Room-temperature ammonia gas sensor for helicobacter pylori detection and preparation method

Abstract

The invention relates to a room temperature ammonia gas sensor for helicobacter pylori detection and a preparation method, and belongs to the technical field of helicobacter pylori detection and ammonia gas sensors. The ammonia gas sensor comprises a substrate, a molybdenum disulfide layer, a modified particle layer, a source electrode and a drain electrode, the modified particle layer is located on the surface of the molybdenum disulfide layer, the molybdenum disulfide layer is located on the surface of the substrate, and the source electrode and the drain electrode are located at two ends of the molybdenum disulfide layer. According to the ammonia gas sensor provided by the invention, the problems of high power consumption and low sensitivity of a common gas sensor are solved, a portable and rapid detection technology for helicobacter pylori is provided, and a new reference means is provided for helicobacter pylori drug sensitivity experiments and precise treatment.

Description

Technical Field

[0001] The invention relates to the technical field of Helicobacter pylori detection and ammonia sensors, in particular to a room temperature ammonia sensor for Helicobacter pylori detection and a preparation method thereof. Background Art

[0002] Helicobacter pylori is a Gram-negative, flagellar, spiral bacillus that parasitizes the gastric mucosal epithelium of the human body. More than 50% of the world's population is infected with Helicobacter pylori, and most people are first infected before the age of 10. Helicobacter pylori infection is often asymptomatic in the early stages, so it does not receive due attention and can easily lead to serious diseases such as superficial gastritis, atrophic gastritis, and even gastric cancer. Since 1994, Helicobacter pylori has been listed as a Class I carcinogen associated with the development of gastric cancer by the World Health Organization and the International Agency for Research on Cancer. Eradicating Helicobacter pylori before precancerous lesions occur has been shown to prevent gastric cancer, so the detection technology research and precise treatment plans for Helicobacter pylori are of great clinical significance.

[0003] At present, the detection of Helicobacter pylori is mainly divided into non-invasive detection and invasive detection. Common non-invasive tests include 13 C urea breath test, fecal antigen test, etc., the accuracy of such tests is affected by many factors such as sample source, and it is impossible to observe the actual situation of gastric tissue in real time. All invasive examinations are based on biopsy samples from gastroscopy, such as rapid urease test, bacterial culture, histological examination, etc. Minimally invasive tests bring certain discomfort to patients. Such detection methods are highly accurate but rely on the technical level of the operator and are limited by factors such as the number and location of biopsy samples. In addition, the precise treatment of Helicobacter pylori is affected by factors such as gene type, genetic factors, and drug resistance, and faces many challenges in clinical practice. Therefore, the development of a technology that can efficiently and non-invasively detect Helicobacter pylori has important application significance in the treatment and prevention of Helicobacter pylori infection.

[0004] The urease produced by H. pylori breaks down urea into ammonia and carbon dioxide, allowing H. pylori to survive in low pH environments and further cause disease. By monitoring ammonia production, the presence of active H. pylori bacteria can be precisely located, effectively avoiding any interference caused by non-viable or dead cells.

[0005] Ammonia sensor is a device that measures the charge conversion between ammonia and the sensitive layer to measure the ammonia concentration. It has been widely used in modern society, including but not limited to medical treatment, environmental monitoring, security monitoring, smart home, etc. Existing gas detection sensors are mainly based on metal oxides, conductive polymers, etc., but generally have disadvantages such as high power consumption and poor selectivity. Summary of the invention

[0006] In view of this, the present invention proposes a room-temperature ammonia sensor and a preparation method for Helicobacter pylori detection, which uses molybdenum disulfide as the sensitive layer, can achieve efficient detection at room temperature, and provide a new non-invasive and portable detection method for the existing Helicobacter pylori detection.

[0007] The technical solution adopted by the present invention is:

[0008] A room temperature ammonia sensor for detecting Helicobacter pylori comprises a substrate 1, a molybdenum disulfide layer 2, a modified particle layer 3, a source electrode 4 and a drain electrode 5. The molybdenum disulfide layer 2 is located on the surface of the substrate 1 and covers the source electrode 4 and the drain electrode 5. The source electrode 4 and the drain electrode 5 are on the surface of the substrate 1 and are located at both ends of the molybdenum disulfide layer 2. The modified particle layer 3 covers the surface of the molybdenum disulfide layer 2.

[0009] Furthermore, the substrate 1 is a thermally oxidized silicon wafer or an Al2O3 crystal substrate.

[0010] Furthermore, the molybdenum disulfide layer 2 is obtained by peeling off the bulk material using a mechanical stripping tape, and the fragments have a thickness of less than 20 nm and a length of more than 20 μm.

[0011] Furthermore, the metal particles in the modified particle layer are iron, platinum or ruthenium oxides, which are uniformly sputtered on the surface of the molybdenum disulfide layer 2 by vacuum electron beam evaporation, with a thickness of Within.

[0012] The method for preparing the room temperature ammonia sensor comprises the following steps:

[0013] (1) using an organic solvent to clean a substrate as a substrate;

[0014] (2) performing photolithography on the front side of the cleaned substrate to form an electrode mask pattern;

[0015] (3) performing vacuum electron beam evaporation on the photolithographic substrate to form a titanium electrode on the front side of the substrate;

[0016] (4) using organic solvents such as acetone and isopropyl alcohol to sequentially perform degumming treatment on the substrate after evaporation to remove the photoresist used as a mask;

[0017] (5) using mechanical stripping to obtain a few layers of molybdenum disulfide film from the molybdenum disulfide bulk material using a mechanical stripping tape;

[0018] (6) using a polycarbonate resin film to transfer a few layers of molybdenum disulfide thin film to the electrode channel region of the substrate;

[0019] (7) performing a film removal treatment on the substrate, using organic solvents such as chloroform, acetone, and isopropanol to soak the substrate in sequence to remove the polycarbonate resin film;

[0020] (8) Annealing the substrate to remove organic residues;

[0021] (9) The annealed substrate is subjected to vacuum electron beam evaporation to modify the surface of the molybdenum disulfide film with metal particles to form a modified particle layer.

[0022] Furthermore, in step (2), the electrode channel width of the electrode mask pattern is 15±3 μm.

[0023] Furthermore, in step (3), the speed of vacuum electron beam evaporation is The thickness of the titanium electrode is

[0024] Furthermore, the number of layers of the few-layer molybdenum disulfide film is 1 to 10 layers.

[0025] Furthermore, in step (8), the atmosphere for the annealing treatment is Ar: 200 sccm, H2: 20 sccm, and the annealing treatment conditions are: keeping at 250°C for 2 hours.

[0026] Furthermore, in step (9), ferrous oxide nanoclusters are used to modify metal particles, and the speed of vacuum electron beam evaporation is The thickness of the modified granular layer is

[0027] The beneficial effects of the present invention are:

[0028] 1. The sensor of the present invention is prepared in a semiconductor compatible mode, the preparation process is easy to implement, and the prepared sensor can be directly connected to a processor and a back-end circuit.

[0029] 2. Most existing sensors require high temperatures (hundreds of degrees) to achieve gas sensing, while the sensor of the present invention can achieve continuous detection of ammonia at room temperature.

[0030] 3. The performance of existing ammonia sensors based on molybdenum disulfide is poor and cannot reach the performance of existing high-temperature oxide ammonia sensors. The present invention can greatly improve the sensing performance of molybdenum disulfide for ammonia by performing metal modification on molybdenum disulfide, and even exceed the performance of high-temperature oxide ammonia sensors.

[0031] In summary, the ammonia sensor provided by the present invention solves the problems of high power consumption and low sensitivity of common gas sensors, provides a portable and rapid detection method for Helicobacter pylori, and provides a new reference means for Helicobacter pylori drug sensitivity testing and precision treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1Schematic diagram of the structure of a room temperature ammonia sensor in an embodiment of the present invention.

[0033] Figure 2 Schematic diagram of the preparation process of the room temperature ammonia sensor in an embodiment of the present invention.

[0034] Among them, 1-substrate, 2-molybdenum disulfide layer, 3-modified particle layer, 4-source electrode, 5-drain electrode. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0036] A room temperature ammonia sensor for detecting Helicobacter pylori, such as Figure 1 As shown, it includes a substrate 1, a molybdenum disulfide layer 2, a modified particle layer 3, a source electrode 4 and a drain electrode 5. The molybdenum disulfide layer 2 is located on the surface of the substrate 1 and covers the source electrode 4 and the drain electrode 5. The source electrode 4 and the drain electrode 5 are on the surface of the substrate 1 and are located at both ends of the molybdenum disulfide layer 2. The modified particle layer 3 covers the surface of the molybdenum disulfide layer 2.

[0037] Among them, molybdenum disulfide is obtained by stripping from the molybdenum disulfide bulk material using a mechanical stripping tape, preferably in the form of fragments with a thickness of less than 10 nm and a length of more than 20 μm.

[0038] The modified particles are iron, platinum or ruthenium oxides, which are uniformly sputtered on the surface of molybdenum disulfide by vacuum electron beam evaporation with a thickness of Inside.

[0039] The sensor uses molybdenum disulfide as the sensitive layer and metal-modified molybdenum disulfide. The modified particles can increase the specific surface area of ​​the sensitive layer, obtain more active sites, and enhance the ammonia sensing performance.

[0040] The room temperature ammonia sensor can be prepared using a semiconductor compatible mode. The preparation process is as follows: Figure 2 As shown, the following steps are included:

[0041] (1) using an organic solvent to clean a substrate as a substrate;

[0042] (2) performing photolithography on the front side of the cleaned substrate to form an electrode mask pattern;

[0043] (3) performing vacuum electron beam evaporation on the photolithographic substrate to form a titanium electrode on the front side of the substrate;

[0044] (4) using organic solvents such as acetone and isopropyl alcohol to sequentially perform degumming treatment on the substrate after evaporation to remove the photoresist used as a mask;

[0045] (5) using a mechanical stripping method to strip a few layers of molybdenum disulfide film from the molybdenum disulfide bulk material using a mechanical stripping tape; the number of layers of the few layers of molybdenum disulfide film is 1 to 10;

[0046] (6) using a polycarbonate resin film to transfer a few layers of molybdenum disulfide thin film to the electrode channel region of the substrate;

[0047] (7) performing a film removal treatment on the substrate, using organic solvents such as chloroform, acetone, and isopropanol to soak the substrate in sequence to remove the polycarbonate resin film;

[0048] (8) Annealing the substrate to remove organic residues; the annealing atmosphere is Ar: 200 sccm, H2: 20 sccm, and the annealing conditions are: 250°C for 2 hours;

[0049] (9) The annealed substrate is subjected to vacuum electron beam evaporation, and metal particles are modified on the surface of the molybdenum disulfide film using ferrous oxide nanoclusters. The speed of vacuum electron beam evaporation is A modified granular layer is formed, and the thickness of the modified granular layer is

[0050] In a specific embodiment, the thickness of the molybdenum disulfide layer 2 is 10-50 nanometers.

[0051] The ammonia sensor was tested with an applied voltage of 1V. At room temperature, the linear slope of its ammonia response with ammonia concentration change was 4.93%·ppm. -1 The detection limit is 6.2ppb, the response is 40.9% at 5.7ppm ammonia, the presence of Helicobacter pylori can be detected within 100s, and the ammonia production curve during the 92h Helicobacter pylori growth cycle can be continuously monitored.

[0052] Compared with existing ammonia sensors, the ammonia sensor of the present invention has the characteristics of room temperature monitoring, high sensitivity, and low detection limit, and can achieve continuous and efficient detection of the ammonia production process during the growth cycle of Helicobacter pylori under room temperature conditions.

[0053] In short, the sensor of the present invention solves the problems of high power consumption and low sensitivity of common gas sensors, provides a portable and rapid detection technology for Helicobacter pylori, and provides a new reference means for Helicobacter pylori drug sensitivity test and precision treatment. Compared with the existing Helicobacter pylori detection technology, it can effectively avoid the interference of dead cells, can realize continuous real-time monitoring of the growth cycle of Helicobacter pylori, and has simple operation requirements, lower cost, wider applicability, and higher research and development cost performance.

Claims

1. A room temperature ammonia sensor for Helicobacter pylori detection, It is characterized in that The invention comprises a substrate (1), a molybdenum disulfide layer (2), a modified particle layer (3), a source electrode (4) and a drain electrode (5); the molybdenum disulfide layer (2) is located on the surface of the substrate (1) and covers the source electrode (4) and the drain electrode (5); the source electrode (4) and the drain electrode (5) are on the surface of the substrate (1) and are located at both ends of the molybdenum disulfide layer (2); and the modified particle layer (3) covers the surface of the molybdenum disulfide layer (2).

2. A room temperature ammonia sensor for detecting Helicobacter pylori according to claim 1, It is characterized in that The substrate (1) is a thermally oxidized silicon wafer or an Al 2 O 3 Crystal substrate.

3. A room temperature ammonia sensor for detecting Helicobacter pylori according to claim 1, It is characterized in that The molybdenum disulfide layer (2) is obtained by peeling off the bulk material using a mechanical peeling tape, and is a fragment with a thickness of less than 20 nm and a length of more than 20 μm.

4. A room temperature ammonia sensor for detecting Helicobacter pylori according to claim 1, It is characterized in that The metal particles in the modified particle layer are iron, platinum or ruthenium oxides, which are uniformly sputtered on the surface of the molybdenum disulfide layer (2) by vacuum electron beam evaporation, with a thickness of Within.

5. The method for preparing the room temperature ammonia sensor according to claim 1, It is characterized in that The following steps are involved: (1) using an organic solvent to clean a substrate as a substrate; (2) performing photolithography on the front side of the cleaned substrate to form an electrode mask pattern; (3) performing vacuum electron beam evaporation on the photolithographic substrate to form a titanium electrode on the front side of the substrate; (4) using organic solvents such as acetone and isopropyl alcohol to sequentially perform degumming treatment on the substrate after evaporation to remove the photoresist used as a mask; (5) using mechanical stripping to obtain a few layers of molybdenum disulfide film from the molybdenum disulfide bulk material using a mechanical stripping tape; (6) using a polycarbonate resin film to transfer a few layers of molybdenum disulfide thin film to the electrode channel region of the substrate; (7) performing a film removal treatment on the substrate, using organic solvents such as chloroform, acetone, and isopropanol to soak the substrate in sequence to remove the polycarbonate resin film; (8) Annealing the substrate to remove organic residues; (9) The annealed substrate is subjected to vacuum electron beam evaporation to modify the surface of the molybdenum disulfide film with metal particles to form a modified particle layer.

6. The preparation method according to claim 5, It is characterized in that In step (2), the electrode channel width of the electrode mask pattern is 15±3 μm.

7. The preparation method according to claim 5, It is characterized in that In step (3), the speed of vacuum electron beam evaporation is The thickness of the titanium electrode is 8. The preparation method according to claim 5, It is characterized in that The number of layers of the few-layer molybdenum disulfide film is 1 to 10 layers.

9. The preparation method according to claim 5, It is characterized in that In step (8), the annealing atmosphere is Ar: 200 sccm, H 2 : 20sccm, annealing conditions: 250℃ for 2 hours.

10. The preparation method according to claim 5, It is characterized in that In step (9), ferrous oxide nanoclusters are used to modify metal particles, and the speed of vacuum electron beam evaporation is The thickness of the modified granular layer is

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