A kaempferol-al for detecting glyphosate 3+ Complex fluorescent probe and preparation method thereof

Abstract

This invention relates to the field of glyphosate detection, and discloses a kaempferol-Al method for detecting glyphosate. 3+ Complex fluorescent probes and their preparation methods. Due to the interaction between glyphosate and Al... 3+ The complexing ability is stronger than that of kaempferol and Al. 3+ Complexing ability of kaempferol-Al 3+ Adding glyphosate to the complex fluorescent probe allows glyphosate to abstract Al. 3+ The probe dissociates and exhibits obvious fluorescence quenching, enabling the detection of glyphosate based on this principle. The fluorescent sensing system constructed in this invention detects glyphosate without interference from other pesticides, and features simple preparation, high selectivity, high sensitivity, and fast response, achieving trace detection of glyphosate. Furthermore, test strips made from the fluorescent probe of this invention can visually detect glyphosate under ultraviolet light.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of glyphosate detection, and in particular to a kaempferol-Al 3+ complex fluorescent probe and a preparation method thereof. BACKGROUND

[0002] Glyphosate (Gly) is an organophosphorus herbicide with strong systemicity and broad-spectrum killing effect, and has become the most widely used and largest-selling herbicide variety. Long-term and widespread use of glyphosate has led to the presence of a large amount of residual glyphosate in crops, soil, water bodies, etc.; glyphosate has reproductive toxicity, mutagenicity, etc., and thus poses great harm to human health and the ecological environment, and the residual level of glyphosate has become one of the key projects for monitoring in the fields of food, environment, etc. At present, more than 30 countries around the world have begun to restrict or even prohibit the use of glyphosate, and to strengthen the detection of its residual level in crops and the environment. The United States Environmental Protection Agency (USEPA) sets the maximum contaminant level (MCL) of glyphosate in drinking water at 4.1 μM. In China, the national standard GB 5749-2022 stipulates that the maximum concentration of glyphosate residue in drinking water is not more than 0.7 μg / mL. At present, the detection methods for the residual amount of organophosphorus pesticides including glyphosate mainly include the following: gas chromatography (GC), capillary electrophoresis (CE) and high performance liquid chromatography (HPLC), etc. These methods have high sensitivity, but require precise instruments and professional operators, and require derivatization treatment of glyphosate, which is complex in sample preparation, and is not conducive to rapid detection of glyphosate. Therefore, it is urgent to develop a convenient and rapid analysis method for detecting glyphosate.

[0003] Fluorescent probes can detect metal ions, anions and small molecules using fluorescence properties, have the advantages of simple operation, high sensitivity and strong specificity, and do not need to rely on expensive instruments, and are very suitable for real-time or in-situ detection. At present, some progress has been made in the related research on the use of fluorescent probes to detect glyphosate, such as Chinese patent CN117723526A “Method for rapid detection of glyphosate and cadmium by single-atom nano-enzyme-based fluorescent probe”, which uses sodium chlorophyll as a ligand, Fe 3+ as the central atom, and synthesizes Fe-N-C single-atom nano-enzyme with a similar structure to the active center of natural metalloenzymes. When Cd 2+ is introduced into the system, the electron transfer of Fe-N-C is strengthened, the Fe-N-C peroxidase activity is strengthened, and the fluorescence of the system is enhanced, while when glyphosate is added, the Fe 3+ is competed for by glyphosate, the fluorescence of the system is weakened, and the method can be used for rapid detection of glyphosate and Cd 2+, Fe-N-C mimics peroxidase activity is inhibited, the system fluorescence intensity decreases, thereby achieving high sensitivity detection of glyphosate. However, heavy metal cadmium needs to be introduced during the detection process, which may cause harm to humans and the environment. Chinese patent CN115494033A "A detection method of glyphosate" obtains nitrogen-doped carbon dots (N-CDs) by hydrothermal reaction after mixing citric acid and ethylenediamine. N-CDs have good recognition ability for Cu 2+ 2+ The static fluorescence quenching effect significantly inhibits the fluorescence thereof; due to the chelation of glyphosate with Cu 2+ being stronger than that of N-CDs, when glyphosate is added to the N-CDs / Cu 2+ system, the N-CDs are converted into a free state, so that the fluorescence thereof is turned on again, thereby achieving the detection of glyphosate. Although the carbon dots have simple preparation process, stable performance, and achieve simple detection of glyphosate to some extent, there are still defects such as long response time and poor visual detection effect. Chinese patent CN114989146B "On-off-on type continuous detection of quinoline fluorescent probe for Cu (II) and glyphosate, and preparation method and application thereof" synthesizes a quinoline fluorescent probe by using quinoline-2-formylhydrazine and 7-(diethylamino) coumarin-3-formaldehyde as raw materials. Although the detection limit of the quinoline fluorescent probe for glyphosate is low, the final product needs to be synthesized in multiple steps, the reaction process is complex, and the preparation cost is high. Therefore, it is of great significance to develop an economic and efficient, environment-friendly, visual, and fast-response fluorescent probe for detecting glyphosate. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a kaempferol-Al 3+ complex fluorescent probe for detecting glyphosate, which is simple to prepare, can achieve efficient and sensitive detection of glyphosate, and the cellulose test paper made of the probe can recognize and detect glyphosate under the irradiation of an ultraviolet lamp.

[0005] The purpose of the present application is to provide an environment-friendly complex fluorescent probe which is simple to prepare and can be visualized, and to provide the application of the fluorescent probe in the field of detecting glyphosate.

[0006] The purpose of the present application is achieved at least by one of the following technical solutions:

[0007] The present application provides a fluorescent probe for detecting glyphosate, which is a kaempferol-Al 3+ complex fluorescent probe (KFR-Al 3+ for short), and the molecular structure formula is as follows:

[0008]

[0009] ​The application provides a kaempferol-Al complex fluorescent probe for detecting glyphosate 3+ The preparation method of the complex fluorescent probe is as follows:

[0010]

[0011] The application provides a kaempferol-Al complex fluorescent probe for detecting glyphosate 3+ The preparation method of the complex fluorescent probe specifically comprises the following steps:

[0012] Kaempferol (KFR) is added into ethanol, and after stirring until completely dissolved, an aluminum salt is added, and stirring reaction is carried out at room temperature to obtain a kaempferol-Al complex ethanol solution; after the reaction is completed, rotary evaporation is carried out to obtain a yellow-brown solid, the precipitate is washed with anhydrous ethanol and water for multiple times, and vacuum drying is carried out to obtain a yellow-brown powdery solid, which is the kaempferol-Al complex fluorescent probe (KFR-Al 3+ ). 3+ ). 3+ ).

[0013] Preferably, the aluminum salt is any one of aluminum chloride hexahydrate, aluminum sulfate and aluminum nitrate.

[0014] Preferably, the molar ratio of the kaempferol to the aluminum salt is 1: (1-1.5).

[0015] Preferably, the molar volume ratio of the kaempferol to ethanol is 1 mol / 12 mL-1 mol / 30 mL.

[0016] Preferably, the stirring reaction time is 1-2 h.

[0017] Preferably, the vacuum drying temperature is 25-40 DEG C, and the time is 6-12 h.

[0018] The principle of the technical scheme is as follows: the two aromatic rings in kaempferol can freely rotate, the energy in an excited state can be dissipated through non-radiative transition, and thus the fluorescence is very weak. However, after complexing with Al 3+ , the rotation is hindered due to the increase of steric hindrance, the energy dissipation of non-radiative transition is weakened, and thus the fluorescence is enhanced. The phosphonic acid group, the secondary amine group and the carboxyl group in the pesticide glyphosate can all complex with Al 3+ , the glyphosate has strong binding force with Al 3+ , can snatch Al 3+ complexed with the kaempferol, and makes the probe fluorescence quench, so that the detection of the glyphosate is realized. The kaempferol has only one ligand to coordinate with Al 3+ , and the complexing capacity of the kaempferol with Al 3+ is weak, so that the glyphosate can quickly snatch Al 3+Based on the above principle, using the probe can realize high response sensitivity to glyphosate and short detection time.

[0019] The application also provides a test paper made of the kaempferol-Al 3+ complex fluorescent probe. 3+ The test paper is made by immersing a cellulose blank test paper strip in a kaempferol-Al 3+ complex ethanol solution and naturally drying.

[0020] Compared with the prior art, the application has the following beneficial effects:

[0021] (1) The fluorescent probe prepared by the application takes natural product kaempferol as the main raw material, has the advantages of being simple to obtain, low toxicity and friendly to the environment.

[0022] (2) The kaempferol-Al 3+ complex fluorescent probe prepared by the application has good selectivity for glyphosate, is not interfered by other pesticides, and has fast response speed. 3+ The detection limit of the kaempferol-Al -7 complex fluorescent probe for glyphosate is 4.9*10 -2 mol / L (i.e. 8.3*10 3+ mg / L), which can meet the detection requirements of the drinking water health standard (GB5749-2022) of China, has high sensitivity, and realizes trace detection of glyphosate.

[0023] (3) The kaempferol-Al 3+ complex fluorescent probe prepared by the application can be made into a test paper, which can visually identify and detect glyphosate under ultraviolet lamp irradiation, has strong practicability, and has good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The figure is the Fourier infrared spectrum of kaempferol and kaempferol-Al 3+ complex.

[0025] Figure 2 The figure is a complex ratio determination graph of kaempferol and Al 3+ .

[0026] Figure 3 The figure is a fluorescence response graph of the kaempferol-Al 3+ complex fluorescent probe with increasing glyphosate concentration.

[0027] Figure 4 The figure is a fluorescence response graph of the kaempferol-Al 3+Linear relationship between fluorescence intensity of complex fluorescent probe at 475 nm and glyphosate concentration.

[0028] Figure 5 For kaempferol-Al 3+ Fluorescence selectivity of complex fluorescent probe for glyphosate.

[0029] Figure 6 For kaempferol-Al 3+ Response time of complex fluorescent probe for glyphosate.

[0030] Figure 7 For kaempferol-Al 3+ Color change of cellulose test paper made of complex fluorescent probe under UV irradiation with glyphosate concentration.

[0031] Figure 8 For kaempferol-Al 3+ Gray scale of color change of cellulose test paper made of complex fluorescent probe under UV irradiation with glyphosate concentration. DETAILED DESCRIPTION

[0032] In order to further understand the present application, the method for detecting glyphosate provided by the present application is described in detail below in combination with examples. However, the implementation and protection of the present application are not limited thereto. It should be noted that, if there are processes not specifically described in detail below, they can be implemented or understood by referring to the prior art by those skilled in the art. If the reagents or instruments used are not specified by the manufacturer, they are considered to be conventional products that can be purchased on the market.

[0033] Example 1

[0034] 286.2 mg (1 mmol / L) of kaempferol was dissolved in 30 mL of ethanol, and 362.1 mg (1.5 mmol / L) of aluminum chloride hexahydrate was added. The reaction was stirred at room temperature for 1 h to obtain kaempferol-Al 3+ Complex ethanol solution. After the reaction was completed, ethanol was removed by rotary evaporation, and the precipitate was washed with anhydrous ethanol and water for several times, and dried under vacuum at 25 °C for 6 h to obtain kaempferol-Al 3+ 365.1 mg (yield 87.0%) of complex fluorescent probe.

[0035] Figure 1 For kaempferol and kaempferol-Al 3+ Main infrared spectrum data of the complex. It was characterized by infrared spectrum, and there was a stretching vibration peak of Al-O at 641 cm -1 -1, indicating the formation of a metal complex. The C=O stretching vibration peak of kaempferol without complexing with metal ions was at 1660 cm -1 -1, and due to the formation of the complex, the stretching vibration of this carbon group shifted to 1606 cm-1 , which indicates that the carbon-based oxygen atom of kaempferol participates in the coordination with Al 3+ . The complex ratio curve of kaempferol and Al 3+ ( Figure 2 ) shows that the complex ratio of kaempferol and Al 3+ is 1:1. Through the above infrared spectrum and complex ratio analysis, it can be determined that the synthesized product is the target fluorescent probe.

[0036] Example 2

[0037] 572.4 mg (2 mmol / L) of kaempferol was dissolved in 30 mL of ethanol, and 579.4 mg (2.4 mmol / L) of aluminum chloride hexahydrate was added, and the reaction was stirred at room temperature for 1.5 h to obtain a kaempferol-Al 3+ complex ethanol solution. After the reaction was completed, the ethanol was removed by rotary evaporation, and the precipitate was washed with anhydrous ethanol and water several times, and vacuum dried at 33°C for 8 h to obtain 719.4 mg (yield 85.7%) of kaempferol-Al 3+ complex fluorescent probe.

[0038] The characterization results of the fluorescent probe obtained in this example are the same as those in Example 1.

[0039] Example 3

[0040] 715.5 mg (2.5 mmol / L) of kaempferol was dissolved in 30 mL of ethanol, and 603.5 mg (2.5 mmol / L) of aluminum chloride hexahydrate was added, and the reaction was stirred at room temperature for 2 h to obtain a kaempferol-Al 3+ complex ethanol solution. After the reaction was completed, the ethanol was removed by rotary evaporation, and the precipitate was washed with anhydrous ethanol and water several times, and vacuum dried at 40°C for 12 h to obtain 924.4 mg (yield 88.1%) of kaempferol-Al 3+ complex fluorescent probe.

[0041] The characterization results of the fluorescent probe obtained in this example are the same as those in Example 1.

[0042] Example 4

[0043] Effect of glyphosate concentration on the fluorescence emission spectrum of kaempferol-Al 3+ complex probe:

[0044] This example explores the effect of glyphosate concentration on the fluorescence emission spectrum of kaempferol-Al 3+ complex probe. The kaempferol-Al 3+The complex fluorescent probe was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. 10 μL of the probe mother liquor was taken in a centrifuge tube each time, diluted with ethanol and water, and then different volumes of glyphosate were added to make the glyphosate concentrations 0, 1.0, 2.0, 3.0, 4.0, 5.0, …, 20 μmol / L, respectively, while the volume fraction of the solvent ethanol was fixed at 90% (V(EtOH) / V(H2O) = 9:1), and the volume of the test solution was also fixed at 3 mL. Under the action of 365 nm excitation light, the fluorescence emission spectrum of the system was measured. The results are shown in Figure 3 As the glyphosate concentration increases, the fluorescence intensity of the probe gradually decreases. Linear fitting was performed with the glyphosate concentration as the horizontal coordinate and the fluorescence intensity at 475 nm as the vertical coordinate, and the results are shown in Figure 4 As shown in the figure, in the range of 0-10 μmol / L of glyphosate concentration, the fluorescence intensity has a good linear relationship with the change of glyphosate concentration, and the standard curve equation obtained by fitting is Y = 1200-86.68X (X is the glyphosate concentration, Y is the fluorescence emission peak intensity value), and the linear correlation coefficient R 2 = 0.99. According to the calculation formula of the detection limit: detection limit = 3σ / k, the detection limit of the kaempferol-Al 3+ complex fluorescent probe for glyphosate is 4.9 x 10 -7 mol / L (i.e. 8.3 x 10 -2 mg / L), which can meet the detection requirements of the Drinking Water Health Standards (GB 5749-2022) of China. The above results show that the kaempferol-Al 3+ complex fluorescent probe has high sensitivity in detecting glyphosate and can realize trace detection of glyphosate.

[0045] Example 5

[0046] The kaempferol-Al 3+ complex probe has selectivity for glyphosate:

[0047] In this example, the selectivity of the kaempferol-Al 3+ complex fluorescent probe for glyphosate was determined. The kaempferol-Al 3+ complex fluorescent probe prepared in Example 1 was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. 10 μL of the probe mother liquor was taken in a centrifuge tube each time, diluted with ethanol and water, and then 20 μL of 3.0 mmol / L of glyphosate, carbofuran and thiram were added in equal amounts, and the volume fraction of the solvent ethanol was fixed at 90% (V(EtOH) / V(H2O) = 9:1), while the volume of the test solution was also fixed at 3 mL. Under the action of 365 nm excitation light, the fluorescence emission spectrum was measured, and the results are shown in Figure 5The probe showed significant fluorescence quenching after the addition of glyphosate, while the addition of other pesticides (carbaryl, thiram) failed to cause significant fluorescence changes. This indicates that kaempferol-Al 3+ The complex fluorescence probe showed excellent selective recognition ability for glyphosate.

[0048] Example 6

[0049] Kaempferol-Al 3+ Time response test of the complex probe for glyphosate:

[0050] In this example, kaempferol-Al 3+ Time response of the complex fluorescence probe for glyphosate was determined. Kaempferol-Al 3+ The complex fluorescence probe was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. For each test, 10 μL of the probe mother liquor was taken in a centrifuge tube, diluted with ethanol and water, and then 20 μL of 3 mmol / L glyphosate was added. The volume fraction of solvent ethanol was fixed at 90% (V(EtOH) / V(H2O)=9:1), while the volume of the test solution was fixed at 3 mL. The change in fluorescence intensity at 475 nm with reaction time was measured, with an excitation wavelength of 365 nm. As shown in Figure 6 The fluorescence intensity gradually decreased with the extension of the reaction time with glyphosate, and reached a plateau at 59 s. This indicates that kaempferol-Al 3+ The complex fluorescence probe reacts rapidly with glyphosate, and rapid detection of glyphosate can be achieved within 1 minute.

[0051] Example 7

[0052] Kaempferol-Al 3+ Detection of glyphosate in actual water samples by the complex probe:

[0053] Two water samples, laboratory tap water and lake water, were selected and pretreated: the water samples were centrifuged at a speed of 12000 rpm for 10 min, filtered, and then a glyphosate solution with a concentration of 1 mmol / L was prepared using the filtered water sample. Kaempferol-Al 3+The complex fluorescent probe was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. 10 μL of the probe mother liquor was taken in a centrifuge tube each time, diluted with ethanol and water, and then the above glyphosate solution was added to make the concentration of glyphosate 2.0 μmol / L, 4.0 μmol / L, 6.0 μmol / L, and 8.0 μmol / L, respectively. Under the action of 365 nm excitation light, the fluorescence emission peak intensity value of the fluorescent probe at 475 nm was measured, and it was brought into the following standard curve equation: Y = 1200 - 86.68X (X is the concentration of glyphosate, and Y is the fluorescence emission peak intensity value), to calculate the concentration of the glyphosate solution to be measured. The detection results are shown in Table 1.

[0054] Table 1 Kaempferol-Al 3+ Detection of glyphosate in actual water samples by the complex fluorescent probe

[0055]

[0056] From the data in Table 1, it can be seen that the recovery rate of glyphosate in the actual water sample is 96.12% to 102.38%, and the relative standard deviation is 1.66% to 3.39%. These results show that the kaempferol-Al 3+ The complex fluorescent probe has high accuracy and good practical performance in the detection of glyphosate in actual water samples.

[0057] Example 8

[0058] Kaempferol-Al 3+ Detection of glyphosate in soil by the complex probe:

[0059] The field soil was pretreated: 1 g of soil was weighed into a centrifuge tube, 50 mL of water was added, and ultrasonic treatment was performed for 30 min. The supernatant was filtered with filter paper after centrifugation at 8000 r / min for 5 min, to obtain a soil extract, which was used to prepare a glyphosate solution with a concentration of 1 mmol / L. The kaempferol-Al 3+ The complex fluorescent probe was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. 10 μL of the probe mother liquor was taken in a centrifuge tube each time, diluted with ethanol and water, and then the above glyphosate solution was added to make the concentration of glyphosate 2.0 μmol / L, 4.0 μmol / L, 6.0 μmol / L, and 8.0 μmol / L, respectively. Under the action of 365 nm excitation light, the fluorescence emission peak intensity value of the fluorescent probe at 475 nm was measured, and it was brought into the following standard curve equation: Y = 1200 - 86.68X (X is the concentration of glyphosate, and Y is the fluorescence emission peak intensity value), to calculate the concentration of the glyphosate solution to be measured. The detection results are shown in Table 2.

[0060] Table 2 Kaempferol-Al 3+Complex fluorescent probe for detecting glyphosate in soil samples

[0061]

[0062] As shown by the data in Table 2, the recovery rate of glyphosate in the soil samples was 95.27% to 100.69%, and the relative standard deviation was 0.94% to 3.38%. These results show that the kaempferol-Al 3+ The complex fluorescent probe for detecting glyphosate in soil has high accuracy and good practical performance.

[0063] Example 9

[0064] Kaempferol-Al 3+ Complex probe for detecting glyphosate in vegetables:

[0065] About 200 g of green vegetable (Shanghai green) samples were ground and passed through a 2.0 mm mesh screen, and mixed. 5 g of the mixture was placed in a 50 mL centrifuge tube, 20 mL of water and 10 mL of dichloromethane were added, and stirred for 20 min, and centrifuged at 5000 r / min for 10 min. The upper aqueous solution was transferred to another centrifuge tube, and the residue was added with 50 mL of water and extracted again. The upper aqueous solutions were mixed, filtered, and prepared into a glyphosate solution with a concentration of 1 mmol / L. The kaempferol-Al 3+ The complex fluorescent probe was dissolved in ethanol to prepare a test mother liquor with a probe concentration of 3 mmol / L. 10 μL of the probe mother liquor was taken in a centrifuge tube, diluted with ethanol and water, and added with the above glyphosate solution to make the concentration of glyphosate 2.0 μmol / L, 4.0 μmol / L, 6.0 μmol / L, and 8.0 μmol / L, respectively. Under the action of 365 nm excitation light, the fluorescence emission peak intensity value of the fluorescent probe at 475 nm was measured, and it was brought into the following standard curve equation: Y = 1200-86.68X (X is the concentration of glyphosate, and Y is the fluorescence emission peak intensity value), to calculate the concentration of the glyphosate solution to be detected. The detection results are shown in Table 3.

[0066] Table 3 Kaempferol-Al 3+ Complex fluorescent probe for detecting glyphosate in vegetable samples

[0067]

[0068] As shown by the data in Table 3, the recovery rate of glyphosate in the green vegetable samples was 93.86% to 98.34%, and the relative standard deviation was 1.27% to 4.08%. These results show that the kaempferol-Al 3+ The complex fluorescent probe for detecting glyphosate on green vegetables has high accuracy and good practical performance.

[0069] Example 10

[0070] Kaempferol-Al 3+ Cellulose test paper made of complex probe for detecting glyphosate:

[0071] Cellulose test paper was made by immersing cellulose blank test paper strip in the kaempferol-Al 3+ complex ethanol solution prepared in Example 1 for 5-6 h, and naturally drying. Glyphosate solutions with concentrations of 6.0 μmol / L, 8.0 μmol / L, 10 μmol / L, 14 μmol / L, and 18 μmol / L were added dropwise to the cellulose test paper, respectively. After the test paper was dried, the cellulose test paper was irradiated with a 365 nm ultraviolet lamp, and the color and brightness of the test paper were observed. As shown in Figure 7 and Figure 8 The test paper without glyphosate (0 μmol / L) was bright blue in color, and as the concentration of glyphosate increased, the color gradually changed to dark yellow, and the fluorescence brightness decreased. This shows that the cellulose test paper made of the kaempferol-Al 3+ complex probe can achieve convenient and visual detection of glyphosate.

[0072] The above examples are preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application are equivalent replacement methods and are included in the protection scope of the present application.

Claims

1. Kaempferol-Al 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, Kaempferol-Al 3+ The structural formula of the complex fluorescent probe is as follows: 。 2. The kaempferol-Al as described in claim 1 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, Kaempferol-Al 3+ The preparation method and synthetic route of the complex fluorescent probe are as follows: 。 3. The kaempferol-Al according to claim 2 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, Kaempferol-Al 3+ The preparation method of the complex fluorescent probe includes the following steps: Kaempferol was added to ethanol and stirred until completely dissolved. Then, aluminum chloride hexahydrate was added, and the reaction was stirred at room temperature to obtain kaempferol-Al. 3+ The complex was dissolved in ethanol; after the reaction was complete, rotary evaporation was performed to obtain a yellowish-brown solid. The precipitate was washed with anhydrous ethanol and water, and then dried under vacuum to obtain a yellowish-brown powdery solid, which was kaempferol-Al. 3+ Complex fluorescent probe.

4. The kaempferol-Al according to claim 3 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, The molar ratio of kaempferol to aluminum chloride hexahydrate is 1:(1-1.5).

5. The kaempferol-Al according to claim 3 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, The molar volume ratio of kaempferol to ethanol is 1 mol / 12 mL to 1 mol / 30 mL.

6. The kaempferol-Al according to claim 3 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, The stirring reaction takes 1-2 hours.

7. Kaempferol-Al according to claim 3 3+ The application of complex fluorescent probes in the detection of glyphosate is characterized by, The vacuum drying temperature is 25-40℃, and the time is 6-12 h.

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