Fluorescent probe containing triphenylamine group as well as preparation method and application of fluorescent probe

Abstract

The invention relates to the technical field of fluorescent probes, in particular to a fluorescent probe containing a triphenylamine group as well as a preparation method and application of the fluorescent probe. The fluorescent probe containing the triphenylamine group is obtained by combining the triphenylamine derivative and the hydrazide rhodamine derivative, when the fluorescent probe containing the triphenylamine group is used for occult blood detection, the excellent color development performance is achieved, and the good color development performance is achieved for samples placed for a long time; therefore, powerful help is provided for criminal investigation and case solving, and theoretical possibility is provided for solving an old case.

Description

Technical Field

[0001] The invention relates to the technical field of fluorescent probes, and in particular to a fluorescent probe containing a triphenylamine group and a preparation method and application thereof. Background Art

[0002] Bloodstains are the most common and important physical evidence at the scene of serious violent crimes. Bloodstains are usually left at the scene of intentional or passionate killings. However, forensic science films and TV shows and case reports are everywhere in the media, which makes criminal suspects have a strong anti-reconnaissance awareness and ability. Usually, bloodstains visible to the naked eye will be destroyed by suspects in various forms in most cases. In the process of technical investigation of homicides, searching for bloodstains invisible to the naked eye on the suspect's clothes, searching for trace amounts of latent blood on the murder weapon after washing, and searching and confirming the bloodstains that have been cleaned at the first scene are key operations for solving cases and improving the chain of evidence.

[0003] Traditional technical means / reagents for searching for potential bloodstains can be roughly divided into the following three categories: 1) chromogenic reagents, 2) chemiluminescent reagents, and 3) cationic protein fluorescent dyes. The three types of reagents cannot be used in combination, have poor complementarity, and poor operability, which makes it difficult for technical police officers to make choices in investigation practice. The detection rate and efficiency of occult blood are both subject to serious technical limitations. This factor has greatly delayed the progress of solving cases and even led to the formation of a backlog of homicide cases.

[0004] Aggregation-induced emission (AIE) materials are materials that are designed with special molecules for different targets, and utilize the characteristic effect that they do not emit light in dilute solutions but emit enhanced light in the aggregated state around the target. Currently, the structures with AIE properties that are widely studied in related fields include tetraphenylethylene (TPE) and triphenylamine (TPA). TPA has a propeller structure that can rotate freely and is the most typical AIE molecule. It has the advantages of simple structure, simple synthesis, easy modification and obvious AIE effect.

[0005] Patent technology document CN201510891442.4 discloses a pyridine vinyl triphenylamine-rhodamine fluorescent molecule PTRh and its preparation method and application. The fluorescent molecule of the invention can be used as an aggregation-induced fluorescent material and as a high-performance fluorescent dye for cell staining, fluorescence imaging, and biomolecule labeling; as a sensitive ratiometric Hg 2+ Metal ion fluorescent probes and pH-responsive fluorescent probes are used as intramolecular fluorescence resonance energy transfer fluorescent compounds, but there is still a lack of research on the application of triphenylamine and rhodamine fluorescent probes in occult blood detection. Summary of the invention

[0006] In view of this, the purpose of the present invention is to propose a fluorescent probe containing a triphenylamine group and a preparation method and application thereof, so as to provide a fluorescent probe for occult blood detection, so that the occult blood detection rate is further improved.

[0007] Based on the above purpose, the present invention provides a fluorescent probe containing a triphenylamine group, wherein the fluorescent probe containing a triphenylamine group is obtained by reacting a hydrazide rhodamine derivative with 4,4'-diformyl triphenylamine through a Schiff base; the molar ratio of the hydrazide rhodamine derivative to 4,4'-diformyl triphenylamine is 2:1;

[0008] The structure of the hydrazide rhodamine derivative is as follows:

[0009]

[0010] Furthermore, the specific preparation steps of the hydrazide rhodamine derivative are as follows:

[0011] S1: In a nitrogen atmosphere, 3-(diphenylamino)phenol, phthalic anhydride, anhydrous aluminum chloride and ethylene dichloride are mixed at 0°C, then stirred at 0°C for 1 hour, then reacted at room temperature for 2 hours, and finally reacted at 45-55°C for 10-12 hours, cooled to room temperature, extracted, washed, dried, and purified to obtain a pre-product;

[0012] S2: Mix the pre-product, 3-(diphenylamino)phenol and trifluoroacetic acid, and reflux at 90-95° C. for 12 h to obtain a rhodamine derivative;

[0013] S3: The rhodamine derivative is dissolved in ethanol, and then 80% hydrazine hydrate solution is added dropwise, and the mixture is heated under reflux for 3-4 hours. The solvent is then dried and purified to obtain the hydrazide rhodamine derivative.

[0014] Furthermore, in step S1, the weight ratio of 3-(diphenylamino)phenol, phthalic anhydride, anhydrous aluminum chloride and vinyl chloride is 0.23-0.27:0.2-0.25:0.18-0.2:8-10.

[0015] Furthermore, in step S2, the weight ratio of the pre-product, 3-(diphenylamino)phenol and trifluoroacetic acid is 0.4-0.42:0.25-0.27:40-50.

[0016] Furthermore, in step S3, the usage ratio of the rhodamine derivative, 80% hydrazine hydrate solution and ethanol is 3.1-3.2 g: 5-8 ml: 20-30.

[0017] Furthermore, the present invention also provides a method for preparing a fluorescent probe containing a triphenylamine group, and the specific preparation steps are as follows:

[0018] Dissolve 4,4'-diformyltriphenylamine and acylhydrazine rhodamine derivative in anhydrous ethanol, react at room temperature for 11-12 hours, cool, add it into saturated saline for precipitation, filter, dry and purify to obtain a fluorescent probe containing a triphenylamine group.

[0019] Furthermore, the present invention also provides an application of a fluorescent probe containing a triphenylamine group for occult blood detection, and the specific operation is as follows:

[0020] A solution containing fluorescent dye probes is sprayed onto the surface of the sample to be tested, and then under the irradiation of excitation light, the fluorescent dye probes emit emission light to achieve fluorescent imaging of occult blood.

[0021] Preferably, the solution is an ethanol / water mixed solution, and the concentration of the fluorescent probe is 1×10 -4 mol / L.

[0022] Preferably, the volume ratio of ethanol / water is 7:3.

[0023] Beneficial effects of the present invention:

[0024] The present invention combines a triphenylamine derivative and a hydrazide rhodamine derivative, and the two can synergistically improve the sensitivity of the probe, thereby making the fluorescent probe have excellent fluorescence properties and can be suitable for occult blood detection.

[0025] The present invention controls the molar ratio of the hydrazide-modified rhodamine derivative to the triphenylamine derivative, so that the structure of the fluorescent probe is relatively stable, the interaction between the fluorophores is less, and the fluorescence performance is better. Together, the fluorescent probe has an excellent color development effect when used for occult blood detection, providing powerful assistance for criminal investigation and solving cases. DETAILED DESCRIPTION

[0026] Example 1: (1) In a nitrogen atmosphere at 0°C, 0.23 g of 3-(diphenylamino)phenol, 0.2 g of phthalic anhydride, 0.18 g of anhydrous aluminum chloride and 8 g of ethylene dichloride were mixed, then stirred at 0°C for 1 h, then reacted at room temperature for 2 h, and finally reacted at 45°C for 10 h, cooled to room temperature, extracted, washed, dried, and purified to obtain a pre-product;

[0027] (2) 0.4 g of the pre-product, 0.25 g of 3-(diphenylamino)phenol and 40 g of trifluoroacetic acid were mixed, refluxed at 90° C. for 12 h, and purified to obtain a rhodamine derivative;

[0028] (3) 3.1 g of a rhodamine derivative was dissolved in 20 g of ethanol, and then 5 ml of an 80% hydrazine hydrate solution was added dropwise, and the mixture was heated under reflux for 3 h. The solvent was then dried and purified to obtain a hydrazide rhodamine derivative;

[0029] (4) dissolving 0.3 g of 4,4'-diformyl triphenylamine and 1.3 g of hydrazide rhodamine derivative in 30-40 g of anhydrous ethanol, reacting at room temperature for 11 h, cooling, adding it to saturated saline for precipitation, filtering, drying, and purifying to obtain a fluorescent probe containing a triphenylamine group;

[0030] (5) Ethanol and water were mixed in a volume ratio of 7:3, and then the fluorescent probe containing triphenylamine groups was added to obtain a concentration of 1×10 -4 mol / L solution containing fluorescent dye probe.

[0031] Example 2: (1) In a nitrogen atmosphere at 0°C, 0.25 g of 3-(diphenylamino)phenol, 0.23 g of phthalic anhydride, 0.19 g of anhydrous aluminum chloride and 9 g of ethylene dichloride were mixed, then stirred at 0°C for 1 h, then reacted at room temperature for 2 h, and finally reacted at 50°C for 11 h, cooled to room temperature, extracted, washed, dried, and purified to obtain a pre-product;

[0032] (2) 0.41 g of the pre-product, 0.26 g of 3-(diphenylamino)phenol and 45 g of trifluoroacetic acid were mixed, refluxed at 93° C. for 12 h, and purified to obtain a rhodamine derivative;

[0033] (3) 3.2 g of the rhodamine derivative was dissolved in 25 g of ethanol, and then 7 ml of 80% hydrazine hydrate solution was added dropwise, and the mixture was heated under reflux for 4 h. The solvent was dried and purified to obtain the hydrazide rhodamine derivative;

[0034] (4) dissolving 0.33 g of 4,4'-diformyl triphenylamine and 1.4 g of hydrazide rhodamine derivative in 35 g of anhydrous ethanol, reacting at room temperature for 12 h, cooling, adding it to saturated saline for precipitation, filtering, drying, and purifying to obtain a fluorescent probe containing a triphenylamine group;

[0035] (5) Ethanol and water were mixed in a volume ratio of 7:3, and then the fluorescent probe containing triphenylamine groups was added to obtain a concentration of 1×10 -4 mol / L solution containing fluorescent dye probe.

[0036] Example 3: (1) Under a nitrogen atmosphere at 0°C, 0.27 g of 3-(diphenylamino)phenol, 0.25 g of phthalic anhydride, 0.2 g of anhydrous aluminum chloride and 10 g of ethylene dichloride were mixed, then stirred at 0°C for 1 h, then reacted at room temperature for 2 h, and finally reacted at 55°C for 12 h, cooled to room temperature, extracted, washed, dried, and purified to obtain a pre-product;

[0037] (2) 0.42 g of the pre-product, 0.27 g of 3-(diphenylamino)phenol and 50 g of trifluoroacetic acid were mixed, refluxed at 95° C. for 12 h, and purified to obtain a rhodamine derivative;

[0038] (3) 3.2 g of the rhodamine derivative was dissolved in 30 g of ethanol, and then 8 ml of 80% hydrazine hydrate solution was added dropwise, and the mixture was heated under reflux for 4 h. The solvent was dried and purified to obtain the hydrazide rhodamine derivative;

[0039] (4) dissolving 0.35 g of 4,4'-diformyl triphenylamine and 1.5 g of hydrazide rhodamine derivative in 40 g of anhydrous ethanol, reacting at room temperature for 12 h, cooling, adding it to saturated saline for precipitation, filtering, drying, and purifying to obtain a fluorescent probe containing a triphenylamine group;

[0040] (5) Ethanol and water were mixed in a volume ratio of 7:3, and then the fluorescent probe containing triphenylamine groups was added to obtain a concentration of 1×10 -4 mol / L solution containing fluorescent dye probe.

[0041] Comparative Example 1:

[0042] The difference from the example is that 1.4 g of the hydrazide rhodamine derivative is replaced by 1 g of rhodamine hydrazide.

[0043] Comparative Example 2:

[0044] The difference from Example 2 is that 4,4'-diformyl triphenylamine is replaced by an equimolar amount of diphenylamino-4-benzaldehyde.

[0045] Comparative Example 3:

[0046] The difference from Example 2 is that 4,4'-diformyltriphenylamine is replaced by an equimolar amount of tris(4-formylphenyl)amine.

[0047] Performance Testing

[0048] Three volunteers were selected, and their fingers were stained with blood. Then they were pressed on a textile (cotton cloth) with moderate printing force and 30 seconds of printing time. Each volunteer printed 30 pieces. After drying, the samples obtained in the embodiment and the comparative example were sprayed on the surface of the textile, sprayed evenly, dried naturally, and placed at room temperature for 24 hours. Then, a 405nm low-power (5W) laser was used for irradiation, and photographs were taken and observed. The test results are shown in Table 1.

[0049] Then let the fingers of three volunteers be stained with blood, and then press them on the textile (cotton cloth) with moderate printing force and 30 seconds of printing time. Each volunteer prints 30 pieces. After being placed in a dry environment for 180 days, the samples obtained in the embodiment and the comparative example are sprayed on the surface of the textile, sprayed evenly, dried naturally, and placed at room temperature for 24 hours. Then, a 405nm low-power (5W) laser is used for irradiation, and photographs are taken and observed. The test results are shown in Table 1.

[0050] According to the fingerprint quality evaluation standards recommended by the UK Home Office, the fingerprint appearance effect is scored and quantified. Among them, a fingerprint score level of 1-4 points indicates that the fingerprint is successfully displayed, a fingerprint score level of 1-2 indicates that the fingerprint identification standard is not met; a fingerprint score level of 3-4 points indicates that the fingerprint identification standard is met.

[0051] Handprint visibility rate: refers to the proportion of samples in the experimental group whose handprints successfully show their outlines. The calculation formula is as follows:

[0052]

[0053] Handprint identification rate: refers to the proportion of samples in the experimental group that can be used for handprint identification. The calculation formula is as follows:

[0054]

[0055] Table 1 Performance test results

[0056]

[0057] From the data analysis, it can be seen from Examples 1-3 in Table 1 that the triphenylamine group-containing fluorescent probe of the present invention can achieve a 100% visibility rate of fingerprints on the cotton surface after 24 hours, and an identification rate of no less than 82%. Most importantly, after 180 days, its visibility and identification rates can also be maintained at a relatively excellent level, which provides a theoretical possibility for solving old cases.

[0058] It can be seen from Example 2 and Comparative Example 1 in Table 1 that, compared with traditional rhodamine hydrazide, the hydrazide rhodamine derivative of the present invention has better fluorescence performance. This is mainly because the hydrazide rhodamine derivative contains a triphenylamine structure, which can synergistically enhance the sensitivity of the probe with 4,4'-diformyl triphenylamine, so that the final fluorescent probe has excellent fluorescence performance and can still maintain a good fluorescence effect after a long time.

[0059] It can be seen from Example 2 and Comparative Examples 2 and 3 in Table 1 that, relative to the hydrazide-modified rhodamine derivative and 4,4'-diformyltriphenylamine at molar ratios of 1:1 and 3:1, the fluorescent probe obtained by Schiff base reaction at a molar ratio of 2:1 has better performance. This is probably because the fluorescent probe generated at this ratio has a more stable structure and less interaction between fluorophores, thereby resulting in better fluorescence performance. When the molar ratio is 3:1, the fluorescent probe generated may have more interactions between fluorescent groups, resulting in fluorescence quenching.

[0060] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

Claims

1. A fluorescent probe containing a triphenylamine group, characterized in that: The triphenylamine group-containing fluorescent probe is obtained by reacting a hydrazide rhodamine derivative with 4,4'-diformyl triphenylamine through a Schiff base; the molar ratio of the hydrazide rhodamine derivative to 4,4'-diformyl triphenylamine is 2:1; The structure of the hydrazide rhodamine derivative is as follows:

2. The fluorescent probe containing triphenylamine group according to claim 1, characterized in that: The specific preparation steps of the hydrazide rhodamine derivative are as follows: S1: In a nitrogen atmosphere, 3-(diphenylamino)phenol, phthalic anhydride, anhydrous aluminum chloride and ethylene dichloride are mixed at 0°C, then stirred at 0°C for 1 hour, then reacted at room temperature for 2 hours, and finally reacted at 45-55°C for 10-12 hours, cooled to room temperature, extracted, washed, dried, and purified to obtain a pre-product; S2: Mix the pre-product, 3-(diphenylamino)phenol and trifluoroacetic acid, and reflux at 90-95° C. for 12 h to obtain a rhodamine derivative; S3: The rhodamine derivative is dissolved in ethanol, and then 80% hydrazine hydrate solution is added dropwise, and the mixture is heated under reflux for 3-4 hours. The solvent is then dried and purified to obtain the hydrazide rhodamine derivative.

3. The fluorescent probe containing triphenylamine group according to claim 2, characterized in that: The weight ratio of 3-(diphenylamino)phenol, phthalic anhydride, anhydrous aluminum chloride and vinyl chloride in step S1 is 0.23-0.27:0.2-0.25:0.18-0.2:8-10.

4. The fluorescent probe containing triphenylamine group according to claim 2, characterized in that: The weight ratio of the pre-product, 3-(diphenylamino)phenol and trifluoroacetic acid in step S2 is 0.4-0.42:0.25-0.27:40-50.

5. The fluorescent probe containing triphenylamine group according to claim 2, characterized in that: In step S3, the usage ratio of the rhodamine derivative, 80% hydrazine hydrate solution and ethanol is 3.1-3.2 g: 5-8 ml: 20-30.

6. A method for preparing a fluorescent probe containing a triphenylamine group according to claim 1, characterized in that: The specific preparation steps are as follows: Dissolve 4,4'-diformyltriphenylamine and acylhydrazine rhodamine derivative in anhydrous ethanol, react at room temperature for 11-12 hours, cool, add it into saturated saline for precipitation, filter, dry and purify to obtain a fluorescent probe containing a triphenylamine group.

7. A use of the fluorescent probe containing triphenylamine group according to claim 1, characterized in that: Applied to occult blood detection, the specific operations are as follows: A solution containing fluorescent dye probes is sprayed onto the surface of the sample to be tested, and then under the irradiation of excitation light, the fluorescent dye probes emit emission light to achieve fluorescent imaging of occult blood.

8. The use of the fluorescent probe containing triphenylamine group according to claim 7, characterized in that: The solution is an ethanol / water mixed solution, and the concentration of the fluorescent probe is 1×10 -4 mol / L.

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