Fluorescent probe for detecting bivalent palladium as well as preparation method and application of fluorescent probe

Abstract

The invention relates to the technical field of fluorescence detection and molecular probes, in particular to a fluorescent probe for detecting bivalent palladium as well as a preparation method and application of the fluorescent probe. The fluorescent probe for detecting bivalent palladium is a compound with a structure shown in a formula (I). The fluorescent probe provided by the invention takes benzopyran as a fluorescent parent nucleus and propynyl as a recognition site, and is novel in structure. When the fluorescent probe is used for divalent palladium detection, the fluorescent probe has the characteristics of single selective recognition, high sensitivity and low detection limit (0.18 mu M) on divalent palladium, and the fluorescence intensity of the fluorescent probe and the concentration of divalent palladium are in a good linear relationship within the range of 0-40 mu M. Meanwhile, an application experiment verifies that when the fluorescent probe is used for detecting the divalent palladium in the traditional Chinese medicinal materials, the adding standard recovery rate ranges from 90.8% to 106.4%. Therefore, the fluorescent probe disclosed by the invention has a wide application prospect in the fields of bivalent palladium detection reagents and rapid detection of heavy metals in traditional Chinese medicinal materials.

Description

Technical Field

[0001] This invention relates to the field of fluorescence detection and molecular probe technology, specifically to a fluorescent probe for detecting divalent palladium, its preparation method, and its application. Background Technology

[0002] Palladium, a platinum group metal, possesses unique catalytic properties and is currently widely used in organic synthesis, pharmaceutical synthesis, and aerospace. For example, in catalytic converters used to treat automobile exhaust, palladium content can reach over 96%. However, palladium is also a common environmental pollutant. It is gradually released into water bodies during production and application processes, spreading through soil, atmosphere, and water, and accumulating through the food chain, ultimately causing adverse effects on the ecological environment. Furthermore, palladium can bind to biomolecules such as DNA, proteins, amino acids, and vitamins in the human body, increasing health risks, including potential respiratory problems, allergic reactions, and the accumulation of toxic palladium compounds in the body. Therefore, effective monitoring of palladium content is crucial for the timely detection and control of palladium pollution.

[0003] Currently, the commonly used methods for detecting palladium metal are atomic adsorption spectrometry (AAS) and inductively coupled plasma mass spectrometry (ICP-MS), both of which have the advantage of high sensitivity. However, these methods typically require sophisticated instruments and involve rather cumbersome sample preparation procedures, and require experienced instrument operators, making them unsuitable for large-scale sample testing or on-site applications. In contrast, fluorescence methods offer advantages such as convenience, ease of operation, speed, efficiency, high detection sensitivity, and visualization.

[0004] Furthermore, divalent palladium remains the primary form found in traditional Chinese medicine (TCM). Currently, there is a lack of feasible methods for detecting divalent palladium in TCM using fluorescent probe technology. Therefore, the technical problem this invention aims to solve is to provide a novel fluorescent probe for detecting divalent palladium and to apply this probe to the detection of divalent palladium in TCM, thereby achieving rapid and convenient detection of divalent palladium in TCM. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the present invention aims to provide a fluorescent probe for detecting divalent palladium, which uses benzopyran as the fluorescent core and propyne group as the recognition site, enabling rapid, sensitive and specific detection of divalent palladium.

[0006] Furthermore, the present invention aims to provide a method for preparing the above-mentioned fluorescent probe for detecting divalent palladium.

[0007] Furthermore, the present invention aims to provide the application of the above-mentioned fluorescent probe for detecting divalent palladium, which can provide a powerful tool for the rapid and convenient detection of divalent palladium in traditional Chinese medicine.

[0008] To achieve the above objectives, the first aspect of the present invention adopts the following technical solution:

[0009] A fluorescent probe for detecting divalent palladium is a compound with the structure shown in formula (I):

[0010] .

[0011] The second aspect of this invention is the following technical solution:

[0012] A method for preparing a fluorescent probe for detecting divalent palladium as described above includes the following steps:

[0013] (1) The compound shown in formula (II) was subjected to a substitution reaction with 3-bromopropyne in solvent A to obtain the intermediate compound shown in formula (III);

[0014] (2) The intermediate compound shown in formula (III) is condensed with 2-hydroxy-5-(methylthio)benzaldehyde in solvent B to obtain the fluorescent probe for detecting divalent palladium.

[0015] The structure of the compound represented by formula (II) is as follows: The structure of the intermediate compound shown in formula (III) is as follows: .

[0016] In a preferred embodiment, in step (1), the molar ratio of the compound represented by formula (II) to 3-bromopropyne is 1:(1~2), more preferably 1:1.5. The substitution reaction is carried out at a temperature of 15~30°C for 10~20 h. The compound represented by formula (II) is named 6-hydroxy-1-tetrahydronaphthone.

[0017] In a preferred embodiment, in step (2), the molar ratio of the intermediate compound shown in formula (III) to 2-hydroxy-5-(methylthio)benzaldehyde is 1:(0.8~1.2), more preferably 1:1. The condensation reaction is carried out at a temperature of 85~95°C for 1~3 hours.

[0018] In a preferred embodiment, in step (1), solvent A is N,N-dimethylformamide; in step (2), solvent B is glacial acetic acid and perchloric acid.

[0019] The third aspect of this invention is the following technical solution:

[0020] An application of the fluorescent probe for detecting divalent palladium as described above, wherein the application is the use of the fluorescent probe in the detection of divalent palladium in traditional Chinese medicine.

[0021] As a preferred embodiment, when using the fluorescent probe to detect divalent palladium in traditional Chinese medicine, the detection steps are as follows: pre-treating the raw materials of traditional Chinese medicine to obtain a sample solution; mixing the sample solution with the fluorescent probe to obtain a mixture; incubating the mixture and then performing fluorescence spectroscopy detection; substituting the fluorescence intensity data obtained from the fluorescence spectroscopy detection into a pre-established standard curve to obtain the content of divalent palladium in the traditional Chinese medicine.

[0022] In a preferred embodiment, the medicinal materials are one or more of the following: peony bark, atractylodes macrocephala, lancea rhizome, and platycodon root; the pretreatment involves sequentially washing, drying, and pulverizing the medicinal materials, followed by acidification and digestion to obtain a medicinal sample solution.

[0023] In a preferred embodiment, the concentration of the fluorescent probe in the mixture is 15-25 μM, more preferably 20 μM. The incubation treatment is performed at a temperature of 30-40°C for 15-25 min, and at a pH of 4-8. More preferably, the incubation treatment is performed at a temperature of 35°C for 20 min, and at a pH of 7.4.

[0024] In a preferred embodiment, the fluorescence spectroscopy detection uses a detection wavelength of 560-580 nm, more preferably 570 nm. The standard curve is a standard curve of divalent palladium concentration versus fluorescence intensity.

[0025] The technical solution of the present invention has the following advantages and beneficial effects:

[0026] The fluorescent probe for detecting divalent palladium provided by this invention uses benzopyran as the fluorescent core and propyne as the recognition site, exhibiting a novel structure and enabling rapid, sensitive, and specific detection of divalent palladium. The preparation method of the fluorescent probe for detecting divalent palladium provided by this invention involves a substitution reaction between 6-hydroxy-1-tetrahydronaphthone and 3-bromopropyne to obtain an intermediate compound, followed by a condensation reaction between the intermediate compound and 2-hydroxy-5-(methylthio)benzaldehyde, thereby preparing the fluorescent probe. The process of this invention is characterized by readily available raw materials, a simple route, and convenient operation.

[0027] Experiments have confirmed that the fluorescent probe of this invention exhibits unique selectivity, high sensitivity, and a low detection limit (0.18 μM) for the detection of divalent palladium. Furthermore, its fluorescence intensity shows a good linear relationship with the concentration of divalent palladium within the range of 0-40 μM. Application experiments have also verified that when the fluorescent probe of this invention is used to detect divalent palladium in traditional Chinese medicine, quantitative determination of divalent palladium is achieved by plotting a standard curve using fluorescence spectroscopy. The results show that the standard curve error for divalent palladium detection is small, and the spiked recovery rate is between 90.8% and 106.4%, confirming that the fluorescent probe of this invention can be used for the quantitative detection of divalent palladium in traditional Chinese medicine.

[0028] Therefore, the fluorescent probe of the present invention can detect divalent palladium in Chinese medicinal materials while detecting divalent palladium, and has the advantages of low cost, high sensitivity and good selectivity. It has broad application prospects in the fields of divalent palladium detection reagents and rapid detection of heavy metals in Chinese medicinal materials. Attached Figure Description

[0029] Figure 1 The 1H NMR spectrum of the intermediate compound (SO-O) prepared in Example 1 of this invention is shown.

[0030] Figure 2 The carbon NMR spectrum of the intermediate compound (SO-O) prepared in Example 1 of this invention is shown.

[0031] Figure 3 The hydrogen nuclear magnetic resonance spectrum of the fluorescent probe (SO-C) prepared in Example 1 of the present invention is shown;

[0032] Figure 4 The carbon NMR spectrum of the fluorescent probe (SO-C) prepared in Example 1 of this invention is shown.

[0033] Figure 5 The diagram shows the change in UV spectrum of the fluorescent probe prepared in Example 1 of the present invention as the concentration of divalent palladium increases when different volumes of divalent palladium mother liquor are added.

[0034] Figure 6 The graph shows the change in fluorescence spectrum of the fluorescent probe prepared in Example 1 of the present invention as the concentration of divalent palladium increases when different volumes of divalent palladium mother liquor are added.

[0035] Figure 7 The following diagram shows the fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of the present invention after the addition of different cations and anions;

[0036] Figure 8 The following diagram shows the fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of the present invention after adding divalent palladium in the presence of different cations and anions;

[0037] Figure 9The graph shows the fluorescence intensity changes of the fluorescent probe prepared in Example 1 of the present invention with different concentrations of divalent palladium as a function of reaction time.

[0038] Figure 10 The following diagram shows the fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of the present invention before and after the addition of divalent palladium under different pH conditions;

[0039] Figure 11 The diagram shows the linear relationship between fluorescence intensity and divalent palladium concentration when different concentrations of divalent palladium are added to the fluorescent probe prepared in Example 1 of the present invention. Detailed Implementation

[0040] To make the objectives and advantages of the technical solution of this invention clearer, the technical solution of this invention will be clearly and completely described below in conjunction with specific embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0041] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the raw materials used are commercially available materials unless otherwise specified. The solvents used in the embodiments of this invention are all commercially available chemically pure or analytically pure. The structure of the compounds was determined by nuclear magnetic resonance (NMR). The NMR determination was performed using a Bruker NMR spectrometer, and the solvents used were CDCl3 (deuterated chloroform) and DMSO-d6 (dimethyl sulfoxide-d6), with TMS (dimethylsilane) as the internal standard.

[0042] Example 1

[0043] This embodiment provides a fluorescent probe for detecting divalent palladium, named SO-C, with the molecular formula C. 21 H 17 O2S + The structural formula is:

[0044] .

[0045] The synthetic route of the fluorescent probe (SO-C) for detecting divalent palladium is shown below:

[0046] ;

[0047] The specific preparation steps of the fluorescent probe (SO-C) for detecting divalent palladium are as follows:

[0048] (1) At room temperature (15~30℃), 2.6 g of potassium carbonate and 0.8 mL of 3-bromopropyne were added sequentially to a 20 mL stirred solution of 6-hydroxy-1-tetrahydronaphthone. The mixture was stirred at room temperature for 12 h, then extracted with ethyl acetate. The organic phases were combined and washed with brine, dried over anhydrous sodium sulfate, and finally concentrated under reduced pressure. The resulting solid was dried in a drying oven to obtain the intermediate compound, denoted as SO-O. The 6-hydroxy-1-tetrahydronaphthone solution contained 1 g of 6-hydroxy-1-tetrahydronaphthone, and the solvent was N,N-dimethylformamide. The molar ratio of 6-hydroxy-1-tetrahydronaphthone to 3-bromopropyne was 1:1.5.

[0049] The intermediate compound (SO-O) was analyzed by nuclear magnetic resonance (NMR) analysis. The resulting proton NMR spectrum is shown below. Figure 1 As shown, the carbon NMR spectrum is as follows: Figure 2 As shown. Figure 1 and Figure 2 The nuclear magnetic resonance characterization results are as follows: 1 H NMR (600 MHz, CDCl3) δ 8.01 (d, J = 8.7 Hz, 1H), 6.89 (dd, J = 8.7, 2.6 Hz, 1H), 6.78 (d, J = 2.6 Hz, 1H), 4.74 (d, J = 2.5 Hz, 2H), 2.93 (t, J = 6.1 Hz, 2H), 2.61 (t, J = 6.5 Hz, 2H), 2.55 (t, J = 2.4 Hz, 1H), 2.13 - 2.10 (m, 2H); 13 HRMS calcd for C 13 H 13 O2 [M+H+]: 201.0910, found 201.0908.

[0050] (2) Take 0.5 g of intermediate compound (SO-O) and 0.42 g of 2-hydroxy-5-(methylthio)benzaldehyde, place them in 15 mL of glacial acetic acid, mix and stir for 2 min, then add 1 mL of perchloric acid and mix. Reflux the resulting mixture at 90 °C for 2 h. After the reaction, cool the resulting reactant to room temperature, add 8 mL of petroleum ether:ethyl acetate (1:1, v / v) mixed solvent, continue stirring for 30 min, and then collect the solid by vacuum filtration. Then wash the solid product with petroleum ether:ethyl acetate (1:1, v / v) and anhydrous ethanol respectively. The obtained solid product does not require purification and is the fluorescent probe for detecting divalent palladium in this example, denoted as SO-C. The molar ratio of intermediate compound (SO-O) to 2-hydroxy-5-(methylthio)benzaldehyde is 1:1.

[0051] The obtained fluorescent probe (SO-C) for detecting divalent palladium was analyzed by nuclear magnetic resonance (NMR) analysis. The resulting proton NMR spectrum is shown below. Figure 3 As shown, the carbon NMR spectrum is as follows: Figure 4 As shown. Figure 3 and Figure 4 The nuclear magnetic resonance characterization results are as follows: 1 H NMR (600 MHz, DMSO) δ 9.05 (s, 1H), 8.51 (d, J = 8.9 Hz, 1H), 8.27 (d, J= 9.0 Hz, 1H), 8.08 (dd, J = 9.0, 2.4 Hz, 1H), 8.00 (t, J = 2.0 Hz, 1H), 7.31(dd, J = 8.9, 2.5 Hz, 1H), 7.26 (d, J = 2.5 Hz, 1H), 5.10 (d, J = 2.5 Hz, 2H), 3.75 (t, J = 2.4 Hz, 1H), 3.28 (t, J = 7.0 Hz, 2H), 3.17 (d, J = 8.1 Hz,2H), 2.66 (s, 3H); 13 C NMR (151 MHz, DMSO) δ 171.16, 165.81, 152.68, 149.86,149.47, 141.97, 135.31, 131.95, 131.13, 125.03, 123.27, 119.65, 119.46,116.85, 115.66, 79.99, 78.50, 57.12, 26.82, 26.13, 15.08. HRMS calcd forC 21 H 17 O2S+ [M+]: 333.0944, found 333.0944.

[0052] The above analysis results show that the structure of the fluorescent probe has been confirmed by nuclear magnetic resonance analysis.

[0053] Experimental Example 1: UV / fluorescence spectral changes of divalent palladium by the fluorescent probe SO-C

[0054] The detection steps are as follows: (1) Using the fluorescent probe (SO-C) prepared in Example 1, a probe stock solution with a concentration of 1 mM was prepared using dimethyl sulfoxide (DMSO). Divalent palladium was dissolved in a mixed solvent of methanol and saturated saline (3:1, v / v) to prepare a divalent palladium stock solution with a concentration of 10 mM. A mixture of ethanol and phosphate buffer (pH=7.4, EtOH / PBS, v / v=4:6) was prepared as the spectral solution. To ensure detection efficiency, a temperature of 35℃ was selected as the condition for the detection of divalent palladium by probe SO-C. (2) Accurately transfer 3 mL of the spectral solution into a cuvette, and then take 60 μL of the probe stock solution into the cuvette (the probe concentration after mixing is 20 μM). Then add different volumes of divalent palladium stock solution, with the volumes of divalent palladium stock solution added being 0, 3, 6, 9, and 12 μL, respectively. After reacting at 35 °C for 20 min, use a UV-Vis spectrometer and a fluorescence spectrometer to test the spectra of the probe and the probe plus the divalent palladium solution.

[0055] in, Figure 5 The graph shows the change in UV spectrum of the fluorescent probe prepared in Example 1 of this invention as the concentration of divalent palladium increases when different volumes of divalent palladium mother liquor are added. Figure 5 In the illustration, the color change of sunlight before and after the reaction of the fluorescent probe with divalent palladium is shown; 0equiv, 1equiv, and 2equiv represent volume equivalents, which are the test results for volumes of 0, 6, and 12 μL of divalent palladium mother liquor, respectively. Figure 5 As shown, the fluorescent probe (SO-C) prepared in Example 1 has no UV absorption peak near 300 nm. After the addition of divalent palladium, the UV absorption is significantly enhanced, and the solution color changes from colorless to pink.

[0056] Figure 6 The graph shows the change in fluorescence spectrum of the fluorescent probe prepared in Example 1 of this invention as the concentration of divalent palladium increases when different volumes of divalent palladium mother liquor are added. Figure 6 In the figures, 0equiv, 0.5equiv, 1equiv, 1.5equiv, and 2equiv represent volume equivalents, which are the test results for volumes of divalent palladium of 0, 3, 6, 9, and 12 μL, respectively. Figure 6As shown, the SO-C probe itself emits almost no fluorescence under 500 nm excitation; however, after the addition of divalent palladium, a significant fluorescence emission peak appears at 570 nm. Simultaneously, the fluorescence intensity at this wavelength gradually increases with increasing divalent palladium concentration, reaching saturation when 12 μL of the divalent palladium stock solution (i.e., a divalent palladium concentration of 40 μM) is added.

[0057] Therefore, it can be seen from the above experimental results that the fluorescent probe of the present invention has a good recognition effect on divalent palladium.

[0058] Experiment Example 2: Selectivity and Anti-interference Test

[0059] The selective assay method is as follows: Accurately transfer 3 mL of the spectral solution into a cuvette, then add 60 μL of the probe stock solution to the cuvette, and then add the following different cations and anions at a concentration of 10 mM: Ca 2+ Fe 3+ Hg 2+ Co 2+ Ni 2+ Zn 2+ Pb 2+ Na + K + Ag + Mn 2+ Mg 2+ Al 3+ Cd 2+ Li + Fe 2+ Cr 3+ Ba 2+ 12 μL of each solution was reacted at 35 °C for 20 min, and the fluorescence intensity at 570 nm was measured using a fluorescence spectrometer. The preparation method and composition of the spectral solution and probe stock solution were the same as in Experiment 1.

[0060] The test method for the anti-interference experiment is as follows: Accurately transfer 3 mL of the spectral solution into a cuvette, then take 60 μL of the probe stock solution into the cuvette, and add the following different cations and anions at a concentration of 10 mM: Ca 2+ Fe 3+ Hg 2+ Co 2+ Ni 2+ Zn 2+ Pb 2+ Na + K + Ag + Mn 2+ Mg 2+ Al 3+ Cd 2+ Li + Fe2+ Cr 3+ Ba 2+ After adding 12 μL of each solution, another 12 μL of divalent palladium stock solution (Pd) was added. 2+ The reaction was carried out at 35℃ for 20 min, and the fluorescence intensity at 570 nm was measured using a fluorescence spectrometer. The preparation methods and compositions of the spectral solution, probe stock solution, and divalent palladium stock solution were the same as in Experiment 1.

[0061] Figure 7 The image shows the fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of this invention after the addition of different cations and anions. Figure 7 The selective experiments showed that the fluorescence intensity changed very little after adding other metal ions to the fluorescent probe of Example 1, but the fluorescence intensity increased significantly after adding divalent palladium, indicating that the fluorescent probe of the present invention has good single selectivity for recognizing divalent palladium. Furthermore, the present invention further verified that the fluorescent probe of Example 1 only responded to divalent palladium and did not respond to zero-valent palladium; therefore, the probe of the present invention can also distinguish between divalent palladium and zero-valent palladium.

[0062] Figure 8 The fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of this invention after adding divalent palladium in the presence of different cations and anions are shown. Figure 8 In the middle, the corresponding bars from left to right are 1, Blank; 2, Ca 2+ 3. Cu 2+ 4. Fe 3+ 5. Hg 2+ 6. Co 2+ 7. Ni 2+ 8. Zn 2+ 9. Pb 2+ 10. Na + 11. K + 12. Ag + 13. Mn 2+ 14. Mg 2+ ;15. Al 3+ 16. Cd 2+ 17. Li + 18. Fe 2+ ;19. Cr 3+ 20. Ba 2+ .like Figure 8 The anti-interference experiment results show that after adding other potential interfering ions to the fluorescent probe of Example 1, the change in the fluorescence signal of the probe recognizing divalent palladium is very small, indicating that the fluorescent probe of the present invention has good anti-interference ability to detect divalent palladium.

[0063] Experiment Example 3: Time Response Experiment

[0064] The time response experiment was conducted as follows: 3 mL of the spectral solution was accurately transferred to a cuvette, followed by 60 μL of the probe stock solution, and then 12 μL of divalent palladium stock solution. The mixture was incubated at 35 °C for 60 min. Fluorescence spectra were recorded every 1 min for the first 15 min, and then every 2 min thereafter. The preparation methods and compositions of the spectral solution, probe stock solution, and divalent palladium stock solution were the same as in Example 1.

[0065] Figure 9 The fluorescence intensity change of the fluorescent probe prepared in Example 1 of this invention with divalent palladium over reaction time. Figure 9 It can be seen that the fluorescent probe of Example 1 of the present invention responds completely to divalent palladium within 20 minutes.

[0066] Experimental Example 4: The Effect of Different pH Values ​​on Fluorescent Probes

[0067] The test procedure for the effect of different pH values ​​on the fluorescent probe was as follows: 3 mL of the spectral solution was accurately transferred to a cuvette, followed by 60 μL of the probe stock solution, and then 12 μL of divalent palladium stock solution. The resulting mixture was incubated at 35 °C under different pH conditions for 20 min, and the fluorescence spectra and fluorescence intensity at 570 nm were recorded. The preparation methods and compositions of the spectral solution, probe stock solution, and divalent palladium stock solution were the same as in Experiment Example 1.

[0068] Figure 10 This is a graph showing the fluorescence spectrum changes of the fluorescent probe prepared in Example 1 of the present invention before and after the addition of divalent palladium under different pH conditions. Figure 10 As shown, the fluorescent probe of this invention exhibits almost no fluorescence intensity at pH values ​​between 2 and 12. Upon addition of divalent palladium, the fluorescence intensity significantly increases within the pH range of 4 to 8, indicating that the probe can effectively detect divalent palladium within this pH range.

[0069] Experimental Example 5: Establishment of Curves for Divalent Palladium Concentration versus Fluorescence Intensity

[0070] The method for establishing the curve of divalent palladium concentration versus fluorescence intensity is as follows: accurately transfer 3 mL of the spectral solution into a cuvette, then add 60 μL of the probe stock solution to the cuvette (the probe concentration after mixing is 20 μM), and then add divalent palladium stock solution sequentially. The volumes of divalent palladium added are 0, 3, 6, 9, and 12 μL (the divalent palladium concentrations after addition are 0, 10, 20, 30, and 40 μM, respectively). After reacting at 35 °C for 20 min, the spectral changes and fluorescence intensity at 570 nm are recorded using a fluorescence spectrometer.

[0071] Figure 11 The graph shows the linear relationship between fluorescence intensity and palladium concentration when different concentrations of divalent palladium are added to the fluorescent probe prepared in Example 1 of this invention. Figure 11As shown, this invention performs linear fitting on the concentration of divalent palladium and fluorescence intensity. It can be seen that divalent palladium exhibits a good linear relationship with fluorescence intensity in the concentration range of 0-40 μM. The established standard curve equation is: y = 2.8426x + 3.0797, R0 2 =0.9786, indicating a good fit, thus the detection limit for divalent palladium was determined to be 0.18 μM.

[0072] Experiment Example 6: Application Experiment for the Detection of Divalent Palladium in Traditional Chinese Medicine Samples

[0073] This experiment investigated the recovery of divalent palladium from different traditional Chinese medicinal materials to evaluate the application effect of the fluorescent probe of this invention. The specific steps are as follows: 0.3g each of peony bark, atractylodes macrocephala, lancea atractylodes lancea, and platycodon grandiflorus were weighed, washed, dried, and pulverized (100 mesh). The powder was then placed in a digestion vessel, and 3mL of nitric acid was added, allowing it to stand overnight. Subsequently, 0.2mL of perchloric acid and 0.3mL of sulfuric acid were added sequentially, and the mixture was heated for acidification digestion. After the digestion solution became clear, the acid was further removed by heating until the remaining volume was less than 0.5mL. The pH of the solution was adjusted to 7.4, and the volume was brought to 25mL to obtain the sample solutions of each traditional Chinese medicine. The sample solutions of the traditional Chinese medicine were mixed with methanol at a volume ratio of 6:4 to construct a detection system. Then, the fluorescent probe SO-C of Example 1 of this invention (the concentration of the fluorescent probe after addition was 20μM) was added to the detection system, followed by the addition of Pd. 2+ The standard solutions were added to achieve concentrations of divalent palladium of 20 μM, 30 μM, and 40 μM, respectively. After reacting at 35 °C for 20 min, the spectral signal at 570 nm was recorded using a fluorescence spectrometer. The fluorescence intensity data was substituted into the standard curve equation y = 2.8426x + 3.0797 to calculate the concentration of divalent palladium. The spiked recovery rate of divalent palladium in the traditional Chinese medicine samples was obtained, as shown in Table 1.

[0074]

[0075] As can be seen from Table 1, when the fluorescent probe of the present invention is used for the detection of divalent palladium in traditional Chinese medicine, the recovery rate is between 90.8% and 106.4%, and the relative standard deviation is less than 3.75%. It can be seen that the fluorescent probe and its detection method of the present invention have good recovery rate and can be effectively applied to the detection of divalent palladium in traditional Chinese medicine.

[0076] In summary, the fluorescent probe provided by this invention exhibits unique selectivity, high sensitivity, and a low detection limit (0.18 μM) for the detection of divalent palladium. Furthermore, its fluorescence intensity shows a good linear relationship with the concentration of divalent palladium within the range of 0-40 μM. Application experiments have also verified that when the fluorescent probe of this invention is used to detect divalent palladium in traditional Chinese medicine, a standard curve is plotted using fluorescence spectroscopy for quantitative determination. The results show that the standard curve error for divalent palladium detection is small, and the recovery rate is between 90.8% and 106.4%. Therefore, this invention confirms that the fluorescent probe can accurately and sensitively achieve the quantitative detection of divalent palladium in traditional Chinese medicine.

[0077] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the protection scope of the present invention.

Claims

1. A fluorescent probe for detecting divalent palladium, characterized in that, Compounds with the structure shown in formula (I): 。 2. A method for preparing a fluorescent probe for detecting divalent palladium as described in claim 1, characterized in that, Includes the following steps: (1) The compound shown in formula (II) was subjected to a substitution reaction with 3-bromopropyne in solvent A to obtain the intermediate compound shown in formula (III); (2) The intermediate compound shown in formula (III) is condensed with 2-hydroxy-5-(methylthio)benzaldehyde in solvent B to obtain the fluorescent probe for detecting divalent palladium. The structure of the compound represented by formula (II) is as follows: The structure of the intermediate compound shown in formula (III) is as follows: .

3. The method for preparing a fluorescent probe for detecting divalent palladium according to claim 2, characterized in that, In step (1), the molar ratio of the compound shown in formula (II) to 3-bromopropyne is 1:(1~2); the temperature of the substitution reaction is 15~30℃ and the time is 10~20h.

4. The method for preparing a fluorescent probe for detecting divalent palladium according to claim 2, characterized in that, In step (2), the molar ratio of the intermediate compound shown in formula (III) to 2-hydroxy-5-(methylthio)benzaldehyde is 1:(0.8~1.2); the temperature of the condensation reaction is 85~95℃ and the time is 1~3h.

5. The method for preparing a fluorescent probe for detecting divalent palladium according to any one of claims 2 to 4, characterized in that, In step (1), solvent A is N,N-dimethylformamide; in step (2), solvent B is glacial acetic acid and perchloric acid.

6. An application of the fluorescent probe for detecting divalent palladium as described in claim 1, characterized in that, The application described is the use of fluorescent probes in the detection of divalent palladium in traditional Chinese medicine.

7. The application of the fluorescent probe for detecting divalent palladium according to claim 6, characterized in that, When using the fluorescent probe to detect divalent palladium in traditional Chinese medicine, the detection steps are as follows: pre-treat the raw materials of traditional Chinese medicine to obtain a sample solution; mix the sample solution with the fluorescent probe to obtain a mixture; incubate the mixture and then perform fluorescence spectroscopy detection. The content of divalent palladium in the Chinese medicinal material is obtained by substituting the fluorescence intensity data obtained from fluorescence spectroscopy into a pre-established standard curve.

8. The application of the fluorescent probe for detecting divalent palladium according to claim 7, characterized in that, The Chinese medicinal materials are one or more of the following: peony bark, atractylodes macrocephala, lancea rhizome, and platycodon root; the pretreatment involves washing, drying, and pulverizing the Chinese medicinal materials in sequence, followed by acidification and digestion to obtain a Chinese medicinal sample solution.

9. The application of the fluorescent probe for detecting divalent palladium according to claim 7, characterized in that, The concentration of the fluorescent probe in the mixture is 15-25 μM; the incubation treatment is carried out at a temperature of 30-40°C for 15-25 min, and at a pH of 4-8.

10. The application of the fluorescent probe for detecting divalent palladium according to claim 7, characterized in that, The fluorescence spectroscopy detection uses a detection wavelength of 560~580nm; the standard curve is a standard curve of divalent palladium concentration versus fluorescence intensity.

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