A fluorescent probe for detecting Ag + , a preparation method, and a preparation and use method of fluorescent filter paper

Abstract

The application belongs to the technical field of detecting Ag + , and particularly relates to a fluorescent probe for detecting Ag + , a preparation method of the fluorescent probe, and a preparation and use method of corresponding fluorescent filter paper. The synthesized fluorescent probe compound AgP for detecting Ag + has the following formula I structure, is simple to synthesize, and is easy to react. The qualitative filter paper is cut into strips, is immersed in a solution containing AgP, and is dried to obtain fluorescent filter paper strips for detecting Ag + . Whether Ag + is contained in a sample is judged by color changes of the filter paper strips under visible light and ultraviolet light, technical problems such as high detection cost, poor selectivity, and inability to perform real-time monitoring of existing Ag + detection are solved, and the application has important theoretical and economic values.

Description

Technical Field

[0001] This invention pertains to the detection of Ag. + The technical field involves the detection of Ag. + Preparation and detection of Ag fluorescent probes + Preparation and application methods of fluorescent filter paper. Background Technology

[0002] Silver is an important industrial metal, widely used in cosmetics, pharmaceuticals, and dressings. Due to its excellent antibacterial properties, Ag... + It has been used to treat post-burn infections, eye infections, and some traumatic infections. Silver nanoparticles (AgNPs) have also shown some potential in cancer treatment by improving drug delivery efficiency and producing anti-tumor effects. However, excessive use of Ag... + It can cause gastrointestinal damage, leading to spasms, weight loss, changes in neurotransmitter levels, and even death. Soluble Ag + AgNPs, when introduced into the ecological environment, can also pose potential toxicity to bacteria, algae, aquatic organisms, and plants. Therefore, the determination of various metal cations in drinking water, especially Ag... + This is crucial for water quality monitoring. Developing highly selective, sensitive, and convenient Ag2 detection methods is essential. + Detection tools will help us monitor Ag in the environment. + And explore its biologically related toxic processes.

[0003] Commonly used Ag + Current detection methods include electrochemical methods, atomic absorption spectrometry, and inductively coupled plasma mass spectrometry. However, most of these methods rely on expensive equipment, are cumbersome to operate, and lack convenience. Therefore, developing methods suitable for detecting Ag in environmental samples and organisms is crucial. + The need for efficient detection tools is urgent. Compared with other methods, detection strategies based on fluorescent probes have attracted widespread attention due to their unique advantages such as simple operation, high detection sensitivity, minimal damage to biological tissues, and real-time monitoring. For example, Velmurugan et al. constructed a fluorescent probe using a pyrene scaffold for the detection of Ag. + Selective. However, Ag has been reported so far. + There are very few detection probes available, and they are being developed for in vitro and in vivo detection of Ag. + Highly selective small molecule fluorescent probes remain in urgent need. Summary of the Invention

[0004] This invention aims to solve the problem of detecting Ag using existing traditional methods. + Due to limitations in equipment and high costs, real-time on-site detection of Ag is not possible. + Technical issues; detection of Ag using fluorescent probe method +At that time, there were technical problems such as poor probe anti-interference ability and long reaction time; detection of Ag + The fabrication process of fluorescent filter paper presents complex technical challenges. A novel Ag-based method using a quinoline ring is proposed. + The preparation method of the detection probe and the preparation and use of fluorescent filter paper are described. This fluorescent probe exhibits good selectivity and high sensitivity, and the fluorescent filter paper strips prepared using this probe enable real-time, visual, on-site detection.

[0005] Detection of Ag in this invention + The fluorescent probe structure is as follows:

[0006]

[0007] The synthesis route is as follows:

[0008]

[0009] Detection of Ag + The preparation method of the fluorescent probe is carried out according to the following steps:

[0010] Step 1: Add (E)-2-butenal (20 mmol, 0.7 g) to a solution of N,N-dimethyl-p-toluidine (10 mmol, 1.36 g) in 22 mL of 6N HCl and stir at room temperature for 1 h. Then add 10 mL of toluene and stir the reaction mixture at 110 °C for 12 h. After cooling the reaction to room temperature, neutralize the aqueous layer to pH 7-8 with NaOH solution. Extract three times with dichloromethane, wash the organic phase 2-3 times with saturated brine, dry to anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the crude product. Purify the crude product by silica gel column chromatography (PE:EA = 40:1, v / v) to obtain compound 2 (1.0 g, 72%) as a yellow-brown solid.

[0011] Step 2: SeO2 (7.5 mmol, 832 mg) was dissolved in 1,4-dioxane / H2O (10 ml: 1 ml, v / v) and heated at 60 °C for 30 min. Then, compound 2 (5 mmol, 931 mg) was added and stirred at 80 °C for 4 h. After the reaction was complete, the reaction product was cooled to room temperature, the precipitate was removed by filtration, and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (PE:EA = 40: 1, v / v) as the eluent to obtain the corresponding aldehyde 3 as a yellow solid (757 mg, 60%).

[0012] Step 3: Dissolve compound 3 (1 mmol, 200 mg) in DMF and cool to 0°C. Then, mix 1-aminohydantoin hydrochloride (1.1 mol, 167 mg) dissolved in ice water with compound 3 and stir the mixture at room temperature for 4 h. Extract and filter the mixture to obtain an orange-red precipitate. Wash the precipitate repeatedly with H2O to obtain the detectable Ag. + The fluorescent probe AgP is a red solid (150 mg, 50.5%).

[0013] Using the above method to detect Ag + The method for preparing fluorescent filter paper strips using fluorescent probes is carried out according to the following steps:

[0014] Step 1: Detect Ag + The fluorescent probe AgP was dissolved in DMSO to obtain an AgP probe solution (10 μM).

[0015] Step 2: Cut the qualitative filter paper into strips, soak them in the probe solution for 2 hours, remove and dry them to obtain the Ag detection solution. + Fluorescent filter paper strips.

[0016] The above detection of Ag + The method for using fluorescent filter paper strips is as follows:

[0017] To detect Ag + A sample containing metal ions is dropped onto a fluorescent filter paper strip. After 1-2 minutes, the fluorescence color change of the filter paper strip is observed under ultraviolet light. If the color of the fluorescent filter paper strip changes from green to bright yellow, it can be determined that the sample contains Ag. + After drying at room temperature, observe the color change of the filter paper strip under visible light. If the color of the filter paper strip changes from white to brown, it can be determined that the sample contains Ag. + .

[0018] Ag in this invention + The fluorescent probe is simple to synthesize, low in cost, highly sensitive, and selective, exhibiting activity against Ag within a pH range of 3-10. + The response was good. The filter paper strips prepared using this fluorescent probe are simple to prepare and use, and can achieve the detection of Ag in aquatic environments. + The detection is unaffected by other metal ions in the aqueous solution. Furthermore, the filter paper strip responds rapidly and effectively, producing a fluorescent color change within 1-2 minutes, thus enabling the detection of Ag in the aquatic environment. + Real-time on-site detection. Attached Figure Description

[0019] Figure 1The fluorescent probe AgP (10 μM) prepared in Example 1 was reacted with AgNO3 (0-300 μM Ag) in PBS buffer (10 mM, 1 mM CTAB, pH 7.4, 1% DMSO). + The fluorescence spectrum after 10 min of reaction, with wavelength on the x-axis and fluorescence intensity on the y-axis;

[0020] Figure 2 It is Without Ag + To test the probe in PBS buffer (10 mM, 1 mM CTAB, pH 7.4, 1% DMSO) with different metal ions (Mg²⁺, ... 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2 + Cu + Cu 2+ The normalized fluorescence response at 532 nm. With Ag + To determine the reaction of the probe with different metal ions (Mg²⁺, ... 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ The normalized fluorescence response at 532 nm.

[0021] Figure 3 The color change of fluorescent filter paper strips under visible and ultraviolet light was determined after adding equal volumes (200 μL) of AgNO3 aqueous solutions of different concentrations (0-500 μM) for 10 min.

[0022] Figure 4To add equal volumes (200 μL) of different metal cations (Mg) of equal concentrations (300 μM) 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ The color change of fluorescent filter paper strips under visible and ultraviolet light after reacting with the aqueous solution for 10 minutes. Detailed Implementation

[0023] Specific Implementation Method 1: Detection of Ag in this Implementation Method + The fluorescent probe structure is as follows:

[0024]

[0025] Detection of Ag + The synthetic route for the fluorescent probe AgP is as follows:

[0026]

[0027] Specific Implementation Method Two: The method for detecting Ag in Specific Implementation Method One + The preparation method of the fluorescent probe is carried out according to the following steps:

[0028] Step 1: Add (E)-2-butenal (20 mmol, 0.7 g) to a solution of N,N-dimethyl-p-toluidine (10 mmol, 1.36 g) in 22 mL of 6N HCl and stir at room temperature for 1 h. Then add 10 mL of toluene and stir the reaction mixture at 110 °C for 12 h. After cooling the reaction to room temperature, neutralize the aqueous layer to pH 7-8 with NaOH solution. Extract three times with dichloromethane, wash the organic phase 2-3 times with saturated brine, dry to anhydrous sodium sulfate, and concentrate under reduced pressure to obtain the crude product. Purify the crude product by silica gel column chromatography (PE:EA = 40:1, v / v) to obtain compound 2 (1.0 g, 72%) as a yellow-brown solid.

[0029] Step 2: SeO2 (7.5 mmol, 832 mg) was dissolved in 1,4-dioxane / H2O (10 ml: 1 ml, v / v) and heated at 60 °C for 30 min. Then, compound 2 (5 mmol, 931 mg) was added and stirred at 80 °C for 4 h. After the reaction was complete, the reaction product was cooled to room temperature, the precipitate was removed by filtration, and the filtrate was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (PE:EA = 40: 1, v / v) as the eluent to obtain the corresponding aldehyde 3 as a yellow solid (757 mg, 60%).

[0030] Step 3: Dissolve compound 3 (1 mmol, 200 mg) in DMF and cool to 0°C. Then, mix 1-aminohydantoin hydrochloride (1.1 mol, 167 mg) dissolved in ice water with compound 3 and stir the mixture at room temperature for 4 h. Extract and filter the mixture to obtain an orange-red precipitate. Wash the precipitate repeatedly with H2O to obtain the detectable Ag. + The fluorescent probe AgP is a red solid (150 mg, 50.5%).

[0031] The proton NMR spectrum of the prepared fluorescent probe AgP: 1 H NMR (600MHz, DMSO-d6) δ 11.36 (s, 1H), 8.14 (d, J=8.4Hz, 1H), 7.89-7.80 (m, 3H), 7.47 (d, J=7.5Hz, 1H), 6.96 (s, 1H), 4.44 (s, 2H), 3.05 (s, 6H).

[0032] Carbon NMR spectrum of the prepared fluorescent probe AgP: 13 C NMR (151MHz, DMSO-d6) δ168.41, 152.73, 148.35, 145.48, 142.91, 133.83, 128.94, 118.91, 116.93, 104.09, 48.27, 39.52.

[0033] Mass spectrometry of the prepared fluorescent probe AgP: HR-MS for C 15 H 16 N5O2[M+H + ]calculated: 298.1304, found 298.1310.

[0034] Specific Implementation Method 3: Detection of Ag by Fluorescent Probe AgP + The fluorescence spectroscopy experiment is performed as follows:

[0035] Step 1: Preparation of the stock solution

[0036] Weigh 1 mg of the fluorescent probe compound AgP and dissolve it in DMSO to prepare a 1 mM AgP DMSO solution.

[0037] Weigh 2 mg of AgNO3 and dissolve it in pure water to prepare a 1 mM AgNO3 stock solution. Dilute the stock solution with water to prepare AgNO3 aqueous solutions of different concentrations.

[0038] Weigh 20 mg of CTAB and dissolve it in pure water to prepare a 100 mM CTAB aqueous solution.

[0039] Step 2: Spectral Performance Testing

[0040] Add 2 μL of DMSO solution containing the probe AgP, 10 μL of aqueous solutions of AgNO3 at different concentrations, and 2 μL of CTAB aqueous solution to 100 μL of PBS buffer. Then add pure water to bring the solution volume to 200 μL. After shaking for 10 min, record the changes in the fluorescence spectrum of AgP before and after the reaction.

[0041] Figure 1 The probe AgP (10 μM) was prepared in PBS buffer (10 mM, 1 mM CTAB, pH 7.4, 1% DMSO) and reacted with AgNO3 (0-300 μM Ag) + Fluorescence spectrum after 10 min of reaction (excitation wavelength 390 nm). From Figure 1 It can be seen that, with the increase of Ag in the solution + As the concentration increases, the fluorescence intensity gradually decreases; Ag + At a concentration of 300 μM, the fluorescence is almost invisible. This phenomenon indicates that the fluorescent probe AgP can respond to liquid conditions.

[0042] Specific implementation method four: Selectivity experiment of fluorescent probe AgP, the steps are as follows:

[0043] Step 1: Preparation of the stock solution

[0044] Weigh 1 mg of the fluorescent probe compound AgP and dissolve it in DMSO to prepare a 1 mM AgP DMSO solution.

[0045] Weigh 2 mg of AgNO3 and dissolve it in pure water to prepare a 30 mM AgNO3 aqueous solution.

[0046] Using pure water as a solvent, a 30 mM Mg solution was prepared using metal chlorides and nitrates. 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Co 2+ Cr3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ Metal cation stock solution is available for use.

[0047] Weigh 20 mg of CTAB and dissolve it in pure water to prepare a 100 mM CTAB aqueous solution.

[0048] Step 2: Spectral Performance Testing

[0049] Detection of Ag + The fluorescent probe and the fluorescence spectroscopy method for measuring the fluorescent probe in mixtures with different metal ions are as follows:

[0050] Add 2 μL of DMSO solution containing the AgP probe, 2 μL of different metal cation stock solutions, and 2 μL of CTAB aqueous solution to 100 μL of PBS buffer. Then add pure water to bring the solution volume to 200 μL. After shaking for 10 min, record the changes in the fluorescence spectrum of AgP before and after the reaction.

[0051] Detection of Ag + fluorescent probes in Ag + The method for determining the resistance to interference from metal ions during testing is as follows:

[0052] Add 2 μL of DMSO solution containing the AgP probe, 2 μL of different metal cation stock solutions, and 2 μL of CTAB aqueous solution to 100 μL of PBS buffer. Then add pure water to bring the total volume to 200 μL. After shaking for 10 min, add 2 μL of AgNO3 aqueous solution to each solution, shake again for 10 min, and record the changes in the fluorescence spectrum of AgP before and after the reaction.

[0053] Figure 2 Without Ag + The normalized fluorescence response at 532 nm of the probe with different metal ions in PBS buffer (10 mM, 1 mM CTAB, pH 7.4, 1% DMSO) is shown. With Ag + The normalized fluorescence response of the probe to different metal ions at 532 nm was determined in PBS buffer containing 300 μM AgNO3 (10 mM, 1 mM CTAB, pH 7.4, 1% DMSO). Figure 2 Without Ag + It can be seen that after adding different metal cations (Mg) 2+ Zn 2+ Fe 3+ Fe 2+Na + Al 3+ Mn 2+ Co 2+ Cr 3 + Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ The fluorescence intensity of the probe did not change significantly. Figure 2 With Ag + It can be seen that in other metal cations (Mg 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Ag + Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ In the presence of ), the probe interacts with Ag. + The fluorescence intensity decreased significantly after treatment. In summary, the probe is effective against Ag. + The detection is not affected by other metal ions and has good selectivity.

[0054] Specific Implementation Method Five: Utilizing the Ag detection method described in Specific Implementation Method One + The method for preparing fluorescent filter paper strips using fluorescent probes is carried out according to the following steps:

[0055] Step 1: Detect Ag + The fluorescent probe AgP was dissolved in DMSO to obtain an AgP probe solution (10 μM).

[0056] Step 2: Cut the qualitative filter paper into strips, soak them in the probe solution for 2 hours, remove and dry them to obtain the Ag detection solution. + Fluorescent filter paper strips.

[0057] Specific Implementation Method Six: Detection of Ag as described in Specific Implementation Method Three + The method for using fluorescent filter paper strips is as follows:

[0058] To detect Ag +A sample containing metal ions is dropped onto a fluorescent filter paper strip. After 1-2 minutes, the fluorescence color change of the filter paper strip is observed under a UV lamp (365nm). If the color of the fluorescent filter paper strip changes from green to bright yellow, it can be determined that the sample contains Ag. + After drying at room temperature, observe the color change of the filter paper strip under visible light. If the color of the filter paper strip changes from white to brown, it can be determined that the sample contains Ag. + .

[0059] Specific Implementation Method Seven: Fluorescent probe AgP filter paper strip for detecting Ag in liquid phase + The detection experiment steps are as follows:

[0060] Weigh 2 mg of AgNO3 and dissolve it in pure water to prepare a 1 mM AgNO3 mother liquor. Dilute the mother liquor with water to prepare AgNO3 aqueous solutions of 500, 400, 300, 200, 100, 80, 50, 40, 30, 20, 10, 5, 2, and 0 μM.

[0061] Place the fluorescent filter paper strips from Specific Embodiment Five on a clean flat surface. Add 200 μL of 500, 400, 300, 200, 100, 80, 50, 40, 30, 20, 10, 5, 2, and 0 μM AgNO3 aqueous solutions to each filter paper strip, respectively.

[0062] Figure 3 The color changes of fluorescent filter paper strips under visible and ultraviolet light were observed after equal volumes of AgNO3 aqueous solutions of different concentrations were added and reacted for 10 minutes. For example... Figure 3 As shown, Ag + When the concentration is between 0-20 μM, the filter paper shows no obvious color change under visible and ultraviolet light; Ag + When the concentration is between 30-100 μM, the filter paper changes color from green to pale yellow under ultraviolet light; when Ag... + When the concentration reaches 200 μM, the filter paper emits yellow fluorescence under ultraviolet light, and changes from white to brown under visible light, indicating the rapid response and high sensitivity of the filter paper strip.

[0063] Specific Implementation Method Seven: Selectivity Experiment of Fluorescent Probe AgP Filter Paper Strip, the steps are as follows:

[0064] Weigh 1 mg of AgNO3 and dissolve it in pure water to prepare a 300 μM AgNO3 aqueous solution.

[0065] A 300 μM Mg solution was prepared using pure water as a solvent and metal chloride and nitrate salts. 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al3 + Mn 2+ Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ Metal cation stock solution is available for use.

[0066] Place the fluorescent filter paper strips from Specific Embodiment Five on a clean, flat surface. Add 200 μL of Ag to each filter paper strip. + Mg 2+ Zn 2+ Fe 3+ Fe 2+ Na + Al 3+ Mn 2+ Co 2+ Cr 3+ Pb 2+ K + Cd 2+ Ca 2+ Cu + Cu 2+ Metal cation stock solution.

[0067] Figure 4 The color change of fluorescent filter paper strips under visible and ultraviolet light was observed after reacting with equal volumes of aqueous solutions of different metal cations of equal concentration for 10 minutes. For example... Figure 4 As shown, the filter paper strip with added AgNO3 aqueous solution changed from green to yellow fluorescence under ultraviolet light, and from white to brown under visible light; the filter paper strip with added other metal cations showed no obvious color change under ultraviolet and visible light, indicating that the fluorescent filter paper strip in Specific Embodiment Five can effectively detect Ag in the liquid phase. + Perform selective detection.

[0068] In summary, the Ag detection method of this invention... + The fluorescent probe compound AgP has a simple synthesis method, good selectivity, high sensitivity, and can rapidly detect Ag. + Portable fluorescent filter paper strips prepared using AgP can be used to detect Ag in the liquid phase. + Real-time, in-situ detection. The fluorescent probe AgP and its fluorescent filter paper pair of this invention are characterized by simple preparation, high selectivity, rapid response, and simple analysis, and have good development prospects. They will provide a new strategy for the future research on harmful heavy metal ions in the external and biological environments.

Claims

1. A fluorescent probe based on quinoline ring for detecting Ag + characterized in that having the structure of Formula I:

2. The method for detecting Ag according to claim 1 + characterized in that it comprising the steps of: Step 1, to the 6N HCl solution of N, N-dimethyl-p-toluidine, (E)-2-butenal was added and stirred at room temperature for 1 h, toluene was added and the reaction mixture was stirred at 110 °C for 12 h, after the reaction was cooled to room temperature, the aqueous layer was neutralized to pH 7-8 with NaOH solution, dichloromethane was extracted, the organic phase was washed with saturated brine 2-3 times, dried over anhydrous sodium sulfate, concentrated under reduced pressure to obtain the crude product, the crude product was purified by silica gel column chromatography to obtain compound 2 as a yellow-brown solid; Step 2, SeO2 was dissolved in 1,4-dioxane / H2O (10:1 v / v) and heated at 60 °C for 30 min, then compound 2 was added and stirred at 80 °C for 4 h, after the reaction was completed, the reaction product was cooled to room temperature, the precipitate was removed by filtration, the filtrate was concentrated under reduced pressure, the crude product was purified by silica gel column chromatography to obtain the corresponding compound 3 as a yellow solid; Step 3, compound 3 was dissolved in DMF and cooled to 0 °C, then 1-amino-hydantoin hydrochloride dissolved in ice water was mixed with compound 3 and the mixture was stirred at room temperature for 4 h, the mixture was extracted and filtered to obtain an orange-red precipitate, the precipitate was repeatedly washed with H2O to obtain formula I as a red solid.

3. A method of preparing a fluorescent filter paper strip for detecting Ag + in accordance with the following steps: Step 1, Ag detection by the fluorescent probe I of claim 1 + in DMSO to obtain a 10 μM probe solution; Step 2, cut qualitative filter paper into strips, soak in probe solution for 2 h, dry after taking out, and get fluorescent filter paper strips for detecting Ag + .

4. A method of using a fluorescent filter paper strip for detecting Ag + in the following steps: To the detection of Ag as described in claim 3 + A sample containing metal ions is dropped onto a fluorescent filter paper strip. After 1-2 minutes, the fluorescence color of the filter paper strip is observed under a UV lamp. If the color of the fluorescent filter paper strip changes from green to bright yellow, it can be determined that the sample contains Ag. + After drying at room temperature, observe the color change of the filter paper strip under visible light. If the color of the filter paper strip changes from white to brown, it can be determined that the sample contains Ag. + .

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