阅读说明：本技术 一种用于连续检测铜离子和草甘膦的荧光探针制备方法与应用 (Preparation method and application of fluorescent probe for continuously detecting copper ions and glyphosate ) 是由 喻艳超 刘洋 由君 吴绵园 武文菊 于 2021-10-13 设计创作，主要内容包括：一种用于连续检测铜离子和草甘膦的荧光探针制备方法与应用,涉及铜离子和草甘膦检测领域,尤其涉及一种用于连续检测铜离子和草甘膦的荧光探针制备方法与应用。是解决现有荧光探针检测法同一测试条件下不利于实现铜离子和草甘膦两种物质连续识别的问题。本发明中探针的制备包括：水合肼与4-溴-1,8-萘二甲酸酐的反应产物,与N,N-二甲基乙二胺反应后,再与水杨醛缩合即得荧光探针L。本发明制备的荧光探针,可高选择性快速识别铜离子,同时探针与铜离子的络合物对草甘膦具有良好的识别选择性,不受其它有机磷农药的干扰,检测灵敏高效,不需要昂贵的大型仪器和复杂的样品前处理,能够实现草甘膦的大规模、常规化检测。本发明用于铜离子和草甘膦的检测领域。(A preparation method and application of a fluorescent probe for continuously detecting copper ions and glyphosate relate to the field of detection of copper ions and glyphosate, in particular to a preparation method and application of a fluorescent probe for continuously detecting copper ions and glyphosate. The method solves the problem that the existing fluorescent probe detection method is not beneficial to realizing continuous identification of copper ions and glyphosate under the same test condition. The preparation of the probe of the invention comprises the following steps: and (3) reacting the reaction product of hydrazine hydrate and 4-bromo-1, 8-naphthalic anhydride with N, N-dimethylethylenediamine, and then condensing with salicylaldehyde to obtain the fluorescent probe L. The fluorescent probe prepared by the invention can quickly identify copper ions with high selectivity, and meanwhile, the complex of the probe and the copper ions has good identification selectivity on glyphosate, is not interfered by other organophosphorus pesticides, has sensitive and efficient detection, does not need expensive large-scale instruments and complex sample pretreatment, and can realize large-scale and conventional detection of the glyphosate. The method is used in the field of detection of copper ions and glyphosate.)

1. A preparation method and application of a fluorescent probe for continuously detecting copper ions and glyphosate are characterized in that the molecular structure of the fluorescent probe is as follows:

2. the preparation method and the application of the fluorescent probe for continuously detecting copper ions and glyphosate according to claim 1, wherein the preparation method of the fluorescent probe L comprises the following steps:

firstly, dropwise adding 80% hydrazine hydrate into an ethanol solution of 4-bromo-1, 8-naphthalic anhydride, carrying out reflux reaction for 4-6 h, removing a solvent, and recrystallizing to obtain a yellow solid intermediate 1;

secondly, refluxing the intermediate 1 and N, N-dimethyl ethylenediamine in ethylene glycol monomethyl ether for 3-5 hours; pouring into water, filtering and drying in vacuum to obtain a yellow solid intermediate 2.

Thirdly, in the presence of a catalyst, carrying out reflux reaction on the intermediate 2 and salicylaldehyde in ethanol for 8-10 hours; and filtering, washing and drying the reaction product to obtain the fluorescent probe L.

3. The preparation method and application of the fluorescent probe for continuously detecting copper ions and glyphosate according to claim 2, wherein the recrystallization solvent in the first step is methanol, ethanol or isopropanol.

4. The preparation method and application of the fluorescent probe for continuously detecting copper ions and glyphosate according to claim 2, characterized in that the catalyst in the third step is hydrochloric acid, acetic acid or trifluoroacetic acid.

5. Use of the fluorescent probe of claim 1 for continuous detection of copper ions and glyphosate.

6. The application of claim 5, wherein the specific method for continuously detecting copper ions and glyphosate by using the fluorescent probe comprises the following steps:

firstly, dissolving a fluorescent probe L in a HEPES buffer solvent to prepare 3.0 multiplied by 10^-4～3.0×10^-6measuring the fluorescence emission peak intensity of the fluorescent probe at 532nm in mol/L solution under the action of 445nm exciting light; adding a copper nitrate aqueous solution into the probe solution, and measuring the fluorescence emission peak intensity of the fluorescent probe at 532 nm;

and secondly, incubating the probe L and copper nitrate for 2-5 min, adding a glyphosate sample into the system, and measuring the fluorescence emission peak intensity value of the fluorescence sensor at 532nm under the action of 445nm exciting light.

7. Use of the fluorescent probe according to claim 5 or 6 for continuous detection of copper ions and glyphosate, characterized in that CH is present in HEPES buffered solvent₃The volume ratio of CN to water is 75: 25.

8. The use of the fluorescent probe according to claim 5 or 6 for the continuous detection of copper ions and glyphosate, characterized in that the HEPES buffer solution has a HEPES concentration of 20 mM; the pH was 7.4.

9. The use of the fluorescent probe according to claim 5 or 6 for continuously detecting copper ions and glyphosate, wherein the molar concentration ratio of the fluorescent probe L, the copper ions and the glyphosate is 1:1: 1.

Technical Field

The invention relates to the field of detection of copper ions and glyphosate, in particular to a preparation method of a fluorescent probe and application of the fluorescent probe in continuous detection of the copper ions and the glyphosate.

Background

As the third major trace element essential to organisms, copper ions can participate in the metabolism of various enzymes such as tyrosinase and superoxide dismutase, and play a vital role in animals and plants. However, excessive intake of copper ions not only leads to growth retardation and death of plants, but also causes metabolic disorder of copper in the living body, resulting in occurrence of various diseases such as alzheimer disease, parkinson disease, wilson disease, and the like. Therefore, the method has important significance for detecting copper ions in the environment.

Glyphosate is a nonselective and biocidal organophosphorus herbicide, has the advantages of high efficiency, broad spectrum and the like compared with other herbicides, and is widely applied to the fields of agriculture, forestry and the like. Recent studies have shown that glyphosate can cause various health hazards, may cause lymphoma, hemangioma, pancreatic cancer, lung cancer, etc., and is classified as a class 2A carcinogen by the World Health Organization (WHO). Currently, over 30 countries or regions worldwide have begun to ban or restrict the use of glyphosate and have enhanced the monitoring of glyphosate residues in the environment. Therefore, the development of a method for detecting glyphosate in the environment rapidly, efficiently and at low cost is of great significance.

In recent years, fluorescent probes for separately recognizing copper ions or glyphosate have been reported, but few documents exist for continuously recognizing copper ions and glyphosate by using the same fluorescent probe molecule. The invention designs and synthesizes the 1, 8-naphthalic anhydride fluorescent probe with a novel structure, can efficiently and quickly identify copper ions in a buffer solution, can realize specific identification of glyphosate by a formed complex, and has the advantages of good selectivity, strong anti-interference performance, high sensitivity and the like. The fluorescent probe prepared by the invention can continuously identify two substances of copper ions and glyphosate under the same test condition, is simple and convenient to operate, and simultaneously reduces the synthesis work of the probe, so that the fluorescent probe detection method is more energy-saving and green.

Disclosure of Invention

The invention aims to solve the problem that continuous detection of copper ions and glyphosate is difficult to realize under the same test condition, and provides a preparation method and application of a fluorescent probe for continuously detecting the copper ions and the glyphosate.

The invention relates to a preparation method of a fluorescent probe for continuously detecting copper ions and glyphosate, wherein the molecular structure of the fluorescent probe L is as follows:

the synthetic route of the fluorescent probe is as follows:

the invention discloses a preparation method of a fluorescent probe for continuously detecting copper ions and glyphosate, which comprises the following steps:

firstly, dropwise adding 80% hydrazine hydrate into an ethanol solution of 4-bromo-1, 8-naphthalic anhydride, carrying out reflux reaction for 4-6 h, removing a solvent, and recrystallizing to obtain a yellow solid intermediate 1;

secondly, refluxing the intermediate 1 and N, N-dimethyl ethylenediamine in ethylene glycol monomethyl ether for 3-5 hours; pouring into water, filtering and drying in vacuum to obtain a yellow solid intermediate 2;

thirdly, in the presence of a catalyst, carrying out reflux reaction on the intermediate 2 and salicylaldehyde in ethanol for 8-10 hours; and filtering, washing and drying the reaction product to obtain the fluorescent probe L.

Preferably, the recrystallization solvent in the first step is methanol, ethanol or isopropanol, wherein ethanol is preferred.

Preferably, the catalyst in step three is hydrochloric acid, acetic acid or trifluoroacetic acid, wherein acetic acid is preferred.

The specific method for continuously detecting the copper ions and the glyphosate by using the fluorescent probe comprises the following steps:

firstly, dissolving a fluorescent probe L in a HEPES buffer solvent to prepare 3.0 multiplied by 10^-4～3.0×10^-6measuring the fluorescent probe in the solution at mol/L under the action of 445nm exciting lightFluorescence emission peak intensity at 532 nm; adding a copper nitrate aqueous solution into the probe solution, and measuring the fluorescence emission peak intensity of the fluorescent probe at 532;

and secondly, incubating the probe L and copper nitrate for 2-5 min, adding a glyphosate sample into the system, and measuring the fluorescence emission peak intensity value of the fluorescence sensor at 532nm under the action of 445nm exciting light.

Preferably, CH in HEPES buffer solvent₃The volume ratio of CN to water is 75: 25.

Preferably, the HEPES buffer solution has a HEPES concentration of 20 mM; the pH was 7.4.

Preferably, the molar concentration ratio of the fluorescent probe L, the copper ions and the glyphosate is 1:1: 1.

When the method is used for detecting the glyphosate-containing sample actually, the sample is subjected to pretreatment of centrifuging and filtering to remove solid particle impurities.

The principle of the invention is as follows:

the structure of the fluorescent probe L prepared by the invention has a larger conjugated system and a rigid coplanar, and can generate stable fluorescence; the group such as carbonyl, hydroxyl and the like contained in the fluorescent probe L can be subjected to complexation with copper ions to form a complex, the electron donating capability of an oxygen atom in the group disappears, and the fluorescence quenching phenomenon is caused, so that the detection of the copper ions can be realized. The glyphosate molecule contains amino, phosphate, carboxyl and other functional groups, the functional groups and copper ions generate strong coordination, and the glyphosate can replace the probe and the copper ions in the copper ion complex, so that the probe recovers the monomer state, the fluorescent effect is recovered, and the fluorescent detection of the glyphosate is realized. The principle of the fluorescent probe for continuously detecting the copper ions and the glyphosate is shown in figure 1.

Compared with the prior art, the invention has the following beneficial effects:

1) the fluorescent probe prepared by the invention can realize continuous detection of copper ions and glyphosate under the same test condition, is simple and convenient to operate, has a good detection effect, reduces the synthesis work of the probe, and enables the fluorescent probe detection method to be more energy-saving and green.

2) Fluorescence prepared by the inventionThe probe has good selectivity to copper ions, is not interfered by other metal ions, has good linear relation between the fluorescence intensity and the copper ion concentration within 0-15 mu M (namely 0-3.6 mu g/mL), and has the detection limit as low as 3.7 multiplied by 10^-7And the mol/L (namely 89.3ng/mL) realizes the qualitative and quantitative detection of the trace amount of the copper ions.

3) The fluorescent probe prepared by the invention has a specific recognition effect on glyphosate after forming a complex with copper ions, can not be interfered by other organophosphorus pesticides, has a good linear relation between the fluorescence intensity and the glyphosate concentration within 0-15 mu M (namely 0-2.5 mu g/mL), and has a detection limit as low as 5.6 multiplied by 10^-7And the mol/L (namely 94.7ng/mL) realizes the qualitative and quantitative detection of the trace amount of the glyphosate.

4) The fluorescent probe prepared by the invention has low use cost, does not need expensive large-scale instruments and complex sample pretreatment, has obvious color/fluorescence change on glyphosate under visible light/ultraviolet light, is convenient for naked eye observation, and can realize simple qualitative detection of copper ions and glyphosate without the help of instruments and equipment.

5) When the method is used for actually detecting the glyphosate-containing sample, the sample is subjected to pretreatment of centrifuging and filtering to remove solid particle impurities, and the sample pretreatment method is simple.

Drawings

FIG. 1 shows the principle of continuous detection of copper ions and glyphosate by the fluorescent probe of the present invention;

FIG. 2 preparation of fluorescent Probe L according to the invention¹H NMR spectrum;

FIG. 3 preparation of fluorescent Probe L according to the invention¹³C NMR spectrum;

FIG. 4 is an IR spectrum of a fluorescent probe L of the present invention;

FIG. 5 shows the selectivity of the fluorescent probe L for recognizing metal ions;

FIG. 6 shows the effect of coexisting metal ions on the detection of copper ions by a fluorescent probe;

FIG. 7 is a graph of the fluorescence response of a fluorescent probe to different concentrations of copper ions;

FIG. 8 fluorescent probes L vs Cu²⁺Job's plot ofA wire;

FIG. 9 fluorescent Probe L-Cu²⁺Selectively identifying a relation graph for organophosphorus pesticide;

FIG. 10 coexisting organophosphorus pesticide pair fluorescent probe L-Cu²⁺Identifying a glyphosate relationship graph;

FIG. 11 fluorescent Probe L-Cu²⁺A graph of the fluorescence response relationship for different concentrations of glyphosate;

FIG. 12 fluorescent Probe L-Cu²⁺Job's plot against glyphosate;

FIG. 13 shows fluorescence probes L (1#), and fluorescence probes L-Cu under visible light (a) and ultraviolet light 365nm (b)²⁺(2#), fluorescent Probe L-Cu²⁺Color and fluorescence change diagrams after respectively reacting with glyphosate (3#), trichlorfon (4#), phosmet (5#), dichlorvos (6#), malathion (7#), omethoate (8#), dimethoate (9#), fenamiphos (10#), fenitrothion (11#), methyl parathion (12#), parathion (13#), and glufosinate (14 #);

Detailed Description

The technical solution of the present invention is not limited to the following specific embodiments, but includes any combination of the specific embodiments.

The first embodiment is as follows: the molecular structure of the fluorescent probe L for continuously detecting copper ions and glyphosate in the embodiment is as follows:

the second embodiment is as follows: the preparation method of the fluorescent probe L comprises the following steps:

firstly, dropwise adding 80% hydrazine hydrate into an ethanol solution of 4-bromo-1, 8-naphthalic anhydride, carrying out reflux reaction for 4-6 h, removing a solvent, and recrystallizing to obtain a yellow solid intermediate 1;

secondly, refluxing the intermediate 1 and N, N-dimethyl ethylenediamine in ethylene glycol monomethyl ether for 3-5 hours; pouring into water, filtering and drying in vacuum to obtain a yellow solid intermediate 2;

thirdly, in the presence of a catalyst, carrying out reflux reaction on the intermediate 2 and salicylaldehyde in ethanol for 8-10 hours; and filtering, washing and drying the reaction product to obtain the fluorescent probe L.

The third concrete implementation mode: the second embodiment is different from the first embodiment in that: in the first step, the recrystallization solvent is methanol, ethanol or isopropanol. The rest is the same as the second embodiment.

The fourth concrete implementation mode: the second or third embodiment is different from the first or second embodiment in that: the catalyst in the third step is hydrochloric acid, acetic acid or trifluoroacetic acid. The other is the same as the second or third embodiment.

The fifth concrete implementation mode: the fluorescent probe of the embodiment is applied to continuous detection of copper ions and glyphosate.

The sixth specific implementation mode: the fifth embodiment is different from the fifth embodiment in that: the specific method for continuously detecting the copper ions and the glyphosate by the fluorescent probe comprises the following steps:

firstly, dissolving a fluorescent probe L in a HEPES buffer solvent to prepare 3.0 multiplied by 10^-4～3.0×10^-6measuring the fluorescence emission peak intensity of the fluorescent probe at 532nm in mol/L solution under the action of 445nm exciting light; adding a copper nitrate aqueous solution into the probe solution, and measuring the fluorescence emission peak intensity of the fluorescent probe at 532 nm;

and secondly, incubating the probe L and copper nitrate for 2-5 min, adding a glyphosate sample into the system, and measuring the fluorescence emission peak intensity value of the fluorescence sensor at 532nm under the action of 445nm exciting light.

The seventh embodiment: the sixth embodiment is different from the sixth embodiment in that: CH in the HEPES buffer solvent₃The volume ratio of CN to water is 75: 25. The rest is the same as the sixth embodiment.

The specific implementation mode is eight: the sixth or seventh embodiment is different from the sixth or seventh embodiment in that: the HEPES concentration in the HEPES buffer solution was 20 mM. The others are the same as the sixth or seventh embodiments.

The specific implementation method nine: this embodiment differs from the sixth, seventh or eighth embodiment in that: the HEPES buffered pH was 7.4. The others are the same as in the sixth or seventh or eighth embodiments.

The HEPES buffer solution is used in this embodiment to prevent the pH change of the probe solution, and to verify whether the probe can be used for cell experiments.

The detailed implementation mode is ten: the sixth embodiment is different from the sixth embodiment in that: the molar concentration ratio of the fluorescent probe L to the copper ions to the glyphosate is 1:1: 1. . The rest is the same as the sixth embodiment.

When the glyphosate-containing sample is actually detected, the sample is subjected to pretreatment of centrifuging and filtering to remove solid particle impurities.

The following examples are given to illustrate the present invention, and the following examples are carried out on the premise of the technical solution of the present invention, and give detailed embodiments and specific procedures, but the scope of the present invention is not limited to the following examples.

Example 1: the preparation method of the fluorescent probe L of the embodiment comprises the following steps:

first, 4.0g of 4-bromo-1, 8-naphthalic anhydride, 4.3g of 80% hydrazine hydrate and 100mL of ethanol were added to a 250mL three-necked flask, and the mixture was reacted for 4 hours under reflux. The solvent was removed under reduced pressure and ethanol recrystallized to yield 13.8 g of a yellow solid intermediate in 89% yield.

Secondly, adding 13.0 g of intermediate, 5mL of N, N-dimethyl ethylenediamine and 100mL of ethylene glycol monomethyl ether into a 250mL three-necked bottle, and carrying out reflux reaction for 6 h; after cooling to room temperature, pour into 100mL water, filter the precipitated solid, wash with water and dry under vacuum to give 22.83 g of yellow intermediate in 92% yield.

Thirdly, adding 22.0 g of intermediate, 1.0g of salicylaldehyde, 0.5mL of glacial acetic acid and 100mL of absolute ethyl alcohol into a 250mL three-necked bottle, and carrying out reflux reaction for 8 h; after cooling to room temperature, the mixture was filtered, dried and washed with ether to obtain fluorescent probe L2.2g with a yield of 83%.¹H NMR(300MHz,DMSO-d₆)δ11.13(s,1H),9.53(s,1H),8.99(s,1H),8.76(d,J＝8.4Hz,1H),8.52(d,J＝7.3Hz,1H),8.35(d,J＝8.5Hz,1H),7.92(s,1H),7.79(dd,J＝8.3,5.9Hz,2H),7.54–7.42(m,1H),7.08–6.98(m,2H),3.81(d,J＝6.0Hz,2H),3.45(d,J＝6.3Hz,2H),3.34(s,6H).¹³C NMR(75MHz,DMSO-d₆)δ169.96,161.08,160.56,159.24,150.73,134.96,134.45,131.74,130.84,129.69，129.23,125.18,122.52,121.02,120.04,118.22,117.22,109.02,105.04,54.89,43.10,39.82,38.28.FT-IR(KBr):3430.65,2923.84,2853.27,1691.56,1655.42,1586.08,1458.73,1351.24,1241.96,1167.88,770.99。

Of fluorescent probe L¹H NMR spectrum,¹³The C NMR spectrum and the IR spectrum are shown in FIGS. 2, 3 and 4, respectively.

Example 2: the fluorescent probe L of the embodiment selectively identifies the copper ions according to the following steps:

cu with the concentration of 0.1M is prepared respectively²⁺、Ni²⁺、Co²⁺、Cd²⁺、Mg²⁺、Pb²⁺、Ca²⁺、Ce³⁺、Hg²⁺、Zn²⁺、Na⁺、K⁺、Fe³⁺、Ag⁺、Ba²⁺、Cs⁺、Al³⁺、Cr³⁺The aqueous solution is ready for use.

Accurately weighed 12.1mg of fluorescent probe L was dissolved in 100mL of HEPES buffer solution (V)_Acetonitrile:V_{Water (W)}75:25, HEPES40mM, pH 7.4), formulated at 3.0 × 10^-4mol/L solution A; taking 10mL of the buffer solution system for solution A (V)_Acetonitrile:V_{Water (W)}75:25, HEPES 20mM, pH 7.4) volumetric flask to 100mL, prepared to 3.0 × 10^-5And (4) using the mol/L solution B for standby.

3mL of the solution B is taken in a cuvette each time, and 2eq.Cu is added in turn²⁺、Ni²⁺、Co²⁺、Cd²⁺、Mg²⁺、Pb²⁺、Ca²⁺、Ce³⁺、Hg²⁺、Zn²⁺、Na⁺、K⁺、Fe³⁺、Ag⁺、Ba²⁺、Cs⁺、Al³⁺、Cr³⁺An aqueous solution. Measuring the fluorescence emission peak intensity value of the fluorescent probe L at 532nm under the action of 445nm exciting light, and adding Cu into the fluorescent probe L²⁺Then, the fluorescent probe has obvious fluorescence quenching effect, while the addition of other metal ions can not cause obvious fluorescence change, and the fluorescent probe L is used for Cu²⁺Specific recognition was shown and the results are shown in FIG. 5.

Example 3: the fluorescent probe L of the embodiment can identify the anti-interference performance of copper ions according to the following steps:

respectively taking 3mL of the solution with the concentration of 3.0X 10^-5Adding 2eq of Cu into the solution B in sequence²⁺、Ni²⁺、Co²⁺、Cd²⁺、Mg^{2 +}、Pb²⁺、Ca²⁺、Ce³⁺、Hg²⁺、Zn²⁺、Na⁺、K⁺、Fe³⁺、Ag⁺、Ba²⁺、Cs⁺、Al³⁺、Cr³⁺Aqueous solution, and fluorescence intensity was measured. 2eq.Cu are added in sequence²⁺Aqueous solution, and the fluorescence intensity was observed and recorded. The results are shown in FIG. 6.

According to data analysis, in the process of identifying and responding copper ions by the probe, even in the presence of other ions, the probe still has an obvious fluorescence quenching effect on the copper ions, and the probe has obvious anti-interference capability when identifying the copper ions.

Example 4: the detection limit of the fluorescent probe L to the copper ions is carried out according to the following steps:

taking 3mL of the solution with the concentration of 3.0X 10^-5mol/L solution B, 1. mu.L each time, 3X 10^-3And measuring the fluorescence intensity of the copper ion solution in mol/L. The results are shown in FIG. 7, in which the concentration of copper ions is plotted on the abscissa and the fluorescence intensity is plotted on the ordinate.

From data analysis, when the concentration of copper ions is in the range of 0 μ M to 15 μ M (i.e. 0 to 3.6 μ g/mL), the fluorescence intensity decreases with the increase of the concentration of copper ions, and the fluorescence intensity and the concentration of copper ions show good linear relationship, the fitting equation is that y is-20.08 x +345.26, R is²0.998. According to the calculation formula 3 sigma/k of the detection limit, the detection limit of the probe molecule to the copper ions is calculated to be 3.7 multiplied by 10^-7mol/L (i.e., 89.3 ng/mL). The probe can realize trace detection of copper ions.

Example 5: the fluorescent probe L and the copper ion complex ratio of the embodiment are carried out according to the following steps:

taking the concentration of 3.0 × 10^-5mol/L solution B and 3X 10^-3The total degree of commonness of the probe and the copper ions in the system is maintained to be 9 multiplied by 10 by mol/L copper ion water solution^-8mol is notAlternatively, the fluorescence intensity was measured by changing the equivalence ratio between the probe and the copper ion, and a Job's Plot was drawn. The results are shown in FIG. 8.

Analysis of the Job's Plot reveals that the fluorescence intensity exhibits an inflection point when the mole fraction of copper ions is 0.47, indicating that probes L and Cu²⁺The complex ratio is 1: 1.

Example 6: fluorescent probe L-Cu²⁺Selectively identifying glyphosate according to the following steps:

taking 3mL of the solution with the concentration of 3.0X 10^-5Adding 1eq of copper ion solution into the mol/L solution B, incubating for 3min to obtain a complex L-copper ion system, sequentially adding 1eq of glyphosate, trichlorfon, phosmet, dichlorvos, malathion, omethoate, dimethoate, ethoprophos, fenitrothion, methyl parathion, parathion and glufosinate, and measuring the fluorescence intensity under the action of 445nm exciting light. The results are shown in FIG. 9.

The data analysis shows that when glyphosate is added, the fluorescence of the system is obviously enhanced, and when other pesticides are added, the fluorescence intensity is not obviously changed, and the fluorescent probe L-Cu²⁺The system realizes the specific recognition of glyphosate.

Example 7: fluorescent probe L-Cu²⁺The glyphosate recognition interference resistance is carried out according to the following steps:

taking 3mL of the solution with the concentration of 3.0X 10^-5Adding 1eq of copper ion solution into the solution B of mol/L, and incubating for 3min to obtain the fluorescent probe L-Cu²⁺The system is characterized in that 1eq of glyphosate, trichlorfon, phosmet, dichlorvos, malathion, omethoate, dimethoate, fenamiphos, fenitrothion, methyl parathion, parathion and glufosinate are sequentially added, the fluorescence intensity of the system is recorded under the action of 445nm exciting light, then 1eq of glyphosate is sequentially added, and the change of the fluorescence intensity is observed and recorded. The results are shown in FIG. 10.

The data analysis shows that after glyphosate is added, under the existence of other coexisting pesticides, fluorescence enhancement can be realized after glyphosate is added, and other pesticides can perform fluorescence enhancement on the fluorescent probe L-Cu²⁺The system identifies glyphosate without interference.

Example 8:fluorescent probe L-Cu²⁺The glyphosate detection limit is carried out according to the following steps:

adding 1eq of copper ion solution into the solution B with the concentration of 3.0X 10-5mol/L, and incubating for 3min to obtain the fluorescent probe L-Cu²⁺Taking 3mL of fluorescent probe L-Cu for later use²⁺System C, 1. mu.L each time of addition, 3X 10^-3And measuring the fluorescence intensity of the glyphosate aqueous solution in mol/L. The results are shown in FIG. 11.

From data analysis, when the concentration of glyphosate is between 0 and 15 μ M (namely between 0 and 2.5 μ g/mL), the fluorescence intensity continuously increases along with the increase of the concentration of glyphosate, and the fluorescence intensity and the concentration of glyphosate present a good linear relation, and the fitting equation is that y is 19.31x +29.79, R is²0.993. Calculating the fluorescent probe L-Cu according to the calculation formula 3 sigma/k of the detection limit²⁺The limit of detection of copper ions is 5.6 multiplied by 10^-7mol/L (i.e., 94.7 ng/mL). Fluorescent probe L-Cu²⁺The system can realize trace detection of glyphosate.

Example 9: fluorescent probe L-Cu²⁺The glyphosate action ratio is carried out according to the following steps:

fluorescent probe L-Cu²⁺Systems C and 3X 10^-3A mol/L glyphosate aqueous solution, and a fluorescent probe L-Cu in a maintenance system²⁺The total common degree of the system and the glyphosate is 9 multiplied by 10^-8mol is not changed, and the fluorescent probe L-Cu is changed²⁺The equivalent ratio of the system and glyphosate, the fluorescence intensity of the system and glyphosate are measured, and a Job's Plot is drawn. The results are shown in FIG. 12.

According to data analysis, when the molar fraction of glyphosate is 0.52, an inflection point appears in fluorescence intensity, thereby indicating that the fluorescent probe L-Cu²⁺The complex ratio of the system to the glyphosate is 1: 1.

Example 10: fluorescent probe L-Cu under visible light and ultraviolet light (365nm)²⁺System qualitative detection of glyphosate

Accurately measuring 1.5mL of fluorescent probe L-Cu²⁺In the system C, 4 eq.glyphosate, trichlorfon, phosmet, dichlorvos, malathion, omethoate, dimethoate, fenamiphos, fenitrothion, methyl parathion, parathion and glufosinate-ammonium are respectively added to obtain the compound shown in the figure 1 under visible light3 (a); the results shown in FIG. 13(b) were obtained under UV 365 nm. As can be seen from FIGS. 13(a) and 13(b), the fluorescent probe L-Cu²⁺After the system and the organophosphorus pesticide act, only glyphosate has obvious color fluorescence change, excellent selectivity is shown for glyphosate, and the glyphosate-sensitive fluorescent dye can be used for qualitative detection of glyphosate, and is simple and convenient to operate and high in detection speed.

Example 11: detection of glyphosate in actual water sample by fluorescent sensor

In order to investigate the potential application of the fluorescent probe in the actual environment, two water samples, namely laboratory tap water and Songhua river water (Harbin, China), are selected and pretreated: centrifuging the water sample at 12000rpm for 10min, filtering with 0.45 μm filter, and preparing at the following concentrations: 0.25. mu.g/mL, 0.5. mu.g/mL, 1.0. mu.g/mL, 2.0. mu.g/mL, 2.5. mu.g/mL glyphosate solution.

Fluorescent probe L-Cu prepared in example 6 was used²⁺System to fluorescent probe L-Cu²⁺Adding the glyphosate solution with different concentrations into the system, and measuring the fluorescent probe L-Cu under the action of 445nm exciting light²⁺The system is characterized in that the fluorescence emission peak intensity value at 532nm is brought into the following equation, and the concentration of the glyphosate solution to be measured is calculated. The results are shown in Table 1.

Y＝19.31×X+29.79

Wherein X is the glyphosate concentration, and Y is the fluorescence emission peak intensity value.

TABLE 1 fluorescent probes L-Cu²⁺System for detecting glyphosate in actual water sample

As can be seen from Table 1, the recovery rate of glyphosate in an actual water sample is 95.5% -100.8%, the relative standard deviation is 2.24% and 1.8%, the error between the measured glyphosate concentration and the corresponding standard addition concentration is very small, and the results show that the fluorescent probe L-Cu prepared by the invention²⁺The system has better accuracy in detecting glyphosate in an actual water sample, and can be within 0-2.5 muThe glyphosate is quantitatively detected within the range of g/mL, and the method has good practical performance.