from person to person by carrying a droplet or aerosol of mycobacterium tuberculosis. However, tubercle bacillus has strong resistance to severe environments and can survive in the air for a long time. At present, the conventional detection methods of the tubercle bacillus mainly comprise a culture method, imaging detection, sputum smear microscopy, tuberculin sensitivity test, serological detection, molecular diagnosis and the like. Most of these techniques are complex, time consuming, sensitive and operationally demanding, thus limiting their use outside the laboratory. In addition, the concentration of tubercle bacillus in the air is extremely low and impurities can cause interference, and the tubercle bacillus is difficult to effectively detect.

Various sensors have been developed for a wide range of fields. Its applicability in the detection of mycobacterium tuberculosis still faces many challenges. One of the challenges is that most of samples detected by the current sensors are liquid samples, and direct collection of air samples for detection is rare. Another is that sensor detection is often performed by drip methods, which makes sample loading and handling difficult to control. This method is susceptible to interference from external physical factors (e.g., light, humidity and temperature), resulting in inaccurate measurements and poor sensing stability. Microfluidic technology integrates sample preparation, reagent manipulation, biological reactions and detection steps into a unique platform, simplifying complex analysis protocols and reducing sample size, detection time and reagent costs. In order to improve the detection efficiency of the biosensor and the portability of outdoor operations, it is required to simultaneously detect a plurality of samples or a plurality of target microorganisms to improve the practicality and flexibility. Therefore, a new method for rapidly detecting mycobacterium tuberculosis aerium is needed in the art.

Disclosure of Invention

In view of this, the present invention is directed to a system and a method for detecting mycobacterium tuberculosis, so as to sample gas, continuously detect a plurality of samples, simplify a complicated analysis scheme, and reduce the amount of samples, the detection time, and the reagent cost.

In order to achieve the purpose, the technical scheme of the invention is realized as follows:

a system for detecting air tubercle bacillus comprises a condensing unit, a peristaltic pump, a switching valve, a microfluidic chip and a signal display unit electrically connected with the microfluidic chip which are sequentially communicated through a pipeline,

the condensing device is used for condensing the exhaled breath into a liquid sample,

the peristaltic pump is used for conveying the liquid sample to the microfluidic chip through the switching valve,

the micro-fluidic chip is used for sending the detection signal to the signal display device.

Preferably, condensing equipment includes the insulation can, locates the condensation box in the insulation can and fills in the condensate solution of insulation can between the condensation box, condensation box both ends are equipped with air inlet and gas outlet, and crisscross a plurality of guide plates that are provided with about being in the condensation box, and condensation box bottom is equipped with gathers the mouth.

Preferably, the bottom of the condensation box is provided with a flow guide wall for guiding the liquid sample to the collection port.

Preferably, the microfluidic chip comprises a shell, a sensor packaged in the shell and a plurality of external round tubes arranged on the shell, wherein a liquid flow channel shaped like a Chinese character 'mi' is arranged in the shell, and the external round tubes are communicated with the liquid flow channel.

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

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

Preferably, a plurality of check valves are provided in the switching valve.

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

A detection method using the system for detecting the tubercle bacillus air as described in any one of the above, comprising the following steps:

and the gas to be detected enters the condensing device through the gas 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.

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

Compared with the prior art, the system and the method for detecting the air tubercle bacillus have the following advantages:

(1) the system for detecting the air tubercle bacillus integrates expired air collection, sample preparation, microfluidic multichannel sample introduction, biological reaction and sensor detection, and feeds back in time through real-time signal detection;

(2) the system for detecting the tubercle bacillus can simplify a complex analysis scheme and reduce the sample amount, the detection time and the reagent cost;

(3) the system for detecting the tubercle bacillus air can continuously detect a plurality of samples, improves the detection efficiency of the tubercle bacillus air and the portability of outdoor operation, and is expected to play a role in primary screening in a tubercle hotspot area.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic structural diagram of a system for detecting M.aerobacter according to an embodiment of the present invention;

FIG. 2 is a graph showing normalized responses of the detection of simulated exhaled breath of Mycobacterium tuberculosis according to the embodiment of the present invention.

Description of reference numerals:

1. a condensing unit; 11. a condensing box; 12. an air inlet; 13. an air outlet; 14. a baffle; 15. a flow guide wall; 16. a collection port; 17. condensing the salt solution; 18. a heat preservation box body; 2. a peristaltic pump; 3. a switching valve; 31. a one-way valve; 4. a microfluidic chip; 41. a housing; 42. a sensor; 43. a liquid flow passage; 44. an external round pipe; 5. and a signal display device.

Detailed Description

Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill 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 are conventional methods unless otherwise specified.

The present invention will be described in detail with reference to the following examples and accompanying drawings.

As shown in figure 1, the system for detecting air tubercle bacillus of the present invention comprises a condensing unit 1, a peristaltic pump 2, a switching valve 3, a microfluidic chip 4 and a signal display unit 5 electrically connected with the microfluidic chip 4 which are sequentially communicated through a pipeline,

the condensation device 1 is used for condensing exhaled breath into a liquid sample,

the peristaltic pump 2 is used to deliver a liquid sample to the microfluidic chip 4 through the switching valve 3,

the micro-fluidic chip 4 generates a detection signal under the action of the liquid sample and sends the detection signal to the signal display device 5.

Preferably, the condensing device 1 comprises a heat preservation box 18, a condensation box 11 arranged in the heat preservation box 18 and a condensate solution 17 filled between the heat preservation box 18 and the condensation box 11, wherein the two ends of the condensation box 11 are provided with an air inlet 12 and an air outlet 13, a plurality of guide plates 14 are arranged in the condensation box 11 in a left-right staggered manner, one end of each guide plate 14 is fixedly connected with the condensation box 11, a gap for air to pass through is reserved between the other end of each guide plate and the side wall of the condensation box 11, the guide plates 14 are arranged in a left-right staggered manner, the air moves forwards along an S-shaped route in the condensation box 11, the bottom of the condensation box 11 is provided with a guide wall 15 for guiding the liquid sample to the collection port 16, the bottom of the condensation box 11 is provided with a collection port 16, the air is condensed into the liquid sample under the cooling effect of the condensate solution 17 in the forward movement process in the condensation box, flows downwards along the diversion plate 14 or the diversion wall 15, is collected at the bottom of the condensation box 11 and is discharged from the collection port 16.

The preparation steps of the microfluidic chip 4 are as follows: firstly, the sensor 42 is packaged with the shell 41 through ultraviolet curable UV glue, the shell 41 is made of PMMA plastic, ultraviolet light is irradiated for 5min for curing, the sensor 42 used in the embodiment is a silicon nanowire field effect tube sensor, then the whole liquid path system is connected, an external round tube 44 is communicated with a liquid flow channel 43 in the shell 41, the liquid flow channel 43 is in a shape of a Chinese character mi, the width of the liquid flow channel is 0.5mm, the external round tube 44 and the end point of the liquid flow channel 43 are correspondingly distributed in a shape of Chinese character mi, the external round tube 44 in the embodiment is provided with 8, 7 of the external round tube are liquid inlets, 1 is a liquid outlet, liquid samples to be detected can enter from different liquid inlets in sequence, the sensor triggers the sensor to detect the liquid samples to be detected, the liquid samples are finally discharged from the liquid outlets, and.

When the device is used, the condensing device 1, the peristaltic pump 2, the switching valve 3 and the microfluidic chip 4 are sequentially communicated through a pipeline, the switching valve 3 is provided with 1 liquid inlet and 7 one-way valves 31 respectively communicated with the liquid inlet, a sample obtained by the peristaltic pump 2 can be selectively sucked into a liquid flow channel to ensure that a liquid path does not return, the one-way valves 31 are correspondingly communicated with the 7 liquid inlets on the microfluidic chip 4 one by one, the microfluidic chip 4 is connected with a signal display device 5, the signal display device 5 used in the embodiment is a Keithley 2400 semiconductor parameter analyzer, the embodiment uses tubercle simulant tubercle bacillus secretion protein to volatilize aerosol, volatilized gas enters the gas inlet 12 through the pipeline, moves forwards along the gas flow channel in the condensing device 1 until the volatilized gas is discharged from the gas outlet 13, the volatilized gas is condensed into a liquid sample under the action of the condensing device 1 and is collected at the bottom of the condensing, at the moment, the switching valve 3 and the signal display device 5 are opened, the peristaltic pump 2 is started, the liquid sample is injected into the microfluidic chip 4, the flow rate of the peristaltic pump is 0.3ml/min, a signal processing module in the signal display device 5 reads and processes an electrochemical signal generated by the sensor 42 and displays the electrochemical signal on a display, a constant voltage of 0.5V is added between a source electrode and a drain electrode of the sensor 42 in the detection process, and the target current is monitored in real time in the whole process. The normalized current response result is shown in fig. 2, which proves that the system and the method for detecting the mycobacterium tuberculosis can rapidly detect the mycobacterium tuberculosis.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A system for detecting air tubercle bacillus is characterized in that: comprises a condensing device, a peristaltic pump, a switching valve, a micro-fluidic chip and a signal display device which is electrically connected with the micro-fluidic chip, wherein the condensing device, the peristaltic pump, the switching valve and the micro-fluidic chip are sequentially communicated through a pipeline,

2. The system for detecting mycobacterium tuberculosis air, according to claim 1, wherein: condensing equipment includes the insulation can, locates the condensation box in the insulation can and fills in the condensate solution of insulation can between the condensation box, condensation box both ends are equipped with air inlet and gas outlet, and crisscross a plurality of guide plates that are provided with about being in the condensation box, and condensation box bottom is equipped with gathers the mouth.

3. The system for detecting mycobacterium tuberculosis as claimed in claim 2, wherein: and a flow guide wall for guiding the liquid sample to the collection port is arranged at the bottom of the condensation box.

4. The system for detecting mycobacterium tuberculosis air, according to claim 1, wherein: the micro-fluidic chip comprises a shell, a sensor packaged in the shell and a plurality of external round tubes arranged on the shell, wherein a liquid flow passage in a shape like a Chinese character mi is arranged in the shell, and the external round tubes are communicated with the liquid flow passage.

5. The system for detecting mycobacterium tuberculosis air, according to claim 4, wherein: the width of the liquid flow channel is 0.5 mm.

6. The system for detecting mycobacterium tuberculosis air, according to claim 4, wherein: the sensor is a silicon nanowire field effect transistor sensor.

7. The system for detecting mycobacterium tuberculosis air, according to claim 1, wherein: a plurality of one-way valves are arranged in the switching valve.

8. The system for detecting mycobacterium tuberculosis air, according to claim 1, wherein: the signal display device comprises a display and a signal processing module.

9. A detection method using the system for detecting mycobacterium tuberculosis as set forth in any one of claims 1 to 8, comprising the steps of:

10. The method for detecting a system for detecting mycobacterium tuberculosis as claimed in claim 9, wherein: the flow rate of the peristaltic pump was 0.3 ml/min.