A long-wavelength reactive copper ion fluorescent probe and its preparation method and application

Abstract

The present invention relates to the field of fluorescent probe technology, and in particular to a long-wavelength reactive copper ion fluorescent probe, a preparation method, and an application thereof. The present invention provides a long-wavelength reactive copper ion fluorescent probe, a preparation method, and an application thereof. Based on the principle of intramolecular charge transfer, a novel Cu ion fluorescent probe is designed and synthesized, which uses picolinate as a recognition site and quenching group, and a hemicyanine derivative as a fluorescent group. 2+ Fluorescent probe H‑Cu, realizing the detection of Cu 2+ The probe has a long emission wavelength, high sensitivity, strong anti-interference ability, good response speed, stability, selectivity, and can quantitatively detect Cu 2+ ; The linear range is 0~15 μmol / L; for Cu 2+ The detection limit is as low as 0.81 μmol / L. In addition, the designed fluorescent probe H-Cu has a simple preparation method, low cost and excellent detection performance. The probe is suitable for rapid detection of Cu in biological samples. 2+ It has good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of fluorescent probes, and in particular to a long-wavelength reactive copper ion fluorescent probe and a preparation method and application thereof. Background Art

[0002] In recent years, the detection method of heavy metal ions has received extensive attention because it plays a very important role in physiological processes. Our daily production and life and human physiological activities are closely related to Cu. 2+ Closely related. 2+ The physiological concentration of Cu in the human body is second only to zinc and iron, and it is the third most abundant trace element in the human body. 2+ The levels of ions ranged from 15.7 to 23.6 µM. Cu 2+ It participates in many physiological activities of the human body, including redox processes, enzyme catalysis reactions, and oxygen transport. Even in the central nervous system, it participates in neuronal signal transduction and neuropeptide activation. Maintaining copper homeostasis is essential for the normal functioning of cells. Intracellular copper deficiency or excess can lead to abnormal cell function and cause diseases. Studies have found that excessive cellular copper is also related to neurological diseases such as Parkinson's, Alzheimer's, and Wilson's. Therefore, the National Research Council of the United States has a high level of copper. 2+ The daily intake of Cu for adults is strictly regulated. 2+ The amount of Cu in drinking water should be less than 3.0 mg; the World Health Organization and the U.S. Environmental Protection Agency (EPA) respectively set the 2+ The maximum acceptable values ​​for Cu ions are set at 30 µM and 20 µM. 2+ In addition, excessive Cu in the environment 2+ It can also have adverse effects on the human body and cause copper-dependent cell death. However, in daily production and life, Cu 2+ It is an important metal catalyst and intermediate product in modern industries (such as electroplating, mining, electronic manufacturing, etc.). The rapid development of urban industrialization and modernization will produce a large amount of toxic and harmful copper-containing wastewater. Our living environment has been polluted by a large amount of copper. In addition to copper-dependent cell death, excessive Cu 2+ It can also cause soil and water toxicity and damage the ecosystem. In order to solve these problems, it is necessary to develop effective methods to analyze and detect Cu in real time with high sensitivity and high selectivity. 2+ Distribution and concentration changes in organisms and the environment.

[0003] Various methods have been developed to detect Cu 2+, such as electrochemical monitoring, atomic emission spectroscopy, gas chromatography, mass spectrometry inductively coupled plasma mass spectrometry (ICP-MS), atomic absorption spectroscopy (AAS) and X-ray fluorescence microscopy (XFM). However, these detection methods are time-consuming and labor-intensive, expensive, and require highly qualified professionals to operate the instruments and prepare samples. In addition, these technologies are difficult to measure and analyze non-invasively in living cells. In recent years, fluorescent probe technology has been widely used in biology, chemistry, environment, and materials. Cu 2+ The design and research of fluorescent probes have also made significant progress. Many researchers are committed to developing highly sensitive and selective Cu 2+ Fluorescent probes are used to meet the needs of different fields. These probes usually use quinoline, benzothiazole, etc. as fluorophores, and achieve the effect of Cu by introducing specific coordination groups. 2+ Fluorescence analysis has many advantages, including excellent selectivity and sensitivity, simple sample preparation, rapid reaction, real-time monitoring of biological imaging, non-invasive detection, and high resolution.

[0004] Currently, fluorescent probes are 2+ Great progress has been made in the detection of Cu, but many challenges still exist. 2+ The nature of Cu leads to low sensitivity to background signal interference or is limited by low selectivity due to interference from other coexisting ions. Most reported fluorescent probes are only in the visible light region, which may lead to insufficient tissue penetration and tissue damage. In order to avoid these shortcomings, it is necessary to further develop long wavelength and high selectivity detection of Cu 2+ An effective method for the future Cu 2+ Fluorescent probe research will focus more on the practicality and stability of the probes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the deficiencies of the above-mentioned prior art and provide a long-wavelength reactive copper ion fluorescent probe and its preparation method and application. Based on the principle of intramolecular charge transfer, a new type of Cu ion fluorescent probe with picolinate as the recognition site and quenching group and hemicyanine derivatives as the fluorescent group is designed and synthesized. 2+ Fluorescent probe H-Cu, to achieve Cu 2+ The probe has a long emission wavelength, high sensitivity, strong anti-interference ability, good response speed, stability, selectivity, and can quantitatively detect Cu 2+ .

[0006] The present invention provides a long-wavelength reactive copper ion fluorescent probe, the structural formula of the fluorescent probe is:

[0007] .

[0008] The present invention also provides a method for preparing the above-mentioned long-wavelength reactive copper ion fluorescent probe, comprising the following steps:

[0009] S1. Dissolve 2-methylbenzothiazole and iodoethane in anhydrous ethanol, stir and reflux, and after completion of the reaction, cool to room temperature and vacuum filter to obtain compound 1;

[0010] S2, dissolving the compound 1 prepared in S1 and 6-hydroxy-2-naphthaldehyde in methanol and adding triethylamine dropwise to obtain a mixture, stirring the mixture in an oil bath for reaction, and filtering and washing the precipitate after the reaction, and recrystallizing the mixture again to obtain compound HQ;

[0011] S3. The compound HQ prepared in S2 was dissolved in dichloromethane to obtain an HQ solution, which was treated with 2-pyridinecarboxylic acid, 4-dimethylaminopyridine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride. The solution was stirred and reacted under an argon atmosphere at room temperature. After the reaction was completed, the solution was diluted with water, the organic phase was separated, and the organic phases were extracted and combined. The crude solid was obtained by washing, drying and evaporation, and the long-wavelength reactive copper ion fluorescent probe H-Cu was obtained by purification by silica gel column chromatography.

[0012] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the molar volume ratio of 2-methylbenzothiazole, iodoethane and anhydrous ethanol in S1 is 1 mmol:1 mmol:15 mL.

[0013] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the temperature of the stirring reflux reaction in S1 is 80° C. and the time of the stirring reflux reaction is 4 h.

[0014] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the molar volume ratio of compound 1, 6-hydroxy-2-naphthaldehyde, methanol and triethylamine in S2 is 1 mmol:1.1 mmol:20 mL:150 μL.

[0015] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the temperature of the oil bath in S2 is 85° C., the stirring reaction time is 8 h, and the washing detergent is ether.

[0016] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the molar volume ratio of the compound HQ, dichloromethane, 2-picolinic acid, 4-dimethylaminopyridine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in S3 is 5 mmol:5 mL:20 mL:3 mmol:10 mmol.

[0017] According to the preparation method of the long-wavelength reactive copper ion fluorescent probe provided by the present invention, the stirring reaction time in S3 is 3 hours, the extraction agent is dichloromethane, the washing detergent is saturated salt water with a concentration of 0.1 mol / L, the drying desiccant is anhydrous sodium sulfate, and the column chromatography conditions are: in the silica gel column, the eluent is dichloromethane: methanol = 10:1.

[0018] The present invention also provides an application of the above-mentioned long-wavelength reaction type copper ion fluorescent probe, which is used to prepare a long-wavelength reaction type copper ion fluorescent probe for detecting Cu in the environment and biological samples. 2+ of reagents.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] The present invention provides a long-wavelength reactive copper ion fluorescent probe and its preparation method and application. Based on the principle of intramolecular charge transfer, a new type of Cu ion fluorescent probe with picolinate as the recognition site and quenching group and hemicyanine derivatives as the fluorescent group is designed and synthesized. 2+ Fluorescent probe H-Cu, to achieve Cu 2+ The probe has a long emission wavelength, high sensitivity, strong anti-interference ability, good response speed, stability, selectivity, and can quantitatively detect Cu 2+ ; The linear range is 0~15 μmol / L; for Cu 2+ The detection limit was as low as 0.81 μmol / L.

[0021] In addition, the designed fluorescent probe H-Cu has a simple preparation method, low cost and excellent detection performance. The probe is suitable for rapid detection of Cu in biological samples. 2+ It has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 is the mass spectrum of probe H-Cu;

[0024] Figure 2 is the mass spectrum of compound HQ;

[0025] Figure 3 H-Cu and Cu as probes 2+ Fluorescence spectra before and after the reaction;

[0026] Figure 4 The probe H-Cu and Cu at different pH 2+ Fluorescence intensity changes of the reaction;

[0027] Figure 5 To add Cu in HEPES buffer 2+ Fluorescence spectra within the last 15 min;

[0028] Figure 6 H-Cu and Cu as probes 2+ Changes in fluorescence intensity at 590 nm over time after the reaction;

[0029] Figure 7 This is the fluorescence intensity change diagram of probe H-Cu within 30 min;

[0030] Figure 8 To add different concentrations of Cu 2+ Changes in the fluorescence intensity of the probe H-Cu after concentration;

[0031] Figure 9 For the probe H-Cu at different concentrations of Cu 2+ Fluorescence intensity change diagram under (0~15 mmol / L);

[0032] Figure 10 is the fluorescence intensity of the probe H-Cu and Cu 2+ The concentration linear relationship diagram;

[0033] Figure 11 For the probe H-Cu to Cu 2+ Response diagram of ;

[0034] Figure 12 To add Cu 2+ (1 μmol / L) and other ions (1 mmol / L), histogram of the fluorescence intensity of the probe H-Cu. DETAILED DESCRIPTION

[0035] The present invention provides a long-wavelength reactive copper ion fluorescent probe and a preparation method thereof, comprising the following steps:

[0036] S1. Dissolve 1 mmol of 2-methylbenzothiazole and 1 mmol of iodoethane in 15 mL of anhydrous ethanol and stir under reflux at 80°C for 4 h. Follow the reaction progress using thin-layer chromatography. After the reaction is complete, cool to room temperature and vacuum filter to obtain compound 1 as a white solid.

[0037] ;

[0038] S2. 1 mmol of compound 1 and 1.1 mmol of 6-hydroxy-2-naphthaldehyde were dissolved in 20 mL of methanol and 150 μL of triethylamine was added dropwise to obtain a mixture. The mixture was stirred in an oil bath at 85°C for 8 h. After the reaction, the precipitate was filtered and washed several times with ether, and then recrystallized to obtain a red solid compound HQ.

[0039] ;

[0040] S3. A 5 mmol HQ solution in 5 mL dichloromethane was treated with 20 mL 2-picolinic acid, 3 mmol 4-dimethylaminopyridine (DMAP), and 10 mmol 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDCI). The mixture was stirred at room temperature under argon atmosphere for 3 h. After the reaction was completed, the mixture was diluted with water, the organic phase was separated, and the aqueous phase was extracted with dichloromethane (DCM). The combined organic phases were washed with 0.1 mol / L saturated brine and then dried over anhydrous sodium sulfate. The solvent was evaporated to obtain a crude solid, which was purified by silica gel column chromatography using dichloromethane:methanol = 10:1 as the eluent to obtain the probe H-Cu.

[0041] .

[0042] The probe H-Cu and compound HQ prepared in this example were diluted with chromatographically pure acetonitrile until colorless, and the molecular weights were detected by mass spectrometry. The detection results were as follows: Figure 1 and 2 As shown;

[0043] Theoretical molecular weight of H-Cu[M] + The theoretical molecular weight of HQ is 437.1329, and the mass spectrometry result is 437.1193. + The mass spectrum was 332.1104, and the mass spectrum was 332.1553. Figure 1 and 2 It can be seen that the actual measured product is consistent with the theoretical molecular weight of the target product, indicating that the actual product obtained is the target product.

[0044] Example 2

[0045] In this example, fluorescence spectrum detection was performed on the probe H-Cu prepared in Example 1.

[0046] First, you need to configure the spectral detection stock solution:

[0047] Preparation of H-Cu stock solution: Accurately weigh 0.0022 g of the synthesized probe H-Cu using an analytical balance and dissolve it in 5 mL of dimethyl sulfoxide (DMSO) to a concentration of 1 mmol / L. Store in a refrigerator, sealed and protected from light.

[0048] Preparation of CuSO4 solution: Accurately weigh 0.0080 g CuSO4 using an analytical balance and dissolve it in 5 mL of distilled water to a volume of 10 mmol / L CuSO4 stock solution. Use a 1000 μL pipette to draw up 1000 μL of CuSO4 liquid and dilute it with 4.9 mL of distilled water to a concentration of 1 mmol / L CuSO4 stock solution. Store in a refrigerator, sealed and protected from light.

[0049] Fluorescence spectrum measurement method:

[0050] S1. Measure the fluorescence intensity of pure H-Cu probe. Use a 100 μL pipette to transfer 10 μL of the prepared 1 mmol / L H-Cu probe solution. Add 500 μL of HEPES buffer (4-hydroxyethylpiperazineethanesulfonic acid) with a pH of 7.4. Add distilled water to the volume in a 5 mL colorimetric tube. After 5 minutes, add the solution to be tested to the cuvette.

[0051] S2, measuring the addition of different concentrations of Cu 2+ After the fluorescence intensity of the probe solution was measured, 10 μL of the prepared 1 mmol / L H-Cu probe solution was transferred with a 100 μL pipette, and 500 μL of HEPES buffer solution with a pH value of 7.4 was added. 2+ , and then dilute to 5 mL in a colorimetric tube with distilled water. After 5 min, add the solution to be tested into the cuvette;

[0052] S3. Measure the fluorescence spectrum on an F-4600 fluorescence photometer and record the data.

[0053] (Fluorescence spectrophotometer parameter settings: λ ex = 396 nm, λ em = 416 nm, the slit widths of Ex (excitation) and Em (emission) are 5 / 5, and the negative high voltage is 750 V).

[0054] By contrast, the addition of Cu 2+ The changes in the H-Cu fluorescence spectrum of the probe before and after were used to verify the use of H-Cu for the detection of Cu 2+ feasibility.

[0055] The fluorescence spectrum shows that the fluorescence intensity of pure probe H-Cu solution reaches the highest at a wavelength of 530 nm. 2+The highest fluorescence intensity of the solution appears at 590 nm. Figure 3 shown.

[0056] By adding pure probe solution H-Cu, Cu 2+ The probe solution H-Cu+ Cu 2+ Comparison of the colors of the three solutions, HQ and Cu, revealed that 2+ The color of the probe solution becomes darker and consistent with the color of the fluorophore solution, indicating that Cu 2+ The probe H-Cu reacts to dissociate the recognition group, and the probe releases the fluorophore HQ, which increases the fluorescence. Figure 3 shown.

[0057] The experimental results show that the probe H-Cu 2+ Can produce a noticeable response.

[0058] The effect of pH on the fluorescence properties of the probe H-Cu was studied. The pH of the solution affects the fluorescence properties of the fluorophore and the probe. HEPES buffers of different pH values ​​were added to the reaction solution to adjust the pH of the system to understand whether the probe H-Cu can be used to detect Cu in complex environments. 2+ .

[0059] The experimental results show that the fluorescence intensity of the probe H-Cu decreases under alkaline conditions. Figure 4 As shown in the figure, the probe H-Cu can detect Cu in the pH range of 6.8 to 8.0. 2+ The fluorescence intensity was the highest at pH 7.4.

[0060] This indicates that the probe H-Cu can be used to evaluate Cu in the pH range of 6.8 to 8.0. 2+ , and when the pH value is 7.4, the probe H-Cu and Cu 2+ The response effect is optimal.

[0061] Example 3

[0062] In this example, a kinetic test was performed on the probe H-Cu prepared in Example 1.

[0063] The concentration of probe H-Cu was 10 μmol / L, pH was 7.4, and temperature was 25 °C. 2+ The probes H-Cu and Cu were further investigated under the experimental conditions of 20 μmol / L concentration. 2+ Dynamics of interaction.

[0064] like Figure 5 As shown, 20 μmol / L Cu was added to the probe H-Cu solution. 2+After that, the fluorescence signal at 590 nm gradually increased within 10 min, and the reaction was basically completed at 15 min.

[0065] like Figure 6 As shown, the fluorescence intensity reached equilibrium within about 300 s and stabilized after 500 s.

[0066] Example 4

[0067] In this example, the stability of the probe H-Cu prepared in Example 1 was tested.

[0068] To test whether the probe H-Cu can exist stably in a HEPES solution with a concentration of 10 mmol / L and a pH of 7.4, the fluorescence intensity of the pure probe H-Cu solution was measured every 5 min until 30 min later.

[0069] The results showed that the fluorescence intensity of pure probe H-Cu solution was stable within 30 min, e.g. Figure 7 As shown, the next step is to 2+ Detection.

[0070] Example 5

[0071] This embodiment optimizes Cu 2+ Concentration method.

[0072] The fluorescence spectra were compared to detect the addition of 0, 5, 10, 15, 20, 25 and 30 μmol / L of Cu 2+ The fluorescence intensity of the system is then used to find the optimal Cu 2+ concentration.

[0073] The experimental results are as follows Figure 8 As shown, with Cu 2+ When the concentration of α-glucose increased from 0 μmol / L to 30 μmol / L, the fluorescence intensity of the system first gradually increased and then decreased, reaching a maximum value at 20 μmol / L.

[0074] Therefore Cu 2+ The optimal concentration of the solution is 20 μmol / L.

[0075] Example 6

[0076] This example studies the H-Cu probe prepared in Example 1 to Cu 2+ Quantitative detection of .

[0077] Under the optimal experimental conditions of temperature 25 °C, pH 7.4, and reaction time 10 min, the effect of probe H-Cu on different concentrations of Cu was determined. 2+ Spectral characteristics of the response.

[0078] Different concentrations of Cu were added to the fluorescent probe H-Cu solution. 2+ , observe the changes in the fluorescence intensity of the solution to explore the performance of the probe H-Cu.

[0079] like Figure 9 As shown, when Cu 2+ When the concentration range is (0~0.5 μmol / L), the fluorescence intensity at 530 nm is measured with the increase of Cu 2+ The concentration of Cu 2+ The concentration range is (1-15 μmol / L). As the concentration increases, the peak red shifts to 590 nm, and the fluorescence intensity also increases with the increase of Cu 2+ Increased with the increase of concentration.

[0080] The experimental results show that the fluorescence intensity of the probe H-Cu increases with the 2+ The fluorescence intensity at 590 nm was significantly higher than that of Cu 2+ There is a good linear relationship between the concentrations of 2 =0.9961), the linear range was 1-15 μmol / L, and the 2+ The detection limit is 0.81 μmol / L, and the linear regression equation is Y=46.8X+233.9, where Y is the relative fluorescence intensity of H-Cu and X is the relative fluorescence intensity of Cu 2+ The concentration, such as Figure 10 As shown, Figure 10 The medium weight is unweighted, the intercept is 233.98667±7.14, the slope is 46.7725±0.7860, the residual square is 2249.22, and the Pearson correlation coefficient is 0.9981.

[0081] The results show that the probe H-Cu can be used to detect Cu 2+ Quantitative detection of .

[0082] Example 7

[0083] This example is the probe H-Cu prepared in Example 1. 2+ reaction mechanism.

[0084] The method provided in this embodiment is based on the ICT principle to design a new type of detection Cu 2+ The fluorescent probe H-Cu is based on thiazole hemicyanine as the fluorophore and picolinate as the recognition site and quenching group.

[0085] Probe and Cu 2+ When the reaction occurs, Cu 2+Catalyzing the hydrolysis reaction of picolinate can restore the ICT process, so that the recognition group is detached, the probe releases the fluorophore HQ, and the fluorescence of the detection system is enhanced, such as Figure 11 shown.

[0086] The experiment used fluorescence spectrometer to analyze the new Cu 2+ The fluorescence performance of the fluorescent probe was tested to evaluate the probe's effect on Cu 2+ The affinity, selectivity and sensitivity of the probe H-Cu and Cu 2+ After the reaction, picolinate acts as a specific response group, which is due to the closure of the ICT process between the two.

[0087] Probe H-Cu and Cu 2+ When the reaction occurs, Cu 2+ Catalyzing the hydrolysis reaction of picolinate itself can restore the ICT process, thereby disengaging the recognition group and releasing the fluorophore from the probe to enhance fluorescence. After the fluorophore reacts with picolinate, the peak red-shifts, the solution color changes from colorless to orange, and the fluorescence color changes from blue to orange.

[0088] Example 8

[0089] This embodiment provides a selectivity test of the probe H-Cu prepared in Example 1.

[0090] This example tests the effects of various common interfering substances on Cu 2+ Interferences detected, such as common amino acids (Glu (glutamic acid), Cys (cysteine), Hcy (homocysteine), Ser (serine), Phe (phenylalanine), Gly (glycine), Gsh (glutathione)) and inorganic salt ions (Na + , CH3COO - , S2O3 2- , Ca 2+ , SO4 2- , Mn 2+ , Cd 2+ , Mg 2+ , Ni 2+ , Fe 2+ , Zn 2+ , Cl - , CO3 2- , K + ,HCO3 - , NO3 - , Hg 2+ , Al 3+ , Cr 3+ , Br - , SO3 - , CrO4 2- )wait.

[0091] When these interfering concentrations are higher than Cu 2+ When the fluorescence intensity was doubled, the peak corresponding to the highest fluorescence intensity was at 530 nm, which was the same as that of the pure probe blank control group and did not move. 2+ The highest fluorescence intensity corresponds to the peak at 590 nm, and the probe H-Cu 2+ Response, such as Figure 12 shown.

[0092] The results showed that the probe H-Cu 2+ Has good selectivity.

[0093] In summary, a new Cu 2+ fluorophore with picolinate as the recognition site and quenching group and hemicyanine derivatives as the fluorescent group was designed and synthesized based on the principle of intramolecular charge transfer (ICT). 2+ Fluorescent probe H-Cu, to achieve Cu 2+ When Cu is added 2+ When the concentration range is (0~0.5 μmol / L), the fluorescence intensity at 530 nm is measured with the increase of Cu 2+ concentration decreases; when Cu 2+ The concentration range is (1-15 μmol / L). As the concentration increases, the peak red shifts to 590 nm, and the fluorescence intensity also increases with the increase of Cu 2+ The probe has a long emission wavelength, high sensitivity, strong anti-interference ability, good response speed, stability, selectivity, and can quantitatively detect Cu 2+ ; The linear range is 0~15 μmol / L; for Cu 2+ The detection limit is as low as 0.81 μmol / L. In addition, the preparation method of the designed fluorescent probe H-Cu is simple, low cost, and has excellent detection performance. The probe is used to quickly detect Cu in biological samples. 2+ It has good application prospects.

[0094] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent variation made to the above embodiment based on the essence of the invention technology shall still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A long-wavelength reactive copper ion fluorescent probe, characterized in that: The structural formula of the fluorescent probe is: 。 2. A method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 1, characterized in that: The following steps are involved: S1. Dissolve 2-methylbenzothiazole and iodoethane in anhydrous ethanol, stir and reflux, and after completion of the reaction, cool to room temperature and vacuum filter to obtain compound 1; ； S2, dissolving the compound 1 prepared in S1 and 6-hydroxy-2-naphthaldehyde in methanol and adding triethylamine dropwise to obtain a mixture, stirring the mixture in an oil bath for reaction, and filtering and washing the precipitate after the reaction, and recrystallizing the mixture again to obtain compound HQ; ； S3, taking the compound HQ prepared in S2, dissolving it in dichloromethane and treating it with 2-picolinic acid, 4-dimethylaminopyridine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, stirring and reacting under an argon atmosphere at room temperature, diluting it with water after completion of the reaction, separating the organic phase, extracting and combining the organic phases, washing, drying and evaporating to obtain a crude solid, and purifying it by silica gel column chromatography to obtain a long-wavelength reactive copper ion fluorescent probe H-Cu; 。 3. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The molar volume ratio of 2-methylbenzothiazole, ethyl iodide and anhydrous ethanol described in S1 is 1 mmol:1 mmol:15 mL.

4. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The temperature of the stirring reflux reaction in S1 is 80° C. and the time of the stirring reflux reaction is 4 h.

5. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The molar volume ratio of compound 1, 6-hydroxy-2-naphthaldehyde, methanol and triethylamine in S2 is 1 mmol:1.1 mmol:20 mL:150 μL.

6. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The temperature of the oil bath in S2 is 85° C., the stirring reaction time is 8 h, and the washing detergent is diethyl ether.

7. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The molar volume ratio of compound HQ, dichloromethane, 2-picolinic acid, 4-dimethylaminopyridine and 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride in S3 is 5 mmol:5 mL:20 mL:3 mmol:10 mmol.

8. The method for preparing the long-wavelength reactive copper ion fluorescent probe according to claim 2, wherein: The stirring reaction time in S3 is 3 h, the extraction solvent is dichloromethane, the washing detergent is saturated saline with a concentration of 0.1 mol / L, the drying desiccant is anhydrous sodium sulfate, and the silica gel column chromatography purification conditions are: in the silica gel column, the eluent is dichloromethane: methanol = 10:

1.

9. An application of the long-wavelength reactive copper ion fluorescent probe as claimed in claim 1, characterized in that: The long-wavelength reaction type copper ion fluorescent probe is used for preparing the detection of Cu in the environment and biological samples. 2+ of reagents.

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