A triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material, its preparation method and applications.

Abstract

This invention discloses a triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material, its preparation method, and its applications in the field of organic semiconductor sensors. The carnosine-perylene diimide derivative possesses amphiphilic properties (hydrophilic and amphiphilic), a donor-acceptor structure, and molecular chirality. The self-assembled material is drop-coated onto an ITO glass surface and dried to form the sensor, which exhibits sensitive photoelectric response. This invention uses a supramolecular material constructed via self-assembly to prepare a photoelectric sensor capable of detecting trace amounts of triethylamine in a liquid environment, with a detection limit as low as 11.8 ppm. It features a simple preparation process, good stability, high sensitivity, and detection capability at room temperature, making it suitable for mass production.

Description

Technical Field

[0001] This invention belongs to the field of organic semiconductor sensors, specifically relating to a triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular nanomaterial, its preparation method, and its applications. Background Technology

[0002] Triethylamine (TEA) has a boiling point of 89.5℃ at room temperature and pressure. It has been widely used in many fields, such as agriculture, fisheries, aviation, medicine, and healthcare, and is also an important raw material for industrial development. It is an excellent solvent, polymer inhibitor, and preservative, but it is also a substance harmful to human health. The main harm of triethylamine to humans manifests as strong irritation to the skin, mucous membranes, and central nervous system. Therefore, for industrial safety and human health, there is an urgent need to develop a sensor for the immediate and sensitive detection of triethylamine. Currently, most sensors for detecting triethylamine are resistance-based gas sensors, and methods for directly detecting triethylamine in liquid states are relatively rare. Triethylamine exists in solutions in chemical experiments, industrial production, and daily life.

[0003] The main methods for detecting triethylamine include gas chromatography-mass spectrometry (GC-MS), high-performance liquid chromatography (HPLC), and infrared spectroscopy (IR). While GC-MS and HPLC offer good separation and high accuracy, they require sophisticated equipment and analytical techniques, involve complex procedures, are expensive, labor-intensive, and time-consuming, and operate at high temperatures. Infrared spectroscopy, although simple to operate, has lower accuracy and is susceptible to interference from other organic compounds. Gas sensors for triethylamine detection generally suffer from high operating temperatures and erroneous responses to humidity changes. Currently, triethylamine sensors are primarily semiconductor metal oxide gas sensors. These sensors utilize transition metal doping and noble metal loading to enhance the gas-sensing performance of semiconductor metal oxides, thereby improving responsiveness and selectivity. For example, patent CN118191038A describes a triethylamine sensor using Au-supported and Nd-doped In₂O₃ nanospheres as the sensing material. However, the high operating temperature remains a problem; these gas-sensing materials typically operate above 250°C, and the high price of noble metals hinders practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material, its preparation method, and its applications. This sensor can detect trace amounts of triethylamine at room temperature and has the advantages of simple preparation process, good stability, and high detection sensitivity.

[0005] The technical solution for achieving the objective of this invention is as follows:

[0006] A triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material is disclosed. The sensor uses ITO glass as the working electrode, and the supramolecular material is coated onto an ITO film on the ITO glass surface to form the sensor. The supramolecular material is an amphiphilic carnosine-perylene diimide derivative, abbreviated as CPe, with the following structural formula:

[0007]

[0008] The method for preparing the triethylamine sensor based on the self-assembly method of carnosine-perylene diimide supramolecular material includes the following steps:

[0009] S1, prepare a CPe self-assembled material solution with a concentration of 0.05–0.8 mM;

[0010] S2, the CPe self-assembled material solution is dropped onto the ITO film surface of the cleaned ITO glass using the drop-coating method, with a drop volume of 0.1 to 0.2 mL per square centimeter;

[0011] S3, under normal temperature conditions, after the solvent evaporates, it is then vacuum dried at 35-65℃ for 24-72 hours to obtain the sensor.

[0012] Further, step S1 includes the following sub-steps:

[0013] S1-1: Dissolve solid CPe in chloroform to a concentration of 1.0–20.0 mM, and sonicate for 10–30 min to obtain the mother liquor;

[0014] S1-2, take 200-2000 μL of the mother liquor into a small bottle, air dry under N2 protection, and then dry under vacuum at 35-65℃ for 48-72 h;

[0015] S1-3, Take the solid dried in step S1-2, dissolve it in tetrahydrofuran, stir at 45-55℃ for 3-5 hours, then lower the temperature to 35℃ and stir for 0.5-2 hours to obtain a clear and transparent sample with a concentration of 0.5-4 mM.

[0016] S1-4: Take the solution obtained after step S1-3, dilute it with tetrahydrofuran, sonicate it for 5-20 minutes, then add water and sonicate it for another 5-20 minutes to obtain a CPe self-assembled material solution. The CPe concentration is 0.05-0.8 mM. The preferred volume ratio of tetrahydrofuran / aqueous solution is 3 / 7.

[0017] In step S2, the supramolecular material is coated on the ITO glass surface with an area of ​​1×1 cm². 2 .

[0018] The cleaning process in step S2 involves ultrasonically cleaning the ITO glass for five minutes in sequence with reagents of different polarities: toluene, acetone, and anhydrous ethanol. Each solvent is used three times for cleaning, followed by vacuum drying for later use.

[0019] The sheet resistance of the ITO glass after cleaning in step S2 is <7 ohm / sq.

[0020] The application of the triethylamine sensor based on the self-assembly method-constructed carnosine-perylene diimide supramolecular material is that it can be used for the sensing and testing of triethylamine. The testing steps are as follows:

[0021] (1) The prepared sensor was fixed in the electrolyte as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum electrode was used as the counter electrode. The sensor was connected to an electrochemical workstation through the working electrode, and the photocurrent value in the dark was recorded.

[0022] (2) Take a specified amount of triethylamine and inject it into the sealed electrolytic cell. Turn on the light source and record the photocurrent change value of the sensor.

[0023] (3) After the set time is reached, turn off the light source, wait for the same time, turn the light source back on, and record the change value of the photocurrent of the sensor.

[0024] (4) Export the photocurrent data collected by the electrochemical workstation. With time as the abscissa and the photocurrent change value as the ordinate, the photocurrent change curve with time under different triethylamine contents can be obtained. After processing, the triethylamine response curve related to the photocurrent can be obtained.

[0025] (5) Under the same conditions as in step (4), with an optical power density of 236-240 mW / cm2, a bias voltage of 0.5V, a light source distance of 3cm, and a temperature of room temperature, the sensor is placed in the triethylamine electrolyte to be tested. Using the triethylamine response curve obtained in step (4), the content of triethylamine is obtained by measuring the change in photocurrent.

[0026] In step (1), the electrolyte is 8 mL of 0.1–0.3 M sodium sulfate aqueous solution. The light source used is a 250 W / 350 W xenon lamp with a wavelength range >420 nm and a light power density of 236–240 mW / cm². 2 The bias voltage is 0.5V, the optical period is 40s, the single test time is 200s, the side of the ITO glass working electrode with the CPe self-assembled material solution dropped on it faces the incident light source, and the distance to the light source is 3cm.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] 1. The carnosine-perylene diimide derivative (CPe) in this invention possesses both hydrophilic and amphiphilic properties and a donor-acceptor structure. The former facilitates the regulation of molecular arrangement within nanomaterials using different solvent compositions, constructing long-range ordered and morphologically diverse assembly structures. The latter can generate an effective internal electric field within the assembly structure. The synergistic effect of these two structures enables efficient transport of photogenerated carriers, inhibits charge recombination, and promotes charge separation of photogenerated electrons and holes, thereby improving its photoelectric responsivity. Furthermore, this invention utilizes the introduction of chiral carnosine to induce CPe self-assembly into a more long-range ordered assembly material with supramolecular chirality through chiral transfer and amplification, further enhancing carrier mobility and thus improving sensor sensitivity. Studies have shown that the sensor constructed from CPe assembly material exhibits a maximum photoresponse current of 95.0 μA / cm² to triethylamine. 2 With a light-to-dark ratio of 38, the detection limit for triethylamine was as low as 11.8 ppm.

[0029] 2. The advantages of this triethylamine sensor are that it can effectively and rapidly determine the content of triethylamine in solution at room temperature without any safety hazards, and it has broad application prospects in detecting trace amounts of triethylamine in solution. Furthermore, the sensor is fabricated by simply drop-coating the sensing film onto ITO glass, a simple method with good processability, and also possesses the advantages of high sensitivity and rapid response. Attached Figure Description

[0030] Figure 1 A process flow diagram for using supramolecular materials formed by the self-assembly of amphiphilic carnosine-perylene diimide derivatives as sensors to detect triethylamine.

[0031] Figure 2 Digital images of CPe assemblies under (a) natural light and 365 nm UV light, (b) UV-Vis absorption spectrum, (c) fluorescence emission spectrum, and (d) circular dichroism spectrum are shown for CPe assemblies in different tetrahydrofuran / water mixed solvents. The excitation wavelength of the fluorescence spectrum is 483 nm, and the CPe concentration is 0.05 mM.

[0032] Figure 3 (a) Cyclic photocurrent response and (b) photocurrent variation curves of CPe drop-cast films constructed at different tetrahydrofuran / water ratios. The inset shows macroscopic images of the CPe drop-cast films before and after the experiment. The CPe concentration was 0.5 mM.

[0033] Figure 4 The images show TEM (af) and SEM (gi) images of the CPe assembly. The water / tetrahydrofuran volume ratios from left to right are 5 / 5, 6 / 4, and 7 / 3. The inset shows the diameter distribution and corresponding histogram of the CPe assembly. The CPe concentration is 0.05 mM.

[0034] Figure 5(a) UV-Vis absorption spectrum, (b) fluorescence emission spectrum, and (c) circular dichroism spectrum of the CPe assembly at different triethylamine contents. water =0.7, CPe concentration is 0.05mM.

[0035] Figure 6 The (a, b) and (c, d) cyclic photocurrent responses of CPe drop-cast films to different contents of triethylamine are shown. The tetrahydrofuran / water mixed solvent composition for preparing the assembled material is f. water =0.7(a), f water =0(b), CPe concentration is 0.5mM.

[0036] Figure 7 To demonstrate the real-time cyclic photocurrent response of CPe drop-cast films to different triethylamine contents, the tetrahydrofuran / water mixed solvent composition of the assembled material was prepared as (a)f water =0.7、(b)f water =0, CPe concentration is 0.5mM. Detailed Implementation

[0037] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings, but the implementation of the present invention is not limited thereto.

[0038] Synthetic route for amphiphilic carnosine-perylene diimide derivatives (CPe):

[0039] (1) Add 2-3g of 12-tetranone, 4-5g of ammonium acetate, and 1-2g of sodium cyanoborohydride to 100-150mL of isopropanol. After stirring for 4 days, add 1-2mL of concentrated hydrochloric acid, rotary evaporate, add potassium hydroxide aqueous solution, wash with dichloromethane, and rotary evaporate to obtain 12-tetranone.

[0040] (2) The 12-tetrazineamine and perylene anhydride prepared in step (1) were added to imidazole and stirred at high temperature for 6-8 hours to obtain the red product perylene-3,4,9,10-tetracarboxylic acid dianhydride.

[0041] (3) The red product perylene-3,4,9,10-tetracarboxylic acid dianhydride prepared in step (2) and potassium hydroxide were added to 30-50 mL of tert-butanol and stirred at high temperature for 1-3 h. After the solution was cooled, acetic acid was added and reacted for 2-3 h. The product was purified and filtered under reduced pressure to obtain the crude product. After separation and purification by column chromatography, the product N-(1-diundecyl)-3,4,9,10-perylenetetracarboxylic acid monoimide was obtained.

[0042] (4) Using N-(1-diundecyl)-3,4,9,10-perylenetetracarboxylic acid monoimide as a precursor, the precursor and carnosine were dissolved in imidazole at 135℃, then heated to 160℃ and stirred for 5 h. The mixture was cooled to 80℃ and reacted with HCl solution for 2 h. After filtration, the filter cake was washed 3-5 times with dichloromethane and then vacuum dried at 60℃ for 48 h to obtain an amphiphilic carnosine-perylene diimide derivative, the structural formula of which is:

[0043]

[0044] The preparation method of the triethylamine sensor based on the self-assembly method of carnosine-perylene diimide supramolecular material is carried out according to the following steps:

[0045] S1, preparing a CPe self-assembled material solution with a concentration of 0.05–0.8 mM; including the following sub-steps:

[0046] S1-1: Dissolve solid CPe in chloroform to a concentration of 1.0–20.0 mM, and sonicate for 10–30 min to obtain the mother liquor;

[0047] S1-2, take 200-2000 μL of the mother liquor into a small bottle, air dry under N2 protection, and then dry under vacuum at 35-65℃ for 48-72 h;

[0048] S1-3, Take the solid dried in step S1-2, dissolve it in tetrahydrofuran, stir at 45-55℃ for 3-5 hours, then lower the temperature to 35℃ and stir for 0.5-2 hours to obtain a clear and transparent sample with a concentration of 0.5-4 mM.

[0049] S1-4: Take the solution after step S1-3, dilute it with tetrahydrofuran, sonicate it for 5-20 minutes, then add water and sonicate it for 5-20 minutes to obtain a CPe self-assembled material solution with a CPe concentration of 0.05-0.8 mM.

[0050] S2, the CPe self-assembled material solution is dropped onto the ITO film surface of the cleaned ITO glass using a drop-coating method. The cleaning method involves ultrasonically cleaning the ITO glass for five minutes each time with toluene, acetone, and anhydrous ethanol, solvents of different polarities, three times for each solvent, followed by vacuum drying. The CPe self-assembled material solution is added at a rate of 0.1–0.2 mL per square centimeter. The area of ​​the supramolecular material coated on the ITO glass surface is 1 × 1 cm². 2 The sheet resistance of the cleaned ITO glass is <7 ohm / sq.

[0051] S3, under normal temperature conditions, after the solvent evaporates, it is then vacuum dried at 35-65℃ for 24-72 hours to obtain the sensor.

[0052] This triethylamine sensor, constructed using a self-assembly method with a carnosine-perylene diimide supramolecular material, was used for triethylamine sensing and testing. The testing steps are as follows:

[0053] (1) The prepared sensor was fixed in the electrolyte as the working electrode, with a saturated calomel electrode as the reference electrode and a platinum electrode as the counter electrode. The sensor was connected to an electrochemical workstation (VMP316channel) via the working electrode. The photocurrent value was recorded in the dark. The electrolyte was 8 mL of 0.1–0.3 M sodium sulfate aqueous solution.

[0054] (2) Take a specified amount of triethylamine and inject it into the sealed electrolytic cell. Turn on the light source, which is a 250W / 350W xenon lamp with a wavelength range >420nm and a light power density of 236~240mW / cm². 2 The bias voltage was 0.5V, the optical period was 40s, and the single test time was 200s. The side of the ITO glass working electrode with the CPe self-assembled material solution dropped on it faced the incident light source, which was 3cm away. The photocurrent changes of the sensor were recorded.

[0055] (3) After the set time is reached, turn off the light source, wait for the same time, turn the light source back on, and record the change value of the photocurrent of the sensor.

[0056] (4) Export the photocurrent data collected by the electrochemical workstation. With time as the abscissa and the photocurrent change value as the ordinate, the photocurrent change curve with time under different triethylamine contents can be obtained. After processing, the triethylamine response curve related to the photocurrent can be obtained.

[0057] (5) Under the same conditions as in step (4), with an optical power density of 236-240 mW / cm2, a bias voltage of 0.5V, a light source distance of 3cm, and a temperature of room temperature, the sensor is placed in the triethylamine electrolyte to be tested. Using the triethylamine response curve obtained in step (4), the content of triethylamine is obtained by measuring the change in photocurrent.

[0058] Example 1

[0059] The specific implementation process is as follows: Figure 1 As shown:

[0060] (1) Preparation of supramolecular self-assembled materials: Dissolve CPe solid in 1.4 mL of chloroform to a concentration of 5.0 mM, and sonicate for 30 min to obtain the mother liquor. Take 400 μL of the mother liquor into a small bottle, dry it under N2 protection, and then dry it under vacuum at 65 °C for 48 h. Dissolve the dried solid in 800 μL of tetrahydrofuran, stir at 45 °C for 3 h, then lower the temperature to 35 °C and stir for 1 h to obtain a clear and transparent solution with a concentration of 2.5 mM. Take 200 μL of the solution, add 100 μL of tetrahydrofuran to dilute it, sonicate for 5 min, and then add different volumes of water and sonicate for 5 min to obtain a series of assembly solutions with different tetrahydrofuran / water solution volume ratios and a CPe concentration of 0.5 mM.

[0061] (2) Sensor preparation: The assembly solution containing amphiphilic carnosine-perylene diimide derivative nanomaterials was dropped onto the surface of the working electrode ITO using the drop-coating method. The amount of drop added was 0.1 mL per square centimeter. After the solvent evaporated, the sensor was dried under vacuum to obtain the sensor.

[0062] (3) Plotting the triethylamine response curve: Place the sensor in a triethylamine electrolyte of known concentration and detect the change of photocurrent over time to obtain the triethylamine response curve.

[0063] (4) Detection of triethylamine content: In step (3), the optical power density is 236 mW / cm². 2 Under the same conditions of bias voltage of 0.5V, light source distance of 3cm, and room temperature, the sensor is placed in the triethylamine electrolyte to be tested. The content of triethylamine is obtained by using the triethylamine response curve obtained in step (3) and the change value of photocurrent.

[0064] Example 2

[0065] Example 2 investigated the effect of different tetrahydrofuran / aqueous solution volume ratios on CPe assemblies.

[0066] The preparation of the CPe assembly mother solution was the same as in Example 1. 200 μL of the mother solution was taken, diluted with 100 μL of tetrahydrofuran, and sonicated for 5 min. Then, different volumes of water were added and sonicated for 5 min each to obtain assembly solutions with different tetrahydrofuran / water solution volume ratios from 0 to 0.9 and a CPe concentration of 0.05 mM. After stabilizing for 2 hours, the ultraviolet absorption spectrum was obtained using a UV-Vis absorption spectrometer (Cary 5000, Varian, USA), with a slit width of 5 nm and an optical path of 0.5 cm. Figure 2 b) Using a fluorescence spectrometer (F-7000, Hitachi, Japan), with a slit width of 2.5 nm, an excitation wavelength of 483 nm, and an optical path of 1 cm, the fluorescence emission spectrum of the assembled solution was measured. Figure 2c) Using a circular dichroism chromatograph (J-810, JASCO, Japan), with a response time of 4 s, a bandwidth of 2 nm, and a path length of 0.5 cm, the circular dichroism of the assembled solution was tested. Figure 2 d).

[0067] Depend on Figure 2 As the water content in different tetrahydrofuran / water ratios increases, the solution color under natural light gradually changes from red to bright orange, then back to red. Under 365nm UV excitation, the fluorescence of the solution gradually increases, then decreases, and the color changes from fluorescent green to orange, then back to red. With increasing water content, the maximum absorption peak of the assembly blue-shifts, accompanied by peak broadening, indicating that increasing water content promotes the transformation of CPe assemblies from monomers to H-type aggregates. The fluorescence intensity first increases and then decreases, reaching its lowest value when the water content is 0.7%, indicating that the degree of π-π stacking is maximized at this water content. The CD signal shows a trend of first increasing, then decreasing, and then increasing again. The change in the CD signal is similar to the trend of the UV absorption peak; the CD signal is strongest when the water content reaches around 0.7%, indicating that the supramolecular chirality of the CPe assembly is strongest.

[0068] Example 3

[0069] Example 3 investigated the response of drop-cast films made from CPe assembly solutions to photocurrent at different tetrahydrofuran / aqueous solution volume ratios.

[0070] The preparation of the CPe assembly mother solution was the same as in Example 1. 200 μL of the mother solution was taken, diluted with 100 μL of tetrahydrofuran, and sonicated for 5 min. Then, different volumes of water were added and sonicated for 5 min each to obtain assembly solutions with different tetrahydrofuran / water solution volume ratios from 0 to 0.85 and a CPe concentration of 0.5 mM. 100 μL of the solution was pipetted and uniformly dropped onto an ITO glass substrate, which was then vacuum-dried at 65 °C for 24 hours. At room temperature, the photocurrent was measured using a standard three-electrode system via an electrochemical workstation (VMP3 16-channel, Biologic, Germany), with 0.1 M sodium sulfate aqueous solution as the electrolyte. The side of the ITO glass working electrode with the CPe self-assembled material solution dropped onto it faced the incident light source. The light source was a 250W / 350W xenon lamp (BBZW-III, wavelength range >420nm), with a bias voltage of 0.5V, a light period of 40s, a single test duration of 200s, and an optical power density of 236–240mW / cm². 2 The distance between the lamp and the working electrode was 3 cm. The prepared sensor was used as the working electrode, the saturated calomel electrode as the reference electrode, and the platinum electrode as the counter electrode. The light source was turned on, the light path was perpendicular to the sample surface, and the photocurrent data was recorded.

[0071] Depend on Figure 3It can be seen that the photoelectric properties increase with the increase of water content in different tetrahydrofuran / water ratios. (b) The inset in the figure shows the state of the samples on the ITO glass before and after the test. It can be seen that the CPe drop-cast film remained intact and did not fall off before and after the test. When the water content is about 0.7, the film-forming properties of the CPe drop-cast film are better. When the water content is greater than 0.7, the drop-cast film may fall off.

[0072] Example 4

[0073] Example 4 investigated the morphological changes of CPe assemblies under different tetrahydrofuran / aqueous solution volume ratios.

[0074] The preparation of the CPe assembly mother solution was the same as in Example 1. Take 200 μL of the mother solution, add 100 μL of tetrahydrofuran for dilution, sonicate for 5 min, add different volumes of water and sonicate for 5 min to obtain assembly solutions with different tetrahydrofuran / water solution volume ratios of 0.5, 0.6 and 0.7, and a CPe concentration of 0.05 mM.

[0075] Depend on Figure 4 It can be seen that as the water content in different tetrahydrofuran / water ratios increases, the morphology of the assembly gradually changes from a coexistence of large short rods and "donut" structures to smaller nanomaterials with "donut" structures as the main component.

[0076] Example 5

[0077] Example 5 investigated the effect of different triethylamine contents on the CPe assembly when the water content was 0.7%.

[0078] The preparation of the CPe assembly mother liquor was the same as in Example 1. Take 200 μL of the mother liquor, add 100 μL of tetrahydrofuran for dilution, sonicate for 5 min, add a certain volume of water and sonicate for 5 min to prepare a clear and transparent 0.05 mM assembly solution with a tetrahydrofuran / water volume ratio of 3 / 7. Add different volumes of triethylamine to the solution, stabilize for 5 min, and then perform the test.

[0079] Depend on Figure 5As the triethylamine content increases, the maximum absorption peak of the CPe assembly narrows and its intensity increases, indicating a weakening of π-π packing and the gradual emergence of fine structures, which in turn increases the fluorescence intensity. The CD signal shows a trend of first rising and then falling. When the molar ratio of triethylamine to CPe assembly reaches 5:1, the CD signal is strongest, indicating that the supramolecular chirality of the CPe assembly is strongest at this point. These results indicate that the addition of a small amount of triethylamine helps to further improve the long-range order and supramolecular chirality of the assembly structure, while the addition of excessive triethylamine induces the supramolecular material structure to disintegrate into oligomers and unimolecular states. In the triethylamine detection system, no supramolecular material disintegration was observed, thus mainly reflecting that triethylamine optimizes the order of the supramolecular material, and the improvement of order helps to further improve photoelectric responsivity.

[0080] Example 6

[0081] Example 6 investigated the response of triethylamine with different water contents to photocurrent when the water content was 0.7% and 0%.

[0082] The preparation of the CPe assembly mother solution was the same as in Example 1. 200 μL of the mother solution was taken, diluted with 100 μL of tetrahydrofuran, and sonicated for 5 min. Then, different volumes of water were added and sonicated for 5 min each, to prepare clear, transparent 0.5 mM assembly solutions with water contents of 0.7% and 0%, respectively. Different volumes of triethylamine were added to the solutions, and the solutions were stabilized for 5 min. 100 μL of the solution was pipetted and uniformly dropped onto ITO glass, then vacuum dried at 65°C for 24 hours. At room temperature, using a standard three-electrode system, the photocurrent was measured via an electrochemical workstation. The prepared sensor was used as the working electrode, a saturated calomel electrode as the reference electrode, and a platinum electrode as the counter electrode. The light source was turned on, with the light path perpendicular to the sample surface, and the photocurrent data was recorded. After 20 s, the light source was turned off, and after another 20 s, it was turned on again. This process was repeated twice. Fifteen points were selected within the triethylamine content range of 0 vol / % to 2.5 vol / % for each point, and the above process was repeated. Using an electrochemical workstation, the photocurrent versus time curves for different triethylamine contents can be obtained. Plotting triethylamine on the x-axis and photocurrent on the y-axis yields the triethylamine response curve.

[0083] Depend on Figure 6 It is evident that when the triethylamine content is below 2.5 vol / %, the photocurrent increases with increasing triethylamine content. When the triethylamine content is above 2.5 vol / %, the increase in photocurrent plateaus. Furthermore, the smaller the triethylamine content, the more significant the change in photocurrent, indicating that the sensor has high sensitivity for detecting trace amounts of triethylamine. The drop-cast film prepared from an assembly solution with a tetrahydrofuran / aqueous solution volume ratio of 3 / 7, used as a sensor, exhibits a maximum photoresponse current of 95.0 μA / cm for triethylamine. 2 With a light-to-dark ratio of 38, the detection limit for triethylamine was as low as 11.8 ppm.

[0084] Example 7

[0085] Example 7 investigated the response of photocurrent to the addition of different amounts of triethylamine online when the water content was 0.7% and 0%.

[0086] This embodiment is largely the same as Example 6, except that different amounts of triethylamine were added during the photocurrent testing process. After adding a trace amount of triethylamine (0.06 vol / %), the photocurrent changed immediately upon turning on the light source. The drop-cast membrane prepared from the assembly solution with a tetrahydrofuran / aqueous solution volume ratio of 3 / 7, used as a sensor, showed a more significant response to triethylamine.

[0087] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. The application of a triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material, characterized in that: The triethylamine sensor uses ITO glass as the working electrode. A supramolecular material is coated on the ITO film on the surface of the ITO glass. The supramolecular material is an amphiphilic carnosine-perylene diimide derivative, abbreviated as CPe, and its structural formula is as follows: The sensor is manufactured using the following steps: S1, prepare a CPe self-assembled material solution with a concentration of 0.05~0.8 mM; It includes the following steps: S1-1: Dissolve solid CPe in chloroform to a concentration of 1.0~20.0 mM, and sonicate for 10~30 min to obtain the mother liquor; S1-2, take 200~2000 μL of the mother liquor into a small bottle, air dry under N2 protection, and then dry under vacuum at 35~65℃ for 48~72 h; S1-3, Take the solid dried in step S1-2, dissolve it in tetrahydrofuran, stir at 45~55℃ for 3~5 h, then lower the temperature to 35℃ and stir for 0.5~2 h to obtain a clear and transparent sample with a concentration of 0.5~4 mM. S1-4: Take the solution after step S1-3, dilute it with tetrahydrofuran, sonicate it for 5-20 min, then add water and sonicate it for 5-20 min to obtain the CPe self-assembled material solution. The CPe concentration is 0.05-0.8 mM, and the volume ratio of tetrahydrofuran / water solution is 3 / 7. S2, the CPe self-assembled material solution is dropped onto the ITO film surface of the cleaned ITO glass using the drop-coating method, with a drop volume of 0.1~0.2 mL per square centimeter; S3, under normal temperature conditions, after the solvent evaporates, it is then vacuum dried at 35~65℃ for 24~72 h to obtain the sensor; The sensor is used for triethylamine sensing and testing. The testing steps are as follows: (1) The prepared sensor was fixed in the electrolyte as the working electrode, a saturated calomel electrode was used as the reference electrode, and a platinum electrode was used as the counter electrode. The sensor was connected to an electrochemical workstation through the working electrode to record the photocurrent value in the dark. (2) Take the prescribed amount of triethylamine, inject it into a sealed electrolytic cell, turn on the light source, and record the change value of the photocurrent of the sensor; (3) After the set time is reached, turn off the light source, wait for the same time, turn the light source back on, and record the change value of the photocurrent of the sensor. (4) Export the photocurrent data collected by the electrochemical workstation. With time as the abscissa and the photocurrent change value as the ordinate, the photocurrent change curve with time under different triethylamine contents can be obtained. After processing, the triethylamine response curve related to the photocurrent can be obtained. (5) Place the sensor in the triethylamine electrolyte to be tested for photocurrent testing. Using the triethylamine response curve obtained in step (4), the content of triethylamine is obtained by the change in photocurrent.

2. The use of the triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material according to claim 1, characterized in that, In step S2, the supramolecular material is coated on the ITO glass surface with an area of ​​1 × 1 cm². 2 .

3. The use of the triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material according to claim 1, characterized in that, The cleaning process in step S2 involves ultrasonically cleaning the ITO glass for five minutes in sequence with reagents of different polarities: toluene, acetone, and anhydrous ethanol. Each solvent is used three times for cleaning, followed by vacuum drying for later use.

4. The use of the triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material according to claim 1, characterized in that, In step (5), the optical power density is 236~240 mW / cm². 2 The bias voltage is 0.5 V, the distance from the light source is 3 cm, and the temperature is room temperature.

5. The use of the triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material according to claim 1, characterized in that, In step (1), the electrolyte is 8 mL of 0.1~0.3 M sodium sulfate aqueous solution.

6. The use of a triethylamine sensor based on a self-assembled carnosine-perylene diimide supramolecular material according to claim 4, characterized in that, The light source is a 250W / 350W xenon lamp with a wavelength range >420 nm and an optical power density of 236~240 mW / cm². 2 The bias voltage is 0.5 V, the optical period is 40 s, the single test time is 200 s, the side of the ITO glass working electrode with the CPe self-assembled material solution dropped on it faces the incident light source, and the distance to the light source is 3 cm.

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