Fluorescent probe for detecting mercury ions, solid-state sensing film and its preparation and application

Abstract

The present invention relates to the field of mercury ion detection technology, and in particular to a fluorescent probe for detecting mercury ions, and the preparation of the fluorescent probe and the application of the fluorescent probe in mercury ion fluorescence detection. The fluorescent probe (TPE-4TA, TPE-2TA) of the present invention has high fluorescence emission intensity, good mercury ion detection sensitivity and reaction speed, and can realize real-time dynamic analysis of mercury ion concentration in situ.

Description

Technical field:

[0001] The invention relates to the technical field of mercury ion detection, and in particular to the design and synthesis of a type of fluorescent probe and a detection method for detecting mercury ions in water using the fluorescent probe. Background technology:

[0002] Human activities put tremendous pressure on the environment on which they depend for survival, and environmental pollution is becoming increasingly serious. Among the many environmental problems, water pollution is more prominent. Heavy metals and their compounds in water are difficult to degrade in the environment and are eventually transferred to the human body through the food chain, posing a great threat to human health. 2+ ) is one of the most common toxic heavy metal ions. Its main sources of pollution include mining production, chemical manufacturing, waste incineration and fossil fuel combustion. In addition, volcanic activity, forest fires and atmospheric mercury deposition may also lead to mercury pollution, and mercury pollution cannot be naturally degraded. Once exposed to the environment, it will further cause air pollution, soil pollution and water pollution, and thus cause great harm to organisms. It is highly toxic whether it exists in the form of inorganic mercury salts or organic mercury. Its toxicity is mainly concentrated in three aspects: neurotoxicity, nephrotoxicity and pulmonary toxicity; and mercury ions have strong bioaccumulation and are not easily excreted after entering the body. When accumulated to a certain extent, they will cause a variety of diseases, such as brain damage, Minamata disease and respiratory diseases. Among them, mercury ions will not only cause damage to the central nervous system, but also cause gastrointestinal ulcers, diarrhea, vomiting, dyspnea, pulmonary edema, respiratory failure and even death. Therefore, there is an urgent need to develop a sensitive Hg in the environment 2+ Establishing a detection method that can be used for rapid, accurate qualitative and quantitative detection of mercury ions is of great significance for environmental monitoring, food safety and medical diagnosis.

[0003] At present, researchers have reported a variety of methods for mercury ion detection, including atomic absorption / emission spectroscopy, inductively coupled plasma mass spectrometry, inductively coupled plasma atomic emission spectroscopy, capillary electrophoresis, high performance liquid chromatography and ion chromatography, etc. However, these traditional analytical methods are limited in their application in mercury ion detection to a certain extent due to factors such as complex sample pretreatment steps, expensive instruments, and damage to sample molecules. Compared with traditional mercury ion detection methods, fluorescent molecular probe detection technology has the advantages of high detection sensitivity, good selectivity, and simple operation, and has attracted widespread attention.

[0004] In order to detect mercury ions, many mercury ion-specific recognition probes have been designed, including probes of various polymer materials, metal nanoparticles, nucleic acids and proteins. Among the many detections for mercury ion signal output, fluorescence signal detection is the most commonly used detection method due to its high selectivity, high sensitivity and rapid response. At present, the sensitivity of "turn-off" type probe molecules is limited by their self-quenching effect in the aqueous environment; while the ratio fluorescent probe has the advantage of self-correction, but the design of the probe molecule is relatively complex; in comparison, the "turn-on" type fluorescent probe is a visualization process of fluorescence from scratch, and the molecular design threshold is low with high sensitivity. Its detection mechanism is summarized as follows: 1. The desulfurization reaction of the probe molecule caused by mercury ions forms a larger conjugated system, thereby enhancing the fluorescence of the probe molecule; 2. The ether bond cleavage catalyzed by mercury ions causes the quenching group of the fluorescent probe to detach, and the fluorescence of the probe is restored; 3. Coordination fluorescence enhancement probe: The probe molecule is coordinated and complexed with mercury ions in the presence of lone pairs of electrons, and further aggregates and accumulates to emit strong fluorescence. It can be seen that based on the above-mentioned fluorescence mechanism, the fluorescent probe method can utilize a rich variety of luminescent groups to design a variety of fluorescent probes with different properties. Summary of the invention:

[0005] The first object of the present invention is to provide a fluorescent probe for detecting mercury ions in water;

[0006] The second object of the present invention is to provide a solid-state sensing film comprising the fluorescent probe and a preparation method thereof;

[0007] The third object of the present invention is to provide a method for detecting mercury ions in water, aiming to improve the detection sensitivity.

[0008] The present invention provides a fluorescent probe for detecting mercury ions in water, which is at least one compound having the structural formula of Formula I or Formula II:

[0009]

[0010] wherein at least one of R, R′, R″ or R′″ is selected from a substituent selected from the following structural formula, The remaining substituents are independently selected from at least one of hydrogen, heteroatoms, alkyl, unsaturated alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl, and heteroaryl.

[0011] The present invention relates to the field of mercury ion detection technology, and in particular to the synthesis of a type of fluorescent probe and a detection method for detecting mercury ions in water using the fluorescent probe. For example, the fluorescent probe of the present invention can be dissolved in water in an appropriate amount, and when the probe is freely dissolved in an aqueous solution, the aggregation-induced luminescence activity of its tetraphenylethylene fluorescent group can annihilate the excitation energy through non-radiative transitions, resulting in the probe being unable to be excited to emit fluorescence; however, when mercury ions in an aqueous environment are coordinated and bound to the probe, the fluorescent probe molecules are complexed with the mercury ions to form a polymer complex, and further aggregation occurs to limit the non-radiative pathway of the tetraphenylethylene group, resulting in the probe being excited to emit strong fluorescence. The fluorescent probe molecules in the present invention have the advantages of high sensitivity to mercury ion detection and rapid detection time.

[0012] The fluorescent probe for detecting mercury ions is preferably a compound having at least one of the following structural formulas 1-A and 1-B:

[0013]

[0014] The R1 and R2 groups are selected from at least one of hydrogen, heteroatom, alkyl, unsaturated alkyl, heteroalkyl, cycloalkyl, heterocycloalkyl, aryl and heteroaryl; preferably H, C1-C6 alkyl, C1-C6 alkoxy, C2-C6 olefin, C3-C6 cycloalkyl, cyclopentyl, cyclohexyl, phenyl, tetrazole, furyl or pyridyl.

[0015] The present invention has found that the preferred formula 1-A and formula 1-B have better mercury ion fluorescence detection effects, especially formula 1-B, which unexpectedly exhibits better mercury ion detection limit, linear range and sensitivity.

[0016] In the present invention, the optimal excitation wavelength of Formula 1-A (TPE-4TA) is 360nm, and the maximum emission wavelength is at 499nm. The optimal excitation wavelength of Formula 1-B (R1 / R2 is H, TPE-2TA) of TPE-2TA is 345nm, and the maximum emission wavelength is at 490nm.

[0017] The present invention also provides a solid-state sensing film for detecting mercury ions, comprising a film substrate and the fluorescent probe for detecting mercury ions compounded in the film substrate.

[0018] The solid-state sensing film for detecting mercury ions of the present invention has no special requirements on the type of material of the membrane substrate. For example, the membrane substrate is a hydrophilic polymer material; more preferably, it is at least one of chitosan, cellulose, and polyvinyl alcohol.

[0019] The present invention also relates to a method for preparing the solid-state sensing film for detecting mercury ions, wherein a film base material and the fluorescent probe for detecting mercury ions are mixed and formed into a film to obtain the material;

[0020] The preferred preparation method of the solid-state sensing film for detecting mercury ions of the present invention is to dissolve the fluorescent probe and mix it with a hydrophilic polymer material such as polyvinyl alcohol and terephthalic acid solution, then place it in a mold, age it, and soak it in water to complete the solvent exchange to obtain the solid-state sensing film for detecting mercury ions.

[0021] The present invention also provides a fluorescence determination method for mercury ions in water, which includes contacting the aqueous solution to be determined with the fluorescent probe, and then performing fluorescence excitation and fluorescence determination.

[0022] In the present invention, the aqueous solution to be tested and the fluorescent probe may be brought into contact with each other in a liquid-liquid or liquid-solid manner.

[0023] The present invention provides a scheme for measuring using the fluorescent probe, the steps of which are, for example: mixing the aqueous solution to be measured and the fluorescent probe in liquid phase contact (liquid-liquid contact), and then performing fluorescence excitation and fluorescence measurement on the mixed solution;

[0024] Another scheme of the present invention for using the fluorescent probe for measurement includes the following steps: bringing the aqueous solution to be measured into liquid-solid contact with the solid-state sensor film; and then performing fluorescence excitation and fluorescence measurement on the solid-state sensor film after the contact.

[0025] In the determination method of the present invention, the pH of the aqueous solution to be measured is 5 to 7.5.

[0026] Preferably, the measurement process is performed under fluorescence excitation under light of 340 to 500 nm; preferably, the fluorescence excitation is performed under light of 340 to 375 nm.

[0027] More preferably, when the fluorescent probe is TPE-2TA, the excitation wavelength is 300 to 350 nm, more preferably 345 to 350 nm; when the fluorescent probe is TPE-4TA, the excitation wavelength is 350 to 380 nm, more preferably 360 to 365 nm.

[0028] In the present invention, the fluorescent probe has stable properties, strong resistance to environmental interference, strong selectivity, and good determination linearity. Taking TPE-4TA and TPE-2TA as examples, the detection limits of mercury ions in water samples can reach 3.4nM (0.682ppb) and 1.2nM (0.241ppb), respectively. The concentration of the fluorescent probe is 1.0×10 -5When the concentration of mercury ions was 0.1447 W / m, the linear ranges of mercury ion detection were [3.4 nM—5 μM] and [1.2 nM—10 μM], respectively, showing excellent measurement effect. Description of the drawings:

[0029] Figure 1 It is a schematic diagram of the fluorescent probe of the present invention being excited to emit fluorescence after combining with mercury ions;

[0030] Figure 2 The UV-Vis images of the fluorescent probes TPE-2TA and TPE-4TA of the present invention before and after the addition of mercury ions;

[0031] Figure 3 The excitation spectra of the fluorescent probes TPE-2TA and TPE-4TA of the present invention and the fluorescence titration curves under different mercury ion concentration systems;

[0032] Figure 4 The fluorescent probes TPE-2TA and TPE-4TA of the present invention are Figure 3 Data fitting linear graph based on data;

[0033] Figure 5 The response curves of the fluorescent probes TPE-2TA and TPE-4TA of the present invention to different metal ions;

[0034] Figure 6 This is a competitive experiment of the fluorescent probes TPE-2TA and TPE-4TA of the present invention under the coexistence of mercury ions and other metal ions;

[0035] Figure 7 The fluorescence lifetime diagrams of the fluorescent probes TPE-2TA and TPE-4TA of the present invention before and after the addition of mercury ions, respectively;

[0036] Figure 8 The DLS graphs of the fluorescent probes TPE-2TA and TPE-4TA of the present invention after adding mercury ions;

[0037] Fig. 9 This is a tolerance diagram of the fluorescent probes TPE-2TA and TPE-4TA of the present invention in response to mercury ions under different pH conditions;

[0038] Fig.10 The response curve of the fluorescent probe TPE-4TA of the present invention to different mercury ion concentration systems after being made into a film and the linear fitting diagram of this group of data;

[0039] Fig.11 This is the H NMR spectrum of the probe molecule TPE-2TA. Specific implementation method:

[0040] The fluorescent probes involved in the present invention are TP4-4TA and TP4-2TA.

[0041]

[0042] The preparation method of the two fluorescent probes of the present invention comprises the following steps:

[0043] TPE-2TA synthesis steps:

[0044] n-Butyl lithium was added to a solution of diphenylmethane in tetrahydrofuran at 0°C to produce an orange-red solution of diphenylmethyl lithium within 30 minutes. Solid 4,4'-dibromodiphenylmethanone was added to this highly colored solution at 0°C and the resulting mixture was warmed to room temperature and stirred for 6 hours. The reaction was quenched with saturated aqueous ammonium chloride followed by standard aqueous workup to afford the corresponding alcohol in nearly quantitative yield; the crude alcohol was dissolved in toluene and refluxed in the presence of a catalytic amount of p-toluenesulfonic acid, water was azeotropically removed using a Dean-Stark trap, and the product TPE-2Br was prepared in 46% isolated yield by simple crystallization from a mixture of dichloromethane and methanol.

[0045]

[0046] S2, TPE-2Br, CuCN and dimethylformamide (DMF) are added to a double-necked round-bottom flask. The mixture is refluxed under N2 for 60 hours and then suspended in 300 ml of water. After adding ethylenediamine, the mixture is stirred at 100 ° C for 1 hour and then filtered. The precipitated solid is extracted with dichloromethane. The combined organic phase is dried over anhydrous magnesium sulfate. After filtration and solvent evaporation, the residue is purified by silica gel column chromatography using hexane / dichloromethane (1 / 1, v / v) as eluent to obtain the product TPE-2CN.

[0047]

[0048] S3. Sodium azide, zinc bromide and water are added to a flask. TPE-2CN is injected into the above solution in N-methylpyrrolidone. The mixture is stirred at 150°C overnight. The mixture is acidified to pH≈1 with aqueous hydrochloric acid solution (3M) and stirred vigorously for 30 minutes. The organic mixture is extracted with ethyl acetate, washed with hydrochloric acid, and concentrated to obtain a crude solid. The crude product is added to a sodium hydroxide solution and then stirred vigorously for 1 hour. Afterwards, the resulting suspension is filtered to remove solids. The filtrate is washed with ethyl acetate and acidified to pH=1 with 3M hydrochloric acid. The tetrazole product is precipitated under stirring, extracted into ethyl acetate again, and the organic layer is separated. The aqueous layer is washed with ethyl acetate. The organic layers are combined, concentrated, and dried in vacuo to obtain the corresponding product TPE-2TA.

[0049]

[0050] The probe molecule TPE-4TA can be synthesized using similar steps to TPE-2TA.

[0051] The process of measuring mercury ions using the fluorescent probes listed above is, for example:

[0052] Determination (1): Liquid phase determination:

[0053] On the basis of synthesizing the above-mentioned fluorescent probe, the present invention discloses a detection method for detecting mercury ions in water. It further includes accessories such as a 365nm portable ultraviolet lamp, a stoppered quartz cuvette, a wash bottle, a gun head box, lens paper, a pipette gun, and fluorescence spectrometer equipment, wherein the portable ultraviolet lamp can be used at any time to provide an excitation light source with a wavelength of 365nm to detect the fluorescence response of the water sample to be tested; the stoppered quartz cuvette is used to observe the fluorescence response of its internal solution under the excitation of the ultraviolet lamp; the wash bottle is used to hold distilled water or deionized water to clean the cuvette after use; the lens paper is used for preliminary wiping of the cuvette after cleaning; the pipette gun is used to accurately absorb the fluorescent probe solution and water sample to ensure the accuracy and repeatability of the test; the fluorescence spectrometer is used to detect the configured water sample in real time, and perform fluorescence intensity tests under its optimal excitation wavelength conditions. The steps for detecting mercury ions are as follows:

[0054] S1. Preparation of fluorescent probe mother solution: Accurately weigh the solid probe sample and dissolve it in methanol solution to a concentration of 5.0×10 -4 The mother liquor of M.

[0055] S2, take the water sample to be tested (pH should be Fig. 9 Add the water sample (within the range shown) into a four-way cuvette, stir evenly and irradiate with an ultraviolet hand lamp with a wavelength of 365nm. It can be preliminarily observed that the solution hardly emits light or only emits weak fluorescence. Then transfer the four-way cuvette containing the water sample to a fluorescence spectrometer for testing to obtain its maximum emission intensity as a reference.

[0056] S3. Use a pipette to add the fluorescent probe stock solution into the cuvette containing the water sample to be tested. The final concentration of the probe is 1.0×10 -5 M, after stirring evenly, use an ultraviolet hand lamp with a wavelength of 365nm to irradiate again. It can be observed that the solution changes from the original weak luminescence to a strong yellow-green fluorescence. Then transfer the four-way dish containing the water sample to the fluorescence spectrometer and set the optimal excitation light excitation test to obtain its maximum emission intensity. By comparing with the existing data, the content of mercury ions in the water can be obtained.

[0057] Based on the above-mentioned fluorescent probe detection method for mercury ions in water, the fluorescent probes TPE-2TA and TPE-4TA used have the advantages of high sensitivity and rapid detection. They can produce strong fluorescence when combined with trace amounts of mercury and are visible to the naked eye under ultraviolet light. The detection limits of mercury ions in water samples can reach 3.4nM (0.682ppb) and 1.2nM (0.241ppb), respectively. In addition, the fluorescent probe also has the advantages of stable properties, strong resistance to environmental interference, and high selectivity. Using a fluorescence spectrometer under 345nm and 360nm excitation light, significant fluorescence enhancement can be observed at 490nm and 499nm, respectively, and the enhanced intensity is proportional to the amount of mercury within a certain range, thereby quantitative detection of mercury ions in water can be performed.

[0058] The present invention uses only a small amount of methanol solution to prepare the fluorescent probe mother solution. Under the actual pH value of the water sample, the fluorescent probe has detection activity, and there is no need to perform mercury ion detection under any buffer system.

[0059] Furthermore, in the detection system, the concentration of TPE-2TA and TPE-4TA fluorescent probes used was 1.0×10 -5 When the concentration of mercury ions was 0.1447 W / m, the linear ranges of mercury ion detection were [3.4 nM—5 μM] and [1.2 nM—10 μM] respectively.

[0060] The two fluorescent probes synthesized by the present invention are respectively added with different metal ions in pure water for fluorescence testing to detect the specificity of the two probes in response to mercury ions. The test results show that the probe molecules have a specific response to mercury ions, but when a large concentration of copper ions exists in the solution, the probes will be inactivated.

[0061] Another test method (determination 2) of the present invention is to compound the fluorescent probe to form a solid-state sensing film and use it for the determination of mercury ions, and the steps are as follows:

[0062] S1. Preparation of fluorescent sensing film: Dissolve the fluorescent probe in methanol solution, prepare polyvinyl alcohol solution and terephthaloyl diboric acid solution with dimethyl sulfoxide as solvent. Take polyvinyl alcohol solution, add fluorescent probe mother solution, further mix with terephthaloyl diboric acid solution, quickly pour the mixed solution into the mold groove, age at room temperature, and soak in water to complete solvent exchange.

[0063] S2. Test of mercury ion detection standard curve: Dissolve HgCl2 or Hg(NO3)2 in water to prepare a mercury concentration of 1.0×10 -3The mother solution of M is further diluted with pure water to form a series of standard solutions with concentration gradients. The gel film is immersed in standard solutions of different concentrations. After the ions are balanced, the film is moved into the fluorescence spectrometer and excited with the optimal excitation light of the probe. The maximum emission can appear at a specific wavelength. The fluorescence intensity at the maximum emission position is linearly fitted with the solution concentration to obtain the standard curve of mercury ion and fluorescence intensity.

[0064] S3. Immerse the hydrogel film in the water sample to be tested. After the mercury ions in the water sample are fully in contact with the probe in the gel, use a fluorescence spectrometer to detect and quantitatively analyze the sample. A UV hand lamp with a wavelength of 365nm can be used for irradiation. By observing the phenomenon that the solution changes from the original weak luminescence to blue-green fluorescence, the concentration of mercury ions in the water sample can be qualitatively determined.

[0065] Embodiment 1:

[0066] Use a pipette to draw 60.0 μL (5×10 -4 M) Add the TPE-2TA solution to a 3 mL stoppered four-way quartz cuvette, then use a pipette to draw 2940 μL of pure water and add it to the cuvette, stir and shake to mix, and ensure that the solution is clear and transparent, without visible suspended matter; then, use a portable ultraviolet lamp with a wavelength of 365 nm to initially irradiate the cuvette, observe the properties of the solution at this time, and then transfer it to a fluorescence spectrometer set to use the optimal excitation wavelength of 345 nm for excitation, and the maximum emission can appear at 490 nm for comparison and reference;

[0067] Use a pipette to draw 60.0 μL (5×10 -4 M) TPE-2TA solution was added to a 3 mL stoppered four-way quartz cuvette. Then 1940 μL of pure water sample was drawn into the cuvette using a pipette and stirred to mix well to ensure that the solution was clear and transparent without visible suspended matter. Then 1000 μL of different concentration gradients (0-1×10 -6 M)HgCl2 (or Hg(NO3)2 solution) is added to the above-mentioned cuvette; then, a portable ultraviolet lamp with a wavelength of 365nm is used to irradiate the cuvette, and the fluorescence of the solution is observed at this time. A yellow-green fluorescence visible to the naked eye can be observed in the cuvette, indicating the presence of mercury ions in the solution. Then, the cuvette is moved into a fluorescence spectrometer and set to use an excitation light with an optimal excitation wavelength of 345nm for excitation. The maximum emission can be seen at 490nm, and the mercury ion concentration in the water sample can be quantitatively detected. The test results are shown in the attached Figure 3 (left), that is, as the mercury ion content increases, the fluorescence intensity gradually increases, and dynamic light scattering characterization and scanning electron microscopy imaging (attached Figure 4 Left) It can be intuitively concluded that the probe molecules will be accompanied by the formation of aggregates during the sensing process.

[0068] Embodiment 2:

[0069] Use a pipette to draw 60.0 μL (5×10 -4 M) Add the TPE-4TA solution to a 3 mL stoppered four-way quartz cuvette, then use a pipette to draw 2940 μL of pure water and add it to the cuvette, stir and shake to mix, and ensure that the solution is clear and transparent, without visible suspended matter; then, use a portable ultraviolet lamp with a wavelength of 365 nm to irradiate the cuvette, observe the properties of the solution at this time, and then transfer it to a fluorescence spectrometer set to use the optimal excitation wavelength of 360 nm for excitation, and the maximum emission can appear at 499 nm for comparison and reference;

[0070] Use a pipette to draw 60.0 μL (5×10 -4 M) TPE-4TA solution was added to a 3 mL stoppered four-way quartz cuvette, and then 1940 μL of pure water sample was pipetted into the cuvette, and stirred and shaken to mix well to ensure that the solution was clear and transparent without visible suspended matter. Then 1000 μL of different concentration gradients (0-1×10 -6 M)HgCl2 or Hg(NO3)2 solution is added to the above cuvette; then, a portable ultraviolet lamp with a wavelength of 365nm is used to irradiate the cuvette, and the fluorescence of the solution is observed. Deep yellow-green fluorescence visible to the naked eye can be observed in the cuvette, indicating the presence of mercury ions in the solution. Then, the cuvette is moved into a fluorescence spectrometer and set to use an excitation light with an optimal excitation wavelength of 360nm for excitation. The maximum emission can be seen at 499nm, and the mercury ion concentration in the water sample can be quantitatively detected. The test results are shown in the attached Figure 3 (right), that is, as the mercury ion content increases, the fluorescence intensity gradually increases, and dynamic light scattering characterization and scanning electron microscopy imaging (Appendix Figure 4 Right) It can be intuitively concluded that the probe molecules will be accompanied by the formation of aggregates during the sensing process.

[0071] Embodiment 3:

[0072] In a 3 mL four-way cuvette, take 60.0 μL (5 × 10 -4 M) TPE-2TA or TPE-4TA was dissolved in 2850 μL of pure water, and 90 μL (1×10 -3 M) metal salt solution (Na + ,K + ,Ca 2+ Mg 2+ ,Mn 2+ ,Zn 2+ ,Cu 2+ ,Hg 2+ ,Pb2+ ,Ni 2+ ,Cd 2+ ,Fe 2+ ,Co 2+ ,Fe 3+ and Al 3+ ), set the optimal excitation wavelength in the fluorescence spectrometer (TPE-2TA optimal excitation light 345nm, TPE-4TA optimal excitation light 360nm) to test the change in fluorescence intensity of the solution. The test results are shown in the attached Figure 5 ; The above test results show that the probe has good selectivity for mercury ions.

[0073] Embodiment 4:

[0074] In a 3 mL four-way cuvette, take 60.0 μL (5 × 10 -4 M) TPE-2TA or TPE-4TA was dissolved in 2820 μL of pure water and 30.0 μL of Hg 2+ Solution (1×10 -3 M) and 90 μL of other metal ion salt solutions ( Figure 6 , the concentration is 1×10 -3 M) was mixed evenly, and then added to the above probe solution with a pipette, and the optimal excitation wavelength (TPE-2TA optimal excitation light 345nm, TPE-4TA optimal excitation light 360nm) was set in the fluorescence spectrometer to test the change in the fluorescence intensity of the solution. The test results are shown in the attached Figure 6 That is, these two probes are in the presence of other metal ions (except Cu 2+ ), and can also have a good sensing effect on mercury ions.

[0075] Embodiment 5:

[0076] Use dimethyl sulfoxide as solvent to prepare 5.0×10 -2 M polyvinyl alcohol solution and 6.0×10 -2 Take 600 μL of polyvinyl alcohol solution and pipette TPE-4TA (5×10 -4 M) was added, and then mixed with 150 μL of terephthaloyl diboric acid solution, and the mixture was quickly poured into the mold groove and aged at room temperature for 10 minutes. The materials were dispersed and soaked in pure water, and the water was replaced every 10 minutes within 4 hours to complete the solvent exchange, and the mercury ion sensing film was obtained.

[0077] Embodiment 6:

[0078] After the mercury ion sensing film (Example 5) is immersed in the water sample to be tested for 2 minutes, an ultraviolet lamp with a wavelength of 365nm is used to irradiate the cuvette and observe the fluorescence of the film at this time. The film can be observed to have enhanced blue-green fluorescence that can be seen by the naked eye, indicating the presence of mercury ions in the solution. Then it is moved into a fluorescence spectrometer and set to use 354nm excitation light for excitation. The maximum emission can be seen at 484nm, and the mercury ion concentration in the water sample can be quantitatively detected.

Claims

1. A solid-state sensing film for detecting mercury ions, characterized in that: It includes a membrane substrate and a fluorescent probe for detecting mercury ions compounded in the membrane substrate; The film substrate is polyvinyl alcohol; The preparation steps of the solid-state sensing film for detecting mercury ions are as follows: dissolving the fluorescent probe and mixing it with polyvinyl alcohol and terephthaloyl boric acid solution, then placing it in a mold, aging it, and soaking it in water to complete solvent exchange, thereby obtaining the solid-state sensing film for detecting mercury ions; The fluorescent probe for detecting mercury ions is at least one compound selected from TPE-2TA and TPE-4TA: TPE-4TA TPE-2TA 。 2. A method for preparing a solid-state sensing film for detecting mercury ions according to claim 1, characterized in that: The fluorescent probe is dissolved and mixed with polyvinyl alcohol and terephthaloyl boric acid solution, then placed in a mold, aged, and immersed in water to complete solvent exchange, thereby obtaining the solid-state sensing film for detecting mercury ions.

3. A fluorescence determination method for mercury ions in water for non-disease diagnosis and treatment purposes, characterized in that: The aqueous solution to be tested is brought into liquid-solid immersion contact with the solid-state sensor film of claim 1; and then the immersed solid-state sensor film is subjected to light excitation and fluorescence measurement.

4. The fluorescence measurement method according to claim 3, characterized in that: The pH of the aqueous solution to be tested is 5-7.

5.

5. The fluorescence measurement method according to claim 3, characterized in that: Fluorescence excitation was performed under 340~500nm light.

6. The fluorescence measurement method according to claim 5, characterized in that: When the fluorescent probe is TPE-2TA, its excitation wavelength is 300-350nm; When the fluorescent probe is TPE-4TA, its excitation wavelength is 350-380 nm.

7. The fluorescence measurement method according to claim 6, characterized in that: When the fluorescent probe is TPE-2TA, its excitation wavelength is 345-350nm; When the fluorescent probe is TPE-4TA, its excitation wavelength is 360-365 nm.

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