A quenching fluorescent probe for specific detection of gold ions, its preparation method and application

Abstract

This invention discloses a quenching fluorescent probe for detecting gold ions, its preparation method, and its application. The fluorescent probe is 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. This invention utilizes 4-(dimethylamino)cinnamaldehyde as a raw material, and undergoes an aldol condensation reaction with 6-hydroxy-2H-benzofuran-3-one to obtain the compound 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. The solution of this compound emits strong near-infrared fluorescence under excitation by a 365nm laser. Upon addition of gold ions, the near-infrared fluorescence of the solution is rapidly quenched, while the addition of other metal ions does not significantly change the near-infrared fluorescence. Therefore, this compound can be used as a near-infrared quenching fluorescent probe for the specific detection of gold ions, exhibiting a low detection limit (8.47 × 10⁻⁶). ‑8 It has many advantages, such as low mol / L concentration and short response time (<6s), and has a promising application prospect.

Description

Technical Field

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

[0002] Gold ions, due to their excellent anti-inflammatory properties, are commonly used as medications to treat diseases such as rheumatoid arthritis, tuberculosis, and cancer. However, gold ions are highly reactive and can bind to biological macromolecules such as DNA, enzymes, and proteins in the human body, thus posing potential risks to human health. Furthermore, because gold ions possess a certain degree of biotoxicity, excessive intake can severely damage vital organs such as the kidneys, liver, and central nervous system. Therefore, real-time monitoring of gold ion levels in cells and within organisms is crucial for safeguarding human health.

[0003] Currently, methods for detecting gold ions mainly include inductively coupled plasma atomic absorption spectrometry (ICP-AES), colorimetry, mass spectrometry, and electrochemical methods. Compared with these traditional detection methods, fluorescent probes are favored due to their advantages such as simple synthesis, good selectivity, and high sensitivity. However, there are currently no reports on the synthesis of near-infrared quenching fluorescent probes for the specific detection of gold ions using 4-(dimethylamino)cinnamaldehyde and 6-hydroxy-2H-benzofuran-3-one as raw materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a quenching-type fluorescent probe for detecting gold ions, which meets the application requirements. Another technical problem this invention aims to solve is to provide a method for preparing 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. A further technical problem this invention aims to solve is to provide an application of the above-mentioned 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

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

[0007]

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

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

[0010] (2) After the solvent was recovered by distillation, the crude product 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was obtained;

[0011] (3) The crude product of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was subjected to silica gel column chromatography (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 selectively recognizes gold ions. Upon excitation with a 365 nm laser, the near-infrared fluorescence of the probe solution is rapidly quenched. This compound can sensitively detect the concentration of gold ions in solution, with a detection limit as low as 8.47 × 10⁻⁶. -8 mol / L.

[0013] Beneficial effects: Compared with existing technologies, this invention uses 4-(dimethylamino)-cinnamaldehyde as a raw material and undergoes an aldol condensation reaction with 6-hydroxy-2H-benzofuran-3-one to obtain compound 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one. This compound can specifically recognize gold ions and sensitively detect the gold ion content in solution. As a fluorescent probe for detecting gold ions, it has many advantages such as convenient synthesis, good selectivity, and high sensitivity, and has good application prospects. Attached Figure Description

[0014] Figure 1 The fluorescence spectra of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one reacting with gold ions of different concentrations are shown.

[0015] Figure 2The fluorescence spectra of 2-(3-(4-(methylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one reacting with different metal ions are shown. Detailed Implementation

[0016] The present invention will be further described below with reference to specific embodiments.

[0017] Example 1

[0018] The preparation of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one is shown in the following reaction formula:

[0019]

[0020] The specific steps are as follows:

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

[0022] 0.1 mol of 6-hydroxy-2H-benzofuran-3-one, 0.3 mol of NaOH, 0.15 mol of 4-(dimethylamino)-cinnamaldehyde, and 20 mL of ethanol were sequentially added to a three-necked flask equipped with a stirrer, and the mixture was refluxed at 78 °C for 5 h under nitrogen protection. After distillation to recover the solvent, crude product 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was obtained. This crude product was then subjected to silica gel column chromatography (petroleum ether: ethyl acetate = 1:1) to obtain a brown powder, 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)enyl)-6-hydroxybenzofuran-3(2H)-one was prepared into a 1×10⁻⁵ M PBS buffer solution (pH = 7.4, 1% DMF, 10 mM). Simultaneously, gold ions were dissolved in distilled water to prepare solutions with concentrations of 0 and 0.25×10⁻⁵. -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 solution of M. Fluorescence emission spectra of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one in the presence of different concentrations of gold ions were measured on a fluorescence spectrophotometer using fluorescence spectrophotometric titration. Figure 1 As shown in the figure. The results indicate that as the concentration of gold ions in the solution gradually increases from 0 M to 5 × 10⁻⁶, -6 M, the fluorescence emission intensity of this compound gradually decreases at 680 nm. This indicates that the compound can be used as a sensitive near-infrared quenching fluorescent probe for the detection of gold ions.

[0025] Example 3

[0026] 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one was prepared into a 1×10 -5 M PBS buffer solution (pH = 7.4, 1% DMF, 10 mM), simultaneously containing different metal ions (Ca) 2+ Cu 2+ Fe 2+ Fe3+ 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+ Dissolve in distilled water to prepare a concentration of 2.0 × 10⁻⁶. -4 The solution of M was analyzed. Fluorescence emission spectra of 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one in the presence of different metal ions were measured using a fluorescence spectrophotometer via fluorescence titration. Figure 2 As shown, the fluorescence emission peak of this compound only decreased significantly after the addition of gold ions, while the fluorescence spectrum of the compound did not change significantly when other metal ions were added for comparison. This indicates that this compound can be used as a near-infrared quenching fluorescent probe that specifically recognizes gold ions.

Claims

1. The application of a near-infrared quenching fluorescent probe, 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one, in the detection of gold ions, with the following structural formula: It can specifically react with gold ions, and the near-infrared fluorescence of the probe solution is rapidly quenched under excitation by a 365 nm laser. The concentration of gold ions can be detected using 2-(3-(4-(dimethylamino)phenyl)enyl)-6-hydroxybenzofuran-3(2H)-one, with a detection range of 0–5 μM and a detection limit as low as 8.47 × 10⁻⁶. -8 mol / L.

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