CN112979519B

CN112979519B - Method for detecting copper ions in solution by using anthracene-thiosemicarbazide derivative

Info

Publication number: CN112979519B
Application number: CN202110247473.1A
Authority: CN
Inventors: 王筱梅; 叶常青
Original assignee: Suzhou University of Science and Technology
Current assignee: Suzhou University of Science and Technology
Priority date: 2019-06-05
Filing date: 2019-06-05
Publication date: 2022-05-17
Anticipated expiration: 2039-06-05
Also published as: CN110283110A; CN110283110B; CN112979519A

Abstract

The invention discloses a method for detecting copper ions in a solution by using an anthracene-thiosemicarbazide derivative, which comprises the steps of adding the anthracene-thiosemicarbazide derivative into the solution, irradiating the solution by using exciting light, and if fluorescence quenching response of emitted light is detected, enabling the solution to contain copper ions; the anthracene-thiosemicarbazide derivative has efficient up-and-down conversion fluorescence quenching response identification characteristic on copper ions as a fluorescent probe.

Description

Method for detecting copper ions in solution by using anthracene-thiosemicarbazide derivative

The invention relates to an anthracene-thiosemicarbazide derivative, a preparation method thereof and a divisional application of the anthracene-thiosemicarbazide derivative as a fluorescent probe, wherein the divisional application is invented by 6 and 5 days in 2019 and has an application number of 2019104880658, and belongs to the part of application methods.

Technical Field

The invention belongs to the field of fluorescent reagents and the technical field of heavy metal ion fluorescent probes, and particularly relates to an anthracene-thiosemicarbazide derivative probe, a preparation method thereof, and application of the probe in detection of copper ions in water environment or organisms.

Background

Copper ion (Cu)²⁺) Pollution has many hazards, it not only affects the growth of animals and plants, microorganisms and the activity of soil enzymes, but also disrupts the balance of the ecosystem. It also can be enriched in animals and plants, increase copper toxicity, and has adverse effect on human health. Detecting Cu²⁺Has important practical significance. At present, there are many methods for determining copper ions, mainly including: spectrophotometry, fluorescence analysis, electrochemistry, atomic absorption spectrometry, and the like. Wherein, the fluorescence analysis method has the advantages of high sensitivity (such as single molecule detection), selectivity, low cost, high cost performance, simple operation, wide application range and the like, so the fluorescence method is used for identifying Cu²⁺Have received a wide range of attention.

So far, it has been designed and synthesized for Cu²⁺There are hundreds of fluorescent probes for detection, all of which adopt down-conversion fluorescent detection method, and the mechanism is the excitation of short wavelength light sourceBy the generation of electrons from zero vibration level (S) of the ground state₀) Transition to a first excited state (S)₁) And then falls back to the ground state and releases long wavelength fluorescence, as can be seen, the spectral characteristics of down-converted fluorescence are "short wavelength (long) excitation, long wavelength (long) emission". The prior art has no report about an ion probe capable of realizing up-conversion fluorescence quenching response.

Disclosure of Invention

The invention provides an anthracene-thiosemicarbazide derivative and a preparation method thereof; the obtained probe molecule not only can detect copper ions through down-conversion fluorescence quenching response, but also has up-conversion fluorescence quenching response, can detect copper ions through up-conversion fluorescence quenching response, and has practical application value in water environment and in living organisms. The up-conversion fluorescence detection adopts 'long wavelength excitation and short wavelength emission', and because the long wavelength light is used as an excitation light source, the penetration depth of an excitation light source in a medium can be deepened, the background fluorescence of an organism can be effectively eliminated, and the signal to noise ratio is improved; meanwhile, long-wavelength light is used as an excitation light source, and the required excitation energy is low, so that the damage to the cells of the living body is small, and compared with the conventional down-conversion, the up-conversion fluorescence quenching response has a favorable value for biological imaging and in-vivo cell environment detection of the living body.

In order to achieve the purpose of the invention, the technical scheme adopted by the invention is as follows:

an anthracene-thiosemicarbazide derivative having the following molecular structure:

。

the invention discloses a preparation method of the anthracene-thiosemicarbazide derivative used as the upconversion of a copper ion fluorescent probe, which comprises the following steps of reacting 4-bromo-2-hydroxybenzaldehyde with 9, 10-diborate anthracene in a nitrogen atmosphere and a solvent to obtain an intermediate product I; and then reacting the intermediate product I with thiosemicarbazide to obtain the up-conversion anthracene-thiosemicarbazide derivative of the copper ion fluorescent probe.

The invention also discloses a method for detecting copper ions in the solution, which comprises the following steps:

(1) reacting 4-bromo-2-hydroxybenzaldehyde and 9, 10-diborate anthracene in a nitrogen atmosphere and a solvent to obtain an intermediate product I; then reacting the intermediate product I with thiosemicarbazide to obtain an anthracene-thiosemicarbazide derivative serving as a copper ion fluorescent probe;

(2) the probe molecules are added to the solution, the solution is irradiated with excitation light, and if a fluorescence quenching response of the emitted light is detected, the solution contains copper ions.

The invention discloses application of the anthracene-thiosemicarbazide derivative in detecting copper ions in a solution.

In the invention, the solvent is one or more of 1, 4-dioxane, ethanol, toluene and water; the solvent system is beneficial to the dissolution of raw materials, the reaction and the improvement of yield. The reaction temperature of the 4-bromo-2-hydroxybenzaldehyde and 9, 10-diborate anthracene reaction is 50-120 ℃, preferably 120 ℃, and the reaction time is 48 hours; the reaction temperature of the intermediate product I and thiosemicarbazide is 50-140 ℃, preferably 130 ℃, and the reaction time is 24 hours. The molar ratio of 4-bromo-2-hydroxybenzaldehyde to 9, 10-diboronic acid ester anthracene is 3: 1; the molar ratio of the intermediate product I to the thiosemicarbazide is 1: 3.

In the invention, when copper ions in a solution are detected, the wavelength of exciting light is 532 nm; or the wavelength of the excitation light is 532 nm. When copper ions are not contained, the wavelength of emitted light of the probe molecules is 400-525 nm under the condition that the wavelength of exciting light is 532 nm; or the wavelength of the emitted light is 430-480 nm under the condition that the wavelength of the exciting light is 532 nm. After containing copper ions, emitting light to generate quenching response at the wavelength of 400-525 nm under the wavelength of excitation light of 532 nm; or under the condition that the wavelength of the exciting light is 532nm, the emitted light generates quenching response at the wavelength of 430-480 nm.

In the invention, when mercury ions in the solution are detected, the solution is a neutral solution, and the pH value is 7. The emitted fluorescence quenching response of the present invention is a conventional term, generally referred to as F₀Has a/F of more than 15, F₀F is the fluorescence intensity integral area of the pure probe molecule and the fluorescence intensity integral area after the metal ions are added。

According to the invention, 9, 10-diboronic ester anthracene is used as a raw material in a nitrogen atmosphere and a solvent, and is sequentially subjected to heating reaction with 4-bromo-2-hydroxybenzaldehyde and thiosemicarbazide to finally obtain an anthracene-thiosemicarbazide derivative serving as a copper ion fluorescent probe molecule. Preferably, the reaction of the 9, 10-diboronic ester anthracene with the 4-bromo-2-hydroxybenzaldehyde is carried out in the presence of potassium carbonate and tetrakis (triphenylphosphine) palladium; the reaction of intermediate I with thiosemicarbazide is carried out in the presence of acetic acid.

In the technical scheme, after the reaction of the intermediate product I and the thiosemicarbazide is finished, the solvent is removed through rotary evaporation, and the anthracene-thiosemicarbazide derivative is obtained through column chromatography and vacuum drying and is light yellow powder.

The invention discloses a specific synthesis method of anthracene-thiosemicarbazide derivative 9, 10-bis (3-hydroxy-4-methyleneamine thiosemicarbazide phenyl) anthracene, which comprises the steps of mixing 4-bromo-2-hydroxybenzaldehyde and 9, 10-diborate anthracene in a molar ratio of 3:1 in a nitrogen atmosphere by using 1, 4-dioxane and ethanol as solvents in the presence of potassium carbonate and tetrakis (triphenylphosphine) palladium, and stirring for reaction to obtain an intermediate product I; and then, under the atmosphere of nitrogen, taking acetic acid as a catalyst, mixing and stirring the intermediate product I and the thiosemicarbazide in a solvent according to the molar ratio of 1:3 for reaction, and finally obtaining the light yellow target copper ion probe molecule anthracene-thiosemicarbazide derivative. The reaction equation can be expressed as follows:

the invention at least has the following technical effects and advantages:

the preparation and purification method of the copper ion probe anthracene-thiosemicarbazide derivative is simple and high in yield; cu can be detected in neutral medium (DMF/buffer solution, 2/1, v/v) with high selectivity²⁺The detection limit reaches 2.78 multiplied by 10^-7 mol·L^-1(ii) a Particularly, the anthracene-thiosemicarbazide derivative can be used for detecting copper ions by adopting a triplet annihilation (TTA-UC) fluorescence detection method, and the detection limit reaches 2.50 multiplied by 10^-6 mol·L^-1. TTA-UC with long wavelength excitation short waveThe long emission characteristic can effectively deduct background fluorescence of the organism and has lower required excitation energy if the detection is carried out in the organism, so that the method has the advantages of small damage to cells of the organism, strong detection resolution and small detection lethality to the living body, and has potential application value in biological imaging and cell environment detection. The TTA-UC detection instrument is a small semiconductor laser and a fiber spectrometer, and a conventional large fluorescence spectrum instrument is not needed, so that the TTA-UC detection instrument is more economical and portable. Therefore, the up-conversion detection technology has more practical application value.

Drawings

FIG. 1 shows nuclear magnetic hydrogen spectrum of intermediate compound I (solvent is CD)₃Cl）；

FIG. 2 is a mass spectrum of an intermediate compound I;

FIG. 3 shows nuclear magnetic hydrogen spectra of probe molecules (deuterated DMSO as solvent);

FIG. 4 is a mass spectrum of a probe molecule;

FIG. 5 shows an absorption spectrum (a) and a fluorescence spectrum (b) (concentration: 10. mu. mol. L) of a probe molecule^-1，DMF:H₂O=2:1，v/v)；

FIG. 6 shows a probe (10. mu. mol. L) according to an example of the present invention^-1) Solution of (4) (DMF: H)₂O =2: 1) fluorescence intensity at different ph values;

FIG. 7 shows a probe (10. mu. mol. L) according to an example of the present invention^-1) Down-converted fluorescence quenching spectra (a) and corresponding histograms of fluorescence response changes (b, ordinate F) for the probes after addition of 11 metal cations₀/F is addition of Cu²⁺Ratio of integrated areas of fluorescence intensities of front and rear probes) (wherein the cation concentration is 100. mu. mol. L)^-1 Probe concentration 10. mu. mol. L^-1DMF buffer =2:1, pH 7);

FIG. 8 is a bar graph of the upconversion fluorescence quenching spectra (a) and the corresponding upconversion responses of the probes after addition of 11 metal cations (b, ordinate F)₀/F is addition of Cu²⁺Ratio of integrated areas of fluorescence intensities of front and rear probes) (wherein the cation concentration is 100. mu. mol. L)^-1 Probe concentration 100. mu. mol. L^-1DMF: buffer solution =2:1,pH 7);

FIG. 9 shows the addition of copper ions (0-100. mu. mol. L) of different concentrations^-1) Down-converted fluorescence spectrum of the probe (a) and corresponding working curve (b, ordinate F)₀/F is addition of Cu²⁺Ratio of integrated areas of fluorescence intensities of front and rear probes) (wherein the concentration of the probe was 10. mu. mol. L)^-1DMF buffer =2:1, pH 7, excitation wavelength 378 nm);

FIG. 10 shows the addition of copper ions (0-10. mu. mol. L) at different concentrations^-1) The up-conversion fluorescence spectrum (a) of the probe corresponds to the working curve (b, ordinate F)₀/F is addition of Cu²⁺Ratio of integrated areas of fluorescence intensities of front and rear probes) (wherein the concentration of the probe was 10. mu. mol. L)^-1DMF buffer =2:1, pH 7, excitation wavelength 532 nm);

FIG. 11 shows a probe (10. mu. mol. L) according to an example of the present invention^-1) To copper ion (10. mu. mol. L) in a solution of (DMF: buffer =2:1, pH 7)^-1) The response time.

Detailed Description

Organic up-conversion luminescence (UC) is typically achieved by a two-photon absorption mechanism (TPA-UC) or a triplet annihilation (TTA-UC) mechanism; TTA up-conversion (TTA-UC) is used in the present invention. Triplet annihilation (TTA-UC) mechanism is that two acceptor molecules in triplet excited state collide with each other (TTA) to generate one acceptor in singlet excited state and one acceptor returning to ground state, and finally, the acceptor in singlet excited state emits high-energy light when returning to ground state. The excitation light source intensity required by TTA up-conversion is small, and the required up-conversion detection equipment is low in price and portable; meanwhile, the concentration of the needed probe is small, and the probe can be detected in the air, so that the method has stronger practicability.

Example one

In a 250ml three-necked flask were placed 4-bromo-2-hydroxybenzaldehyde (2.84 g, 11.19 mmol), 9, 10-diboronic acid anthracene (2 g, 4.73 mmol) in 100ml1, 4-dioxane and 24ml ethanol and K was added₂CO₃(3.92 g, 28.38 mmol) was dissolved in 48mL of distilled water and mixed into the above solution. Then mixing inThe combined solution was purged with nitrogen for 15 minutes, followed by addition of tetrakis (triphenylphosphine) palladium (0) (0.39 g, 1.2 mmol), and further purged with nitrogen for 5 minutes, and the reaction was carried out at 120 ℃ under nitrogen atmosphere, with the progress of the reaction being followed by a dot plate, with a developing agent of dichloromethane: petroleum ether =1:1, and the reaction proceeded for 48 hours, and the dots of the raw material, 9, 10-diboronated anthracene were almost disappeared, and the reaction was stopped. After the reaction is finished, distilling the reaction solution under reduced pressure to obtain a black solid mixture, extracting and separating an organic phase for multiple times by selecting dichloromethane and saturated saline solution, and adding anhydrous Na₂SO₄After removal of water, the product was isolated using column chromatography using dichloromethane to petroleum ether =1:1, and then purified twice by recrystallization to obtain 1.2g of intermediate yellow product I with a yield of 60%.

¹H NMR (400 MHz, Chloroform-d) δ 11.29 (d, J = 2.9 Hz, 2H), 10.11 (s, 2H), 7.83 (dd, J = 8.0, 2.7 Hz, 2H), 7.72-7.66 (m, 4H), 7.41 (dd, J = 6.9, 3.3 Hz, 4H), 7.23-7.13 (m, 4H) (see fig. 1). MS, calculated: [ M ] A⁺]= 418.12, test value: [ M ] A⁺+H]= 418.12 (see fig. 2).

The intermediate product (1 g, 2.39 mmol) and thiosemicarbazide (3 g, 7.17 mmol) were weighed and dissolved in 40ml of toluene, dissolved by ultrasonic oscillation, nitrogen gas was bubbled into the mixed solution for 15 minutes, then 5ml of acetic acid was added as a catalyst, the reaction was carried out at 130 ℃ under nitrogen atmosphere, the reaction process was followed by a point plate, the reaction was carried out for 24 hours, the point of the intermediate product almost disappeared, and the reaction was stopped. After the reaction is finished, carrying out reduced pressure distillation on the reaction solution to obtain a solid mixture, separating a product by using a column chromatography method, wherein a developing agent is dichloromethane 1: petroleum ether 1, and carrying out secondary purification by recrystallization to obtain a light yellow final product, namely the anthracene-thiosemicarbazide derivative 0.8g, wherein the yield is 59%, and the product is called probe molecules.¹H NMR (400 MHz, DMSO-d6) δ 11.47 (s, 2H), 10.19 (s, 1H), 8.55 (s, 2H), 8.27-7.95 (m, 6H), 7.73-7.63 (m, 4H), 7.46 (d, J = 8.3 Hz, 3H), 7.02-6.82 (m, 3H) (see fig. 3). MS, calculated: [ M ] A⁺]= 564.11, test value: [ M ] A⁺+H]= 565.11 (see fig. 4).

Example two

The probe molecule of example one was added to DMF and a stock solution of the probe molecule in DMF was prepared at a concentration of 1 mM.

1.97 mL of DMF solution and 1 mL of aqueous buffer solution (Na as buffer solution) were added to a quartz cuvette₂HPO₄/NaH₂PO₄pH 7, 1/2, v/v), and 30 μ L of probe molecule DMF stock (concentration: 1 mM) was added to the above quartz cuvette and dissolved by sonication to prepare a 10. mu.M probe molecule solution.

Similarly, 1.7 mL of DMF solution and 1 mL of aqueous buffer (Na) solution were added to the quartz cuvette₂HPO₄/NaH₂PO₄pH 7, 1/2, v/v), and 300. mu.L of the probe molecule DMF stock solution (concentration: 1 mM) was added to the above quartz cuvette and dissolved by sonication to prepare a 100. mu.M probe molecule solution.

Test apparatus and conditions

Down-conversion test: the test is carried out by an Edinburgh fluorescence spectrometer, and the excitation wavelength is 378 nm.

And performing up-conversion test, namely selecting a 532nm semiconductor laser as an excitation light source, and using an optical fiber spectrometer as signal receiving and processing equipment.

Absorption spectrum and fluorescence spectrum of probe molecule solution

FIG. 5 shows an absorption spectrum (a) and a fluorescence spectrum (b) (concentration: 10. mu. mol. L) of a probe molecule^-1，DMF/H₂O: 2/1, v/v); the absorption spectrum and fluorescence spectrum of the probe were measured in a neutral medium. As can be seen, the absorption peak of the probe is 378nm (FIG. 5 a); the probe solution is excited by light with the wavelength of 378nm, the fluorescence spectrum of the probe solution is very weak, and the peak position is 400-525 nm (shown in figure 5 b).

Influence on fluorescence spectrum of copper ion

In a solution (10. mu. mol. L) of probe molecules in DMF^-1) Respectively adding quantitative water solution (acid or alkali) with the pH value of 1-14 into 11 cuvettes to test a system (DMF/H) before and after adding₂O, 2/1, v/v) (excitation wavelength 378 nm). When the pH value is 1-3, the fluorescence intensity is obviously reduced; when the pH value is between 3 and 7, fluorescence is generatedThe light intensity is increasing; when the pH value is 7-9, the fluorescence intensity is basically unchanged; there was almost no fluorescence at pH =12,13,11 (see fig. 6), indicating that it was relatively stable at this pH range. HEPES at pH 7.0 was selected as the buffer solution herein, thereby confirming that detection of the probe molecules of the present invention can be performed in a neutral solution.

Probe pair Cu²⁺Up-conversion and down-conversion response of

Down-conversion of the fluorescence response: in 11 containers of probe molecules (10. mu. mol. L)^-1) To the cell of the solution (DMF/buffer solution: 2/1, pH 7), 11 kinds of metal cation aqueous solutions (concentration: 100. mu. mol. L) were added, respectively^-1) They are: cu²⁺、Mn²⁺、NH₄ ⁺、Zn²⁺、Mg²⁺、Cd²⁺、Pb²⁺、Li⁺、Na⁺、K⁺And Ca²⁺. The down-converted fluorescence spectrum (excitation wavelength of 378 nm) was then measured, as shown in FIG. 7 (a, b). As can be seen, Cu²⁺The addition of (2) significantly quenches the fluorescence intensity of the copper ion probe, while the addition of other cations shows that the copper ion probe is directed to Cu without any substantial change²⁺Has obvious selective fluorescence response.

Up-conversion fluorescence response: in 11 containers of probe molecules (100. mu. mol. L)^-1) To the cell of the solution (DMF/buffer solution: 2/1, pH = 7), 11 kinds of metal cation aqueous solutions (concentration: 100. mu. mol. L) were added, respectively^-1) They are: cu² ⁺、Mn²⁺、NH₄ ⁺、Zn²⁺、Mg²⁺、Cd²⁺、Pb²⁺、Li⁺、Na⁺、K⁺And Ca²⁺. Then, the up-converted fluorescence spectrum (excitation wavelength: 532 nm) was measured as shown in FIG. 8 (a, b). As can be seen, Cu²⁺The addition of (2) significantly quenches the fluorescence intensity of the probe, and there is substantially no change in fluorescence intensity after the addition of other cations. Shows the target probe pair Cu²⁺Has up to 97.1 percent of up-conversion fluorescence quenching response.

Probe molecule pair Cu²⁺Response of concentration

Down-conversion of the fluorescence response: in the probe molecule (10. mu. mol. L)^-1) Cu was added to the solution (DMF/buffer: 2/1, pH 7) at various concentrations²⁺The change of the down-conversion fluorescence spectrum (excitation wavelength 378 nm) of the probe molecule was observed and shown in FIG. 9 a. As can be seen, Cu was not added²⁺The fluorescence of the probe molecule was very strong, when 6. mu. LCu was added²⁺Aqueous solution (10 mmol. L)^-1) In the above probe solution (Cu)²⁺The concentration is reduced to 20 mu mol.L^-1) When the fluorescence intensity of the probe molecule is decreased, the fluorescence intensity of the probe molecule is decreased sharply (see FIG. 9 a).

Adding 1.2-30 mu L Cu respectively according to a similar method²⁺Mother liquor (1 mmol. L)^-1) And 6 to 30 mu L of Cu²⁺Mother liquor (10 mmol. L)^-1) In the above-mentioned probe molecule solution (Cu)²⁺The concentration is 0.4 to 100 mu mol.L^-1Wherein Cu of curve i in FIG. 7a²⁺The concentration is 0.4. mu. mol. L^-1Curve ii Cu²⁺The concentration is 0.8 mu mol.L^-1Curve iii to xiii of Cu²⁺The concentration is 2-100 mu mol.L^-1) The fluorescence intensity of the probe molecules continuously decreases (see FIG. 9 a). As can be seen from FIG. 9b, in Cu²⁺Concentration of 0 to 10. mu. mol. L^-1In the range of fluorescence intensity and Cu²⁺The concentration shows a good linear relation, the correlation coefficient R²= 0.98. The detection of Cu by fluorescence spectroscopy can be calculated according to the formula' detection limit =3 delta/k²⁺Has a detection limit of 2.78 × 10^-7 mol·L^-1。

Up-conversion fluorescence response: in the probe molecule (100. mu. mol. L)^-1) Cu was added to the solution (DMF/buffer 2/1, pH 7) at various concentrations²⁺The change of the converted fluorescence spectrum (excitation wavelength 532 nm) on the probe molecule was observed and shown in FIG. 10 a. As can be seen, Cu was not added²⁺The fluorescence of the probe was very strong and when 30. mu. LCu was added²⁺Aqueous solution (10 mmol. L)^-1) In the above probe solution (Cu)²⁺The concentration is 100 mu mol.L^-1) At this time, the fluorescence intensity of the probe sharply decreases (see FIG. 10 a).

Adding 3 mu L-30 mu LCu according to a similar method²⁺Mother liquor (10 mmol. L)^-1) In the above probe solution, (Cu)² ⁺The concentration is 25 to 100 mu mol.L^-1Wherein Cu of curve i in FIG. 10a²⁺The concentration is 25. mu. mol. L^-1Curve ii Cu²⁺The concentration is 50 mu mol.L^-1Cu of curve iii²⁺The concentration is 75 mu mol.L^-1Cu of curve iv²⁺The concentration is 100 mu mol.L^-1) The fluorescence intensity of the probe continuously decreased (see FIG. 10 a). As can be seen from FIG. 10b, in Cu²⁺The concentration of the surfactant is 0 to 100. mu. mol. L^-1In the range of fluorescence intensity and Cu²⁺The concentration shows a good linear relation, the correlation coefficient R²= 0.95. The detection of Cu by fluorescence spectroscopy can be calculated according to the formula' detection limit =3 delta/k²⁺Has a detection limit of 2.50X 10^-6 mol·L^-1。

The prior thiourea compound with the following structural formula is used as a probe to detect copper ions (probe molecule is 100 mu mol. L)^-12/1 in DMF/buffer solution, pH 7), no up-conversion fluorescence response was observed at an excitation wavelength of 532nm for both pure probe molecules and probe molecules with copper ions added.

Response time of probe to copper ion fluorescence

In the probe molecule (10. mu. mol. L)^-1) To the solution (DMF: buffer =2:1, pH 7) was added Cu²⁺（Cu²⁺The concentration is 10 mu mol.L^-1) The fluorescence spectrum (excitation wavelength 378 nm) is tested every 1min, and the change of the fluorescence spectrum of the probe molecules is observed. Referring to the time response spectrogram of FIG. 11, the fluorescence of the probe gradually decreases with time, and the fluorescence intensity rapidly decreases in 0-2 min, which indicates that the target copper ion probe can be used for detecting Cu²⁺And the quick response is realized.

TTA-UC mainly comprises three processes, namely, the singlet state of a photosensitizer to the triplet stateThe process of intersystem crossing of linear states (ISC), the process of energy transfer of photosensitizer triplet states to luminescent agent triplet states (TTET) and the triplet-triplet annihilation process of luminescent agent molecules (TTA). The photosensitizer molecule absorbs light of low energy (long wavelength) and is excited to a singlet excited state ((¹PS) and then reaches triplet excited state by intersystem crossing (ISC) (³PS), the photosensitizer molecule in triplet state transfers triplet energy to the receptor molecule to generate a receptor molecule in triplet state (³A), two receptor molecules in triplet excited state collide with each other to produce a singlet receptor molecule: (¹A), the other falls back to the ground state, to which the acceptor molecule in its singlet state falls by emitting fluorescence. The whole process absorbs low-energy light and emits high-energy light, so that the process is called an up-conversion process. It can be seen that triplet-triplet annihilation up-conversion (TTA-UC) is "long wavelength excitation, short wavelength emission", which can effectively eliminate background fluorescence of the organism, making the probe more practical. The anthracene-thiosemicarbazide derivative disclosed by the invention can be used as an up-conversion fluorescent probe, and can be used for detecting copper ions by utilizing triplet state-triplet state annihilation up-conversion (TTA-UC), and the up-conversion fluorescent detection method is rarely reported.

Claims

1. A method for detecting copper ions in a solution by using an anthracene-thiosemicarbazide derivative is characterized by comprising the following steps:

(1) reacting 4-bromo-2-hydroxybenzaldehyde and 9, 10-diborate anthracene in a nitrogen atmosphere and a solvent to obtain an intermediate product I; then reacting the intermediate product I with thiosemicarbazide to obtain an anthracene-thiosemicarbazide derivative;

(2) adding the anthracene-thiosemicarbazide derivative into the solution, irradiating the solution with exciting light, and if fluorescence quenching response of emitted light is detected, enabling the solution to contain copper ions;

the intermediate product I has the chemical formula:

the chemical formula of the anthracene-thiosemicarbazide derivative is as follows:

。

2. the method for detecting copper ions in solution by using the anthracene-thiosemicarbazide derivative according to claim 1, characterized in that the solvent is one or more of 1, 4-dioxane, ethanol, toluene and water; the reaction temperature of the 4-bromo-2-hydroxybenzaldehyde and 9, 10-diborate anthracene is 50-120 ℃, and the reaction time is 48 hours; the reaction temperature of the intermediate product I and thiosemicarbazide is 50-140 ℃, and the reaction time is 24 hours.

3. The method for detecting copper ions in a solution using an anthracene-thiosemicarbazide derivative according to claim 1, wherein: the molar ratio of 4-bromo-2-hydroxybenzaldehyde to 9, 10-diboronic acid ester anthracene is 3: 1; the molar ratio of intermediate I to thiosemicarbazide was 1: 3.

4. The method for detecting copper ions in a solution using an anthracene-thiosemicarbazide derivative according to claim 1, wherein the excitation light has a wavelength of 378 nm; or the wavelength of the excitation light is 532 nm.

5. The method for detecting copper ions in a solution using an anthracene-thiosemicarbazide derivative according to claim 1, wherein: the solution is a neutral solution.