CN109946349B - Organic field effect transistor and preparation method thereof, and biogenic amine gas sensor - Google Patents

Abstract

The invention discloses an organic field effect transistor, a preparation method thereof, and a biogenic amine gas sensor. The organic field effect transistor comprises a substrate, an organic semiconductor layer, a biogenic amine sensitive layer, an insulating layer and a gate which are sequentially stacked from bottom to top. The substrate is also provided with a drain electrode and a source electrode, and the organic semiconductor layer covers the source electrode and the drain electrode and the area on the substrate that is not covered by the source electrode and the drain electrode; the sensitivity of the biogenic amine sensitive layer to the biogenic amine is set is greater than the sensitivity of the organic semiconductor layer to biogenic amines. In the present invention, the organic field effect transistor in the energized state will form a conductive channel in the biological amine sensitive layer and the organic semiconductor layer. When biological amine exists, the biological amine and the biological amine sensitive layer and the organic semiconductor layer will undergo chemical reactions to change the conductive channel. The resistance of the channel can be sensed by sensing the change of the resistance, which can effectively improve the sensitivity of the detection, achieve the purpose of optimizing the detection effect and improving the detection efficiency.

Description

Organic field effect transistor and preparation method thereof, and biogenic amine gas sensor

technical field

The invention relates to the technical field of gas detection, in particular to the technical field of gas detection using organic semiconductor materials, and in particular to an organic field effect transistor, a preparation method thereof, and a biological amine gas sensor.

Background technique

Biogenic amines are a kind of nitrogen-containing low-molecular-weight organic bases, which are mainly formed by the decarboxylation of amino acids, and are widely found in meat products, aquatic products and fermented products rich in amino acids and proteins. Biogenic amines can be divided into three categories according to their structure: aliphatic, including putrescine, cadaverine, spermine, spermidine, etc.; aromatic, including tyramine, phenethylamine, etc.; heterocyclic amines, including histamine, chromophore, etc. Amines etc. An appropriate amount of biogenic amines is necessary to maintain the normal physiological functions of the human body, but if the human body ingests excessive amounts of biogenic amines, it will cause allergic reactions, which may be life-threatening in severe cases. In addition, biogenic amines are often produced in the process of food decay or fermentation. The onset of food poisoning and some toxicological properties are closely related to histamine and tyramine. The content of biogenic amines in food can be used as an important indicator of food quality. Therefore, the effective and rapid detection of biogenic amines in food is of great significance to food quality and safety.

Due to the lack of chromophoric groups in biogenic amine molecules, it has neither ultraviolet absorption nor fluorescence and electrochemical activity, making the separation and determination of various biogenic amines very difficult. The traditional determination of biogenic amines mainly relies on biochemical methods, such as enzyme biosensor method, thin layer chromatography, gas chromatography, ion chromatography, capillary electrophoresis and high performance liquid chromatography. It has the advantages of high efficiency, high separation efficiency, fast analysis speed, high sensitivity, and accurate quantitative analysis. Most scholars use it as the main method for analyzing biogenic amines in food. high, the overall efficiency is low. In order to solve the above problems, a method for measuring biogenic amines through inorganic metal oxide semiconductor gas sensors is proposed at present, but this method has disadvantages such as high operating temperature, requiring heaters, low detection sensitivity for most organic gases, and narrow detection range. .

SUMMARY OF THE INVENTION

The main purpose of the present invention is to provide an organic field effect transistor, a preparation method and a biogenic amine gas sensor, aiming to solve the problems of low detection sensitivity and low detection efficiency existing in traditional detection methods.

In order to achieve the above purpose, an organic field effect transistor proposed by the present invention is used for sensing biogenic amines in food, and the organic field effect transistor comprises a substrate, an organic semiconductor layer, a biogenic amine sensitive layer, an insulating layer and a gate electrode, the upper end of the substrate is further provided with a source electrode and a drain electrode, the organic semiconductor layer covers the drain electrode and the source electrode, and the substrate is not covered the area covered by the drain and the source;

Wherein, the sensitivity of the biogenic amine sensitive layer to the biogenic amine is set to be greater than the sensitivity of the organic semiconductor layer to the biogenic amine.

Optionally, the material of the organic semiconductor layer is any one of the compounds having the structures represented by the following structural formulas (I), (II), (III), and (IV):

Optionally, the material of the biogenic amine sensitive layer is any one of the compounds having the structures shown in the following structural formulas (V) and (VI):

Wherein, in structural formula (V): M=Au or M=Co.

Optionally, the material of the insulating layer is water or phosphate buffered saline.

Optionally, the material of the substrate is glass, silicon wafer or ceramic; or,

The source electrode, the drain electrode and the gate electrode are made of aluminum or gold.

Optionally, the thickness of the organic semiconductor layer is 60 nm˜70 nm; or,

The thickness of the biogenic amine sensitive layer is 8nm-12nm; or,

The thickness of the substrate is 45 nm˜55 nm.

In addition, the present invention also provides a method for preparing the above organic field effect transistor, comprising the following steps:

providing a substrate;

a drain electrode and a source electrode are provided on the substrate;

an organic semiconductor layer is provided on the source electrode and the drain electrode and on the region of the substrate not covered by the drain electrode and the source electrode;

A biogenic amine sensitive layer is arranged on the organic semiconductor layer;

an insulating layer is provided on the biogenic amine sensitive layer;

A gate is provided on the insulating layer to obtain the organic field effect transistor.

Optionally, the methods for setting the gate electrode, the source electrode and the drain electrode are vacuum thermal evaporation, magnetron sputtering or plasma-enhanced chemical vapor deposition.

Optionally, the step of disposing an insulating layer on the biogenic amine sensitive layer includes: dripping 1-3 μL of water or a phosphate buffered saline solution on the biogenic amine sensitive layer to form the insulating layer.

In addition, the present invention also provides a biogenic amine gas sensor, comprising the above organic field effect transistor.

In the technical solution provided by the present invention, the organic field effect transistor in the power-on state will form a conductive channel in the biogenic amine sensitive layer and the organic semiconductor layer. When biogenic amine exists in the environment, the biogenic amine and all The biological amine sensitive layer and the organic semiconductor layer produce chemical reaction, which will change the resistance of the conductive channel, so the purpose of sensing the biological amine in the environment can be realized by sensing the change of the resistance; The organic semiconductor layer is arranged above the drain electrode and the source electrode, and the biological amine sensitive layer that is more sensitive to biological amine is added above the organic semiconductor layer, which is not only conducive to increasing the organic field effect transistor. The contact area with the biogenic amine can also effectively improve the detection sensitivity, so as to optimize the detection effect and improve the detection efficiency.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained according to the structures shown in these drawings without creative efforts.

FIG. 1 is a schematic structural diagram of an embodiment of an organic field effect transistor provided by the present invention.

Description of reference numbers:

label name label name 100 Organic Field Effect Transistor 3 organic semiconductor layer 1 substrate 4 biogenic amine sensitive layer twenty one drain 5 Insulation twenty two source 6 gate

The realization, functional characteristics and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

It should be noted that if there are directional indications (such as up, down, left, right, front, back, etc.) involved in the embodiments of the present invention, the directional indications are only used to explain a certain posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication also changes accordingly.

In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for the purpose of description, and should not be construed as indicating or implying Its relative importance or implicitly indicates the number of technical features indicated. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. In addition, the meaning of "and/or" in the whole text includes three parallel schemes. Taking "A and/or B" as an example, it includes scheme A, scheme B, or scheme satisfying both of A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that the combination of such technical solutions does not exist. , is not within the scope of protection required by the present invention.

Due to the lack of chromophoric groups in biogenic amine molecules, it has neither ultraviolet absorption nor fluorescence and electrochemical activity, making the separation and determination of various biogenic amines very difficult. The traditional determination of biogenic amines mainly relies on biochemical methods, such as enzyme biosensor method, thin layer chromatography, gas chromatography, ion chromatography, capillary electrophoresis and high performance liquid chromatography. It has the advantages of high efficiency, high separation efficiency, fast analysis speed, high sensitivity, and accurate quantitative analysis. Most scholars use it as the main method for analyzing biogenic amines in food. high, the overall efficiency is low. In order to solve the above problems, a method for measuring biogenic amines through inorganic metal oxide semiconductor gas sensors is proposed at present, but this method has disadvantages such as high operating temperature, requiring heaters, low detection sensitivity for most organic gases, and narrow detection range. .

In view of this, the present invention provides a biogenic amine gas sensor, which includes an organic field effect transistor and other components. FIG. 1 is an embodiment of the organic field effect transistor provided by the present invention. The main invention lies in the improvement of the organic field effect transistor. The organic field effect transistor will be mainly described below with reference to the specific drawings.

Referring to FIG. 1 , in this embodiment, the organic field effect transistor 100 is used for sensing biogenic amines and their content in the environment, especially for sensing biogenic amines in food, and the organic field effect transistor 100 includes The substrate 1, the organic semiconductor layer 3, the biogenic amine sensitive layer 4, the insulating layer 5 and the gate electrode 6 are sequentially stacked from bottom to top. In addition, the upper end of the substrate 1 is also provided with a drain electrode 21 and a source electrode 22, The organic semiconductor layer 3 covers the drain electrode 21 and the source electrode 22 and the region of the substrate 1 that is not covered by the drain electrode 21 and the source electrode 22 . In addition, the sensitivity of the biogenic amine sensitive layer 4 to biogenic amine is set to be greater than the sensitivity of the organic semiconductor layer 3 to biogenic amine, which can be embodied in the following: the material of the biogenic amine sensitive layer 4 is sensitive to biogenic amine. The sensitivity is greater than the material of the organic semiconductor layer 3, or the contact area of the biological amine sensitive layer 4 and the biological amine is larger than the contact area of the organic semiconductor layer 3 and the biological amine. During operation, a positive voltage is applied to the gate electrode 6 and the drain electrode 21, and a negative voltage or grounding is applied to the source electrode 22. The source electrode 22, the drain electrode 21 and the gate electrode 6 are Equivalent to the two pole plates of a capacitor, the organic semiconductor layer 3, the biological amine sensitive layer 4 and the insulating layer 5 are in contact with each other layer by layer, so that the organic field effect transistor 100 is in an electrified state as a whole, form a capacitor.

In the technical solution provided by the present invention, the organic field effect transistor 100 in the power-on state will form a conductive channel in the biological amine sensitive layer 4 and the organic semiconductor layer 3. When biological amine exists in the environment, biological The chemical reaction between amine and the biological amine sensitive layer 4 and the organic semiconductor layer 3 will change the resistance of the conductive channel. Therefore, the purpose of sensing the biological amine in the environment can be realized by sensing the change of the resistance. In addition, the organic semiconductor layer 3 is arranged above the drain electrode 21 and the source electrode 22, and the biological amine sensitive layer 4 that is more sensitive to biological amine is added above the organic semiconductor layer 3, not only It is beneficial to increase the contact area between the organic field effect transistor 100 and the biogenic amine, and can also effectively improve the detection sensitivity, so as to achieve the purpose of optimizing the detection effect and improving the detection efficiency.

Further, in this embodiment, the material of the organic semiconductor layer 3 is any one of the compounds having the structures represented by the following structural formulas (I), (II), (III), and (IV):

Wherein, the compound in structural formula (I) is PDI8-CN2 material, the compound in structural formula (II) is P3HT material, the compound in structural formula (III) is Pentacene material, the compound in structural formula (IV) is PEDOT:PSS material, The above compounds can react sensitively with biogenic amines at room temperature. Specifically, the biogenic amine gas can quickly pass through the organic semiconductor layer 3 through the grain boundaries and enter the charge accumulation layer, and then generate traps in the grain boundaries to reduce electrical charges. The mobility of carriers can rapidly change the resistance of the conductive channel and achieve the purpose of sensitive detection of biogenic amines; the above compounds are all existing products, which are compatible with the substrate 1 and are suitable for low temperature processing and mass production.

In addition, in this embodiment, the material of the biogenic amine sensitive layer 4 is any one of the compounds having the structures shown in the following structural formulas (V) and (VI):

Wherein, in structural formula (V): M=Au or M=Co. The compound in the structural formula (V) is an Au-EHO material, and the compound in the structural formula (VI) is a Co-EHO material, and the biological amine sensitive layer 4 covers the organic semiconductor layer 3 and directly contacts the biological organisms in the environment. amine, since the Au-EHO material and the Co-EHO material are more sensitive to biogenic amines than the PDI8-CN2 material, the P3HT material, the Pentacene material and the PEDOT:PSS material Specifically, the biogenic amine gas molecules will enter the holes of the biogenic amine sensitive layer 4 and then bond with the molecules of the biogenic amine sensitive layer 4 to generate electric dipoles, further affecting the organic semiconductor layer 3 Therefore, the organic field effect transistor 100 is more sensitive to biological amine gas, which helps to widen the detection range of the organic field effect transistor 100, and helps to speed up the detection speed, thereby improving the detection efficiency.

Next, in this embodiment, the material of the insulating layer 5 is water or phosphate buffered saline solution. Compared with traditional inorganic insulating materials, the insulating layer 5 formed by water or phosphate buffered saline solution has a higher dielectric constant. , which can effectively increase the capacitance of the organic field effect transistor 100 , thereby increasing the on-current in the organic field effect transistor 100 and reducing the operating voltage required by the organic field effect transistor 100 . When in use, the gate 6 can be directly inserted into water or a phosphate buffered saline solution.

Further, in this embodiment, the material of the substrate 1 is glass, silicon wafer or ceramic, which has good insulation and low material price, which is beneficial to reduce the economic cost burden; The source electrode 22 and the gate electrode 6 are made of aluminum or gold, which helps to expand the capacitance without increasing the volume and mass of the organic field effect transistor 100 .

Further, in this embodiment, the thickness of the organic semiconductor layer 3 is 60 nm to 70 nm, or the thickness of the biological amine sensitive layer 4 is 8 nm to 12 nm, or the thickness of the substrate 1 is 45 nm to 55 nm, And it is preferably 50 nm. The thicknesses of the organic semiconductor layer 3 , the biogenic amine sensitive layer 4 and the insulating layer 5 affect the capacitive sensing between the source electrode 22 , the drain electrode 21 and the gate electrode 6 . If the thickness is large, the change in capacitance sensed by the organic field effect transistor 100 is small or even unable to form a good capacitance sensing, which affects the real-time sensing of biogenic amines; on the contrary, if the thickness is small, the required operating voltage is large , which is not conducive to the use of users, so preferably, the thickness of the organic semiconductor layer 3 is 65 nm, and the thickness of the biological amine sensitive layer 4 is 10 nm.

In addition, the present invention also provides a method for preparing the organic field effect transistor 100, which specifically includes the following steps:

Step S10: providing a substrate 1;

Step S20: disposing a drain electrode 21 and a source electrode 22 on the substrate 1;

Step S30: Disposing an organic semiconductor layer 3 on the drain electrode 21 and the source electrode 22 and on the region of the substrate 1 not covered by the drain electrode 21 and the source electrode 22;

Step S40: disposing a biogenic amine sensitive layer 4 on the organic semiconductor layer 3;

Step S50: disposing an insulating layer 5 on the biological amine sensitive layer 4;

Step S60 : disposing the gate 6 on the insulating layer 5 to obtain the organic field effect transistor 100 .

In this embodiment, according to the actual application, select the appropriate material and thickness of the substrate 1, take a silicon wafer as the substrate 1 as an example, use acetone, isoacetone, etc. to ultrasonically clean the silicon wafer in sequence, and then Rinse the silicon wafer with ethanol and deionized water, and finally dry the surface of the silicon wafer with nitrogen; 21. Continue to sequentially evaporate the organic semiconductor layer 3 and the biological amine sensitive layer 4 on the source electrode 22 and the substrate 1; prepare the insulating layer 5 on the biological amine sensitive layer 4, and finally The gate electrode 6 is disposed on the insulating layer 5 , for example, at least the lower end of the gate electrode 6 is inserted into the insulating layer 5 to obtain the organic field effect transistor 100 .

Further, in this embodiment, the methods for setting the gate 6 , the source 22 and the drain 21 are vacuum thermal evaporation, magnetron sputtering or plasma-enhanced chemical vapor deposition. For example, the substrate 1 is placed in a vacuum coating machine, and gold is evaporated on the substrate 1 at a speed of 1 A/s under the condition of a vacuum degree of 6.5×10 ^-4 Pa to obtain the drain electrode 21 and the source 22. The specific preparation method of the gate 6 is similar to the above, and will not be described in detail. In addition, the specific steps and related requirements of magnetron sputtering or plasma-enhanced chemical vapor deposition may refer to the prior art, and will not be described in detail here.

Further, in this embodiment, the step S50 includes: dripping 1-3 μL of water or a phosphate buffered saline solution on the biogenic amine sensitive layer 4 to form the insulating layer 5 . For example, in an environment where biogenic amine needs to be detected, about 2 μL of water or phosphate buffered saline solution can be dropped onto the biogenic amine sensitive layer 4 with a dropper, and then the gate 6 is inserted into the water or phosphate buffered saline solution, so as to form a complete organic field effect transistor 100 . The specific value, composition, etc. of the insulating layer 5 can be adaptively adjusted according to practical applications, so as to detect different biogenic amines in different environments in a targeted manner, and obtain more accurate results more quickly and effectively.

Taking a specific embodiment of the organic field effect transistor 100 as an example to illustrate, at room temperature, a 50nm-thick glass can be used as the substrate 1, and gold drains can be arranged on the substrate by magnetron sputtering. electrode 21 and source electrode 22; then on the drain electrode 21 and the source electrode 22, and on the region of the substrate 1 not covered by the drain electrode 21 and the source electrode 22, by evaporation The organic semiconductor layer 3 with a thickness of 65 nm is arranged in a manner of 10 nm thick, and the material of the organic semiconductor layer 3 is P3HT; on the organic semiconductor layer 3, a biogenic amine sensitive layer 4 with a thickness of 10 nm is arranged by evaporation, and the material of the organic semiconductor layer 3 is P3HT; The material of the biogenic amine sensitive layer 4 is Co-EHO; 2 μL of phosphate buffered saline solution is drawn on the biogenic amine sensitive layer 4 with a pipette and added dropwise to the biogenic amine sensitive layer 4 to form an insulating layer 5 ; The gate electrode 6 made of gold is disposed on the insulating layer 5 by vacuum thermal evaporation, so as to obtain the organic field effect transistor 100 . Using the measurement technology of the existing measurement equipment, it can be effectively detected that when Vg=0.6V, the corresponding saturation current of the organic field effect transistor 100 is 0.9μA, and the carrier mobility is 2.3x10 ^-3 cm ² /Vs, The threshold voltage is 0.03V and the response speed is 0.2s, indicating that the organic field effect transistor 100 prepared by the present invention has good response results to biogenic amines at room temperature, with fast response speed and high sensitivity.

The above descriptions are only the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Under the inventive concept of the present invention, the equivalent structural transformations made by the contents of the description and drawings of the present invention, or the direct/indirect application Other related technical fields are included in the scope of patent protection of the present invention.

Claims (9)

1. An organic field effect transistor is used for sensing biogenic amine in food and is characterized by comprising a substrate, an organic semiconductor layer, a biogenic amine sensitive layer, an insulating layer and a grid which are sequentially stacked from bottom to top, wherein the upper end of the substrate is also provided with a drain electrode and a source electrode, the organic semiconductor layer covers the drain electrode and the source electrode and the substrate is not covered by the drain electrode and the source electrode;

wherein the sensitivity of the biogenic amine sensitive layer to biogenic amines is set to be greater than the sensitivity of the organic semiconductor layer to biogenic amines;

the material of the organic semiconductor layer is any one of compounds with structures shown in the following structural formulas (I), (II), (III) and (IV):

2. the organic field-effect transistor according to claim 1, wherein a material of the biogenic amine sensitive layer is a compound having a structure represented by the following structural formula (v):

wherein, in structural formula (v): and M ═ Au or M ═ Co.

3. The organic field-effect transistor according to claim 1, wherein a material of the insulating layer is water or phosphate buffered saline.

4. The organic field-effect transistor according to claim 1, wherein a material of the substrate is glass, a silicon wafer, or ceramic; or,

the source electrode, the drain electrode and the grid electrode are made of aluminum or gold.

5. The organic field-effect transistor according to claim 1, wherein the thickness of the organic semiconductor layer is 60nm to 70 nm; or,

the thickness of the biogenic amine sensitive layer is 8 nm-12 nm; or,

the thickness of the substrate is 45 nm-55 nm.

6. A method of manufacturing an organic field effect transistor according to any of claims 1 to 5, comprising the steps of:

providing a substrate;

arranging a drain electrode and a source electrode on the substrate;

providing an organic semiconductor layer on the drain electrode and the source electrode and on a region of the substrate not covered by the drain electrode and the source electrode;

disposing a biogenic amine sensitive layer on the organic semiconductor layer;

arranging an insulating layer on the biogenic amine sensitive layer;

and arranging a grid electrode on the insulating layer to obtain the organic field effect transistor.

7. The method of claim 6, wherein the gate electrode, the source electrode and the drain electrode are disposed by vacuum thermal evaporation, magnetron sputtering or plasma enhanced chemical vapor deposition.

8. The method of manufacturing an organic field effect transistor according to claim 6, wherein the step of providing an insulating layer on the biogenic amine sensitive layer comprises: and dripping 1-3 mu L of water or phosphate buffer solution on the biogenic amine sensitive layer to form the insulating layer.

9. A biogenic amine gas sensor, comprising an organic field effect transistor according to any one of claims 1 to 5.

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