CN113501822A

CN113501822A - Purine-vanillin-based palladium and copper ion detection fluorescent probe and preparation method and application thereof

Info

Publication number: CN113501822A
Application number: CN202110599522.8A
Authority: CN
Inventors: 沈贤锋; 陆鸿飞; 鞠立鑫; 邵琦; 王震霄; 张可敬; 庹鹏
Original assignee: Jiangsu University of Science and Technology
Current assignee: Jiangsu University of Science and Technology
Priority date: 2021-05-31
Filing date: 2021-05-31
Publication date: 2021-10-15
Anticipated expiration: 2041-05-31
Also published as: CN113501822B

Abstract

The invention discloses a purine-vanillin-based palladium and copper ion detection fluorescent probe, and a preparation method and application thereof. The invention takes purine derivatives and vanillin as fluorescent groups and hydrazine hydrate as connecting groups, and the prepared fluorescent probe is used for Pd in solution²⁺And Cu²⁺Exhibit a high degree of selectivity and sensitivity; the preparation method of the fluorescent probe is simple in steps, raw materials are easy to obtain, the obtained product is solid powder, the storage is easy, the fluorescent probe has a wide application prospect, and the fluorescent probe can be produced and applied on a large scale.

Description

Purine-vanillin-based palladium and copper ion detection fluorescent probe and preparation method and application thereof

Technical Field

The invention belongs to the technical field of fluorescent probes, and particularly relates to a purine-vanillin-based fluorescent probe for detecting palladium and copper ions, and a preparation method and application thereof.

Background

Copper element is widely present in nature and is widely used in industry and emerging industry due to its good electrical conductivity and corrosion resistance. Copper is second to aluminum in China, and at the same time, copper is a third metal element in the human body and is also a necessary trace element for the human body, and the lack of copper in the human body can cause anemia and even cause abnormal growth of hair and arteries. However, once the human body takes too much copper, metabolic disturbance and even sensory nerve disorder are caused. Cu in drinking water according to the standards of the world health organization²⁺Should be less than 2ppm (31.5. mu.M). Although palladium is not an essential element for human body, it is widely used in industry, such as electronic products, medical devices, etc., due to its unique physical and chemical properties. Because of its wide application, palladium ions are easily taken into the body by humans. Several studies have shown that Pd²⁺Can combine with DNA, protein and other biological macromolecules to form a complex, and the complex can cause various cell processes of human to be blocked. The dietary palladium intake is 1.5-15mg per person per day, as recommended by the european medicines evaluation office. Therefore, there is an urgent need to develop a method for rapidly tracking or detecting Pd²⁺And Cu²⁺The technique of (1).

In recent years, various methods for detecting Pd have been reported²⁺And Cu²⁺Fluorescent probes of (2), but for the simultaneous detection of Pd²⁺And Cu²⁺Almost none of the purine fluorescent probes was used.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problems in the prior art, the invention provides a purine-vanillin-based fluorescent probe for detecting palladium ions and copper ions, which takes purine as a matrix and can detect the purine quickly and simultaneouslyMeasuring Pd²⁺And Cu²⁺The Schiff base type fluorescent probe has the advantages of specific identification of palladium ions and copper ions, short response time, high sensitivity and the like.

The invention also provides a preparation method and application of the purine-vanillin based palladium ion and copper ion detection fluorescent probe.

The technical scheme is as follows: in order to achieve the above object, the purine-vanillin based fluorescent probe for detecting palladium and copper ions has a structural formula shown in formula I below:

the preparation method of the purine-vanillin based palladium and copper ion detection fluorescent probe comprises the following steps:

firstly, carrying out substitution reaction on 4, 6-dichloro-5-aminopyrimidine and 1-naphthylamine to obtain an intermediate II; then taking the intermediate II and 2-naphthoic acid as raw materials, and carrying out cyclization reaction in an organic solvent to obtain an intermediate III; dissolving the intermediate III in an organic solvent to perform substitution reaction with hydrazine hydrate to obtain an intermediate IV; finally, carrying out condensation reaction on the intermediate IV and vanillin to obtain a purine-vanillin-based fluorescent probe I;

the reaction route is as follows:

adding the 4, 6-dichloro-5-aminopyrimidine and 1-naphthylamine into an organic solvent, adding concentrated hydrochloric acid after solid is dissolved, refluxing and stirring, removing the organic solvent through reduced pressure distillation after the reaction is completed, dissolving the organic solvent with NaOH, extracting with ethyl acetate, removing the ethyl acetate through reduced pressure distillation, and recrystallizing with methanol and water to obtain the intermediate of formula II.

Further, the organic solvent is methanol, ethanol, propanol or isopropanol.

Preferably, the organic solvent is methanol.

Dissolving the intermediate of the formula II, 2-naphthoic acid and dodecyl trimethyl ammonium chloride in xylene, slowly dropwise adding phosphorus oxychloride into the reaction solution, refluxing and stirring, completely cooling the reaction solution to room temperature after complete reaction, removing the organic solvent through reduced pressure distillation, and performing column chromatography separation and purification to obtain the intermediate of the formula III.

Preferably, the purification is carried out by silica gel column chromatography using CH₃OH/CH₂Cl₂(v/v, 1/250) and the solvent was removed by distillation under reduced pressure to give the intermediate of formula III.

After the intermediate of the formula III is dissolved in ethanol, adding hydrazine hydrate after the solid is dissolved, carrying out reflux stirring, after the reaction is completed, cooling the reactant to room temperature, carrying out suction filtration, and washing the solid with an organic solvent to obtain the intermediate of the formula IV.

And after the reaction is finished, cooling the reaction liquid to room temperature, precipitating a large amount of light yellow solids, filtering, collecting, and washing with cold ethanol to obtain the purine-vanillin-based palladium and copper ion detection fluorescent probe with the structure of the formula I.

Preferably, the organic solvent is ethanol, propanol or isopropanol.

Further, the intermediate of formula IV and vanillin were dissolved in ethanol and the mixture was stirred under reflux at 78 ℃ for 2 hours. And (3) cooling the reaction liquid to room temperature, precipitating a large amount of light yellow solid, filtering, collecting, and washing with cold ethanol to obtain the fluorescent probe compound I.

Preferably, the synthetic route of the probe of the present invention is as follows:

wherein the intermediate in the formula II is 6-chloro-N- (naphthalene-1-yl) pyrimidine-4, 5-diamine, the intermediate in the formula III is 6-chloro-9- (naphthalene-1-yl) -8- (naphthalene-2-yl) -9H-purine, the intermediate in the formula IV is 6-hydrazino-9- (naphthalene-1-yl) -8- (naphthalene-2-yl) -9H-purine, and the compound in the formula I, namely (E) -3-methoxy-4- ((2- (9- (naphthalene-1-yl) -8- (naphthalene-2-yl) -9H-purin-6-yl) hydrazino) methyl) phenol, is the fluorescent probe for detecting palladium and copper ions.

Further, the preparation process comprises:

(1) preparation of intermediate II

Adding 4, 6-dichloro-5-aminopyrimidine and 1-naphthylamine into an organic solvent, adding 12mol/L concentrated hydrochloric acid after dissolving, refluxing and stirring at 65 ℃, removing the organic solvent under reduced pressure after completely reacting, dissolving with 1M NaOH, extracting with ethyl acetate, distilling under reduced pressure to remove ethyl acetate, and recrystallizing with methanol and water to obtain an intermediate II.

(2) Preparation of intermediate III

Dissolving the intermediate II, 2-naphthoic acid and dodecyl trimethyl ammonium chloride in xylene, and slowly dropwise adding POCl into the reaction solution₃The mixture was stirred under reflux at 80 ℃ for 72 hours. After the reaction is finished, after the reaction liquid is cooled to room temperature, removing the organic solvent by reduced pressure distillation to obtain a black viscous crude product, and separating and purifying by column Chromatography (CH)₃OH/CH₂Cl₂(v/v, 1/250)) to yield a white solid, intermediate III.

(3) Preparation of intermediate IV

The intermediate iii was dissolved in ethanol, followed by addition of hydrazine hydrate to the flask. The mixture was stirred at 65 ℃ under reflux for 3 hours. After the reaction was complete (monitored by TLC), the reaction mixture was cooled to room temperature, a large amount of yellow solid material precipitated, filtered, washed with a large amount of cold ethanol, and dried to obtain a white solid material, i.e., intermediate IV.

(4) Preparation of purine-vanillin-based fluorescent probe I for detecting palladium and copper ions

Intermediate IV and vanillin were dissolved in ethanol and the mixture was stirred under reflux at 78 ℃ for 2 h. And (3) cooling the reaction liquid to room temperature, precipitating a large amount of light yellow solid, filtering, collecting, and washing with cold ethanol to obtain the fluorescent probe compound I.

The fluorescent probe disclosed by the invention is applied to detection of palladium and copper ions in a solution.

The Schiff base framework adopted by the invention is an effective ligand combined with metal ions, and meanwhile, a novel fluorescent probe is prepared on the basis of considering purine and vanillin. The purine derivatives used in the present invention have not only a large planar conjugated structure but also a structure containing a plurality of nitrogen atoms and can coordinate a metal. Vanillin is widely present in natural plants such as beet and vanilla bean, is a widely used edible perfume, and in addition, the vanillin of the present invention has an excellent fluorophore, which contains a strong donor site, such as phenoxy atom, providing a lone electron pair, as a coordinating atom to form a coordinate bond with a copper or palladium ion metal ion, and has an aldehyde group to undergo Schiff base reaction, and can be used as a raw material for synthesizing Schiff base. The invention synthesizes a novel purine-vanillin-based fluorescent probe molecule for detecting copper and palladium ions by taking purine derivatives and vanillin as fluorescent groups, and fills up the problem of simultaneous Pd detection²⁺And Cu²⁺The purine fluorescent probe has almost no technical blank, and the Pd is simultaneously detected in the invention²⁺And Cu²⁺Means that the probe can detect Pd²⁺And can detect Cu²⁺。

The probe prepared by the invention comprises the following components:

1. the metal ion type can be rapidly identified, and the fluorescent probe molecule can also rapidly and accurately identify and complex specific metal ions under the condition that multi-component metal ions exist. Thereby producing a particular change in the physical phenomenon indicative of whether the sample contains such metal ions.

2. Can accurately quantify the concentration of metal ions

The fluorescent probe molecules are complexed with specific metal ions, and completely accord with the Lambert beer law, namely the linear relation between the absorption intensity of light with a certain wavelength and the concentration of light-absorbing substances. According to data obtained by multiple tests, a Lambert beer law curve can be fitted, and the relation between the metal ion concentration and the specific absorption light intensity can be obtained, so that the accurate quantification effect is achieved.

Has the advantages that: compared with the prior art, the invention has the following advantages:

the purine ring and vanillin are used as fluorescent groups, hydrazine hydrate is used as a connecting group, and the purine-vanillin-based palladium and copper ion fluorescent probe is synthesized; the purine derivatives are selected as rigid planes, 9 central atoms are arranged on a heterocyclic ring, the electron delocalization is large, and four nitrogen atoms in the ring provide potential coordination sites for metal ions; vanillin is selected as a starting material for the synthesis of schiff bases, which have excellent fluorophores containing a strong donor site, such as a phenoxy atom. The fluorescent probe has specific recognition on palladium and copper ions, short response time, high sensitivity and capability of detecting trace Pd in solution²⁺And Cu²⁺High sensitivity and high selectivity are shown.

Drawings

FIG. 1 shows DMSO/H ratio of the fluorescent probe for detecting palladium and copper ions prepared in example 1₂O (v/v ═ 3:2) solution to the fluorescent probe itself and palladium ion (Pd) was added²⁺) And copper ion (Cu)²⁺) Comparing the ultraviolet absorption of the fluorescent probe with a spectrogram;

FIG. 2 shows DMSO/H ratio of the fluorescent probe for detecting palladium ions and copper ions prepared in example 1₂A selective fluorescence spectrum diagram for different metal ions in an O (v/v ═ 3:2) solution;

FIG. 3 shows DMSO/H ratio of the fluorescent probe for detecting palladium ions and copper ions prepared in example 1₂For different concentrations of palladium ion (Pd) in O (v/v ═ 3:2) solution²⁺) And copper ion (Cu)²⁺) A fluorescence spectral response map of (a); the left panel shows the probe in DMSO/H₂Pd in O solution²⁺(0-5equiv, 0-50 μ M, curve top to bottom) fluorescence spectra at titration time; the right panel shows the probe in DMSO/H₂Cu in O solution²⁺(0-5equiv, 0-50. mu.M, curve top to bottom) fluorescence spectra at drop-out times.

FIG. 4 shows the fluorescent probe for detecting palladium ion and copper ion prepared in example 1DMSO/H₂A fluorescence response diagram for selective interference detection of different metal ions in O (v/v ═ 3:2) solution;

FIG. 5 is a graph showing response times when palladium and copper ions are detected by the fluorescent probe for detecting palladium and copper ions prepared in example 1;

FIG. 6 shows DMSO/H ratio of the fluorescent probe for detecting palladium ions and copper ions prepared in example 1₂O (v/v ═ 3:2) and palladium ion (Pd)²⁺) And copper ion (Cu)²⁺) The Job's-plot of the complex ratio;

FIG. 7 shows the fluorescent probes for detecting palladium ion and copper ion prepared in example 1 and different concentrations of palladium ion (Pd)² ⁺) And copper ion (Cu)²⁺) The prepared probe test paper;

FIG. 8 is a MS spectrum of the fluorescent probe for detecting palladium and copper ions prepared in example 1;

FIG. 9 shows NMR of fluorescent probes for detecting Pd and Cu ions prepared in example 1¹H-NMR spectrum;

FIG. 10 shows NMR of fluorescent probes for detecting Palladium ions and copper ions prepared in example 1¹³C-NMR spectrum.

Detailed Description

The invention is further illustrated by the following figures and examples.

The experimental methods used in the present invention are all conventional methods unless otherwise specified. Materials, reagents and the like used in the experiments can be obtained from commercial sources unless otherwise specified. All reagents used in the examples below were either commercially available, analytically pure or chemically pure.

In the embodiment, the metal ion solutions are prepared by adding deionized water into chloride chemical reagents with purity of more than 99%, such as anhydrous palladium chloride, anhydrous cadmium chloride, anhydrous ferric chloride and the like.

Example 1

The purine-vanillin based palladium and copper ion detection fluorescent probe is prepared by the following method:

(1) preparation of intermediate II (6-chloro-N)⁴- (naphthalen-1-yl) pyrimidine-4, 5-diamines)

In a 50mL round bottom flask, 4, 6-dichloro-5-aminopyrimidine (2.50g, 15mmol) and 1-naphthylamine (4.29g, 30mmol) were added and dissolved in methanol (25mL), concentrated HCl (98%, 2.5mL, 30mmol) was added dropwise slowly and stirred at 65 ℃ under reflux for 5 days. After the reaction solution is cooled to room temperature, solid matters precipitated in the reaction solution are firstly filtered, and then the solvent is removed through reduced pressure distillation to obtain a dark purple crude product. To the crude product was added a 1M NaOH solution (25mL) to dissolve it, and extracted with ethyl acetate (3X 25mL), and after the organic phases were combined and dried, the crude product was obtained after distillation under reduced pressure. Finally, the obtained crude product is used as CH₃OH/H₂Recrystallization from O (v/v,1:5) gave a pale purple solid (2.87g, 70%) as intermediate II.

The structural formula of the obtained intermediate II is as follows:

(2) preparation of intermediate III (6-chloro-9- (naphthalen-1-yl) -8- (naphthalen-2-yl) -9H-purine)

Intermediate II (1.00g, 3.70mmol), 2-naphthoic acid (3.19g, 18.50mmol) and dodecyltrimethylammonium chloride (0.10g, 10% mmol) were dissolved in 25mL of xylene, and POCl was slowly added dropwise to the reaction solution₃(25mL) and stirred at 80 ℃ for 72 h. After the reaction is finished, the reaction liquid is cooled to room temperature, reduced pressure distillation is carried out to obtain a black viscous crude product, and the crude product is separated and purified by column Chromatography (CH)₃OH/ CH₂Cl₂(v/v, 1/250)) to yield a white solid (0.62g, 48%) as intermediate III.

The structural formula of the obtained intermediate III is as follows:

(3) preparation of intermediate IV (6-hydrazino-9- (naphthalen-1-yl) -8- (naphthalen-2-yl) -9H-purine)

Intermediate III (212mg, 0.8mmol) was dissolved in 20mL of ethanol, followed by addition of hydrazine hydrate to the flask (0.25 mg, 4 mmol). The mixture was stirred at 65 ℃ under reflux for 3 hours. After completion of the reaction (monitored by TLC), the reaction mixture was cooled to room temperature, a large amount of yellow solid precipitated, and the solid was filtered, washed with a large amount of cold ethanol, and dried to give a white solid (192mg, 83%) which was intermediate IV.

The structural formula of the obtained intermediate IV is as follows:

Intermediate IV (200mg,0.56mmol) and vanillin (128mg,0.84mmol) were dissolved in 25mL ethanol and the mixture was stirred at 78 ℃ under reflux for 2 hours. After the reaction solution was cooled to room temperature, a large amount of pale yellow solid precipitated, which was collected by filtration, washed with cold ethanol, and dried to obtain probe compound (PHM) as a white solid (217mg, 80%).

The structural formula of the obtained fluorescent probe compound is as follows:

the fluorescent probe for detecting palladium ions and copper ions prepared by the invention¹H-NMR(400MHz,DMSO-d₆) δ12.01–11.68(m,1H),8.46–8.17(m,3H),7.93(ddd,J＝31.9,8.5,5.6Hz,5H), 7.70–7.60(m,1H),7.53–7.44(m,5H),7.42(d,J＝3.9Hz,2H),7.30(t,J＝7.7Hz, 1H),7.08(d,J＝8.1Hz,1H),6.80(d,J＝8.1Hz,1H).

¹³C-NMR(100MHz,DMSO-d₆)δ153.07,150.23,149.13,148.37,133.81, 133.20,131.70,131.42,130.28,130.15,129.87,129.09,128.52,128.42,127.76, 127.63,127.35,127.19,126.97,126.62,126.18,125.64,124.82,122.78,121.84, 118.55,115.63,109.07,79.50,56.34,55.21,18.85.

ESI-MS:calcd for[M+H]⁺536.6,found 537.0.

Mass spectrum MS spectrum and nuclear magnetic resonance spectrum of fluorescent probe prepared in example 1¹H-NMR spectrum, nuclear magnetic resonance¹³The C-NMR spectra are shown in FIG. 8, FIG. 9 and FIG. 10, respectively, and illustrate the successful synthesis of the fluorescent probe of the present invention.

Example 2

The fluorescent probe for detecting palladium and copper ions prepared in example 1 was prepared as a 1mM stock solution using dimethyl sulfoxide, each metal ion was prepared as a 3mM stock solution using deionized water, and 3mL of a blank solution of DMSO/H was added₂Adding 30 mu L of probe stock solution and 50 mu L of metal ion stock solution into O (v/v is 9: 1), and detecting by using a fluorescence spectrometer and an ultraviolet spectrophotometer, wherein the test shows that the maximum excitation wavelength of the fluorescence probe is 352nm and the maximum emission wavelength is 425nm, and the specific test results are as follows:

to a 3mL stock blank (DMSO/H)₂O solution (9/1, v/v, pH 7.4, HEPES buffer, 0.2mM)) was added to 30. mu.L of the probe stock, followed by 50. mu.L of Cu²⁺Or Pd²⁺And standing the stock solution for half an hour, and then testing the ultraviolet spectrum. As shown in FIG. 1, the probe had a strong absorbance at 352nm, and Cu was continuously added to the probe solution²⁺Or Pd²⁺Then, the probe-Cu is generated due to blue shift of the wavelength corresponding to the peak (from 352nm to 287nm/302nm)²⁺And probe-Pd²⁺A complex compound. Thus, the probe is detecting Pd²⁺And Cu²⁺As a macroscopic colorimetric probe, as shown in FIG. 1, the probe has a distinct absorption peak at 350 nm.

As shown in FIG. 2, the fluorescence spectra of the fluorescent probe added with various metal ions. To a 3mL blank solution DMSO/H₂And (2) respectively adding 30 mu L of probe stock solution and 50 mu L of various metal ion stock solutions into O (v/v ═ 9: 1), and experimental results show that the probe has stronger fluorescence, and the fluorescence intensity is not obviously changed after other metal ion stock solutions are added. However, PdCl was added to the probe solutions separately₂,CuCl₂·2H₂After O, the fluorescence intensity decreases abruptly, and a phenomenon of fluorescence quenching occurs, and the same holds true forThe solution went from colorless to pale yellow. The above results show that the fluorescent probe of the present invention is directed to Cu²⁺And Pd²⁺Has good selectivity.

In addition, as shown in FIG. 2, the probe solution is added with other metal ions, such as Zn²⁺，Sn²⁺，Fe³⁺， Fe²⁺，Na⁺，Mn²⁺，Al³⁺，Ca²⁺，Ba²⁺，K⁺，Cd²⁺，Mg²⁺，Ag⁺，Cs²⁺，Pb²⁺，Cr³⁺Very strong fluorescence is emitted at 452 nm. And Pd is added²⁺When the fluorescence of the probe solution is completely quenched. Adding Cu²⁺When the fluorescence of the probe solution is quenched. The results clearly show that the probe has a Pd pairing structure²⁺And Cu²⁺And can be used for Pd by quenching fluorescence intensity²⁺And Cu²⁺A distinction is made.

FIG. 3 is a graph showing the fluorescence spectrum response of the fluorescent probe of the present invention to different concentrations of palladium and copper ions. To a 3mL blank stock DMSO/H₂To O (v/v ═ 9: 1) was added 30 μ L of the probe stock solution and 0 to 50 μ L (0, 1, 2, 3 … … 40, 45, 50 μ L) of each of the palladium ion or copper ion stock solutions. When Pd²⁺When the concentration is gradually increased, the fluorescence intensity of the probe at 480nm is slowly reduced, and the final fluorescence intensity is stabilized at 3.0X 10⁴. In the presence of Cu²⁺While the fluorescence intensity gradually decreased, Cu was added²⁺At a concentration of more than 2 equivalents (20. mu.M), the fluorescence intensity suddenly decreases, indicating that all free probe molecules in solution are bound to Cu²⁺Complexation occurs.

To ensure that the probe is detecting Pd²⁺And Cu²⁺Without external interference, two groups of competitive experiments are designed. I.e. in 3mL each of the blank stock DMSO/H₂O (v/v ═ 9: 1) was added with 30. mu.L of the probe stock solution and 50. mu.L of any other metal ion stock solution including CdCl₂,FeCl₃,SnCl₂·2H₂O, CaCl₂,FeCl₂·4H₂O,CuCl₂·2H₂O,MgCl₂·6H₂O,CoCl₂·6H₂O,ZnCl₂,,PdCl₂,NaCl, MnCl₂,AgNO₃,Cs₂CO₃And Pb (NO)₃)₂. Subsequently 50. mu.L of a palladium ion or copper ion stock solution, respectively, were added to the sample. As a result, as shown in FIG. 4, Pd was removed by adding Pd to the probe solution²⁺Or Cu²⁺And (3) performing fluorescence tests (red bar chart and higher bar chart) on other metal ions after standing to find that the samples have stronger fluorescence and the fluorescence intensity of the samples is almost the same as that of the probes. Immediately after the addition of Pd to the sample²⁺Or Cu²⁺The stock solution was again allowed to stand and fluorescence measurements (black bar, lower bar) were performed, and the fluorescence of the above samples was found to be quenched due to the formation of a stable complex without fluorescence. The experiment shows that the probe has stronger anti-interference capability and can be used for detecting Pd in complex environment²⁺And Cu²⁺。

In 3mL of a blank solution DMSO/H₂To O (v/v ═ 9: 1) was added 30 μ L of the probe stock solution and 50 μ L of each of the palladium ion or copper ion stock solutions, and the fluorescence intensity of the sample was measured every 1 minute. As shown in FIG. 5, the probes themselves emitted high fluorescence intensity, and Cu was added to the probe solutions respectively²⁺、 Pd²⁺The fluorescence intensity immediately dropped to its minimum value within the last 1-2 minutes and remained stable for the next ten minutes. The above results all show that the probe is directed to Cu²⁺、Pd²⁺The detection is rapid and stable, so the probe has good application prospect.

As shown in FIG. 6, the fluorescent probe and Pd were investigated by the Job's plot method²⁺And Cu²⁺Binding rate of (2) to 3mL of blank solution DMSO/H₂O (v/v. 9: 1) to a volume of probe stock (1mM) and Pd separately²⁺Or Cu²⁺Stock solutions (both 3mM) were used, the sum of the concentrations of the fluorescence probe for detecting palladium and copper ions and palladium or copper ions was 50. mu.M, and the concentration ratios of the fluorescence probe and the metal ion species were varied (the ratio of the amounts of the fluorescence probe and the metal ion species was 1: 9, 2: 8, 3: 7, 4: 6, 5: 5, 6: 4, 7: 3,8: 2, 9: 1) to obtain the difference value of the fluorescence intensity at 352nm and the combined autofluorescence intensity of the metal ion fluorescent probe at the concentration, and drawing the ratio of the ions to the total concentration. From FIG. 6, when probe + Pd²⁺The maximum peak value is reached at a value of 0.61; when probe + Cu²⁺The maximum peak is reached at a value of 0.5. This indicates that the probe was bound to Pd²⁺And Cu²⁺Are 2:1 and 1:1, respectively. From this, the probe and Pd can be obtained²⁺/Cu²⁺The combination of (1).

Pd was detected as a solid as in FIG. 7²⁺And Cu²⁺The use of (1). The filter paper was immersed in DMSO-H containing a probe (10mM)₂O (v/v ═ 9: 1) stock solutions were soaked for half an hour, dried and then placed in solutions of palladium or copper ions at different concentrations (0, 0.1, 0.3, 0.5 and 1.0mM) for 30 minutes, respectively, after drying, their fluorescence colour was recorded under a 365nm uv lamp. As shown in FIG. 7, the color of the filter paper changed from strong blue fluorescence to dull grayish black, that is, whether Pd was present or not was visually recognized²⁺And Cu²⁺While indicating that the probe of the present invention can detect palladium ions and copper ions in a solid state.

Claims

1. A purine-vanillin based palladium and copper ion detection fluorescent probe has a structural formula shown as the following formula I:

2. the method for preparing purine-vanillin based palladium and copper ion detection fluorescent probe according to claim 1, wherein the method preferably comprises the following steps:

the reaction route is as follows:

3. the preparation method of claim 2, wherein the 4, 6-dichloro-5-aminopyrimidine and 1-naphthylamine are added into an organic solvent, concentrated hydrochloric acid is added after the solid is dissolved, the mixture is refluxed and stirred, after the reaction is completed, the organic solvent is removed by reduced pressure distillation, the mixture is dissolved by NaOH, then the ethyl acetate is extracted by ethyl acetate, the ethyl acetate is removed by reduced pressure distillation, and the mixture is recrystallized by methanol and water to obtain the intermediate of formula II.

4. The method according to claim 3, wherein the organic solvent is methanol, ethanol, propanol or isopropanol.

5. The preparation method of claim 2, wherein the intermediate of formula II, 2-naphthoic acid and dodecyl trimethyl ammonium chloride are dissolved in xylene, then phosphorus oxychloride is slowly added dropwise into the reaction solution, reflux stirring is carried out, after the reaction is completed, the reaction solution is completely cooled to room temperature, the organic solvent is removed by reduced pressure distillation, and the intermediate of formula III is obtained by column chromatography separation and purification.

6. The preparation method of claim 2, wherein the intermediate of formula iii is dissolved in ethanol, and after the solid is dissolved, hydrazine hydrate is added, reflux stirring is performed, after the reaction is completed, the reaction product is cooled to room temperature, and then suction filtration and solid cleaning are performed to obtain the intermediate of formula IV.

7. The preparation method according to claim 2, wherein the intermediate of formula IV and vanillin are dissolved in an organic solvent, the mixture is refluxed and stirred, after the reaction is completed, the reaction solution is cooled to room temperature, a large amount of light yellow solid is precipitated, and the reaction solution is filtered, collected and washed with cold ethanol to obtain the purine-vanillin based palladium and copper ion detection fluorescent probe with the structure of formula I.

8. The method according to claim 7, wherein the organic solvent is ethanol, propanol or isopropanol.

9. Use of the fluorescent probe of claim 1 for detecting palladium and copper ions in a solution.