Synthesis method and application of fluorescent probe for detecting cyanide ions

Abstract

The invention relates to the technical field of chemical analysis and detection, and discloses a synthesis method and application of a fluorescent probe for detecting cyanide ions, and the synthesis method comprises the following steps: A, reacting a derivative of R1 with a compound with a reactive group to form a connecting unit X; and B, carrying out a cross-linking reaction on the obtained intermediate product and a cyanide ion reaction group R2 to form a final product of the fluorescent probe, and C, purifying the synthesized fluorescent probe. By optimizing the synthesis method of the fluorescent probe and utilizing the characteristics of simple chemical reaction steps, wide adjustable range of reaction conditions and selection of a reaction solvent, the synthesis method has relatively high operability and industrial production potential. In addition, after synthesis, purification is carried out through recrystallization, liquid chromatography or thin-layer chromatography, and the purity and quality of the product are further improved. The simple and effective synthesis strategy not only reduces the production cost, but also improves the market competitiveness of the fluorescent probe.

Description

Technical Field

[0001] The invention relates to the technical field of chemical analysis detection, in particular to a synthesis method of a fluorescent probe for detecting cyanide ions and application thereof. Background Art

[0002] In the field of modern chemical analysis, cyanide ion has become an important target substance for environmental monitoring and food safety testing due to its widespread presence in industrial wastewater, pesticides, chemical synthesis, fuel and other fields. Although traditional cyanide ion detection methods, such as colorimetry, ion chromatography and electrochemical methods, can meet the detection needs of cyanide ions to a certain extent, they often face problems such as insufficient sensitivity, complex operation and long detection time. In addition, many traditional methods also require complex sample pretreatment, which increases the difficulty of operation and detection cost. At the same time, these methods have low selectivity for cyanide ions and are easily affected by other interfering substances in the sample, resulting in false positive or false negative results. Therefore, it is particularly important to develop a highly sensitive, highly selective and easy-to-operate cyanide ion detection method.

[0003] In recent years, fluorescent probes have gradually become a research hotspot for detecting cyanide ions because of their excellent optical properties and high sensitivity. Existing fluorescent probes are usually based on the reaction principle of cyanide ions with specific functional groups, and their fluorescence properties are changed by recognizing and responding to the presence of cyanide ions. However, the synthesis method of existing fluorescent probes requires multiple reaction steps. The reaction steps include multiple chemical reactions, such as halogenation, esterification, condensation, etc. These steps not only increase the time and complexity of the synthesis, but also require purification after each step to remove unreacted reagents and by-products, thereby further prolonging the synthesis. The synthesis is often complicated, the reaction conditions are harsh, and it is difficult to meet the needs of industrial production. In addition, the selectivity and sensitivity of many probes are also limited, especially in complex matrices, and cyanide ions may not be effectively distinguished from other interfering substances.

[0004] To this end, those skilled in the art have proposed a method for synthesizing a fluorescent probe for detecting cyanide ions and its application to solve the above problems. Summary of the invention

[0005] In view of the deficiencies of the prior art, the present invention provides a method for synthesizing a fluorescent probe for detecting cyanide ions and its application, which solves the problems raised in the above-mentioned background technology.

[0006] To achieve the above objectives, the present invention is implemented by the following technical scheme: a fluorescent probe, the structural formula of the fluorescent probe is:

[0007] R 1 -XR 2 ,

[0008] Where R 1 is a fluorescent group, wherein the fluorescent group is selected from: 1,8-naphthyridine, fluorescein, rhodamine and carboxyl fluorophore;

[0009] X is a linking unit comprising at least one amino, hydroxyl or thiol group;

[0010] R 2 is a cyanide ion reactive group, and the cyanide ion reactive group is selected from a nitrile group, a thiourea group or other functional groups suitable for reacting with cyanide ions.

[0011] Preferably, in the presence of cyanide ions, the emission wavelength of the probe is 500 nm to 700 nm, and its fluorescence intensity is enhanced by at least 2 times compared with the state without cyanide ions.

[0012] Preferably, the probe maintains stability in a buffer solution with a pH value of 6 to 8 and has good selectivity for detecting cyanide ions.

[0013] A method for synthesizing a fluorescent probe for detecting cyanide ions comprises the following steps:

[0014] A. R 1 The derivative of is reacted with a compound having a reactive group to form a linking unit X;

[0015] B. Reaction of the intermediate product with the cyanide ion reaction group R 2 Performing a cross-linking reaction to form a final product of a fluorescent probe;

[0016] C. Purify the synthesized fluorescent probe.

[0017] Preferably, the reaction temperature in step A is 20° C.-80° C., the reaction time is 1 h-48 h, and the reaction solvent is dimethylsulfamide, ethanol or acetonitrile.

[0018] Preferably, the purification method in step C comprises recrystallization, liquid chromatography or thin layer chromatography.

[0019] An application of a fluorescent probe for detecting cyanide ions. The fluorescent intensity of the fluorescent probe is significantly enhanced when cyanide ions are present, and the fluorescent probe has a detection capability with a sensitivity reaching the nanomolar level.

[0020] Preferably, the fluorescent probe is used for detecting cyanide ions in water samples, soil samples or biological samples.

[0021] A detection method for a fluorescent probe for detecting cyanide ions, the detection method comprising the following steps:

[0022] Step 1, mixing the sample to be detected with the fluorescent probe;

[0023] Step 2: irradiate the mixed solution with an appropriate excitation light source;

[0024] Step 3: Measure the fluorescence intensity by a fluorescence detection instrument, and determine the concentration of cyanide ions in the sample based on the change in fluorescence intensity.

[0025] Preferably, the fluorescence detection instrument is a fluorescence spectrometer or a fluorescence microscope.

[0026] The invention provides a synthesis method of a fluorescent probe for detecting cyanide ions and application thereof.

[0027] It has the following beneficial effects:

[0028] 1. The synthesis method of the fluorescent probe of the present invention includes simple chemical reaction steps, a wide range of adjustable reaction conditions, and flexible reaction solvent selection, which makes the synthesis method highly operable and has industrial production potential. In addition, after synthesis, purification is carried out by recrystallization, liquid chromatography or thin layer chromatography, which further improves the purity and quality of the product. This simple and effective synthesis strategy not only reduces production costs, but also improves the market competitiveness of fluorescent probes.

[0029] 2. The fluorescent probe prepared by the present invention can significantly enhance the fluorescence intensity when there is cyanide ion, and its fluorescence intensity is at least enhanced by 2 times relative to the state without cyanide ion. This characteristic enables the probe to have extremely high sensitivity and can detect the cyanide ion concentration at the nanomolar level. Its selectivity is achieved by a rationally designed cyanide ion reactive group, so that cyanide ion can be effectively distinguished from other interfering substances, ensuring that the concentration of cyanide ion can still be accurately determined in a complex group, thereby reducing the risk of false positives and false negatives. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the specification of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1:

[0033] Please refer to the attached Figure 1 The embodiment of the present invention provides a method for synthesizing a fluorescent probe for detecting cyanide ions and its application. The general structural formula of the fluorescent probe is:

[0034] R 1 -XR2 ,

[0035] Where R 1 is a fluorescent group, and the fluorescent group is selected from: 1,8-naphthyridine, fluorescein, rhodamine and carboxy fluorophore;

[0036] X is a linking unit comprising at least one amino, hydroxyl or thiol group;

[0037] R 2 The cyanide ion reactive group is selected from a nitrile group, a thiourea group or other functional groups suitable for reacting with cyanide ions.

[0038] In the presence of cyanide ions, the probe emits an emission wavelength of 500 nm to 700 nm, and its fluorescence intensity is enhanced by at least 2 times compared with the state without cyanide ions. The probe maintains stability in a buffer solution with a pH value of 6 to 8 and has good selectivity for detecting cyanide ions.

[0039] A method for synthesizing a fluorescent probe for detecting cyanide ions comprises the following steps:

[0040] A. R 1 The derivative of is reacted with a compound having a reactive group to form a linking unit X;

[0041] The reaction temperature in step A is 20°C-80°C, the reaction time is 1h-48h, and the reaction solvent is dimethylsulfamide, ethanol or acetonitrile

[0042] B. Reaction of the intermediate product with the cyanide ion reaction group R 2 Performing a cross-linking reaction to form a final product of a fluorescent probe;

[0043] C. Purify the synthesized fluorescent probe.

[0044] Specifically, step A: synthesis of reaction unit

[0045] In this step, the derivative of the fluorescent group (R1) reacts with the compound containing the reactive group to form the connecting unit X. The specific operation is as follows:

[0046] Reactant preparation: Select a fluorescent group R1 (such as 1,8-naphthyridine, fluorescein, rhodamine or carboxyfluorophore) and its derivatives and mix it with a compound having an amino, hydroxyl or thiol group.

[0047] Temperature: The reaction is carried out in the range of 20°C to 80°C. The appropriate temperature is selected according to the nature of the reactants and the desired reaction rate.

[0048] Reaction time: The reaction duration is adjustable from 1 hour to 48 hours, and the specific time should be monitored according to the progress of the reaction.

[0049] Solvent selection: Dimethylsulfamide, ethanol or acetonitrile can be selected as the reaction solvent to ensure good solubility of the reactants and reaction effect.

[0050] Reaction monitoring: Thin layer chromatography or high performance liquid chromatography can be used to monitor the progress of the reaction to ensure that the reaction is complete.

[0051] Step B: Cross-linking reaction

[0052] A cyanide ion reactive group R2 is introduced into the obtained intermediate product, and the final fluorescent probe is formed through a cross-linking reaction.

[0053] Reaction conditions: The intermediate product obtained in step A is mixed with the cyanide ion reactive group R2.

[0054] Reaction medium: An appropriate solvent can be selected according to the solubility of the reactants.

[0055] Reaction control: The reaction temperature and time are adjustable and need to be optimized according to the properties of the reactants and the rate of the cross-linking reaction.

[0056] Step C: Purification process

[0057] The synthesized fluorescent probes need to be purified to improve their purity and performance.

[0058] Purification method:

[0059] Liquid chromatography: Liquid chromatography is used to further remove unreacted raw materials and by-products to ensure the purity of the final product.

[0060] Thin Layer Chromatography: The product was subjected to TLC analysis to confirm the purity and composition.

[0061] Post-purification testing: Characterize and analyze the purified fluorescent probes, and confirm their structure and purity using nuclear magnetic resonance or mass spectrometry.

[0062] This synthesis method has the following advantages:

[0063] Strong operability: the reaction steps are simple, the reaction conditions are adjustable, and it is easy to implement.

[0064] Flexibility: The diverse selection of reaction solvents allows the synthesis conditions to be flexibly adjusted according to specific circumstances.

[0065] Industrialization Potential: The synthesis process has good scalability and is suitable for large-scale production.

[0066] High sensitivity: The synthesized fluorescent probe can significantly enhance the fluorescence intensity in the presence of cyanide ions and has excellent sensitivity and selectivity.

[0067] The purification method in step C includes recrystallization, liquid chromatography or thin layer chromatography.

[0068] The fluorescence intensity of the fluorescent probe is significantly enhanced in the presence of cyanide ions, and the fluorescent probe has a detection capability with a sensitivity of nanomolar level. The fluorescent probe is used to detect cyanide ions in water samples, soil samples or biological samples.

[0069] The detection method includes the following steps:

[0070] Step 1, mixing the sample to be detected with the fluorescent probe;

[0071] Step 2: irradiate the mixed solution with an appropriate excitation light source;

[0072] Step 3: Measure the fluorescence intensity by a fluorescence detection instrument, and judge the concentration of cyanide ions in the sample according to the change of fluorescence intensity. The fluorescence detection instrument is a fluorescence spectrometer or a fluorescence microscope.

[0073] Example 2

[0074] The general structural formula of the fluorescent probe is: R1-X-R2

[0075] Fluorophore R1: Fluorescein

[0076] Linking unit X: amino group

[0077] Cyanide ion reactive group R2: Nitrile group

[0078] Synthesis method:

[0079] Step A: reacting a fluorescein derivative with a compound having an amino reactive group at 60° C. for 12 hours, using dimethylsulfamide as the reaction solvent.

[0080] Step B: cross-linking the obtained intermediate product with the nitrile group to form the final fluorescent probe.

[0081] Step C: Purify the synthesized fluorescent probe by liquid chromatography.

[0082] Performance: Emission wavelength: 550nm, fluorescence intensity is 3 times stronger than that without cyanide ion. pH stability: 6 to 8.

[0083] Example 3

[0084] The general structural formula of the fluorescent probe is: R1-X-R2

[0085] Fluorophore R1: Rhodamine

[0086] Linking unit X: Hydroxyl

[0087] Cyanide ion reactive group R2: thiourea group

[0088] Synthesis method:

[0089] Step A: reacting a rhodamine derivative with a compound having a hydroxyl reactive group at 25° C. for 24 hours, using ethanol as the reaction solvent.

[0090] Step B: cross-linking the intermediate product with a thiourea group.

[0091] Step C: Purify the synthesized fluorescent probe by thin layer chromatography.

[0092] Performance: Emission wavelength: 600nm. Fluorescence intensity is 2.5 times stronger than that without cyanide ions. pH stability: 6.5 to 7.5.

[0093] Example 4

[0094] The general structural formula of the fluorescent probe is: R1-X-R2

[0095] Fluorophore R1: Carboxyl fluorophore

[0096] Linking unit X: thiol group

[0097] Cyanide ion reactive group R2: Nitrile group

[0098] Synthesis method:

[0099] Step A: reacting a carboxyl fluorophore derivative with a compound having a thiol reactive group at 40° C. for 8 hours in acetonitrile as the reaction solvent.

[0100] Step B: cross-linking the intermediate product with a nitrile group.

[0101] Step C: Purify the synthesized fluorescent probe by recrystallization.

[0102] Performance: Emission wavelength: 520nm, fluorescence intensity is 2 times higher than that in the state without cyanide ions.

[0103] pH stability: 6 to 8.

[0104] The following table 1 compares the data of implementation 1 and implementation 4:

[0105]

[0106]

[0107] Table 1

[0108] Conclusion: Through the comparison of the above examples, it can be seen that different fluorescent groups and connecting units have an impact on the emission wavelength, fluorescence enhancement multiple and pH stability of the probe. The fluorescence enhancement effect of Example 2 is the best, while Examples 3 and 4 also show good fluorescence intensity and stability. These examples demonstrate the diversified synthesis possibility and application potential of the fluorescent probe in cyanide ion detection.

[0109] In summary: the fluorescent probe synthesis method of the present invention has simple chemical reaction steps, widely adjustable reaction conditions and flexible reaction solvent selection, these characteristics make the method have great potential in operability and industrial production. In addition, the synthesized product is purified by recrystallization, liquid chromatography or thin layer chromatography, thereby further improving its purity and quality. This simple and effective synthesis strategy not only reduces production costs, but also enhances the market competitiveness of fluorescent probes. In the presence of cyanide ions, the prepared fluorescent probe can significantly enhance its fluorescence intensity, and compared with the state without cyanide ions, the fluorescence intensity is at least increased by 2 times. This characteristic makes the probe extremely sensitive and can detect nanomolar cyanide concentrations. Its selectivity is achieved by rationally designed cyanide ion reaction groups, which can effectively distinguish cyanide ions from other interfering substances, ensure that the concentration of cyanide ions can be accurately measured in complex matrices, and reduce the incidence of false positives and false negatives.

[0110] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A fluorescent probe, characterized in that The general structural formula of the fluorescent probe is: R 1 -X-R 2 , Where R 1 is a fluorescent group, wherein the fluorescent group is selected from: 1,8-naphthyridine, fluorescein, rhodamine and carboxyl fluorophore; X is a linking unit comprising at least one amino, hydroxyl or thiol group; R 2 is a cyanide ion reactive group, and the cyanide ion reactive group is selected from a nitrile group, a thiourea group or other functional groups suitable for reacting with cyanide ions.

2. A fluorescent probe according to claim 1, characterized in that: In the presence of cyanide ions, the probe emits an emission wavelength of 500 nm to 700 nm, and its fluorescence intensity is enhanced by at least 2 times compared with the state without cyanide ions.

3. A fluorescent probe according to claim 1, characterized in that: The probe maintains stability in a buffer solution with a pH value of 6 to 8 and has good selectivity for detecting cyanide ions.

4. A method for synthesizing a fluorescent probe for detecting cyanide ions, according to a fluorescent probe according to any one of claims 1 to 3, characterized in that: The following steps are involved: A. R 1 The derivative of is reacted with a compound having a reactive group to form a linking unit X; B. Reaction of the intermediate product with the cyanide ion reaction group R 2 Performing a cross-linking reaction to form a final product of a fluorescent probe; C. Purify the synthesized fluorescent probe.

5. The method for synthesizing a fluorescent probe for detecting cyanide ions according to claim 4, characterized in that: The reaction temperature in step A is 20° C.-80° C., the reaction time is 1 h-48 h, and the reaction solvent is dimethylsulfamide, ethanol or acetonitrile.

6. The method for synthesizing a fluorescent probe for detecting cyanide ions according to claim 4, characterized in that: The purification method in step C includes recrystallization, liquid chromatography or thin layer chromatography.

7. Use of a fluorescent probe for detecting cyanide ions, according to a fluorescent probe according to any one of claims 1 to 3, characterized in that: The fluorescence intensity of the fluorescent probe is significantly enhanced in the presence of cyanide ions, and has a detection capability with a sensitivity reaching the nanomolar level.

8. The use of a fluorescent probe for detecting cyanide ions according to claim 7, characterized in that: The fluorescent probe is used for detecting cyanide ions in water samples, soil samples or biological samples.

9. A method for detecting a fluorescent probe for detecting cyanide ions, according to a fluorescent probe according to any one of claims 1 to 3, characterized in that: The detection method comprises the following steps: Step 1, mixing the sample to be detected with the fluorescent probe; Step 2: irradiate the mixed solution with an appropriate excitation light source; Step 3: Measure the fluorescence intensity by a fluorescence detection instrument, and determine the concentration of cyanide ions in the sample based on the change in fluorescence intensity.

10. The method for detecting a fluorescent probe for detecting cyanide ions according to claim 9, characterized in that: The fluorescence detection instrument is a fluorescence spectrometer or a fluorescence microscope.

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