Terpyridyl fluorescent compound and application

Abstract

The invention belongs to the field of fluorescent compound synthesis, and particularly relates to a terpyridyl fluorescent compound and application. The terpyridyl fluorescent compound is named as (E)-4-(5-((3, 2 ': 6', 3 '-tripyridyl)-4'-yl) styryl) thiophene-2-yl) morpholine in Chinese, the structural formula is # imgabs0, terpyridyl serves as a fluorophore, thiophene serves as a reaction site, morpholine is introduced to serve as an electron withdrawing group, a push-pull result is formed in a molecular structure, the reaction sensitivity is improved, and the fluorescent compound can be applied to the field of fluorescence detection. The Fe < 3 + > is coordinated with the empty orbital of the thiophenic sulfur element, so that the energy distribution of the probe is changed, the fluorescence intensity of the probe is changed, and finally the purpose of identifying the iron ions is achieved. Therefore, the invention also provides application of the terpyridyl fluorescent compound as a fluorescent probe in detection of Fe < 3 + >.

Description

Technical Field

[0001] The invention relates to the field of fluorescent compound synthesis, and in particular to a terpyridine fluorescent compound and application thereof. Background Art

[0002] Iron is one of the essential trace elements for the human body. It can maintain red blood cell metabolism and assist bone marrow hematopoiesis. If the human body lacks iron ions, it will lead to low immunity and symptoms such as iron deficiency anemia. However, long-term intake of excessive iron is also harmful to the human body. Therefore, it is crucial to detect the iron ion content in living water to ensure that it is within a safe range to protect human health. A moderate amount of iron in drinking water is beneficial to the human body, but excessive iron can cause drinking water to have a different color and taste and increase turbidity. In addition, excessive iron content will accelerate the growth of iron bacteria in water delivery equipment, leading to an increase in the rust rate of metal water delivery equipment. Therefore, detecting the iron ion content in living water helps to ensure the quality and safety of drinking water. Excessive iron ion concentration will increase the production of iron hydroxide products, and will also form sediments during the transportation of urban tap water, and make the tap water brown in color, which has always been one of the main problems of urban secondary water supply quality. By detecting the iron ion content in living water, these problems can be discovered and solved in a timely manner to protect the environment. The iron ion content is also very important for certain industrial production processes. For example, in industries such as textiles, printing and dyeing, and papermaking, water with excessive iron content may affect product quality.

[0003] Therefore, the detection of iron ions in domestic water is of great significance for protecting human health, ensuring drinking water quality, environmental protection and industrial applications. 3+ The existing Fe 3+ The detection methods mainly include spectrophotometry, ion selective electrode method, voltammetry, chemiluminescence, electrochemical sensing, etc. However, these methods require expensive instruments, professional testers or are not simple enough to measure samples. Fluorescent probes are accepted by more and more people due to their low cost and fast and easy measurement. Therefore, a new type of probe that can detect Fe 3+ The fluorescent probe is of great significance. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a terpyridine fluorescent compound that can be used to detect Fe 3+ of fluorescent probes.

[0005] Specifically, a terpyridine fluorescent compound having the structural formula The Chinese name of the compound is: (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine.

[0006] The preparation method of the above-mentioned terpyridine fluorescent compound comprises the steps of:

[0007] Synthesis of compound e: 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine and triphenylphosphine (TPP) were reacted in anhydrous toluene at a molar ratio of 1:0.9-1.2 at a reflux temperature of 110°C-120°C for 2-4h to generate an off-white precipitate, which was filtered and dried to obtain compound e, with the structural formula Chinese name: 4-(2,2′:6′,2″-terpyridyl)-4′-benzyltriphenylphosphine bromide;

[0008] Synthesis of target compound: Compound e, NaH and 5-morpholinothiophene-2-carboxaldehyde (intermediate d) undergo Wittig reaction to synthesize the target compound, wherein the molar ratio of compound e to NaH is 1:4-5, and the molar ratio of 5-morpholinothiophene-2-carboxaldehyde to compound e is 1:1-1.3.

[0009] The compound e is mainly synthesized by reacting 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine and TPP (triphenyl phosphate), and the synthesis route is as follows:

[0010]

[0011] The synthesis method of 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine comprises: using 4′-(4-tolyl)-2,2′:6′,2″-terpyridine and N-bromosuccinimide (NBS) as raw materials, stirring and heating in carbon tetrachloride under the action of catalyst benzoyl peroxide (BPO), and reflux at 80°C-90°C for 7-10h, cooling to room temperature, filtering to remove precipitates, and purifying the filtrate to obtain white crystals. The synthesis path of this step is:

[0012]

[0013] The synthesis method of 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine (Compound 3) comprises the following steps:

[0014] Preparation of compound 1: 2.8-3.2 mL of p-methylbenzaldehyde, 2.8-3.2 mL of 2-acetylpyridine and 90-110 mL of 1.2-2.4% sodium hydroxide solution, react at room temperature for 6-9 hours to synthesize light yellow monoketone compound 1: 3-phenyl-1-pyridyl-1-propenone;

[0015] Preparation of compound 2: The concentration of the sodium hydroxide solution in the synthesis system of compound 1 was increased to 18-22%, 2.8-3.5 mL of 2-acetylpyridine was added, the temperature was raised to 75-90° C. and stirred for 6-9 h to obtain a brown-red viscous compound 2: 1,5-di-(2′-pyridyl)-3-p-tolyl-1,5-pentanedione;

[0016] Preparation of 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine: Cool the compound 2 with ice, filter and wash to obtain a brown transparent solution, add 16-20 g of ammonium acetate in batches at 80°C-90°C reflux to obtain a dark green solution, concentrate and recrystallize to obtain pure white needle-shaped crystals of compound 3.

[0017] The synthetic route of 4′-(4-methylphenyl)-2,2′:6′,2″-terpyridine is as follows:

[0018]

[0019]

[0020] The steps of synthesizing the target compound include: stirring compound e, NaH, and anhydrous tetrahydrofuran at room temperature for 20-40 minutes, and then adding 5-morpholinothiophene-2-carboxaldehyde (intermediate d) to react at 70-90°C for 10-16 hours to synthesize the target compound. Specifically, firstly, compound e, NaH solution and tetrahydrofuran are stirred at room temperature for reaction until the system changes from yellow to brick red; then, 5-morpholinothiophene-2-carboxaldehyde (intermediate d) is added and stirred evenly, and then heated in an oil bath at 70-90°C for reflux reaction for 12-15 hours, cooled to room temperature, and water is added to remove NaH, and then extracted with dichloromethane, washed with water, washed with saturated NaCl, dried with anhydrous sodium sulfate, filtered and concentrated, and column chromatographed to obtain the target product crystals. The synthetic reaction equation of the target compound is:

[0021]

[0022] The synthesis method of 5-morpholinothiophene-2-carboxaldehyde comprises: 5-bromothiophene-2-carboxaldehyde (intermediate b) and morpholine are mixed with tetrahydrofuran aqueous solution at a molar ratio of 1:2.5-3.5, and heated in an oil bath to 70°C-80°C under nitrogen protection and refluxed for 24-28 hours to generate a precipitate; cooled, extracted with ethyl acetate, dried with anhydrous sodium sulfate, concentrated, and column chromatographed to obtain a gray solid intermediate d. The synthesis reaction equation of intermediate d is:

[0023]

[0024] The synthesis method of 5-bromothiophene-2-carboxaldehyde (intermediate b) includes: first adding 2-bromothiophene to a phosphorus oxychloride system under ice-water bath conditions, and then heating to 50°C-60°C for reflux reaction for 5-7h after the dropwise addition is completed under the ice-water bath system to obtain a pale yellow liquid intermediate b with a bitter almond flavor, wherein the molar ratio of 2-bromothiophene to phosphorus oxychloride is 1:9-11. Intermediate b becomes solid after being frozen in a refrigerator. The synthesis reaction equation of intermediate b is:

[0025]

[0026] The second object of the present invention is to provide a target compound as a fluorescent probe in detecting and identifying Fe 3+ The above target compounds are used as fluorescent probes to detect Fe 3+ The mechanism is as follows: terpyridine is used as the fluorophore, thiophene is used as the reaction site, and morpholine is introduced as an electron-withdrawing group to form a push-pull result in the molecular structure, thereby improving the sensitivity of the reaction and coordinating the iron ions with the empty orbitals of the thiophene sulfur element, thereby changing the energy distribution of the probe and causing the fluorescence intensity of the probe to change, ultimately achieving the purpose of identifying iron ions.

[0027] The third object of the present invention is to provide a method for detecting Fe using the above-mentioned target compound terpyridine fluorescent compound. 3+ The method comprises the steps of: firstly dissolving the target compound in an organic solvent and a HEPES solution, and then adding a Fe-containing 3+ The test solution is reacted for 4-8 minutes to obtain a system to be detected; and then the fluorescence intensity of the system to be detected is detected at an emission wavelength of 490-800 nm.

[0028] The organic solvent is one or a mixture of acetonitrile, ethanol, methanol, dimethyl sulfoxide, N,N-dimethylformamide, acetone and tetrahydrofuran. Preferably, the volume ratio of the organic solvent to the HEPES solution is 0-10:0.5-10. The concentration of the fluorescent compound is preferably 1-20 μM.

[0029] The above method also includes: according to Fe 3+The relationship between concentration and fluorescence intensity, constructing Fe 3+ Concentration detection standard curve: y1 = 1878.133-722.970x, R1 2 =0.9862, 1≤x≤10μM; y2=1319.257-172.35x, R2 2 =0.9926, 10≤x≤70μM.

[0030] Therefore, the target compound provided by the present invention: (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine is used as a fluorescent probe to detect Fe 3+ It has the characteristics of rapid response, obvious change and good specificity, and can be used for domestic water quality testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is the infrared spectrum of (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophen-2-yl)morpholine;

[0032] Figure 2 (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine 1 H NMR spectra;

[0033] Figure 3 (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine 13 C NMR spectrum;

[0034] Figure 4 As a fluorescent probe for the recognition of Fe in different solvent systems 3+ Fluorescence intensity change at 615 nm;

[0035] Figure 5 The fluorescence intensity change diagram of the fluorescent probe in different volume ratios of acetone and HEPES solutions;

[0036] Figure 6 As fluorescent probes for different Fe 3+ Fluorescence emission spectra of concentrations (0-110 μM);

[0037] Figure 7 To add Fe 3+ Afterwards, the fluorescence intensity change diagram of the fluorescent probe at 615nm;

[0038] Figure 8 This is the specific recognition diagram of the fluorescent probe. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention.

[0040] Unless otherwise specified, the terms used in the present invention are commonly used terms in the relevant field. The preparation processes, testing methods, etc. used in each embodiment are conventional means well known to those skilled in the art unless otherwise specified. The raw materials and equipment used can be obtained from public commercial channels.

[0041] The following instruments and equipment were used in the following examples: tetramethylsilane (TMS) was used as the internal standard and the data were recorded on a Bruker AV-400 spectrometer. 1 H NMR and 13 C NMR spectra. UV was recorded on a Hitachi TU-1950 spectrometer. Fluorescence spectra were recorded on a Hitachi FL-4600 fluorimeter.

[0042] Example 1

[0043] This embodiment provides a terpyridine fluorescent compound and a preparation method thereof. The compound is: (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, with a structural formula of

[0044] The preparation method of the compound comprises the steps of:

[0045] Synthesis of compound e: 5.0 g (0.013 mol) of 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine and 3.6 g (0.014 mol) of TPP were added to a 150 mL round-bottom flask, dissolved in 80 mL of toluene, heated to 115°C and refluxed, a large amount of gray-white precipitate was generated, the reaction was complete in 3 h, filtered and dried to obtain compound e, the structural formula Chinese name: 4-(2,2′:6′,2″-terpyridyl)-4′-benzyltriphenylphosphine bromide.

[0046] Synthesis of target compound: In a 50 ml double-buckle round-bottom flask, add 0.6227 g (0.9370 mmol) of compound e, 0.1600 g (4.00 mmol) of 60.00% NaH solution, and 8.00 ml of dried tetrahydrofuran (THF). Stir at room temperature for 30 min. Hydrogen is generated and the system turns yellow first and then brick red. 0.1580 g (0.80 mmol) of 5-morpholinothiophene-2-carboxaldehyde was added, stirred evenly, refluxed in an oil bath at 80°C, followed by TLC (PE:EA=2:1). After 13 hours, the reaction was complete, cooled to room temperature, a small amount of water was added to remove NaH, extracted with 3×30 ml of dichloromethane, washed with water, washed with saturated NaCl, dried over anhydrous sodium sulfate, filtered and concentrated, and column chromatography (PE:EA=2:1, 1 ml of concentrated ammonia was added for every 200 ml) was performed to obtain 0.2326 g of (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine crystals, with a yield of 57.86%. The infrared, hydrogen and carbon spectra of the crystals are as follows: Figure 1-3 shown. IR:3546.45,3467.38,3411.46,1637.27,1617.98,1585.20,1481,06,1118.51,788.74,620.97. 1 H NMR (400MHz, CDCl3): δ8.75,8.73,8.68,8.66,7.90,7.88,7.86,7.86,7.54,7.52,7.37,7.36,7.35,7.34, 7.22,7.18,6.80,6.79,6.62,6.58,5.95,5.94,3.21,3.20,3.19,1.75,1.74,1.73,1.71,1.70,1.62,1.60. 13 C NMR (101MHz, CDCl3): δ159.47,156.39,155.93,149.79,149.14,138.84,136.85,136.13,128 .40,127.70,127.50,126.18,123.78,122.41,121.38,118.39,103.98,51.90,25.19,23.79.

[0047] Example 2

[0048] This embodiment provides a method for preparing (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, which is basically the same as the method provided in Example 1, except that the method for preparing 4'-(4-bromo-tolyl)-2,2':6',2"-terpyridine in the synthesis of compound e comprises:

[0049] Preparation of compound 1: Add 3 mL (0.0255 mol) of p-tolualdehyde, 3 mL of 2-acetylpyridine (0.0267 mol) and 100 mL of 2% aqueous sodium hydroxide solution into a 250 mL round-bottom flask, and stir vigorously at room temperature for 8 h to obtain a light yellow monoketone, namely compound 1;

[0050]

[0051] Preparation of compound 2: The solubility of the sodium hydroxide solution was increased to 20%, 3 mL of 2-acetylpyridine was added, the temperature was raised to 80°C and the mixture was stirred vigorously for 8 h to obtain a brown-red viscous compound 2;

[0052]

[0053] Preparation of compound 3: Compound 2 was cooled by pouring ice, filtered to remove the aqueous phase, washed with distilled water, 250 mL of ethanol was added to dissolve the viscous material, the insoluble material was filtered to obtain a brown transparent solution, 18 g of ammonium acetate was added in batches under reflux at 85°C, TLC (PE: EA = 4: 1, a few drops of ammonia were added) to track the reaction, a dark green solution was obtained after the reaction was complete, part of the solvent was evaporated, cooled to room temperature, and allowed to stand for crystallization, and a bright yellow needle-shaped crystal product was precipitated, and the crude product 3 was obtained by suction filtration, and the pure white needle-shaped crystal compound 3 was obtained by recrystallization from anhydrous ethanol;

[0054]

[0055] Preparation of 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine (Compound 4): 5.0 g (1.5 mmol) of compound 3, 2.9 g (1.6 mmol) of NBS and a catalytic amount of BPO were added to a 250 mL round-bottom flask, and then 200 mL of carbon tetrachloride was added to dissolve. The mixture was stirred and heated to 85°C for reflux. TLC tracking (PE:EA=4:1, a few drops of ammonia water were added). The reaction was complete after about 8 hours, and the mixture was cooled to room temperature. The precipitate was removed by suction, and the filtrate was washed with water and saturated brine, dried over anhydrous MgSO4 overnight, filtered and concentrated to obtain a crude product of compound 4, and recrystallized from dried anhydrous ethanol to obtain 5.0 g of a white crystalline product: 4′-(4-bromo-tolyl)-2,2′:6′,2″-terpyridine.

[0056]

[0057] Example 3

[0058] The present embodiment provides a method for preparing (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, which is basically the same as the preparation method provided in Example 1, except that: Synthesis of the target compound: the amount of compound e used is 0.5308 g (0.80 mmol), the amount of NaH used is 0.0769 g (3.20 mmol), the amount of 5-morpholinothiophene-2-carboxaldehyde used is 0.1580 g (0.80 mmol), and the reaction time is 12 h to obtain 0.2146 g of the target compound; the remaining steps are the same.

[0059] Example 4

[0060] The present embodiment provides a method for preparing (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, which is basically the same as the preparation method provided in Example 1, except that: Synthesis of the target compound: the amount of compound e used is 0.5380 g (0.80 mmol), the amount of NaH used is 0.1600 g (4.00 mmol), the amount of 5-morpholinothiophene-2-carboxaldehyde used is 0.1383 g (0.70 mmol), and the reaction time is 15 h to obtain 0.2283 g of the target compound; the remaining steps are the same.

[0061] Example 5

[0062] This embodiment provides a method for preparing (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, which is basically the same as the method provided in Example 1, except that the method for preparing 5-morpholinothiophene-2-carboxaldehyde used in the step of synthesizing the target compound comprises the following steps:

[0063] Preparation of 5-bromothiophene-2-carboxaldehyde: In a 100 ml two-necked flask under ice-water bath conditions, add 20.00 ml (258.7 mmol) of N,N-dimethylformamide (DMF), add 30.00 ml of 1,2-dichloromethane, add 18.00 ml (193.0 mmol) of phosphorus oxychloride dropwise, and slowly add 2.00 ml (20.00 mmol) of 2-bromothiophene dropwise. The reaction was followed by thin layer chromatography (TLC). The mixture was refluxed at 55°C for 6 h and then heated. The mixture was cooled to room temperature and poured into 300.00 ml of ice water with stirring. The pH was adjusted to neutral with saturated NaOH solution. After the ice was completely melted, the mixture was extracted with 3×30 ml of dichloromethane, washed with saturated NaCl solution, dried over anhydrous sodium sulfate, filtered, concentrated, and subjected to column chromatography (petroleum ether: ethyl acetate = 5:1) to obtain 2.324 g of a pale yellow liquid with a bitter almond flavor (which became solid after being frozen in a refrigerator). The yield was 71.28%.

[0064] Preparation of 5-morpholinothiophene-2-carboxaldehyde: 0.9551g (5.00mmol) 5-bromothiophene-2-carboxaldehyde, 1.307g (15.00mmol) morpholine, 5.00ml tetrahydrofuran (THF), 20.00ml distilled water were added to a 100ml double buckle flask, refluxed in an oil bath at 75°C under nitrogen protection, followed by TLC detection. After 26h, the reaction was complete and solid was generated in the system. Cooled to room temperature, extracted with 3×40ml ethyl acetate, dried over anhydrous sodium sulfate, concentrated, and column chromatography (petroleum ether: ethyl acetate = 2:1) was performed to obtain 0.2904g of gray solid with a yield of 29.20%. IR:3550.31,3471.24,3415.32,2967.91,2925.48,2867.63,1637.27,1617.98,1481.09,1112.73,1066.44,1027.87,896.74,642.18.

[0065] In the detection of Fe 3+ Applications

[0066] (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine as a fluorescent probe for the detection of Fe 3+ The method comprises the steps of: dissolving the fluorescent probe in a mixed solvent of an organic solvent and a HEPES solution, and then adding a Fe 3+ The test solution is reacted for 4-8 minutes to obtain the test system; then the fluorescence intensity of the test system is detected at an emission wavelength of 490-800nm. In the following tests, the concentration of HEPES solution is 20mM, pH=7.4 (25℃); Fe 3+ Source: ferric chloride (FeCl3).

[0067] (1) Effect of organic solvents on fluorescence intensity

[0068] In order to explore the optimal detection system of the probe, the probe recognition of Fe was tested in different solvent systems. 3+ Fluorescence changes before and after.

[0069] 1) Influence of organic solvent types

[0070] Experimental parameters: 30 μL of 1 mM fluorescent probe, 30 μL of 100 μM Fe 3+ , excitation wavelength 410nm, emission wavelength 615nm, reaction time 5min, 3mL organic / HEPES solution, wherein the volume ratio of the organic solvent to the HEPES solution in the organic / HEPES solution is 95:5, and the organic solvents are acetonitrile (CH3CN), ethanol (EtOH), methanol (MeOH), dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), acetone (Acetone), tetrahydrofuran (THF), and the results are as follows Figure 4 shown. Figure 4 It is shown that in the acetone and HEPES system, the fluorescent probe and Fe 3+ The fluorescence intensity before and after the reaction changed by a large multiple, 544 times. The reaction results were obvious and the rate was fast.

[0071] 2) Effect of the volume ratio of acetone / HEPES solution on fluorescence intensity

[0072] In the optimal solvent system, the effects of different volume ratios of acetone / HEPES solutions on the fluorescent probe were explored. Figure 5 As shown. Figure 5 It can be seen that with the increase of the volume of HEPES solution, the fluorescence intensity in the system decreases first and then increases after 5 minutes of reaction. Therefore, the volume ratio of acetone to HEPES solution is preferably 95:5-9:1, and the volume ratio of acetone / HEPES solution is 95:5 as the best.

[0073] (2)Fe 3+ Effect of concentration

[0074] In order to study the sensitivity of the probe to iron ions, fluorescence spectroscopy was used to detect the response of 1 mM fluorescent probe to 10 mM Fe 3+ The sensitivity of the reaction, the results are as follows Figure 6 shown.

[0075] Experimental method: 30 μL of 1 mM fluorescent probe was added to 3 mL of acetone / HEPES solvent system with a volume ratio of 95:5. After scanning the baseline twenty times, 3 μL×1 mM Fe 3+, add 10 times, then add 3 μL × 10 mM Fe 3+ After titration until the reaction time is 5 min, the fluorescence intensity of the probe no longer changes. Figure 6 shown. Figure 6 It shows that the fluorescence intensity of the fluorescent probe at 615 nm increases with Fe 3+ It is gradually quenched with the increase of concentration.

[0076] (3) Construction of standard curve

[0077] Experimental method: Add 30 μL of 1 mM fluorescent probe to 3 mL of acetone / HEPES (volume ratio 95:5) solvent system, then add 3 μL of 1 mM Fe 3+ solution, add 10 times, then add 3 μL 1×10 mM Fe 3+ The solution was added to the system for 5 minutes until the fluorescence intensity at the emission wavelength of 615 nm no longer changed. Figure 7 shown.

[0078] from Figure 7 It can be seen that Fe 3+ The concentration is in the range of 0.1-1 equivalent, that is, Fe 3+ When the concentration is 1≤x≤10μM, Fe 3+ The concentration and fluorescence intensity form a linear relationship, and the standard curve is: y1 = 1878.133-722.970x, R1 2 =0.9862; when Fe 3+ The concentration is in the range of 1-7 equivalents, that is, Fe 3+ When the concentration is 10≤x≤70μM, Fe 3+ The concentration and fluorescence intensity form a linear relationship, and the standard curve is: y2 = 1319.257-172.35x, R2 2 =0.9926, according to the formula LOD=3σ / k, its detection limit is 325μM.

[0079] (4) Specificity detection

[0080] 30 μL of 1 mM fluorescent probe and different interfering ions were added to 3 mL of acetone / HEPES (volume ratio 95:5) solvent system, and the fluorescence intensity was measured. 3+ The solution reacted for 5 minutes, and the fluorescence intensity was measured again. The amount of each interfering ion added was 30 μL, 10 mM. The results are as follows: Figure 8 shown.

[0081] Figure 8 It shows that in the presence of different ions, the probe has a strong affinity for Fe 3+It still has good selectivity. Although the fluorescence intensity is reduced to a certain extent, it can still quickly identify Fe after adding iron ions. 3+ , to achieve the purpose of specific identification.

[0082] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A terpyridine fluorescent compound, characterized in that: The Chinese name is: (E)-4-(5-(4-([3,2':6',3'-tripyridine]-4'-yl)phenylvinyl)thiophene-2-yl)morpholine, the structural formula is 2. A terpyridine fluorescent compound as claimed in claim 1 as a fluorescent probe for detecting and identifying Fe 3+ Application in.

3. A method for detecting Fe using the terpyridine fluorescent compound according to claim 1 3+ The method comprises the steps of: firstly dissolving the terpyridine fluorescent compound in an organic solvent and a HEPES solution, and then adding a Fe-containing 3+ The test solution is reacted for 4-8 minutes to obtain a system to be detected; and then the fluorescence intensity of the system to be detected is detected at an emission wavelength of 490-800 nm.

4. The method according to claim 3, characterized in that: The organic solvent is one or a mixture of several of acetonitrile, ethanol, methanol, dimethyl sulfoxide, N,N-dimethylformamide, acetone and tetrahydrofuran.

5. The method according to claim 3 or 4, characterized in that: The volume ratio of the organic solvent to the HEPES solution is 0-10:0.5-10.

6. The method according to claim 5, characterized in that The concentration of the terpyridine fluorescent compound is 1-20 μM.

7. The method according to claim 6, characterized in that Also includes Fe 3+ The relationship between concentration x and fluorescence intensity y1 is constructed by 3+ Concentration detection standard curve: y1 = 1878.133-722.970x, R1 2 =0.9862, 1≤x≤10μM.

8. The method according to claim 6, characterized in that Also includes Fe 3+ The relationship between concentration x and fluorescence intensity y2 is constructed by Fe 3+ Concentration detection standard curve: y2 = 1319.257-172.35x, R2 2 =0.9926, 10≤x≤70μM.

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