Preparation method of gaseous nicotine electrochemical sensing material

Abstract

The invention relates to the technical field of environmental monitoring, and discloses a preparation method of a gaseous nicotine electrochemical sensing material, which comprises the following steps: adding sodium alginate, aniline and acrylamide into an ethanol solution, stirring and dissolving to obtain a mixed solution; introducing nitrogen into the mixed solution, adding black phosphorus and a nicotine molecularly imprinted material into the mixed solution, stirring and reacting, then adding a cross-linking agent solution and an initiator solution, performing ultrasonic reaction, adding a calcium-lithium mixed solution after the ultrasonic reaction is finished, stirring and standing to obtain wet gel; drying the wet gel in a freeze dryer to obtain dry gel; and before use, putting the xerogel into an atomization device, and carrying out water vapor activation treatment to obtain the gaseous nicotine electrochemical sensing material. Response current can be generated based on specific recognition combination of the molecularly imprinted material and nicotine, the intensity of the response current is positively correlated with the content of nicotine, and the nicotine content can be accurately tested by combining with a material formed by black phosphorus and hydrophilic gel.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental monitoring, and in particular to a method for preparing a gaseous nicotine electrochemical sensor material. Background Art

[0002] Nicotine is one of the characteristic pollutants of tobacco smoke, and its concentration can directly reflect the pollution level of tobacco smoke. In the process of detecting nicotine in the air, there are two methods: active sampling and passive sampling. Active sampling is also called dynamic sampling. The principle is to use a vacuum pump to cut off the air sample through the absorption liquid in the collector, so that the gaseous pollutants are concentrated in the absorption medium, thereby achieving the purpose of concentrated sampling. The international and Chinese tobacco industries use active sampling for the detection of nicotine in the air. Passive sampling does not require any power supply and suction power. It is a sampling method for collecting gaseous pollutants in the air based on the principle of gas molecule diffusion, so it is also called pumpless sampling method, and its sampling device is a passive sampler. However, whether it is active sampling or passive sampling, the test process is relatively cumbersome, the test time is long, the accuracy is poor, and it is not suitable for in-situ online detection. Summary of the invention

[0003] The purpose of the present invention is to provide a method for preparing a gaseous nicotine electrochemical sensor material to solve the problems of poor accuracy, long time and inability to detect gaseous nicotine online.

[0004] To achieve the above object, the present invention provides the following technical solutions: The present invention discloses a method for preparing a gaseous nicotine electrochemical sensor material, which specifically comprises the following steps: Step S1: adding 10-15 parts by mass of sodium alginate, 20-35 parts by mass of aniline, and 20-50 parts by mass of acrylamide into 1000 parts by mass of ethanol solution, stirring and dissolving to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 25-50 parts by weight of black phosphorus and 5-10 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, then 50-300 parts by weight of cross-linking agent solution and 100-500 parts by weight of initiator solution are added, ultrasonic reaction is performed, and after the reaction is completed, 30-60 parts by weight of calcium-lithium mixed solution is added, stirred for 0.5-1 hour, and allowed to stand for 20-40 hours to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomization device and subjected to a water vapor activation treatment to obtain a gaseous nicotine electrochemical sensing material.

[0005] Preferably, the volume fraction of the ethanol solution in step S1 is 40% to 60%.

[0006] Preferably, the crosslinking agent solution in step S2 is one of a divinylbenzene solution, a diisocyanate solution, and an N,N-methylenebisacrylamide solution, and the concentration is 0.1-1 mol / L.

[0007] Preferably, the initiator solution in step S2 is one of potassium persulfate solution, sodium persulfate solution and ammonium persulfate solution, and the concentration is 0.05-1 mol / L.

[0008] Preferably, the calcium-lithium mixed solution in step S2 is composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of (2.5-5):1:20.

[0009] Preferably, in step S3, the drying temperature is -40 to -60°C and the drying time is 20 to 30 hours.

[0010] Preferably, the steam flow rate of the steam activation treatment in step S4 is 0.1-0.5 L / min, and the treatment time is 5-10 min.

[0011] Beneficial effects of the present invention: 1. Based on the specific recognition and binding of molecular imprinting materials and nicotine, a response current can be generated, the intensity of which is positively correlated with the nicotine content, and the nicotine content can be accurately tested; 2. Black phosphorus has abundant terminal phosphorus atoms, which can effectively improve the catalytic activity of the material and the transmission of electrons, and effectively increase the transmission speed and intensity of the response current, thereby extending the detection limit of nicotine; 3. The composite gel of polycalcium alginate, polylithium alginate and polyacrylamide can enrich water molecules in the air, increase the number of hydrogen bonds between the material and nicotine, effectively collect gaseous nicotine molecules in the air, and further improve the detection accuracy of the material for nicotine; 4. The electrochemical sensing material prepared by the method of the present invention can be used to produce a nicotine electrochemical sensor, which can realize rapid real-time online monitoring of gaseous nicotine and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 Flow chart of the preparation method of the gaseous nicotine electrochemical sensor material of the present invention; Figure 2 Contact angle test diagram of the sensing material prepared in Example 1. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below through the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0014] like Figure 1 As shown, a method for preparing a gaseous nicotine electrochemical sensor material specifically comprises the following steps: Step S1: adding 10-15 parts by mass of sodium alginate, 20-35 parts by mass of aniline, and 20-50 parts by mass of acrylamide into 1000 parts by mass of an ethanol solution having a volume fraction of 40% to 60%, stirring and dissolving, to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 25-50 parts by weight of black phosphorus and 5-10 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 50-300 parts by weight of a cross-linking agent solution and 100-500 parts by weight of an initiator solution are added, and ultrasonic reaction is performed. After the reaction is completed, 30-60 parts by weight of a calcium-lithium mixed solution is added, stirred for 0.5-1 hour, and allowed to stand for 20-40 hours to obtain a wet gel; the cross-linking agent solution is one of a divinylbenzene solution, a diisocyanate solution, and an N,N-methylenebisacrylamide solution, and the concentration is 0.1-1 mol / L; the initiator solution is one of a potassium persulfate solution, a sodium persulfate solution, and an ammonium persulfate solution, and the concentration is 0.05-1 mol / L; the calcium-lithium mixed solution is composed of calcium chloride, lithium chloride, and water mixed uniformly in a weight ratio of (2.5-5):1:20; Step S3: placing the wet gel in a freeze dryer at -40 to -60°C for 20 to 30 hours to obtain a dry gel; Step S4: before use, the dry gel is placed in an atomizer and subjected to a water vapor activation treatment to obtain a gaseous nicotine electrochemical sensing material; the water vapor flow rate of the water vapor activation treatment is 0.1-0.5 L / min, and the treatment time is 5-10 min.

[0015] Example 1: In this example, the gaseous nicotine electrochemical sensing material is obtained by the following scheme Step S1: adding 10 parts by mass of sodium alginate, 20 parts by mass of aniline, and 20 parts by mass of acrylamide into 1000 parts by mass of a 40% ethanol solution, stirring and dissolving, to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 25 parts by weight of black phosphorus and 5 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 50 parts by weight of a 0.1 mol / L divinylbenzene solution and 100 parts by weight of a 0.05 mol / L potassium persulfate solution are added, and ultrasonic reaction is performed. After the reaction is completed, 30 parts by weight of a calcium-lithium mixed solution composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of 2.5:1:20 is added, stirred for 0.5 h, and allowed to stand for 20 h to obtain a wet gel; Step S3: placing the wet gel in a freeze dryer at -40°C for 20 h to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomizer, and the water vapor flow rate is set to 0.1 L / min for water vapor activation treatment for 5 minutes to obtain a gaseous nicotine electrochemical sensing material.

[0016] Figure 2 This is a contact angle test diagram of the sensing material prepared in this embodiment. Figure 2 (A) is the water drop image at 0s. Figure 2 (B) is a picture of a water drop at 2 s, from which it can be clearly seen that the water drop disappears, indicating that the sensing material prepared in this example has strong hydrophilicity.

[0017] Example 2: In this example, the gaseous nicotine electrochemical sensing material is obtained by the following scheme Step S1: adding 15 parts by mass of sodium alginate, 35 parts by mass of aniline, and 50 parts by mass of acrylamide into 1000 parts by mass of an ethanol solution having a volume fraction of 60%, stirring and dissolving, to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 50 parts by weight of black phosphorus and 10 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 300 parts by weight of a 1 mol / L diisocyanate solution and 500 parts by weight of a 1 mol / L sodium persulfate solution are added, and ultrasonic reaction is performed. After the reaction is completed, 60 parts by weight of a calcium-lithium mixed solution composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of 5:1:20 is added, stirred for 1 hour, and allowed to stand for 40 hours to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer at -60°C for 30 h to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomizer, and the water vapor flow rate is set to 0.5 L / min for water vapor activation treatment for 10 minutes to obtain a gaseous nicotine electrochemical sensing material.

[0018] Example 3: In this example, the gaseous nicotine electrochemical sensing material is obtained by the following scheme Step S1: adding 13 parts by mass of sodium alginate, 30 parts by mass of aniline, and 30 parts by mass of acrylamide into 1000 parts by mass of a 50% by volume ethanol solution, stirring and dissolving, to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 35 parts by weight of black phosphorus and 7 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 200 parts by weight of 0.5 mol / L N,N-methylenebisacrylamide solution and 300 parts by weight of 0.5 mol / L ammonium persulfate solution are added, and ultrasonic reaction is performed. After the reaction is completed, 50 parts by weight of a calcium-lithium mixed solution composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of 4:1:20 is added, stirred for 0.8 h, and allowed to stand for 30 h to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer at -50°C for 25 h to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomizer, and the water vapor flow rate is set to 0.3 L / min for water vapor activation treatment for 8 minutes to obtain a gaseous nicotine electrochemical sensing material.

[0019] Example 4: In this example, the gaseous nicotine electrochemical sensing material is obtained by the following scheme Step S1: adding 10 parts by mass of sodium alginate, 35 parts by mass of aniline, and 40 parts by mass of acrylamide into 1000 parts by mass of a 50% by volume ethanol solution, stirring and dissolving, to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 40 parts by weight of black phosphorus and 9 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 100 parts by weight of a 0.7 mol / L divinylbenzene solution and 400 parts by weight of a 0.2 mol / L potassium persulfate solution are added, and ultrasonic reaction is performed. After the reaction is completed, 40 parts by weight of a calcium-lithium mixed solution composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of 4:1:20 is added, stirred for 0.6 h, and allowed to stand for 20 h to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer at -60°C for 30 h to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomizer, and the water vapor flow rate is set to 0.2 L / min for water vapor activation treatment for 6 minutes to obtain a gaseous nicotine electrochemical sensing material.

[0020] Example 5: In this example, the gaseous nicotine electrochemical sensing material is obtained by the following scheme Step S1: adding 15 parts by mass of sodium alginate, 35 parts by mass of aniline, and 50 parts by mass of acrylamide into 1000 parts by mass of an ethanol solution having a volume fraction of 45%, stirring and dissolving the mixture to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 35 parts by weight of black phosphorus and 9 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, and then 180 parts by weight of a 0.9 mol / L divinylbenzene solution and 300 parts by weight of a 0.7 mol / L potassium persulfate solution are added, and ultrasonic reaction is performed. After the reaction is completed, 45 parts by weight of a calcium-lithium mixed solution composed of calcium chloride, lithium chloride and water uniformly mixed in a weight ratio of 3:1:20 is added, stirred for 0.5 h, and allowed to stand for 40 h to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer at -60°C for 30 h to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomizer, and the water vapor flow rate is set to 0.3 L / min for water vapor activation treatment for 6 minutes to obtain a gaseous nicotine electrochemical sensing material.

[0021] Comparative Example 1 Nicotine molecular imprinting molecular materials.

[0022] Comparative Example 2 The difference from Example 1 is that there is no sodium alginate and acrylamide in step S1.

[0023] Comparative Example 3 The difference from Example 1 is that there is no black phosphorus in step S2.

[0024] Nicotine test: Examples 1-5 and Comparative Examples 1-3 were simultaneously tested for gases containing the same nicotine concentration, and the test time and error were recorded. The results are shown in Table 1.

[0025] The test results are shown in Table 1: Table 1 Test results summary

[0026] As can be seen from Table 1, compared with Comparative Examples 1 and 2, Examples 1-5 have higher accuracy and response current, mainly due to the specific recognition and binding of molecular imprinting materials with nicotine, which can generate response current, the intensity of which is positively correlated with the content of nicotine, and can accurately test the nicotine content. The composite gel of polycalcium alginate, polylithium alginate and polyacrylamide can enrich water molecules in the air, increase the number of hydrogen bonds between the material and nicotine, and can effectively collect gaseous nicotine molecules in the air, further improving the detection accuracy of the material for nicotine. Compared with Comparative Examples 1 and 3, Examples 1-5 have higher accuracy and response current, mainly because black phosphorus has abundant terminal phosphorus atoms, which can effectively improve the catalytic activity of the material and the transmission of electrons, effectively improve the transmission speed and intensity of the response current, and then expand the detection limit of nicotine. In addition, the electrochemical sensing material prepared by the method of the present invention can produce a nicotine electrochemical sensor, realize rapid real-time online monitoring of gaseous nicotine, and has broad application prospects.

[0027] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification, equivalent substitution or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a gaseous nicotine electrochemical sensing material, characterized in that: The specific steps include: Step S1: adding 10-15 parts by mass of sodium alginate, 20-35 parts by mass of aniline, and 20-50 parts by mass of acrylamide into 1000 parts by mass of ethanol solution, stirring and dissolving to obtain a mixed solution; Step S2: nitrogen is introduced into the mixed solution, 25-50 parts by weight of black phosphorus and 5-10 parts by weight of nicotine molecular imprinting material are added to the mixed solution, stirred for reaction, then 50-300 parts by weight of cross-linking agent solution and 100-500 parts by weight of initiator solution are added, ultrasonic reaction is performed, and after the reaction is completed, 30-60 parts by weight of calcium-lithium mixed solution is added, stirred for 0.5-1 hour, and allowed to stand for 20-40 hours to obtain a wet gel; Step S3: drying the wet gel in a freeze dryer to obtain a dry gel; Step S4: Before use, the dry gel is placed in an atomization device and subjected to a water vapor activation treatment to obtain a gaseous nicotine electrochemical sensing material.

2. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: The volume fraction of the ethanol solution in step S1 is 40% to 60%.

3. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: In step S2, the crosslinking agent solution is one of a divinylbenzene solution, a diisocyanate solution, and an N,N-methylenebisacrylamide solution, and the concentration is 0.1-1 mol / L.

4. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: In step S2, the initiator solution is one of potassium persulfate solution, sodium persulfate solution, and ammonium persulfate solution, and the concentration is 0.05-1 mol / L.

5. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: In step S2, the calcium-lithium mixed solution is composed of calcium chloride, lithium chloride, and water mixed evenly in a weight ratio of (2.5-5):1:

20.

6. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: In step S3, the drying temperature is -40 to -60°C and the drying time is 20 to 30 hours.

7. The method for preparing a gaseous nicotine electrochemical sensor material according to claim 1, characterized in that: The steam flow rate of the steam activation treatment in step S4 is 0.1-0.5 L / min, and the treatment time is 5-10 min.

8. The sensing material obtained by the method for preparing a gaseous nicotine electrochemical sensing material according to claim 1 is used in an electrochemical sensor for nicotine content in air.

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