Probe for detecting zinc ions, preparation method thereof and kit
Patent Information
- Application Number
- CN202411677946.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-22
- Publication Date
- 2025-02-25
Smart Images
Figure CN119504779A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of chemistry and relates to a probe for detecting zinc ions and a preparation method and a kit thereof, and in particular to a bifunctional fluorescent probe compound for detecting zinc ions and mercury ions and a kit containing the probe. Background Art
[0002] Among metal cations, zinc ions (Zn 2+ ) is the second most abundant transition metal ion in the human body and plays an extremely important role. It plays a key role in maintaining normal metabolism and physiological functions. 2+ The balance of Zn concentration is crucial to human health as it is closely related to many diseases. For example, zinc deficiency can lead to developmental delays and neurological diseases, affecting the normal growth and development of the body. On the other hand, excessive Zn 2+ It may inhibit the activity and antibacterial ability of immune cells and have an adverse effect on the immune system. In addition to its role in the human body, Zn 2+ It also regulates plant growth. Its functions in plants include maintaining plant growth and development, and promoting basic life activities such as photosynthesis and respiration.
[0003] It should also be noted that high concentrations of Zn in the environment 2+ It may cause environmental pollution problems. This may be caused by industrial emissions, wastewater discharge or other human factors. High concentrations of Zn 2+ It may have adverse effects on aquatic organisms and terrestrial ecosystems, thereby affecting the ecological balance.
[0004] In addition, mercury ions are considered to be one of the most toxic cations, and their serious damage to the central nervous and endocrine systems cannot be ignored. In addition to posing a threat to human health, environmental pollution from mercury also endangers ecosystems and wildlife. Mercury pollution comes from a variety of sources, including activities such as primary metal production, fossil fuel combustion, chemical manufacturing, and coal mining. Even at low concentrations, mercury and its compounds are considered to be extremely dangerous neurotoxins to organisms. Due to their accumulation and persistence in organisms, they can cause a series of serious health problems, such as DNA damage, mitotic disorders, and may even cause permanent damage to the central nervous system. To meet this challenge, the U.S. Environmental Protection Agency (EPA) has set Hg in drinking water as the 999 national environmental pollution risk. 2+ The maximum permissible level is set at 2 μg / L (about 0.01 μmol / L).
[0005] Therefore, it is necessary to develop a reliable, convenient, selective and sensitive analytical method to determine Zn 2+ and Hg 2+It is of great research value and significance. At present, the commonly used method for determining Zn 2+ and Hg 2+ Methods for detecting mercury and zinc ions include atomic absorption spectroscopy (AAS), atomic emission spectroscopy (AES), atomic fluorescence spectroscopy (AFS) and inductively coupled plasma mass spectrometry (ICP-MS). However, these methods usually require expensive and complicated sample pretreatment and instrumentation. No method has been found that can simultaneously detect mercury ions and zinc ions under different conditions. Therefore, it is necessary to develop a composite fluorescent probe that can quickly and sensitively detect the content of zinc ions and mercury ions in samples, especially one with dual response properties under different conditions for Zn 2+ and Hg 2+ Simultaneous monitoring is extremely important. Summary of the invention
[0006] In order to overcome the defects in the prior art, the present invention provides a method for detecting Hg under different conditions. 2+ 、Zn 2+ The multifunctional fluorescent probe, preparation method and kit containing the probe are used for rapid and sensitive detection of zinc ion and mercury ion content in solution systems and life systems.
[0007] The present invention also provides an application of a fluorescent probe compound for detecting zinc ions in plants. The compound can be used to detect zinc ions in plants under detection environment and physiological conditions.
[0008] The present invention also provides an application of a fluorescent probe compound for detecting mercury ions in plants. The compound can be used to detect mercury ions in plants under detection environment and physiological conditions.
[0009] The technical solution is as follows:
[0010] A probe for detecting zinc ions, the probe is 4',5'-bis((bis(pyridine-2-methylene)amino)methyl)-2',7'-dichloro-3'-hydroxyfluorescein 4-((4-dimethylamino)phenyl)azo)benzoic acid (FL-ZJ), and its chemical structure is shown in Formula 1 below:
[0011]
[0012] A method for preparing a probe for detecting zinc ions according to the present invention comprises the following steps:
[0013] Step 1, dissolving paraformaldehyde and 2,2'-dipicolylamine in acetonitrile according to a preset material amount ratio of 1:1 to 1:1.2, placing in a round-bottom flask and reflux for 25 to 40 minutes;
[0014] Step 2: Add a mixed solution of acetonitrile and water (v / v=1:1) containing 1 / 3 molar equivalent of paraformaldehyde in step 1 and 2',7'-dichlorofluorescein to the reaction system, and continue the reflux reaction for 24 hours. Monitor the reaction endpoint by TLC. After the reaction is completed, cool to room temperature, concentrate under reduced pressure to remove acetonitrile, heat the remaining solution to 75°C, add a certain amount of 75°C ethanol, and continue stirring for 1.5 hours.
[0015] Step 3, placing the solution obtained in step 2 in a refrigerator at -20°C for 12 hours, at which time a pink precipitate will form at the bottom of the solution;
[0016] Step 4, filter under reduced pressure, wash the filter cake with ice water 3-4 times, and dry to obtain a pink solid;
[0017] Step 5, dissolving 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine and 4-dimethylaminoazobenzene-4-carboxylic acid in a ratio of 1:0.1:0.8 to 1:0.3:0.5 in a round-bottom flask containing a mixture of dichloromethane and N,N-dimethylformamide (DMF), reacting at 50° C. for 12 h, and cooling to room temperature after the reaction is completed;
[0018] Step 6, add the product obtained in step 4, continue the reaction at 50°C for 10-15h, and cool to room temperature after the reaction is completed;
[0019] Step 7. The reaction system is diluted with dichloromethane, placed in a separatory funnel, washed with water two to three times, washed once with a saturated sodium chloride aqueous solution, the organic phase is dried over anhydrous sodium sulfate, the solvent is distilled off under reduced pressure, and the by-products are removed by silica gel column chromatography to obtain a red solid, which is a probe for detecting zinc ions.
[0020] Preferably, step 1, dissolving 1.590 g (7.99 mmol) of 2,2'-dipicolylamine and 0.224 g (7.47 mmol) of paraformaldehyde in 20 mL of acetonitrile, placing the mixture in a 100 mL round-bottom flask and refluxing for 30 min;
[0021] Step 2, add 30 mL of a mixed solution of acetonitrile and water (v / v=1:1) containing 1.001 g (2.49 mmol) of 2',7'-dichlorofluorescein to the reaction system, continue the reflux reaction for 24 h, monitor the reaction endpoint by TLC, cool to room temperature after the reaction is completed, concentrate under reduced pressure to remove acetonitrile, heat the remaining solution to 75°C, add 30 mL of 75°C ethanol, and continue stirring for 1.5 h;
[0022] Step 3, placing the solution obtained in step 2 in a refrigerator at -20°C for 12 hours, at which time a pink precipitate will form at the bottom of the solution;
[0023] Step 4, filter under reduced pressure, wash the filter cake with ice water 3 times, and dry to obtain 1.5 g of pink solid with a yield of 38.46%;
[0024] Step 5, 0.19 g (0.99 mmol) of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.0245 g (0.20 mmol) of 4-dimethylaminopyridine and 0.25 g (0.93 mmol) of 4-dimethylaminoazobenzene-4-carboxylic acid were dissolved in a 20 ml round-bottom flask containing 5 ml of a mixture of dichloromethane and N,N-dimethylformamide (DMF) (3.4 mL of dichloromethane, 1.6 mL of DMF), and reacted at 50 ° C for 12 h. After the reaction was completed, the mixture was cooled to room temperature;
[0025] Step 6, add 0.3364 g (0.41 mmol) of the product obtained in step 4, continue the reaction at 50°C for 12 h, and cool to room temperature after the reaction is completed;
[0026] Step 7. The reaction system was diluted with 20 mL of dichloromethane, placed in a separatory funnel, washed three times with 10 mL of water and once with 10 mL of water, the organic phase was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the by-products were removed by silica gel column chromatography to obtain 0.076 g of a red solid, which was a probe for detecting zinc ions, with a yield of 14.26%.
[0027] A kit for detecting zinc ions, comprising the probe according to claim 1 or the probe prepared according to any one of claims 2 to 3 and a PB buffer.
[0028] Furthermore, the concentration of the probe is 5×10 -6 mol / L, the pH of the PB buffer solution is 9.0, and the concentration of the PB buffer solution is 10 mM.
[0029] A kit for detecting mercuric ions, comprising the probe according to claim 1 or the probe prepared according to any one of claims 2 to 3 and a buffer system of MeOH:PB=8:2.
[0030] Furthermore, the concentration of the probe is 5×10 -7 mol / L, the pH of the buffer system is 10, and the concentration of the buffer system is 10 mM.
[0031] Compared with the prior art, the present invention has the following beneficial effects:
[0032] The present invention utilizes the modification of the quenching group to overcome the shortcomings of the existing methods, such as high background fluorescence and insufficient sensitivity. The probe is a dual-function fluorescent probe that can detect Hg under different conditions. 2+ and Zn 2+, other ions will hardly interfere with it, and it has high sensitivity and specificity. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 pH Effect of Fluorescence Response of Probe FL-ZJ on Zn 2+ and Hg 2+ The impact of
[0034] Figure 2 The probe FL-ZJ reacts with different concentrations of Zn 2+ The fluorescence response of
[0035] Figure 3 The probe FL-ZJ reacts with different concentrations of Zn 2+ The linear response relationship of
[0036] Figure 4 The linear response of probe FL-ZJ to different ions and amino acids;
[0037] Figure 5 Fluorescence response of probe FL-ZJ to Hg 2+ The impact of
[0038] Figure 6 The probe FL-ZJ reacts with different concentrations of Hg 2+ The fluorescence response of
[0039] Figure 7 Probe FL-ZJ and different concentrations of Hg 2+ The linear response relationship of
[0040] Figure 8 The linear response of probe FL-ZJ to different ions and amino acids;
[0041] Fig. 9 Probe FL-ZJ for Hg 2+ Reversible response;
[0042] Fig.10 Probe FL-ZJ for Zn in daisy 2+ Detection (bright field);
[0043] Fig.11 Probe FL-ZJ for Zn in daisy 2+ Detection (fluorescence). DETAILED DESCRIPTION
[0044] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0045] Example 1
[0046] In this example, 4',5'-bis((bis(pyridine-2-methylene)amino)methyl)-2',7'-dichloro-3'-hydroxyfluorescein 4-((4-dimethylamino)phenyl)azo)benzoic acid (synthesis of probe FL-ZJ) was synthesized according to the following synthetic route:
[0047]
[0048] The specific process is:
[0049] 1.590g (7.99mmol) of 2,2'-dipicolylamine and 0.224g (7.47mmol) of paraformaldehyde were dissolved in 20mL of acetonitrile and placed in a 100mL round-bottom flask for reflux for 30min. A mixed solution (v / v=1:1) of 30mL of acetonitrile and water containing 1.001g (2.49mmol) of 2',7'-dichlorofluorescein was added to the reaction system, and the reflux reaction was continued for 24h. The end point of the reaction was monitored by TLC. After the reaction was completed, the mixture was cooled to room temperature, concentrated under reduced pressure to remove acetonitrile, and the remaining solution was heated to 75°C, and 30mL of 75°C ethanol was added, and stirring was continued for 1.5h. Subsequently, the solution was placed in a refrigerator at -20°C and allowed to stand for 12h. At this time, a pink precipitate will form at the bottom of the solution. Filter under reduced pressure, wash the filter cake with ice water 3 times, and dry to obtain 1.5g of pink solid with a yield of 38.46%. 1 HNMR(400MHz,Chloroform-d)δ8.60(d,J=4.8Hz,4H),8.04(d,J=7.3Hz,1H),7.75-7.60(m, 6H),7.36(d,J=7.8Hz,4H),7.24-7.14(m,5H),6.64(s,2H),4.20(s,4H),4.09-3.92(m,8H). 13 C NMR(101MHz,Chloroform-d)δ168.98,157.63,155.89,151.60,148.80,148.71,137.22,135 .27,130.15,127.70,127.06,124.10,122.52,117.53,111.79,110.01,83.30,59.05,49.15.
[0050] Take a 20mL round-bottom flask, dissolve 0.19g (0.99mmol) of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC), 0.0245g (0.20mmol) of 4-dimethylaminopyridine, and 0.25g (0.93mmol) of 4-dimethylaminoazobenzene-4-carboxylic acid in 5ml of a mixture of dichloromethane (DCM) and N,N-dimethylformamide (DMF) (3.4mL of DCM, 1.6mL of DMF), react at 50℃ for about 12h, and cool to room temperature after the reaction is completed. Then add 0.3364g (0.41mmol) of compound 3-1, react at 50℃ for 12h, and cool to room temperature after the reaction is completed. Dilute with DCM, wash with distilled water to remove excess 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and 4-dimethylaminopyridine, evaporate the reaction solvent under reduced pressure, and purify the crude product by column chromatography (dichloromethane:methanol=15:1) to obtain 0.076 g of a red solid with a yield of 14.26%. MS (ESI): m / z calc.for C 61 H 49 Cl2N9O6:1073.3; found:1074.3[M+H] + .
[0051] In this example, all spectral experiments involved were measured in a PB system (10 mM) unless otherwise specified.
[0052] The probe FL-ZJ was dissolved in dimethyl sulfoxide (DMSO) to prepare a 10 mM stock solution, which was stored in a refrigerator for later use. + , K + 、Zn 2+ , Ba 2+ , Cu 2+ Mg 2+ , Pb 2+ , Hg 2+ 、Ni 2+ 、Co 2+ 、Cd 2+ , Fe 2+ , Fe 3+ , Tyr, Ser, Met, Pro, GSH, Leu, Cys, Sec, NAC) were dissolved in deionized water to make a 10 mM stock solution. 2+ The detection was conducted under the condition of pH=9 buffer. The excitation light was 505nm, and the spectral data were collected at 515-650nm. 2+All tests were conducted under the conditions of MeOH-PB (8:2, v:v, 10 mM, pH = 10). The excitation light was 315 nm, and the spectral data were collected at a wavelength of 500-620 nm. The excitation and emission slits of the fluorescence spectrometer were 5.0 nm and 5.0 nm, respectively, unless otherwise specified.
[0053] Zinc ion determination pH selectivity experiment
[0054] In order to select the optimal pH value of the recognition system, a pH selectivity experiment was designed in this example. The pH value of the recognition system was adjusted from 2 to 12, the excitation and emission slit widths were both 5 nm, and the ultraviolet light with a wavelength of 390 nm was used for excitation. The FL-ZJ and FL-ZJ-Zn 2+ The fluorescence intensity of the system at 526 nm at various pH values showed that the recognition effect was best at pH = 9.0 and Hg 2+ Do not interfere (such as Figure 1 ). Therefore, all spectral experiments were carried out in PB buffer solution with pH = 9.0 prepared with deionized water.
[0055] Zinc ion fluorescence titration
[0056] Different concentrations of Zn 2+ After adding it to a 5μM probe solution and reacting at room temperature for 2h, the probe test system was excited with an excitation light of 505nm and the spectral data of 515nm-650nm were collected. The experimental results show ( Figure 2 ), the fluorescence of the probe in PB buffer is very weak. 2+ The fluorescence at 526nm gradually increased. 2+ When the concentration of Zn increased to 20 μM, the fluorescence intensity of the system increased by about 12 times, showing a higher sensitivity. 2+ The presence of α coordinates with the bipyridine site of the probe FL-ZJ and further induces the release of the quencher DABCYL, resulting in fluorescence recovery. Figure 3 It can be seen that in the range of 0-2 μM, the fluorescence intensity is 2+ The concentration showed a good linear relationship (R 2 =0.9909).
[0057] Zinc ion selectivity experiment
[0058] In the selectivity experiment, the concentration of probe FL-ZJ was 5.0×10-6mol·L -1 , Zn 2+ The concentration is 1.0×10-5mol·L -1 The concentrations of other anions, cations and amino acids were all 2.5×10-5mol·L-1 A series of final concentrations of 5.0 × 10 -6 mol·L -1 probe PB solution (10 mM, pH = 9.0), and a final concentration of 1.0 × 10 -5 mol·L -1 Zn 2+ , and the concentration was 2.5×10-5mol·L -1 After shaking and reacting for 2 hours at room temperature, the mixture was excited with λex=505nm and the spectral data was collected at a wavelength of 526nm. Figure 4 As shown, FL-ZJ has a significant effect on Zn 2+ It shows good selectivity and other ions have almost no interference.
[0059] pH Selectivity Experiment for Mercury Ion Determination
[0060] To screen the probe FL-ZJ for detecting Hg 2+ Suitable pH range, pH selectivity experiment was designed in this example. Buffers with different pH values were pipetted with a pipette and mixed with MeOH at a volume ratio of 2:8, the pH value of the recognition system was adjusted from 2 to 12, the excitation and emission slit widths were both 5nm, and ultraviolet light with a wavelength of 315nm was used for excitation, and FL-ZJ and FL-ZJ-Hg were measured respectively. 2+ The fluorescence intensity of the system at 538nm at various pH values showed that the recognition effect was best at pH = 10.0 and Zn 2+ Do not interfere (such as Figure 5 ). 2+ All the spectroscopic experiments related to the detection were carried out in PB buffer solution with pH = 10.0 prepared with deionized water.
[0061] Mercury ion fluorescence titration
[0062] The different concentrations of Hg 2+ Add to the probe solution containing 500nM, react at room temperature for 2h, excite the probe test system with an excitation light of 315nm, and collect spectral data from 500nm to 620nm. The experimental results show ( Figure 6 ), the fluorescence of the probe in the solvent system is very weak, however, with the increase of Hg 2+ The fluorescence of the system gradually increased with the gradual addition of Hg, and the fluorescence enhancement phenomenon was observed at 538nm. 2+ When the concentration of increased to 2 μM, the fluorescence intensity of the system increased by about 386 times, showing a very high sensitivity. Figure 7 It can be seen that in the range of 0-0.7μM, the fluorescence intensity is 2+The concentration showed a good linear relationship (R 2 =0.9870).
[0063] Mercury ion selectivity experiment
[0064] In the selectivity experiment, the concentration of probe FL-ZJ was 5.0 × 10 -6 mol·L -1 , Hg 2+ The concentrations of other anions, cations and amino acids were all 2.5×10 -5 mol·L -1 A series of final concentrations of 5.0 × 10 -6 mol·L -1 probe PB solution (10 mM, pH = 9.0), and a final concentration of 2.5 × 10 -5 mol·L -1 Hg 2+ As well as other anions, cations and amino acids, shake well and react at room temperature for 2 hours, then excite with λex=315nm excitation light and collect spectral data at 538nm wavelength. Figure 8 As shown, FL-ZJ has a significant effect on Hg 2+ It shows good selectivity and other ions have almost no interference.
[0065] Hg 2+ Detection of reversibility
[0066] Using Hg 2+ With S 2- The larger coordination constant is obtained by repeatedly adding S 2- With -Hg 2+ The fluorescence response of the probe at 538 nm was investigated. This experiment simulated the Hg 2+ The probe's response to changes in the environment and fluctuations in concentration can be used to evaluate the probe's sensitivity to Hg in the actual system. 2+ Dynamic detection performance. The results show that ( Fig. 9 ), Hg was added to the probe solution 2+ After that, the fluorescence of the system at 538nm was significantly enhanced. 2- When added to the system, Hg in the solution and coordinated with the probe 2+ Combined with it to form a stable HgS complex, resulting in the ring closure of the fluorescein parent, and the fluorescence intensity is almost restored to the original state. 2+ After the addition of , the free mercury ions coordinate with the pyridine ring and the 3 / 3'-position O atom on the probe, and the fluorescein ring opens again and the fluorescence is restored. After multiple cycles, the probe still shows good dynamic response performance to mercury ions. This proves that the probe FL-ZJ and Hg2+ The sensing process is dynamically reversible and has high stability.
[0067] This embodiment provides a kit containing a zinc ion detection probe, including a concentration of 1×10 -4 mol·L -1 FL-ZJ, pH = 9.0, PB buffer with a concentration of 10 mM. The kit was prepared as follows: 60 μL of 1×10 -2 mol·L -1 The probe stock solution was mixed with PB buffer solution (1×10 -2 mol·L -1 ) was diluted to 1×10 -4 mol·L -1 probe.
[0068] Application of probe FL-ZJ in the detection of zinc ions in plants
[0069] Under the above kit preparation conditions, the diluted probe solution was loaded into a 30 mL spray bottle and the Zn content in the petals of white daisy was measured. 2+ Take 60 μL of 1×10 -2 mol·L -1 The probe was treated with PB buffer solution (1×10 - 2 mol·L -1 ) was diluted to 1×10 -4 mol·L -1 Take three white daisies from the same plant and soak them in 0 mol·L -1 , 5×10 -5 mol·L -1 , 1×10 -3 mol·L -1 Zn 2+ After 48 h in the solution, a small amount of millet was placed at the bottom of the bottle to provide nutrients, and 2 mL of 100 μM probe was evenly sprayed on each flower with a 30 mL spray bottle. The flowers were irradiated with a 365 nm ultraviolet lamp to observe their fluorescence and bright field conditions.
[0070] The results are as follows Fig.10 As shown in the figure, when observed in the bright field, it is found that as the zinc ion concentration increases, the white petals of the daisy become darker. This may be because, under this condition, Zn 2+ The ester bond is broken by coordinating with 2,2'-dipicolylamine and 3'-position O in the probe FL-ZJ, freeing the quencher DABCYL, further inducing the ring opening of fluorescein, and showing a pink color. At the same time, in the case of the control sample, FL-ZJ was found to have no fluorescence. As the color of the daisy turned red, ( Fig.11 ) found that the fluorescence of daisy was enhanced at 365nm. These results prove that Zn can be achieved in plant samples 2+ The in situ detection of Zn content showed that the probe FL-ZJ has the potential to detect Zn in plants. 2+ ability.
[0071] The above is only a preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with the technical field within the technical scope disclosed in the present invention falls within the protection scope of the present invention.
Claims
1. A probe for detecting zinc ions, characterized in that: The probe is 4',5'-bis((bis(pyridine-2-methylene)amino)methyl)-2',7'-dichloro-3'-hydroxyfluorescein 4-((4-dimethylamino)phenyl)azo)benzoic acid, and its chemical structure is shown in Formula 1 below:
2. A method for preparing a probe for detecting zinc ions according to claim 1, characterized in that: The following steps are involved: Step 1, dissolving paraformaldehyde and 2,2'-dipicolylamine in acetonitrile according to a preset material amount ratio of 1:1 to 1:1.2, placing in a round-bottom flask and reflux for 25 to 40 minutes; Step 2: Add a mixed solution of acetonitrile and water containing 1 / 3 molar equivalent of paraformaldehyde in step 1 and 2',7'-dichlorofluorescein in a ratio of v / v=1:1 to the reaction system, continue the reflux reaction for 24 hours, monitor the reaction endpoint by TLC, cool to room temperature after the reaction is completed, concentrate under reduced pressure to remove acetonitrile, heat the remaining solution to 75°C, add a certain amount of 75°C ethanol, and continue stirring for 1.5 hours; Step 3, placing the solution obtained in step 2 in a refrigerator at -20°C for 12 hours, at which time a pink precipitate will form at the bottom of the solution; Step 4, filter under reduced pressure, wash the filter cake with ice water 3-4 times, and dry to obtain a pink solid; Step 5, dissolving 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 4-dimethylaminopyridine and 4-dimethylaminoazobenzene-4-carboxylic acid in a ratio of 1:0.1:0.8 to 1:0.3:0.5 in a round-bottom flask containing a mixture of dichloromethane and N,N-dimethylformamide, reacting at 50° C. for 12 h. After the reaction is complete, cooling to room temperature; Step 6, add the product obtained in step 4, continue the reaction at 50°C for 10-15h, and cool to room temperature after the reaction is completed; Step 7. The reaction system is diluted with dichloromethane, placed in a separatory funnel, washed with water two to three times, washed once with a saturated sodium chloride aqueous solution, the organic phase is dried over anhydrous sodium sulfate, the solvent is distilled off under reduced pressure, and the by-products are removed by silica gel column chromatography to obtain a red solid, which is a probe for detecting zinc ions.
3. The method for preparing the probe for detecting zinc ions according to claim 1 according to claim 2, characterized in that: Step 1, dissolve 1.590 g of 2,2'-dipicolylamine and 0.224 g of paraformaldehyde in 20 mL of acetonitrile, place in a 100 mL round-bottom flask and reflux for 30 min; Step 2, add 30 mL of a mixed solution of acetonitrile and water (v / v=1:1) containing 1.001 g of 2',7'-dichlorofluorescein to the reaction system, continue the reflux reaction for 24 h, monitor the reaction endpoint by TLC, cool to room temperature after the reaction is completed, concentrate under reduced pressure to remove acetonitrile, heat the remaining solution to 75°C, add 30 mL of 75°C ethanol, and continue stirring for 1.5 h; Step 3: Place the solution obtained in step 2 in a refrigerator at -20°C for 12 hours, at which time a pink precipitate will form at the bottom of the solution; Step 4, filter under reduced pressure, wash the filter cake with ice water 3 times, and dry to obtain 1.5 g of pink solid with a yield of 38.46%; Step 5, dissolve 0.19 g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride, 0.0245 g of 4-dimethylaminopyridine and 0.25 g of 4-dimethylaminoazobenzene-4-carboxylic acid in a 20 ml round-bottom flask containing 5 ml of a mixture of dichloromethane and N,N-dimethylformamide, react at 50° C. for 12 h, and cool to room temperature after the reaction is complete; Step 6, add 0.3364 g of the product obtained in step 4, continue the reaction at 50° C. for 12 h, and cool to room temperature after the reaction is completed; Step 7. The reaction system was diluted with 20 mL of dichloromethane, placed in a separatory funnel, washed three times with 10 mL of water and once with 10 mL of water, the organic phase was dried over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and the by-products were removed by silica gel column chromatography to obtain 0.076 g of a red solid, which was a probe for detecting zinc ions, with a yield of 14.26%.
4. The method for preparing the probe for detecting zinc ions according to claim 1 according to claim 3, characterized in that: In step 5, 3.4 mL of dichloromethane and 1.6 mL of N,N-dimethylformamide.
5. A kit for detecting zinc ions, characterized in that, The kit comprises the probe according to claim 1 or the probe prepared according to any one of claims 2 to 3 and a PB buffer.
6. The kit for detecting zinc ions according to claim 5, characterized in that, The concentration of the probe was 5×10 - 6 mol / L, the pH of the PB buffer solution is 9.0, and the concentration of the PB buffer solution is 10 mM.
7. A kit for detecting mercury ions, characterized in that: The kit comprises the probe according to claim 1 or the probe prepared by any one of claims 2 to 3 and a buffer system of MeOH:PB=8:
2.
8. The kit for detecting mercury ions according to claim 7, characterized in that: The concentration of the probe was 5×10 - 7 mol / L, the pH of the buffer system is 10, and the concentration of the buffer system is 10 mM.