Preparation method and application of pyrene fluorescent probe for series detection of copper ions and picric acid

Abstract

The invention discloses a preparation method and application of a pyrene fluorescent probe for tandem detection of copper ions and picric acid, and relates to the field of detection of copper ions and picric acid, in particular to a preparation method of a pyrene fluorescent probe and application of the pyrene fluorescent probe in tandem detection of copper ions and picric acid. The method solves the problem that the existing fluorescent probe detection method does not realize serial identification of two substances, namely copper ions and picric acid under the same test condition. The preparation method of the fluorescent probe provided by the invention comprises the following step: carrying out condensation reaction on 1-pyrene aldehyde and 1, 3-benzothiazole-2-formyl hydrazine, 6-amino-m-cresol and 7-(diethylamino) coumarin-3-formyl hydrazine respectively to prepare the fluorescent probe. The preparation method is safe and simple, the product yield is high, the purity is good, probe molecules can respond and recognize the copper ions in a high-selectivity mode, meanwhile, a complex of the probe and the copper ions has good recognition selectivity on picric acid, interference of other nitro-aromatic hydrocarbons is avoided, the detection limit is low, and trace detection of the picric acid can be achieved. The method is applied to the field of detection of copper ions and picric acid, the detection process is easy to operate, sensitive, efficient and visual, and the method has wide application prospects in the fields of food, environment and the like.

Description

Technical Field

[0001] The invention relates to the field of copper ion and picric acid detection, in particular to a preparation method of a pyrene fluorescent probe and application of the probe in the tandem detection of copper ions and picric acid. Background Art

[0002] Copper ions are one of the indispensable trace metal ions in the human body and other biological systems, and play a vital role in the basic physiological processes of many organisms, such as antioxidant defense, neurotransmitter synthesis and metabolism. However, copper deficiency may lead to diseases such as anemia, brain diseases and arterial abnormalities; excessive intake of copper can also lead to diarrhea, adrenal failure, Alzheimer's disease, schizophrenia and Wilson's disease, and may even lead to death. Copper ions in organisms may accumulate through the circulation of the food chain, so the detection of copper ions in the environment is of great significance.

[0003] 2,4,6-Trinitrophenol, commonly known as picric acid, is a typical polynitroaromatic compound. It is the main component of landmines and industrial explosives, and is widely used in the production of rocket fuel, pharmaceuticals, leather and dye industries. Therefore, it is easy to enter the environment through pollutant infiltration, wastewater treatment, etc. Compared with other nitroaromatic hydrocarbons, picric acid has higher water solubility and difficulty in degradation. Exposure to the environment will cause serious water and soil pollution. More importantly, picric acid is an organic compound with strong toxicity and carcinogenicity. It can irritate the eyes and skin and damage the respiratory system. Its vapor can cause headaches, weakness, anemia and liver damage, thereby endangering human personal safety. It has been recognized as one of the main sources of environmental pollutants and human carcinogens. Therefore, it is of great practical significance to develop a method that can detect picric acid in a highly selective and sensitive environment.

[0004] Traditional Cu 2+ The detection of picric acid uses atomic absorption spectroscopy, chromatography, plasma atomic emission spectroscopy, gas chromatography coupled energy dispersive X-ray diffraction, surface enhanced Raman spectroscopy, nuclear quadruple resonance spectroscopy, etc., but these methods have the disadvantages of high cost, complex operation, and long test time. The fluorescent probe method has the advantages of low cost, simple operation, rapid response and visualization, and has broad application prospects in the fields of life sciences, medicine, food, and environmental monitoring.

[0005] In recent years, fluorescent probes that can identify copper ions and picric acid alone or simultaneously have been reported, but there is no literature reporting on the use of the same fluorescent probe molecule to identify copper ions and picric acid in series. The present invention designs and constructs a variety of pyrene-based fluorescent probes with pyrene as a fluorescent group and an imine bond (C=N) as a connecting group, which can efficiently and quickly identify copper ions in an organic solvent buffer system, and the complex formed can also achieve specific recognition of picric acid, with the advantages of good selectivity, strong anti-interference, high sensitivity, and simple operation, making the fluorescent probe detection method more energy-saving and green, and having a broad application space. Summary of the invention

[0006] The invention aims to solve the problem that copper ions and picric acid are difficult to detect in series under the same test conditions, and provides a preparation method of a pyrene fluorescent probe for detecting copper ions and picric acid in series and an application thereof.

[0007] The fluorescent probe structural formula of the present invention is as follows:

[0008]

[0009] The fluorescent probe of the invention is prepared by condensation reaction of 1-pyrene aldehyde with 1,3-benzothiazole-2-carboxylic hydrazide, 6-amino-meta-cresol and 7-(diethylamino)coumarin-3-carboxylic hydrazide respectively.

[0010] The specific method of the present invention using fluorescent probe PY to detect copper ions and picric acid in series is:

[0011] 1. Dissolve the fluorescent probe PY in the organic solvent buffer system to prepare 1.0×10 -5 mol / L solution, and measure its fluorescence emission peak intensity; after adding copper nitrate aqueous solution to the probe solution, measure the change in fluorescence emission peak intensity to achieve copper ion detection.

[0012] 2. After incubation for a period of time, the fluorescent probe PY and copper nitrate form a complex PY-Cu 2+ , add picric acid aqueous solution to the system, measure the change in fluorescence emission peak intensity, and realize the detection of picric acid.

[0013] Furthermore, the complex PY-Cu 2+ In the detection of picric acid, it can resist the interference of 4-nitrobenzyl alcohol, 2-nitrotoluene, 2-nitrophenol, 3-nitrotoluene, nitrobenzene, toluene, phenol, 2-nitrobenzaldehyde, 2-nitrochlorobenzene, 2-nitrofluorobenzene, 2-nitrobenzoic acid and 2-nitrobenzonitrile.

[0014] Furthermore, the complex PY1-Cu 2+ The response time for detecting picric acid is 2s.

[0015] Furthermore, the complex PY1-Cu 2+ The detection limit for picric acid is 8.7×10 -7 mol / L.

[0016] Furthermore, the complex PY1-Cu 2+ It can realize the detection of picric acid in water.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1) The fluorescent probe PY prepared in the present invention realizes the tandem detection of copper ions and picric acid under the same test conditions for the first time. The operation is simple and fast, reflecting the multifunctional application of fluorescent probes.

[0019] 2) The complex PY-Cu prepared by the present invention 2+ It can achieve a rapid response to picric acid, is not interfered by other nitroaromatic hydrocarbons, has a low detection limit, and has an obvious fluorescence change to picric acid under ultraviolet light, which is easy to detect with the naked eye. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The present invention prepares the fluorescent probe PY1 1 H NMR spectrum;

[0021] Figure 2 The present invention prepares the fluorescent probe PY2 1 H NMR spectrum;

[0022] Figure 3 The present invention prepares the fluorescent probe PY3 1 H NMR spectrum;

[0023] Figure 4 Fluorescent probe PY tandem recognition of Cu 2+ with the effect of picric acid;

[0024] Figure 5 Fluorescent probe PY1 for Cu 2+ Anti-interference performance;

[0025] Figure 6 Fluorescent probe PY1 for Cu 2+ Job's plot curve;

[0026] Figure 7 Under ultraviolet light at 365 nm, the fluorescent probe PY1(4#) was 2+ (5#), Ni 2+ (1#), Co 2+ (2#), Cd 2+ (3#),Mg 2+ (6#), Pb2+ (7#), Ca 2+ (8#), Ce 3+ (9#), Hg 2+ (10#), Zn 2+ (11#), Na + (12#), K + (13#), Fe 3+ (14#), Ag + (15#), Ba 2+ (16#), Li + (17#), Al 3+ (18#), Cr 3+ (19#), Bi 3+ (20#) Fluorescence change diagram after action;

[0027] Figure 8 Complex PY1-Cu 2+ Identify the anti-interference of picric acid;

[0028] Fig. 9 Complex PY1-Cu 2+ Response time graph to picric acid;

[0029] Fig.10 Complex PY1-Cu 2+ Linear relationship diagram of fluorescence response to different concentrations of picric acid;

[0030] Fig.11 Under ultraviolet light at 365 nm, the complex PY1-Cu 2+ Fluorescence changes after the reaction with picric acid (7#), 4-nitrobenzyl alcohol (6#), 3-nitrotoluene (1#), 2-nitrophenol (2#), 2-nitrotoluene (3#), nitrobenzene (4#), toluene (5#), phenol (8#), 2-nitrobenzaldehyde (9#), 2-nitrochlorobenzene (10#), 2-nitrofluorobenzene (11#), 2-nitrobenzoic acid (12#) and 2-nitrobenzonitrile (13#). DETAILED DESCRIPTION

[0031] The technical solution of the present invention is not limited to the specific implementation modes listed below, but also includes any combination of the specific implementation modes.

[0032] Specific implementation method 1: The molecular structure of the pyrene fluorescent probe PY used for tandem detection of copper ions and picric acid in this implementation method is:

[0033]

[0034] Specific implementation method 2: The fluorescent probe PY described in this implementation method is prepared by condensation reaction of 1-pyrenealdehyde with 1,3-benzothiazole-2-carboxylic acid hydrazide, 6-amino-meta-cresol and 7-(diethylamino)coumarin-3-carboxylic acid hydrazide.

[0035] Specific implementation method three: Application of the fluorescent probe in this implementation method in the continuous detection of copper ions and picric acid.

[0036] Specific embodiment 4: This embodiment is different from specific embodiment 3 in that the specific method of continuous detection of copper ions and picric acid by fluorescent probe PY is:

[0037] 1. Dissolve the fluorescent probe PY in an organic solvent buffer system to prepare 1.0×10 -5 mol / L solution, and measure its fluorescence emission peak intensity; after adding copper nitrate aqueous solution to the probe solution, measure the change in fluorescence emission peak intensity to achieve copper ion detection.

[0038] 2. After incubation for a period of time, the fluorescent probe PY and copper nitrate form a complex PY-Cu 2+ , add picric acid aqueous solution to the system, measure the change in fluorescence emission peak intensity, and realize the detection of picric acid.

[0039] Specific embodiment 5: This embodiment is different from the specific embodiment 4 in that the complex PY1-Cu 2+ The response time with picric acid is 2s. Others are the same as those in the fourth embodiment.

[0040] Specific embodiment 6: This embodiment is different from specific embodiment 4 or 5 in that the complex PY1-Cu 2+ The detection limit for picric acid is 8.7×10 -7 mol / L.

[0041] When actually testing samples containing picric acid, the samples can be pre-treated by centrifugation and filtration to remove solid particle impurities.

[0042] The embodiments of the present invention are described in detail below. The following embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation schemes and specific operation processes are given, but the protection scope of the present invention is not limited to the following embodiments.

[0043] Example 1: The preparation method of fluorescent probe PY1 is as follows: add 1-pyrenealdehyde (2.3 g, 0.01 mol), 1,3-benzothiazole-2-carboxylic acid hydrazide (1.93 g, 0.01 mol), 0.5 mL of glacial acetic acid and 30 mL of anhydrous ethanol into a round-bottom flask, and reflux for 4 hours; after cooling to room temperature, filter, vacuum dry, and wash with ethanol to obtain fluorescent probe PY1 with a yield of 82%. 1H NMR (300 MHz, DMSO-d6) δ12.80 (s, 1H), 9.85 (s, 1H), 8.81 (d, J = 9.4 Hz, 1H), 8.63 (d, J = 8.2 Hz, 1H), 8.41 (d, J = 4.0 Hz, 2H), 8.38 (d, J = 2.5 Hz, 2H), 8.33–8.31 (m, 1H), 8.31–8.28 (m, 1H), 8.27 (d, J = 1.4 Hz, 1H), 8.25–8.22 (m, 1H), 8.14 (t, J = 7.7 Hz, 1H), 7.74–7.62 (m, 2H) ppm. 1 H NMR spectrum Figure 1 shown.

[0044] Example 2: The preparation method of fluorescent probe PY2 is as follows: This example is different from Example 1 in that the nitrogen-containing compound used is 6-amino-meta-cresol, and the rest is the same as Example 1. The yield is 91.5%. 1 H NMR (300 MHz, DMSO-d6) δ9.78 (s, 1H), 9.19 (d, J = 9.4 Hz, 1H), 9.08–9.01 (m, 2H), 8.40 (d, J = 2.8 Hz, 1H), 8.39–8.36 (m, 2H), 8.33 (d, J = 5.6 Hz, 1H), 8.30–8.23 (m, 2H), 8.13 (t, J = 7.6 Hz, 1H), 7.46 (d, J = 8.0 Hz, 1H), 6.83–6.70 (m, 2H), 2.30 (s, 3H) ppm. 1 H NMR spectrum Figure 2 shown.

[0045] Example 3: Preparation method of fluorescent probe PY3: This example is different from Example 1 in that the nitrogen-containing compound used is 7-(diethylamino)coumarin-3-carboxylic acid hydrazide, and the rest is the same as Example 1. Yield: 87.3%. 1 H NMR (300 MHz, DMSO-d6) δ12.02 (s, 1H), 9.56 (s, 1H), 9.01 (d, J = 9.0 Hz, 1H), 8.83 (s, 1H), 8.63 (d, J = 8.6 Hz, 1H), 8.36 (t, J = 8.1 Hz, 4H), 8.26 (d, J = 6.0 Hz, 2H), 7.78 (d, J = 9.0 Hz, 1H), 6.87 (d, J = 9.2 Hz, 1H), 6.71 (s, 1H), 3.52 (d, J = 7.4 Hz, 4H), 1.17 (t, J = 6.9 Hz, 6H) ppm. 1 H NMR spectrum Figure 3 shown.

[0046] Example 4: The tandem recognition of copper ions and picric acid by the fluorescent probe PY of this example is carried out according to the following steps:

[0047] In 3mL, the concentration is 1.0×10 -5 mol / L solutions of fluorescent probes PY1, PY2, and PY3 were each added with 3 eq. of Cu 2 + After incubation for a period of time, the fluorescent probe PY-Cu 2+ System C1, C2, C3, and then add 10eq. of picric acid aqueous solution. First, measure the fluorescence intensity values ​​of fluorescent probes PY1, PY2, and PY3 respectively. All fluorescent probes have no fluorescence or little fluorescence. Add Cu 2+ After adding picric acid, the fluorescence intensity was measured and the fluorescence was significantly enhanced. After adding picric acid, the fluorescence was measured again and the fluorescence was obviously quenched. Figure 4 As shown. It shows that fluorescent probes PY1, PY2, and PY3 are all sensitive to Cu 2+ Tandem recognition with picric acid.

[0048] Example 5: The fluorescent probe PY1 of this example recognizes Cu 2+ To test the anti-interference performance, follow these steps:

[0049] Take 3mL each time with a concentration of 1.0×10 -5 mol / L probe PY1 solution, and 3 eq. of Ni 2+ 、Co 2+ 、Cd 2+ Mg 2+ , Pb 2+ , Ca 2+ 、Ce 3+ , Hg 2+ 、Zn 2+ 、Na + , K + , Fe 3+ 、Ag + , Ba 2+ , Li + 、Al 3+ Cr 3+ 、Bi 3+ The fluorescence intensity was measured. Then 3 eq. Cu 2+ The fluorescence intensity is observed and recorded. Figure 5 As shown. From the data analysis, the probe recognizes and responds to Cu 2+ In the process, even in the presence of other ions, Cu 2+ The probe shows strong fluorescence when it recognizes Cu2+ It has obvious anti-interference ability.

[0050] Example 6: Fluorescent probe PY1 and Cu 2+ Complexation ratio, follow the steps below:

[0051] The concentration is 1.0×10 -5 mol / L probe PY1 solution and 1×10 -3 mol / L Cu 2+ Aqueous solution, keep the probe and Cu in the system 2+ The total concentration is 1×10 -5 mol / L remains unchanged. By changing the equivalent ratio of the probe and copper ions, the fluorescence intensity is measured and the Job's Plot curve is drawn. The results are shown in Figure 6 As shown. From the Job's Plot curve analysis, it can be seen that when Cu 2+ When the molar fraction of Cu is 0.51, the fluorescence intensity shows an inflection point, which indicates that the fluorescence probe PY1 and Cu 2+ The complexation ratio is 1:1.

[0052] Example 7: Qualitative detection of Cu by fluorescent probe PY1 under ultraviolet light (365 nm) 2+ , follow these steps:

[0053] Accurately measure 3 mL of a concentration of 1.0×10 -5 mol / L probe PY1 solution, and 3 eq. of Cu 2+ 、Ni 2+ 、Co 2+ 、Cd 2+ Mg 2+ , Pb 2+ , Ca 2+ 、Ce 3+ , Hg 2+ 、Zn 2+ 、Na + , K + , Fe 3+ 、Ag + , Ba 2+ , Li + 、Al 3+ Cr 3+ 、Bi 3+ Aqueous solution, obtained under ultraviolet light 365nm Figure 7 As shown in the figure, after the fluorescent probe PY1 interacts with metal ions, the fluorescent probe solution with only copper ions added has obvious fluorescence changes, showing excellent selectivity for copper ions, and can be used for qualitative detection of copper ions. It is easy to operate, fast in detection speed, and can be detected with the naked eye.

[0054] Example 8: Complex PY1-Cu 2+ For the anti-interference of picric acid recognition, follow the steps below:

[0055] Take 3mL of complex PY1-Cu 2+ System C1: In a cuvette, 10 eq. of picric acid, 4-nitrobenzyl alcohol, 2-nitrotoluene, 2-nitrophenol, 3-nitrotoluene, nitrobenzene, toluene, phenol, 2-nitrobenzaldehyde, 2-nitrochlorobenzene, 2-nitrofluorobenzene, 2-nitrobenzoic acid and 2-nitrobenzonitrile were added in sequence, and their fluorescence intensities were recorded. Then, 10 eq. of picric acid was added in sequence, and the changes in fluorescence intensity were observed and recorded. The results are shown in FIG. Figure 8 From the data analysis, it can be seen that in the presence of other coexisting nitroaromatic hydrocarbons, fluorescence quenching can still be achieved after adding picric acid. Other nitroaromatic hydrocarbons have a significant effect on the complex PY1-Cu 2+ The system recognizes picric acid without interference.

[0056] Example 9: Complex PY1-Cu 2+ The time response to picric acid was performed as follows:

[0057] Take 3mL of complex PY1-Cu 2+ The fluorescence intensity of system C1 was measured in a cuvette, and then 10 eq. of picric acid was added. After 2 s, the fluorescence intensity was measured again. Fig. 9 After adding picric acid, the fluorescence intensity decreased rapidly and reached complete quenching after 2s. 2+ It can respond quickly to picric acid in a short time, with a response time of 2s.

[0058] Example 10: Fluorescent probe PY1-Cu 2+ For the detection limit of picric acid, follow the steps below:

[0059] Take 3mL of complex PY1-Cu 2+ System C1, each time 0.3 μL of 0.1 mol / L picric acid aqueous solution was added, and its fluorescence intensity was measured. The results are as follows Fig.10 As shown in the data analysis, when the picric acid concentration is within 0-70 μM, the fluorescence intensity decreases with the increase of picric acid concentration until it is completely quenched, and the complex PY1-Cu 2+ The fluorescence intensity showed a good linear relationship with the picric acid concentration, and the fitting equation was Y = -23.35X + 1396.89, R 2 =0.99. According to the calculation formula of detection limit 3σ / k, the complex PY1-Cu 2+ The detection limit for picric acid is 8.7×10 -7mol / L. Complex PY1-Cu 2+ The system can realize trace detection of picric acid.

[0060] Example 11: Complex PY1-Cu under UV light (365 nm) 2+ The qualitative detection of picric acid in the system is carried out according to the following steps:

[0061] Accurately measure 3mL of complex PY1-Cu 2+ System C1, 10 eq. of picric acid, 4-nitrobenzyl alcohol, 2-nitrotoluene, 2-nitrophenol, 3-nitrotoluene, nitrobenzene, toluene, phenol, 2-nitrobenzaldehyde, 2-nitrochlorobenzene, 2-nitrofluorobenzene, 2-nitrobenzoic acid and 2-nitrobenzonitrile were added respectively, and the reaction mixture was obtained under ultraviolet light at 365 nm. Fig.11 The results are shown. Fig.11 It can be seen that the complex PY1-Cu 2+ After the system reacts with nitroaromatic hydrocarbons, only picric acid has obvious fluorescence quenching, showing excellent selectivity for picric acid. It can be used for qualitative detection of picric acid and has the advantages of simple operation and fast detection speed.

[0062] Example 12: The fluorescence sensor detects picric acid in an actual water sample according to the following steps:

[0063] In order to investigate the potential application of fluorescent probes in actual environments, laboratory tap water samples were selected and pretreated: the water samples were centrifuged at 12000 rpm for 10 min, filtered with a 0.45 μm filter, and picric acid solutions with concentrations of 20 μM, 30 μM, and 40 μM were prepared.

[0064] The fluorescent probe PY1-Cu prepared in Example 4 was used 2+ system.

[0065] Y=-23.35X+1396.89

[0066] Wherein, X is the concentration of picric acid and Y is the peak intensity of fluorescence emission.

[0067] Table 1 Complex PY1-Cu 2+ The system detects picric acid in real water samples

[0068] Actual water sample Addition amount (μM) Detection amount (μM) Recovery rate (%) RSD(%) 1(tap water) 20 19.8 99.6 0.88 2(tap water) 30 28.3 94.3 1.36 3(Tap water) 40 39.2 98.0 0.60

[0069] It can be seen from Table 1 that the recovery rate of picric acid in the actual water sample is 94.3% to 99.6%, the relative standard deviation is 0.60% to 1.36%, and the error between the measured picric acid concentration and the corresponding spiked concentration is very small. These results show that the PY1-Cu prepared by the present invention 2+The system detects picric acid in actual water samples with good accuracy and has good practical performance.

Claims

1. A pyrene-based fluorescent probe PY for serial detection of copper ions and picric acid, characterized in that The fluorescent probe structural formula is as follows:

2. The fluorescent probe PY for tandem detection of copper ions and picric acid according to claim 1, characterized in that The fluorescent probe was prepared by condensation reaction of 1-pyrenealdehyde with 1,3-benzothiazole-2-carboxylic acid hydrazide, 6-amino-m-cresol and 7-(diethylamino)coumarin-3-carboxylic acid hydrazide.

3. Use of the fluorescent probe according to claim 1 in tandem detection of copper ions and picric acid.

4. The use according to claim 3, characterized in that The fluorescent probe PY itself has no fluorescence or little fluorescence. After adding copper nitrate aqueous solution, a highly fluorescent complex PY-Cu is generated. 2+ This causes a significant enhancement in fluorescence, which is then quenched after the addition of picric acid, thereby achieving tandem recognition of copper ions and picric acid.

5. The use according to claim 4, characterized in that Complex PY-Cu 2+ In the detection of picric acid, it can resist the interference of 4-nitrobenzyl alcohol, 2-nitrotoluene, 2-nitrophenol, 3-nitrotoluene, nitrobenzene, toluene, phenol, 2-nitrobenzaldehyde, 2-nitrochlorobenzene, 2-nitrofluorobenzene, 2-nitrobenzoic acid and 2-nitrobenzonitrile.

6. The use according to claim 4, characterized in that Complex PY1-Cu 2+ The response time for detecting picric acid is 2s.

7. The use according to claim 4, characterized in that Complex PY1-Cu 2+ The detection limit for picric acid is 8.7×10 - 7 mol / L.

8. The use according to claim 4, wherein the complex PY1-Cu 2+ It can realize the detection of picric acid in water.

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