KR101709626B1 - Gas sensor for selectively sensing NO and method for fabricating the same - Google Patents

Abstract

The present invention relates to a gas sensor for selectively sensing nitrogen monoxide and a method of manufacturing the same. The gas sensor senses nitrogen monoxide selectively and comprises at least one gas sensing area on a substrate, wherein the gas sensing area comprises an amino compound and a carbon nanotube. According to the present invention, it is possible to provide a gas sensor which can operate at room temperature by using an amino compound and a carbon nanotube as a sensing material, and can detect a low concentration NO gas with high sensitivity, and a method of manufacturing the same.

Description

[0001] The present invention relates to a gas sensor for selectively sensing nitrogen monoxide and a method for manufacturing the same,

The present invention relates to a gas sensor and a manufacturing method thereof, and more particularly, to a gas sensor for selectively sensing nitrogen monoxide by using an amino compound and a carbon nanotube as a sensing material, and a manufacturing method thereof.

Recently, research on disease diagnosis using the analysis of human expiration has been continuously increasing. This method is noninvasive and can be easily applied to infants and elderly people because it does not cause pain and infection like blood sampling. It has a relatively short diagnostic time and has a great advantage of being able to monitor our health condition from time to time in everyday life .

There are about 3 million alveoli in the lungs of the human body and they are surrounded by a very thin capillary network so that the carbon dioxide (CO ₂ ) in the blood and the oxygen (O ₂ ) in the air can be easily transmitted through diffusion. This unique structure causes interdiffusion between the blood and the air over an average surface area of 70 m ² in the normal adult lungs. Blood contains chemicals that reflect the physiological phenomena and metabolic states that occur in the human body. Of these, compounds with low molecular weight are included in the respiratory gas component through the lungs during the breathing process and are discharged outside the human body. There are various volatile organic compounds (VOCs) that reflect the state of health of the human body. Respiratory gases related to the disease include nitrogen monoxide (NO), carbon monoxide (CO), hydrogen peroxide (H ₂ O ₂ ), acetone and hydrocarbon-based VOCs such as benzene and toluene. Recently, a number of studies have been reported on the diagnostic applications of respiratory gas analysis in relation to many diseases including asthma, chronic obstructive disease, lung cancer and pulmonary tuberculosis.

In particular, nitrogen monoxide (NO) is associated with various biological functions such as peripheral blood flow, platelet function, immune response, neurotransmission, and inflammatory mediators. NO is used as a biomarker to diagnose asthma and chronic obstructive disease because it is expressed in patients with bronchial inflammation such as asthma and chronic obstructive disease (COPD) at a higher concentration than normal. The incidence of COPD and asthma is increasing every year, and CODP is the fourth leading cause of death worldwide. In addition, since the above two diseases have chronic disease characteristics, a medical device which can easily diagnose anyone at the early stage of the onset is needed.

Conventional sensor for detecting NO gas has a problem in that it is operated by an electric chemical formula, has a high product price, and has a very high maintenance cost. Therefore, it was impossible to detect the disease early unless visiting a hospital specializing in the disease.

Therefore, a semiconductor type gas sensor using metal oxide as a sensing material can be manufactured inexpensively in a small size, and has been extensively studied because of its many advantages such as high sensitivity and high response speed as well as high stability at high temperature. For example, a semiconductor sensor has been reported in which an amine gas is treated on a tin dioxide (SnO ₂ ) nanowire to detect NO gas. However, in the case of the semiconductor sensor, the sensor has a low sensitivity of about 6% in the case of 2 ppm NO gas, and is not suitable for selectively detecting only NO gas in human breath. In addition, in the case of a semiconductor type gas sensor using a metal oxide, generally, in order to increase the sensitivity and response characteristics due to the surface reaction between the reaction gas and the sensing body, it is required to operate at a high temperature of 200 to 600 ° C, .

Therefore, carbon nanotubes, which have the advantage of being able to operate at room temperature and have a high sensitivity when the sensitivity is high, are attracting attention as a sensing material.

As a conventional method, a nanocomposite layer (MWCNT-PTTCA) composed of a polythiophene polymer (PTTCA) and a multi-walled carbon nanotube (MWCNT) is disclosed in Patent Document 1 (Japanese Patent Laid-Open Publication No. 10-2012-0103911) Discloses a biosensor having an enzyme layer immobilized on its surface with an enzyme such as acroperoxidase (MP), catalase (CAS), and superoxide dismutase (SOD). Patent Document 1 discloses that the above-mentioned enzyme layer can avoid the interference effect by other factors such as hydrogen peroxide and superoxide, so that the selectivity to NO detection is high, and that low concentration of NO can be sensitively detected. However, the sensor manufactured by the above method has an optimum analysis condition (pH 4, temperature 25 ° C) for NO detection, and the current reaction of NO is reduced when the sensor is released. That is, there is a disadvantage in that the analysis conditions such as the pH concentration and the temperature are limited in the detection of the NO gas.

KR 10-2012-0103911 A

A problem to be solved by the present invention is to provide a gas sensor capable of operating at room temperature and capable of selectively sensing a low concentration of NO gas without being restricted by analysis conditions such as pH concentration and temperature and a manufacturing method thereof .

Another problem to be solved by the present invention is to provide a gas sensor having improved quantity and uniformity of a sensing substance adsorbed on a substrate and a method of manufacturing the same.

According to an aspect of the present invention, there is provided a gas sensor including at least one gas sensing area on a substrate, wherein the gas sensing area includes an amino compound and a carbon nanotube. A gas sensor is provided.

Preferably, the amino compound includes aminosilane, more preferably the aminosilane is 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3-aminopropyltri 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and (N, N-dimethylaminopropyl) trimethoxysilane (hereinafter referred to as " (N, N-dimethylaminopropyl) trimethoxysilane).

The gas sensing region may be formed of a plurality of layers, and the plurality of layers may include at least one of a carbon nanotube layer (hereinafter referred to as a "carbon nanotube layer") and at least one of upper and lower layers of the carbon nanotube layer (Hereinafter referred to as "aminosilane layer") located in a layer of an aminosilane. Preferably, the plurality of layers comprises a layer comprising APTES (hereinafter referred to as "APTES layer") formed on the substrate, a carbon nanotube layer formed on the APTES layer, and an en- APTAS layer (hereinafter referred to as "en-APTAS layer").

The present invention also provides a method of manufacturing a gas sensor comprising adsorbing carbon nanotubes on a substrate, the method further comprising adsorbing the amino compound to at least one of the steps before and after adsorbing the carbon nanotube A method of manufacturing a gas sensor for selectively sensing nitrogen monoxide is provided.

According to the present invention, there is provided a gas sensor capable of operating at room temperature by using an amino compound and a carbon nanotube as a sensing material, capable of detecting low concentration NO gas at a high sensitivity, .

According to the present invention, there is provided a gas sensor having a high detection amount and uniformity of a sensing material on a substrate, thereby providing a gas sensor capable of stably detecting NO gas, and also improving the production yield and performance of a gas sensor .

1 is a schematic view schematically showing a shape in which NO molecules are adsorbed on a gas sensor according to an embodiment of the present invention.
Fig. 2 is an enlarged sectional view of the portion I in Fig. 1. Fig.
3 is a schematic view schematically showing a manufacturing process of a gas sensor according to an embodiment of the present invention.
FIG. 4 is a SEM photograph showing a case where carbon nanotubes are adsorbed on a substrate to which APTES is not adsorbed (left), and carbon nanotubes are adsorbed after adsorbing APTES on a substrate (right).
5 and 6 are graphs showing surface analysis results of X-ray photoelectron spectroscopy (XPS) after adsorbing en-APTAS on a substrate on which carbon nanotubes are adsorbed.
7 is a graph showing the adsorption amount of en-APTAS according to the adsorption time.
8 is a schematic diagram showing one embodiment of a manufacturing process for manufacturing a gas sensor using a substrate on which a sensing material is adsorbed.
9 is an atomic force microscope (AFM) in which the extent to which carbon nanotubes are etched according to electric power for generating oxygen plasma in a dry etching process of the manufacturing process shown in FIG. 8, ) It is a photograph.
10 is a graph showing resistance values measured over time when 2 ppm nitrogen monoxide (NO) gas is applied to the gas sensor manufactured according to the embodiment.

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings. It will be apparent to those skilled in the art that the following embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is not.

The present invention relates to a gas sensor comprising at least one gas sensing area on a substrate, wherein the gas sensing area comprises an amino compound and a carbon nanotube.

FIG. 1 is a schematic view schematically showing a shape in which NO molecules are adsorbed to a gas sensor according to an embodiment of the present invention, and FIG. 2 is an enlarged cross-sectional view of part I of FIG.

The material used for the substrate may include, but is not limited to, III-V compound semiconductor such as Si, GaAs, InP, InGaAs, glass, oxide thin film, dielectric thin film, metal thin film and the like. Preferably, the substrate may include a silicon substrate, and more preferably, a silicon substrate having an insulating film formed on a surface thereof. For example, the substrate may be a silicon substrate having a silicon oxide film (SiO ₂ ) formed on its surface, as shown in FIG.

In the present invention, carbon nanotubes (CNTs) and amino compounds are used as sensing materials. When a carbon nanotube that is not an oxide is used as the sensing material, a gas sensor capable of operating at room temperature can be provided. Carbon nanotubes are graphite plates of a hexagonal honeycomb structure that are dried in a straw shape and can have a single wall, a double wall, or multiple walls. The carbon nanotubes may have electrically conductive or semi-conductive properties depending on the drying direction. The carbon nanotube preferably includes a single-walled carbon nanotube (SWCNT). This is because single-walled carbon nanotubes exhibit superior performance in terms of sensitivity and reaction rate as compared with multi-walled carbon nanotubes.

Further, the present invention provides a highly sensitive gas sensor that sensitively reacts with a very small amount of NO gas by using an amino compound together with the carbon nanotube as a sensing material. Preferably, the amino compound includes aminosilane, more preferably the aminosilane is 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3-aminopropyltri 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane and (N, N-dimethylaminopropyl) trimethoxysilane (hereinafter referred to as " (N, N-dimethylaminopropyl) trimethoxysilane). The amino compound improves the reactivity of the gas sensor to the NO gas by helping the NO gas molecules in the air to be adsorbed well on the carbon nanotubes.

The gas sensing region may be formed of a plurality of layers, and the plurality of layers may include at least one of a carbon nanotube layer (hereinafter referred to as a "carbon nanotube layer") and at least one of upper and lower layers of the carbon nanotube layer (Hereinafter referred to as "aminosilane layer") located in a layer of an aminosilane. That is, the aminosilane layer may be formed between the substrate and the carbon nanotube layer, may be formed on the carbon nanotube layer adsorbed on the substrate, or may be formed on both sides.

Preferably, the gas sensing region comprises a layer comprising APTES (hereinafter referred to as "APTES layer") formed on a substrate, a carbon nanotube layer formed on the APTES layer, (Hereinafter referred to as "en-APTAS layer") formed on the layer. In this case, the APTES increases the amount of adsorbed carbon nanotubes on the substrate and uniformly adsorbs the carbon nanotubes, thereby providing a stable gas sensor and improving the production yield and performance of the gas sensor. In addition, the APTES serves to help adsorb NO gas molecules floating in the air to the sensor. When the NO gas is adsorbed on the carbon nanotubes, charge transfer occurs between the NO gas molecules and the carbon nanotubes, so that the distance between the source electrode and the drain electrode So that the current of the battery is changed. That is, since the amino compounds APTES and en-APTAS capture the NO gas molecules in the air, it is possible to provide a sensor having high reactivity to NO gas.

According to another aspect of the present invention, there is provided a method of manufacturing a gas sensor including a step of adsorbing carbon nanotubes on a substrate, the method further comprising adsorbing an amino compound on at least one of the steps before and after adsorbing the carbon nanotubes A method of manufacturing a gas sensor is provided.

Hereinafter, one embodiment of a method of manufacturing a gas sensor according to the present invention will be described in detail with reference to FIG.

(a) preparing a substrate

First, a substrate is prepared. As it described above, the substrate is a silicon substrate (SiO ₂ / Si substrate) formed on the surface may comprise a silicon substrate, a silicon oxide film (SiO ₂₎ formed on the surface and, or the insulating film comprise silicon substrate Lt; / RTI >

The insulating layer may be formed on the substrate by a method such as thermal oxidation, vapor deposition, or spin coating, but is not limited thereto. In the case of the thermal oxidation method, the thermal insulating film can be formed by heating to a temperature of 1000 캜 or more by using a heat diffusion furnace. In the case of the deposition method, a SiO ₂ thin film can be formed by using plasma-enhanced chemical vapor deposition (PECVD) or low-pressure chemical vapor deposition (LPCVD). In the case of the spin coating method, a SiO ₂ thin film can be formed on a silicon substrate by using SOG (Silica-On-Glass). The thickness of the insulating film may be 120 to 300 nm.

The substrate is preferably a substrate that has undergone an O ₂ plasma pretreatment step. The pretreatment removes contaminants on the surface of the substrate and makes the substrate surface hydrophilic. This makes the surface of the substrate well-adsorbable to the sensing material, and as a result, the adsorption force between the substrate and the sensing material can be improved.

(b) On the substrate  Step of adsorbing the sensing material

The sensing material used in the present invention includes amino compounds and carbon nanotubes. As described above, the amino compound may include aminosilane. Preferably, the aminosilane is 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3- Aminopropyltrimethoxysilane, en-APTAS, 3-mercaptopropyltrimethoxysilane and (N, N-dimethylaminopropyl) trimethoxysilane. (N, N-dimethylaminopropyl) trimethoxysilane).

The step of adsorbing the sensing material may include adsorbing the amino compound and attaching the carbon nanotube. The step of adsorbing the amino compound may be included in at least one of the steps before and after the adsorption of the carbon nanotubes. Preferably, the method of manufacturing a gas sensor of the present invention comprises the steps of (i) adsorbing an amino compound on a substrate, (Ii) adsorbing the carbon nanotubes on the substrate on which the amino compound is adsorbed, and (iii) adsorbing the amino compound on the substrate on which the carbon nanotubes are adsorbed. The amino compound adsorbed in step (i) and step (iii) may be the same or different. Preferably, the amino compound adsorbed in step (i) is APTES, and the amino compound adsorbed in step (iii) Lt; / RTI > FIG. 3 is a schematic view showing the steps of adsorbing APTES on a substrate, adsorbing carbon nanotubes on a substrate on which APTES is adsorbed, and adsorbing en-APTAS on a substrate on which the carbon nanotubes are adsorbed Are shown.

The APTES adsorbed on the substrate increases the adsorption amount of the carbon nanotubes and helps to uniformly adsorb the carbon nanotubes on the entire substrate. FIG. 4 shows SEM photographs of carbon nanotubes adsorbed on a pristine substrate without adsorbing APTES (left), adsorbing APTES on a substrate and adsorbing carbon nanotubes (right) Respectively. Referring to FIG. 4, it can be seen that the amount of adsorbed carbon nanotubes on the substrate and the uniformity of the adsorbed carbon nanotubes are increased.

The en-APTAS serves to adsorb NO gas in the air on the carbon nanotubes, thereby enhancing the reactivity to the NO gas. FIGS. 5 and 6 show results of adsorbing en-APTAS on a substrate on which carbon nanotubes are adsorbed, and then analyzing the substrate using XPS. 5 and 6, it can be confirmed that carbon nanotubes are well adsorbed on the substrate through the carbon (C) peak shown in FIG. 5, and it is confirmed that the carbon nanotubes are adsorbed on the substrate through the nitrogen (N) It can be confirmed that the amine compound en-APTAS is well adsorbed. 7 is a graph showing the adsorption amount of en-APTAS according to the adsorption time of en-APTAS. It can be seen that the amount of en-APTAS adsorbed on the carbon nanotubes can be quantitatively controlled by adjusting the adsorption time.

On the other hand, the amino compound is in the form of a viscous solution. The adsorption of the amino compound can be carried out by immersing the substrate in an amino compound in a solution state as it is or by immersing the substrate in a solution in which an amino compound is dispersed in ethanol in order to lower the viscosity of the amino compound. For example, when the solution is composed of ethanol and N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (en-APTAS) , The ethanol may be contained at a volume ratio of 50 to 200 times the en-APTAS, more preferably the en-APTAS: ethanol may be contained at a volume ratio of 1: 100, The same applies to the case of an amino compound. When the content of ethanol is more than 200 times the volume of the amino compound, it may be difficult to contribute to the improvement of the NO gas adsorption amount. On the other hand, when the content of ethanol is less than 50 times the dispersion of the amino compound, There is a concern.

The adsorption of the carbon nanotubes can be performed by immersing the substrate in a solution in which carbon nanotubes are dispersed. The solution was prepared by dissolving dichlorobenzene (DCB), ortho-dichlorobenzene (o-DCB), N-methyl-2-pyrrolidinone (NMP), hexamethylphosphoramide (HMPA), monochlorobenzene (MCB), N, Ndimethylformamide isopropyl alcohol (IPA), ethanol, chloroform, and toluene. Further, by irradiating the solution with ultrasonic waves, the carbon nanotubes can be dispersed evenly in the solution. The concentration of the carbon nanotubes in the solution in which the carbon nanotubes are dispersed may be 0.01-0.50 mg / ml. When the concentration is less than 0.01 mg / ml, the amount of adsorbed carbon nanotubes is too small to sufficiently function as a sensor. On the other hand, when the concentration exceeds 0.5 mg / ml, time for dispersing the carbon nanotubes The sensitivity of the sensor is decreased and the carbon nanotube is consumed more than necessary, which may cause a rise in manufacturing cost.

When the substrate is immersed in a solution in which the amino compound or amino compound is dispersed, the substrate may be immersed for 2 to 12 minutes at one time of immersion, and may be repeated at 1 to 15 times. When the substrate is immersed in a solution in which carbon nanotubes are dispersed, the substrate can be immersed in the dispersion solution for 5 to 100 seconds at one time of immersion, and can be repeated 1 to 15 times. If the immersion time is short or the immersion time is small, the amount of the adsorbed substance can not exhibit the respective effects properly. If the immersion time is long or the immersion time is long, the process time may become long and the productivity may be decreased. The optimum conditions can be secured by suitably adjusting the immersion time and the number of times of immersion.

(c) fabricating a gas sensor using the substrate on which the sensing material is adsorbed

FIG. 8 is a schematic view showing one embodiment of a manufacturing process for manufacturing a gas sensor using a substrate on which a sensing material is adsorbed, and the steps after the step of adsorbing a sensing material on a substrate using the same will be described in detail.

The method of manufacturing a gas sensor according to the present invention may further include a step of heat-treating a substrate on which the sensing material is adsorbed. The heat treatment is preferably performed at 50 to 100 ° C for 30 minutes to 2 hours, and the amino compound adsorbed on the carbon nanotubes is cured by the heat treatment.

Then, an electrode may be formed on the substrate after the heat treatment step. The electrode may be a source electrode and a drain electrode. The electrode may be made of gold (Au), silver (Ag), chromium (Cr), tantalum (Ta), titanium (Ti), copper (Cu) ), Molybdenum (Mo), tungsten (W), nickel (Ni), palladium (Pd), and platinum (Pt) The process of forming the electrode may be performed according to a conventional photolithography process. For example, as shown in FIG. 8, an electrode is formed on the substrate through the heat treatment step using photolithography, developing, metal deposition, and lift-off processes. Can be generated.

Next, photolithographic patterning may be performed again to form a carbon nanotube network channel between the source electrode and the drain electrode. The photolithographic patterning may be performed by photo-lithography and developing .

Subsequently, the substrate on which the photoresist patterning has been performed is dry-etched using oxygen plasma (O ₂ plasma) to remove carbon nanotubes existing in regions other than the channel, A gas sensor for selectively sensing nitrogen can be manufactured. FIG. 9 shows an AFM photograph showing the degree of etching of carbon nanotubes according to electric power for generating oxygen plasma in the dry etching process. Referring to FIG. 9, the highest etching rate was observed at 80 W, and the O ₂ plasma etching was performed at 80 W in this embodiment.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Example

A SiO ₂ / Si substrate on which a silicon oxide insulating film (SiO ₂ ) is formed is provided on a silicon substrate.

Single-walled carbon nanotubes are introduced into dichlorobenzene (DCB), and a solution in which single-walled carbon nanotubes are uniformly dispersed is prepared using ultrasonic waves. The concentration of single-walled carbon nanotubes in the dispersion solution was 0.02 mg / ml.

0.01 ml of APTES and 0.01 ml of en-APTAS are added to 1 ml of ethanol, respectively, and then a solution in which the APTES and en-APTAS are uniformly dispersed is prepared using ultrasonic waves.

Then, the substrate on which the insulating film was formed was immersed in a solution in which APTES was dispersed for 10 minutes, immersed in a solution in which single-walled carbon nanotubes were dispersed for 50 seconds, immersed in a solution in which en-APTAS was dispersed for 8 minutes Thereby allowing APTES, carbon nanotubes, and en-APTAS to be successively adsorbed on the substrate.

The substrate on which APTES, carbon nanotubes and en-APTAS are adsorbed is heat-treated at 60 ° C for 1 hour.

Subsequently, a substrate source electrode and a drain electrode on which APTES, carbon nanotubes, and en-APTAS are adsorbed are formed using conventional photolithography, development, metal deposition, and lift-off processes. The metal used for the source electrode and the drain electrode was gold (Au) / titanium (Ti).

Next, a photolithography and a development process are performed again to form a carbon nanotube channel between the source electrode and the drain electrode, patterning the photoresist, and then dry etching using O ₂ plasma at a power of 80 W. Then, the photoresist was removed to prepare a gas sensor.

Comparative Example

After an Al ₂ O ₃ substrate is provided, an electrode (Au) is formed thereon. Then tin oxide (SnO ₂ ) is synthesized on the substrate by chemical vapor deposition (CVD).

0.01 ml of N- [3- (trimethoxysilyl) propyl] ethylenediamine (N- [3- (trimethoxysyl) propyl] ethylenediamine) was added to 1 ml of ethanol and the mixture was stirred with a magnetic stirrer And stirred for 6 hours to prepare a solution in which N- [3- (trimethoxysilyl) propyl] ethylenediamine is uniformly dispersed.

The substrate on which the tin oxide was formed was dipped in a solution of N- [3- (trimethoxysilyl) propyl] ethylenediamine dispersed for 10 minutes to form N- [3- (trimethoxysilyl) propyl] ethylene So that the diamine is adsorbed.

Then, the substrate on which the N- [3- (trimethoxysilyl) propyl] ethylene diamine is adsorbed is heat-treated at 60 ° C for 2 hours to prepare a gas sensor.

Characteristic analysis of gas sensor

The gas sensor manufactured according to the above-described embodiment and comparative example was connected to a source meter (keithley 2400), and nitrogen monoxide (NO) gas was flowed using a mass flow controller, and simultaneously with the application of a constant DC power The resistance change in the sensing body was measured.

All measurements were made at room temperature. The response of the sensor to NO gas was evaluated by the following equation (1), and the results are shown in Table 1 below. At this time, the reactivity measurement was carried out at a gas concentration of 2 ppm.

Response (%) = (? R / R) x 100 ... (One)

In the formula (1), R represents an initial resistance value in the absence of a reactive gas, and? R represents a value obtained by subtracting the R from a resistance value in the presence of a reactive gas.

Example Comparative Example Response (%) 13.29% 6%

As shown in Table 1, in the case of a gas sensor using carbon nanotubes and an amine compound as sensing materials as a sensing material, the sensitivity of the gas sensor is significantly improved as compared with the gas sensor of the comparative example using SnO ₂ and an amine compound as sensing materials .

10 is a graph showing resistance values measured over time when 2 ppm of NO gas is applied to a gas sensor manufactured according to an embodiment of the present invention. 10, NO gas can be detected even at a very low concentration of 2 ppm, and it is confirmed that the characteristic of the resistance value with time is stable and repetitive.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Should be construed as being included in the scope of the present invention.

Claims (15)

A gas sensor comprising at least one gas sensing area on a substrate,
Wherein the gas sensing region comprises an amino compound and a carbon nanotube,
APTES layer formed on the substrate, the carbon nanotube layer formed on the APTES layer, and the en-APTAS formed on the carbon nanotube layer. (Hereinafter referred to as "en-APTAS layer"). The method according to claim 1,
Characterized in that the substrate comprises a silicon substrate. The method according to claim 1,
Wherein the substrate comprises a silicon substrate having a silicon oxide film formed on the surface thereof. The method according to claim 1,
Characterized in that the amino compound comprises aminosilane. 5. The method of claim 4,
The aminosilane may be selected from the group consisting of 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (N, N-dimethylaminopropyl) trimethoxysilane), 3-mercaptopropyltrimethoxysilane, and (N, N-dimethylaminopropyl) trimethoxysilane. Or two or more gas sensors. The method according to claim 1,
Wherein the gas sensing area comprises a plurality of layers,
(Hereinafter referred to as " carbon nanotube layer ") and a layer containing aminosilane in at least one of the upper and lower layers of the carbon nanotube layer (hereinafter referred to as " , "Aminosilane layer"). ≪ / RTI > delete The method according to claim 1,
Wherein the carbon nanotube comprises a single-walled carbon nanotube (SWCNT). A method of manufacturing a gas sensor, comprising: adsorbing carbon nanotubes on a substrate,
And adsorbing the amino compound to at least one of the steps before and after adsorbing the carbon nanotube,
Adsorbing APTES on the substrate,
Adsorbing carbon nanotubes on the APTES adsorbed substrate,
And adsorbing en-APTAS on the substrate on which the carbon nanotubes are adsorbed. 10. The method of claim 9,
Wherein the substrate is a substrate subjected to an O ₂ plasma pretreatment step. 10. The method of claim 9,
Wherein the amino compound comprises aminosilane. ≪ RTI ID = 0.0 > 21. < / RTI > 12. The method of claim 11,
The aminosilane may be selected from the group consisting of 3-aminopropyltriethoxysilane (APTES), N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (N, N-dimethylaminopropyl) trimethoxysilane), 3-mercaptopropyltrimethoxysilane, and (N, N-dimethylaminopropyl) trimethoxysilane. Or two or more of the nitrogen monoxide and the nitrogen monoxide. delete 10. The method of claim 9,
Further comprising the step of heat treating the substrate on which the step of adsorbing the carbon nanotube and the amino compound is completed. 15. The method of claim 14,
Wherein the heat treatment is performed at 50 to 100 DEG C for 30 minutes to 2 hours.

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