Cadmium ion fluorescent probe as well as synthesis method and application thereof

Abstract

The invention discloses a cadmium ion fluorescent probe as well as a synthesis method and application thereof, and belongs to the technical field of environmental analysis and biological analysis and detection. The structural formula is shown in the specification. The synthesis method comprises the following specific synthesis steps: by taking absolute ethyl alcohol as a solvent, adding 4-chloro-3-formyl coumarin, stirring at room temperature, then adding 2-(2-aminophenyl) benzimidazole, carrying out heating reflux reaction, cooling to room temperature, purifying an obtained crude product by using silica gel column chromatography, and separating by using ethyl acetate and petroleum ether as eluents, thereby obtaining the 4-chloro-3-formyl coumarin. The invention provides a simple and convenient cadmium ion fluorescent probe which can be synthesized and has specific response, and in cadmium ion detection, the cadmium ion fluorescent probe has the advantages of rapid detection, low detection limit value, good selectivity and strong anti-interference capability.

Description

Technical Field

[0001] This invention relates to the fields of environmental analysis and biological analysis detection technology, and in particular to a cadmium ion fluorescent probe, its synthesis method and application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Cadmium, a heavy metal, is widely used in industrial production, such as electroplating, military applications, pigment production, plastics manufacturing, metallurgy, and batteries. In recent years, with the widespread use of cadmium compounds, its concentration in the environment has increased significantly, causing irreversible damage to the environment and organisms. Cadmium is one of the most easily accumulated toxic substances in the human body, and its elimination rate is very slow, with a metabolic half-life of 10-30 years. Cadmium-related toxicological studies have shown that low-dose cadmium exposure can reduce bone density, impair kidney function, and induce increased calcium excretion. Furthermore, cadmium is listed as the seventh hazardous substance to human health by the U.S. Environmental Protection Agency and is reported as a human carcinogen by the International Agency for Research on Cancer. Therefore, researching rapid, simple, and effective methods for detecting cadmium ion content in the ecological environment and organisms is of great significance.

[0004] To date, methods for detecting cadmium ions include atomic absorption spectrometry, inductively coupled plasma mass spectrometry, and other methods. Methods such as analytical spectroscopy, ultraviolet spectrophotometry, oscillometric polarography, and electrochemical analysis are available. However, most of these methods require large and complex instruments, are expensive, involve cumbersome detection procedures, are time-consuming, and require highly skilled personnel. Therefore, they are very limited in their application environments and do not meet the requirements of rapid on-site evaluation in modern environmental monitoring. Fluorescent probe detection methods, with their high selectivity, ease of operation, high sensitivity, easy visual identification, and low intracellular toxicity, have attracted widespread attention and are highly suitable for the detection of cadmium ions in the environment and within organisms.

[0005] In recent years, numerous probes for detecting cadmium ions have been reported. However, the synthesis of these probes is cumbersome, their complexation ability is low, and their sensitivity is low, leading to reduced applicability of fluorescent cadmium probes. Therefore, the development of novel fluorescent cadmium ion probes has significant practical importance and application value for the ecological environment and organisms. Summary of the Invention

[0006] In view of this, the present invention provides a cadmium ion fluorescent probe, its synthesis method and application.

[0007] In a first aspect, the present invention provides a cadmium ion fluorescent probe, the structural formula of which is as follows: .

[0008] Secondly, this invention provides a method for synthesizing the above-mentioned cadmium ion fluorescent probe, the reaction formula of which is:

[0009] The specific synthesis steps are as follows: Using anhydrous ethanol as solvent, 4-chloro-3-carboxycoumarin was added and stirred at room temperature. Then, 2-(2-aminophenyl)benzimidazole was added, and the mixture was heated under reflux. After cooling to room temperature, the crude product was purified by silica gel column chromatography, using ethyl acetate and petroleum ether as eluents for separation.

[0010] Preferably, the molar ratio of 4-chloro-3-carboxycoumarin to 2-(2-aminophenyl)benzimidazole is 1:1 to 1:1.1.

[0011] Preferably, the molar volume ratio of 4-chloro-3-formylcoumarin to anhydrous ethanol is 1 mmol: 25-100 mL.

[0012] Preferably, the stirring is performed at room temperature for 10 to 15 minutes.

[0013] Preferably, the temperature of the heating reflux reaction is 60–80°C.

[0014] Preferably, the heating reflux reaction time is 0.5 to 2 hours.

[0015] Preferably, the volume ratio of ethyl acetate to petroleum ether is 1:1 to 1:5.

[0016] Thirdly, the present invention provides the application of the above-mentioned cadmium ion fluorescent probe in fluorescence detection.

[0017] Preferably, the cadmium ion fluorescent probe is used for cadmium ion sensing, detection, analysis, and tracing in aquatic environmental systems or biological cell systems.

[0018] Compared with the prior art, the present invention has achieved the following beneficial effects: (1) This invention enables rapid detection of Cd in neutral solution using a fluorescent probe for cadmium ions. 2+ This probe possesses characteristics such as low detection limit, good selectivity, strong anti-interference ability, and the ability to eliminate the influence of other metal ions on the detection results. Based on its specificity and significant color change, it can serve as a specific indicator for detecting cadmium ions in solution. This invention provides a rapid, simple, and sensitive cadmium ion detection reagent with broad application prospects in environmental and life systems fields.

[0019] (2) The synthesis of the novel cadmium ion fluorescent probe prepared by the present invention can be completed in one step, and the raw materials are readily available, the operation is simple, and the subsequent purification process is also relatively simple. Attached Figure Description

[0020] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation thereof. Obviously, those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0021] Figure 1 The mass spectrum of BCBH prepared in Example 1; Figure 2 The image shows the fluorescence characteristics of different metals detected by BCBH prepared in Example 1. Figure 3 BCBH prepared for Example 1 was used to detect different concentrations of Cd. 2+ Fluorescence results image; Figure 4 The chromatogram of BCBH prepared in Example 1; Figure 5 The chromatogram of the product prepared in Example 2; Figure 6 The image shows the BCBH anti-interference detection pattern prepared in Example 1. Detailed Implementation

[0022] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] The technical solution of the present invention will be further described below with reference to specific embodiments. The present invention does not impose any special restrictions on the source of reagents used in the following embodiments; commercially available products well known to those skilled in the art can be used.

[0024] Example 1 (1) Reaction formula for synthesizing cadmium ion fluorescent probe:

[0025] (2) Specific steps for synthesizing cadmium ion fluorescent probes: Weigh 208.6 mg (1 mmol) of 4-chloro-3-formylcoumarin, dissolve it in 100 mL of anhydrous ethanol, stir at room temperature for 10 min, add 230.17 mg (1 mmol) of 2-(2-aminophenyl)benzimidazole, heat under reflux at 80 °C for 30 min, cool to room temperature, filter, wash three times with deionized water, dry, and obtain a brown crude product. Purify by silica gel column chromatography, using ethyl acetate and petroleum ether = 1:1 (v / v) as eluent to obtain the target product with a yield of 75% and a purity of 100% (see [link to article]). Figure 4 ). This is denoted as BCBH.

[0026] Example 2 Weigh 208.6 mg (1 mmol) of 4-chloro-3-formylcoumarin, dissolve it in 100 mL of anhydrous ethanol, stir at room temperature for 10 min, add 253.19 mg (1.1 mmol) of 2-(2-aminophenyl)benzimidazole, heat under reflux at 80 °C for 30 min, cool to room temperature, filter, wash three times with deionized water, dry, and obtain a brown crude product. Purify by silica gel column chromatography, using ethyl acetate and petroleum ether = 1:1 (v / v) as eluent to obtain the target product with a yield of 72% and a purity of 98% (see [link to article]). Figure 5 ).

[0027] Example 3 Weigh 208.6 mg (1 mmol) of 4-chloro-3-carboxycoumarin, dissolve it in 100 mL of anhydrous ethanol, stir at room temperature for 10 min, add 230.17 mg (1 mmol) of 2-(2-aminophenyl)benzimidazole, heat and reflux at 80 °C for 1 h, cool to room temperature, filter, wash three times with deionized water, dry, and obtain a brown crude product. Purify by silica gel column chromatography, using ethyl acetate and petroleum ether = 1:1 (v / v) as eluent to obtain the target product with a yield of 75% and a purity of 98%.

[0028] Example 4 Weigh 208.6 mg (1 mmol) of 4-chloro-3-carboxycoumarin, dissolve it in 100 mL of anhydrous ethanol, stir at room temperature for 10 min, add 230.17 mg (1 mmol) of 2-(2-aminophenyl)benzimidazole, heat under reflux at 60 °C for 2 h, cool to room temperature, filter, wash three times with deionized water, dry, and obtain a brown crude product. Purify by silica gel column chromatography, using ethyl acetate and petroleum ether = 1:1 (v / v) as eluent to obtain the target product with a yield of 68% and a purity of 93%.

[0029] Test case 1. The fluorescent probe BCBH of Example 1 for Cd 2+ Selective detection: The detection method is as follows: 1 μmol / L of the fluorescent probe BCBH in a HEPES:CH3CN = 1:1 (v / v, pH = 7.4) buffer solution, with 10 μmol / L of the metal cation (Cd) added to each solution. 2+ Ca 2+ Na + Mn 2+ Sn 2+ Mg 2+ K + ), to detect changes in the fluorescence emission spectrum of the solution, such as Figure 2 As shown.

[0030] from Figure 2 As can be seen from this, when Cd is added... 2+ At that time, only Cd 2+ The addition of Cd can cause a significant change in fluorescence intensity. 2 + The fluorescence intensity at 684 nm was quenched in situ, while the addition of other metal cations had no significant effect on the fluorescence intensity, except for K. + It causes a change in fluorescence intensity, but the change is not significant. Therefore, the fluorescent probe BCHC is effective against Cd. 2+ It offers a good selection.

[0031] 2. The fluorescent probe BCBH from Example 1 for Cd 2+ Titration test: Test method: 1 μmol / L of the fluorescent probe BCBH in a HEPES:CH3CN = 1:1 (v / v, pH = 7.4) buffer solution was added, followed by the addition of 1 mM, 0.1 mM, 10 μM, 0.1 μM, and 10 nM Cd, respectively. 2+ The changes in the fluorescence emission spectrum of the solution were detected, and the color changes of the solution were observed under a 684nm ultraviolet lamp. Figure 3 As shown.

[0032] Depend on Figure 3 It can be seen that, with Cd 2+ With the continuous addition of 10 μM Cd, the fluorescence intensity of the emission peak at 684 nm continuously increased. 2+ It reaches saturation at that time.

[0033] 3. The fluorescent probe BCBH from Example 1 for Cd 2+ Anti-interference capability test: Test method: 1 μmol / L of the fluorescent probe BCBH in a HEPES:CH3CN = 1:1 (v / v, pH = 7.4) buffer solution was used, and equal amounts of metal cations (Ca) were added to each solution. 2+ Na + Mn 2+ Sn 2+ Mg 2+ K + Then, an equivalent amount of cadmium ions was added dropwise, and the anti-interference ability of the probe to detect cadmium ions in the presence of different metal ions was measured, such as... Figure 6 As shown.

[0034] The results showed that metal ions such as Ca 2+ Na + Mn 2+ Sn 2+ Mg 2+ The enhancement of fluorescence signal has little effect, but K + It will cause some degree of interference.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A cadmium ion fluorescent probe, characterized in that, Its structural formula is as follows: 。 2. The method for synthesizing the cadmium ion fluorescent probe as described in claim 1, characterized in that, The reaction formula is: The specific synthesis steps are as follows: Using anhydrous ethanol as solvent, 4-chloro-3-carboxycoumarin was added and stirred at room temperature. Then, 2-(2-aminophenyl)benzimidazole was added, and the mixture was heated under reflux. After cooling to room temperature, the crude product was purified by silica gel column chromatography, using ethyl acetate and petroleum ether as eluents for separation.

3. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, The molar ratio of 4-chloro-3-carboxycoumarin to 2-(2-aminophenyl)benzimidazole is 1:1 to 1:1.

1.

4. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, The molar volume ratio of 4-chloro-3-carboxycoumarin to anhydrous ethanol is 1 mmol: 25-100 mL.

5. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, Stir at room temperature for 10–15 minutes.

6. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, The temperature of the heating reflux reaction is 60–80°C.

7. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, The heating and reflux reaction time is 0.5 to 2 hours.

8. The method for synthesizing the cadmium ion fluorescent probe as described in claim 2, characterized in that, The volume ratio of ethyl acetate to petroleum ether is 1:1 to 1:

5.

9. The application of the cadmium ion fluorescent probe as described in claim 1 in fluorescence detection.

10. The application as described in claim 9, characterized in that, The cadmium ion fluorescent probe is used for cadmium ion sensing, detection, analysis, and tracing in aquatic or biological cell systems.

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