Quenching type fluorescent probe for specifically detecting gold ions as well as preparation method and application of quenching type fluorescent probe

Abstract

The invention discloses a quenching type fluorescent probe for detecting gold ions as well as a preparation method and application of the quenching type fluorescent probe. The fluorescent probe is 2-(3-(4-(dimethylamino) phenyl) alkenyl)-6-hydroxybenzofuran-3 (2H)-ketone. The structural formula of the fluorescent probe is shown in the description. 4-(dimethylamino) cinnamyl aldehyde is used as a raw material and is subjected to aldol condensation reaction with 6-hydroxy-2H-benzofuran-3-ketone to obtain a compound 2-(3-(4-(dimethylamino) phenyl) alkenyl)-6-hydroxybenzofuran-3 (2H)-ketone, and a compound solution can emit strong near-infrared fluorescence under excitation of laser with the wavelength of 365 nm, so that the near-infrared fluorescence can be used for detecting the near-infrared fluorescence. Near-infrared fluorescence of the solution can be rapidly quenched after gold ions are added into the solution, and the near-infrared fluorescence of the solution cannot be obviously changed after other metal ions are added into the solution. Therefore, the compound can be used as a near-infrared quenching type fluorescent probe for specifically detecting gold ions, has the advantages of low detection limit (8.47 * 10 <-8 > mol / L), short response time (less than 6s) and the like, and has a very good application prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of fine organic synthesis, and relates to a near-infrared quenching fluorescent probe for specific detection of gold ions, and a preparation method and application thereof. Background Art

[0002] Gold ions are commonly used as drugs to treat rheumatoid arthritis, tuberculosis, cancer and other diseases due to their good anti-inflammatory properties. However, gold ions are highly reactive and can bind to biological macromolecules such as DNA, enzymes, and proteins in the human body, thereby posing potential risks to human health. At the same time, since gold ions have certain biological toxicity, once excessive gold ions are ingested, they will seriously damage important organs of the human body such as the kidneys, liver, and central nervous system. Therefore, being able to monitor the gold ion content in cells and organisms in real time is crucial to protecting human health.

[0003] At present, the main methods for detecting gold ions include inductively coupled plasma, colorimetry, mass spectrometry and electrochemical methods. Compared with these traditional detection methods, fluorescent probes are favored due to their simple synthesis, good selectivity and high sensitivity. There is no relevant report on the synthesis of near-infrared quenching fluorescent probes for specific detection of gold ions using 4-(dimethylamino)cinnamaldehyde and 6-hydroxy-2H-benzofuran-3-one as raw materials. Summary of the invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a quenching fluorescent probe for detecting gold ions, which can meet the use requirements. Another technical problem to be solved by the present invention is to provide a method for preparing 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. The present invention also solves a technical problem of providing an application of the above-mentioned 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A near-infrared quenching fluorescent probe for specific detection of gold ions is 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one, and its structural formula is:

[0007]

[0008] The method for preparing a near-infrared quenching fluorescent probe for specific detection of gold ions uses 4-(dimethylamino)cinnamaldehyde as a raw material and performs an aldol condensation reaction with 6-hydroxy-2H-benzofuran-3-one to obtain 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one. Specifically, the method comprises the following steps:

[0009] (1) 0.1 mol of 6-hydroxy-2H-benzofuran-3-one, 0.10-0.15 mol of 4-(dimethylamino)-cinnamaldehyde, and 20-45 mL of anhydrous ethanol were sequentially added into a three-necked flask equipped with a stirrer, and refluxed at 75-85° C. for 3-8 h under nitrogen protection;

[0010] (2) the reaction solution is distilled to recover the solvent, thereby obtaining a crude product of 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one;

[0011] (3) The crude product of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was chromatographed on a silica gel column (petroleum ether:ethyl acetate=1:1) to obtain a brown powder of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one.

[0012] The compound 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one can selectively recognize gold ions. Under the excitation of a 365nm laser, the near-infrared fluorescence of the probe solution is rapidly quenched. The compound can sensitively detect the gold ion content in the solution, with a detection limit as low as 8.47×10 -8 mol / L.

[0013] Beneficial effects: Compared with the prior art, the present invention uses 4-(dimethylamino)-cinnamaldehyde as a raw material to undergo an aldol condensation reaction with 6-hydroxy-2H-benzofuran-3-one to obtain the compound 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one. The compound can specifically identify gold ions and can sensitively detect the gold ion content in a solution. As a fluorescent probe for detecting gold ions, it has many advantages such as convenient synthesis, good selectivity, high sensitivity, etc., and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a fluorescence spectrum of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one acting on gold ions of different concentrations;

[0015] Figure 2It is the fluorescence spectrum of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one acting on different metal ions. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with specific embodiments.

[0017] Example 1

[0018] Preparation of 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one, the reaction formula is as follows:

[0019]

[0020] The specific steps are as follows:

[0021] Preparation of 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one:

[0022] 0.1mol 6-hydroxy-2H-benzofuran-3-one, 0.3mol NaOH and 0.15mol 4-(dimethylamino)-cinnamaldehyde and 20mL ethanol were added into a three-necked flask equipped with a stirrer in sequence, and the mixture was refluxed at 78°C for 5h under nitrogen protection. The reaction solution was distilled to recover the solvent, and a crude product of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was obtained. The crude product was then chromatographed on a silica gel column (petroleum ether: ethyl acetate = 1:1) to obtain a brown powder of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. 1 H NMR (600MHz, DMSO-d6) δ11.02(s,1H),7.56(d,J=8.2Hz,1H),7.46(d,J=8.4Hz,1H),7.37(d,J=8.4Hz, 1H), 7.11 (d, J = 15.4Hz, 1H), 6.99 (dt, J = 15.5, 10.1Hz, 1H), 6.76-6.61 (m, 5H), 2.96 (d, J = 3.8Hz, 6H). 13 C NMR(150MHz,DMSO-d6)δ180.55,167.17,166.32,151.49,146.78,142.62,129.45,129.04, 125.93,124.31,115.58,114.68,114.44,113.06,112.60,112.47,98.76.HRMS(m / z):[M+H] + calcdfor C 19H 18 NO3,308.1287; found,308.1284.

[0023] Example 2

[0024] 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one was prepared into 1×10 -5 M PBS buffer solution (pH = 7.4, 1% DMF, 10 mM), and gold ions were dissolved in distilled water to prepare concentrations of 0, 0.25 × 10 -6 , 0.5×10 -6 , 0.75×10 -6 , 1×10 -6 , 1.25×10 -6 , 1.5×10 -6 , 1.75×10 -6 , 2×10 -6 , 2.25×10 -6 , 2.5×10 -6 , 2.75×10 -6 , 3×10 -6 ,3.25×10 -6 , 3.5×10 -6 , 3.75×10 -6 , 4×10 -6 , 4.25×10 -6 , 4.5×10 -6 , 4.75×10 -6 , 5×10 -6 The fluorescence emission spectrum of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one in the presence of different concentrations of gold ions was measured on a fluorescence spectrophotometer by fluorescence spectrometry. Figure 1 The results show that as the concentration of gold ions in the solution gradually increases from 0 M to 5×10 -6 M, the fluorescence emission intensity of the compound at 680nm gradually decreased. This shows that the compound can be used as a near-infrared quenching fluorescent probe for sensitive detection of gold ions.

[0025] Example 3

[0026] 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one was prepared into 1×10 -5 M PBS buffer solution (pH = 7.4, 1% DMF, 10mM), and different metal ions (Ca 2+ , Cu 2+ , Fe2+ , Fe 3+ , Zn 2+ , Na + ,Mg 2+ , Cd 2+ , K + , Cu + , Ni 2+ , Ce 3+ , Ag + ,Cr 3+ , Ba 2+ , Pb 2+ , Hg 2+ ,Co 2+ , Au 3+ ) was dissolved in distilled water to a concentration of 2.0×10 -4 M solution. The fluorescence emission spectra of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one in the presence of different metal ions were measured on a fluorescence spectrophotometer by fluorescence spectrometry, such as Figure 2 As shown. The fluorescence emission peak of the compound at 680nm decreased significantly only after the addition of gold ions, while the fluorescence spectrum of the compound did not change significantly when other metal ions were added for reference and comparison. This shows that the compound can be used as a near-infrared quenching fluorescent probe that specifically recognizes gold ions.

Claims

1. A near-infrared quenching fluorescent probe for specific detection of gold ions and its preparation method and application, characterized in that: Its structural formula is:

2. The method for preparing the near-infrared quenching fluorescent probe for specific detection of gold ions according to claim 1, characterized in that: The steps include: 4-(Dimethylamino)cinnamaldehyde reacts with 6-hydroxy-2H-benzofuran-3-one to form 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one.

3. The method for preparing a near-infrared quenching fluorescent probe for specific detection of gold ions according to claim 2, characterized in that: 4-(Dimethylamino)cinnamaldehyde and 6-hydroxy-2H-benzofuran-3-one undergo an aldol condensation reaction to obtain 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one. The specific preparation method includes: (1) 0.1 mol of 6-hydroxy-2H-benzofuran-3-one, 0.10-0.15 mol of 4-(dimethylamino)-cinnamaldehyde, and 20-45 mL of anhydrous ethanol were sequentially added into a three-necked flask equipped with a stirrer, and refluxed at 75-85° C. for 3-8 h under nitrogen protection; (2)) The reaction solution was distilled to recover the solvent, thereby obtaining a crude product of 2-(3-(4-(dimethylamino)phenyl)alkenyl)-6-hydroxybenzofuran-3(2H)-one. (3) The crude product of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was chromatographed on a silica gel column (petroleum ether:ethyl acetate=1:1) to obtain a brown powder of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one.

4. Use of the near-infrared quenching fluorescent probe 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one according to claim 1 in detecting gold ions.

5. The use according to claim 4, characterized in that: 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one can specifically react with gold ions. Under the excitation of a 365nm laser, the near-infrared fluorescence of the probe solution is rapidly quenched.

6. The use according to claim 4, characterized in that: The concentration of gold ions was detected by 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. The detection limit was as low as 8.47×10 -8 mol / L.

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