Benzothiazole fluorescent molecule as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of fluorescent probes, and particularly relates to a benzothiazole fluorescent molecule as well as a preparation method and application thereof. The benzothiazole fluorescent molecule as shown in the structural formula (1) provided by the invention is synthesized by taking amino thiol and salicylaldehyde as raw materials. The benzothiazole fluorescent molecule is selectively and specifically combined with a boron-containing compound, the fluorescence intensity is remarkably enhanced, open-type detection of the boron-containing compound is realized, and the benzothiazole fluorescent molecule has the advantages of quick response, high selectivity, interference resistance and low cost, and has important application value in the fields of environmental science, biological science, material engineering and the like.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent probe technology, specifically relating to a benzothiazole fluorescent molecule, its preparation method, and its application. Background Technology

[0002] Boric acid compounds, as important reagents in modern organic synthesis, play an irreplaceable role in catalysis, materials science, and biomedicine. In recent years, their groundbreaking application in boron neutron capture therapy (BNCT) has attracted particular attention: through tumor-targeted boric acid drugs (such as 4-boron-L-phenylalanine, approved in Japan in 2020, trade name...). ) Specifically enriched within cancer cells 10 B isotope, triggered by thermal neutron radiation 10 B(n,α) 7 Li nucleus reactions generate high-energy alpha particles that precisely kill tumor cells. However, the efficacy of BNCT directly depends on the location of the tumor. 10 The concentration of boron (needs to be maintained at ≥20 μg / g) is crucial, but existing clinical monitoring methods such as inductively coupled plasma atomic emission spectrometry (ICP-OES / MS) require tissue ashing and cannot resolve the subcellular localization of boron. Although secondary ion mass spectrometry (SIMS) and positron emission tomography (PET) can achieve spatial resolution, they are limited by bottlenecks such as high equipment cost and complex preprocessing.

[0003] Against this backdrop, the development of novel fluorescent probe technology has become a key breakthrough in overcoming the detection dilemma. With its advantages of non-invasiveness, real-time in-situ imaging, single-cell resolution, and controllable cost, it is expected to achieve dynamic tracking and precise quantification of BPA metabolism in the tumor microenvironment, providing key technical support for optimizing BNCT dosing regimens and evaluating efficacy, while also opening up innovative methodological pathways for the bioanalysis of borate drugs. Summary of the Invention

[0004] The present invention aims to provide a benzothiazole fluorescent molecule, its preparation method and application. This benzothiazole fluorescent molecule can be used to detect borates, especially BPA, solving the problems of long detection time and narrow detection range of BPA in urine after human injection of BPA drugs.

[0005] The technical solution of the present invention is a benzothiazole fluorescent molecule with the structural formula shown in formula (1):

[0006]

[0007] The preparation method of the benzothiazole fluorescent molecule shown in formula (1) includes the following steps:

[0008] 1) At room temperature, 2-aminobenzylthiol and 4-methoxysalicylaldehyde were added to a methanol solution containing I2 to react and obtain 2-(2-benzothiazolyl)-4-methoxyphenol. The synthetic route is shown in formula (2).

[0009] 2) 2-(2-benzothiazolyl)-4-methoxyphenol was reacted with hexamethylenetetramine by heating and reflux in acetic acid to obtain 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde. The synthetic route is shown in formula (3).

[0010] 3) 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde and 2-hydrazine were reacted by heating and reflux in ethanol to obtain QWF with the structure shown in formula (1). The synthetic route is shown in formula (4).

[0011]

[0012]

[0013] In step 1), the molar ratio of 4-methoxysalicylaldehyde, 2-aminobenzylthiol and iodine molecules is 1:1-3:0.3-2, preferably 1:1.2-1.8:0.5-1 or 1:1.5:0.5; the concentration of 2-aminobenzylthiol is 0.5-2 mmol / mL, preferably 0.8-1.5 mmol / mL, and more preferably 0.9-1.3 mmol / mL.

[0014] In step 2), the molar ratio of 2-(2-benzothiazolyl)-4-methoxyphenol to hexamethylenetetramine is 1:3-7, preferably 1:4-6, more preferably 1:4.5-5.5; the concentration of 2-(2-benzothiazolyl)-4-methoxyphenol is 0.05-1.5 mmol / mL, preferably 0.1-1 mmol / mL, more preferably 0.1-0.5 mmol / mL.

[0015] In step 2), after the reaction is complete, 2M hydrochloric acid is added to the reaction solution and stirred to separate the solid, which is the crude product. The crude product is then purified by column chromatography, with the mobile phase being dichloromethane (DCM): polyethylene (PE) = 1:1.

[0016] In step 3), the molar ratio of 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde to 2-hydrazine is 1:1-3, preferably 1:1.5-2.5, more preferably 1:1.5-2; the concentration of 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde is 0.01-1 mmol / mL, preferably 0.03-0.1 mmol / mL, more preferably 0.03-0.05 mmol / mL.

[0017] In step 3), after the reaction is completed, the reaction solution is cooled to room temperature, and washed with ethanol to obtain QWF with the structure shown in formula (1).

[0018] The benzothiazole fluorescent molecule of formula (1) provided in this invention, upon binding with a boron-containing compound (such as 4-boron-L-phenylalanine), disrupts the ESIPT mechanism of the benzothiazole fluorescent molecule of formula (1), resulting in significantly enhanced fluorescence and achieving "on-type" fluorescence detection of boron-containing compounds. The benzothiazole fluorescent molecule of formula (1) can be used for the detection of boron-containing compounds, especially 4-boron-L-phenylalanine.

[0019] The benzothiazole fluorescent molecules of formula (1) provided above can be used to prepare products for the detection of boron-containing compounds. The products include, but are not limited to, detection reagents, kits, elements, devices or equipment. The reagents include, but are not limited to, solutions containing benzothiazole fluorescent molecules of formula (1). The elements include, but are not limited to, magnetic beads, panels, chips, channels, pathways, etc., loaded with benzothiazole fluorescent molecules of formula (1). The devices or equipment are equipped with the above-mentioned elements.

[0020] This invention provides a product for detecting boron-containing compounds, wherein the product contains benzothiazole fluorescent molecules represented by the structural formula (1) provided above. The product includes, but is not limited to, detection reagents, kits, components, devices, or equipment. Reagents include, but are not limited to, solutions containing benzothiazole fluorescent molecules represented by the structural formula (1). Components include, but are not limited to, magnetic beads, panels, chips, channels, and pathways loaded with benzothiazole fluorescent molecules represented by the structural formula (1). Devices or equipment are equipped with the aforementioned components.

[0021] The present invention provides a method for detecting boron-containing compounds, comprising the steps of: using a benzothiazole fluorescent molecule as shown in the structural formula (1) as a probe, mixing it with the sample to be tested to form a detection system, scanning in the range of 430nm to 800nm ​​at an excitation wavelength of 410nm, and performing qualitative and / or quantitative determination of boron-containing compounds in the sample.

[0022] Furthermore, using the concentration of boron-containing compounds and the fluorescence intensity of benzothiazole fluorescent molecules shown in formula (1) at 562 nm as the x and y axes, the qualitative and / or quantitative determination of boron-containing compounds in the sample is carried out by external standard method, internal standard method or standard addition method.

[0023] The solvent used in the detection system includes any one or any combination of dimethyl sulfoxide, N,N-dimethylformamide, a mixed solvent of dimethyl sulfoxide and water, and a mixed solvent of N,N-dimethylformamide and water, preferably a mixed solvent of dimethyl sulfoxide and water, with a volume ratio of dimethyl sulfoxide to water of 1:0.1-50, preferably 1:1-20, preferably 1:5-15, and as one embodiment, 1:9.

[0024] The boron-containing compounds mentioned above in this invention include, but are not limited to, boron oxyacids and their salts, boron hydrides, metal borides, organoborides, and other functional boron compounds. Boron oxyacids and their salts include, but are not limited to, boric acid and borates. Boron hydrides include, but are not limited to, diborane, butyrate, pentoborane, and organoboranes. Metal borides include, but are not limited to, titanium diboride, chromium diboride, and calcium hexaboride. Organoborides include, but are not limited to, alkylboranes and organoboronic acids (esters), organoborates and their complexes, carborane clusters, and boron heterocyclic compounds, such as 4-boron-L-phenylalanine, which was verified as an embodiment. Other functional boron compounds include, but are not limited to, boron nitrides and boron halides.

[0025] Compared with the prior art, the advantages of the present invention are: 1) It provides a new benzothiazole fluorescent molecule for the detection of boron-containing compounds; 2) The benzothiazole fluorescent molecule shown in formula (1) has the advantages of fast response, high selectivity, anti-interference and low cost. It can specifically bind to boron-containing compounds, has strong anti-interference ability and good specificity; 3) It has the advantages of good linear range, low detection limit, high sensitivity and wide applicability for the detection of boron-containing compounds. It can be used for the detection of various samples, such as different pH and different solvent environments; 4) It can be used for the detection of boron-containing compounds in environmental science, biological science, materials engineering and other fields, especially the detection of 4-boron-L-phenylalanine BPA or its metabolites in the human body. It has important application prospects and application value. Attached Figure Description

[0026] Figure 1 This is a synthetic route diagram for benzothiazole fluorescent probes.

[0027] Figure 2 These are fluorescence images of the QWF fluorescent probe solution before and after the addition of BPA, under 365nm UV light.

[0028] Figure 3The UV absorption spectra of the fluorescent probe QWF in dimethyl sulfoxide (DMSO), water (H2O), dichloromethane (DCM), acetonitrile (ACN), N,N-dimethylformamide (DMF), ethanol (EtOH), ethyl acetate (EA), tetrahydrofuran (THF), phosphate buffered saline (PBS), 4-hydroxyethylpiperazine ethanesulfonic acid (Hepes), and toluene (TOL) are shown.

[0029] Figure 4 The fluorescence spectra of the fluorescent probe QWF in water (H2O), dichloromethane (DCM), acetonitrile (ACN), ethanol (EtOH), ethyl acetate (EA), tetrahydrofuran (THF), phosphate buffered saline (PBS), 4-hydroxyethylpiperazine ethanesulfonic acid (Hepes), and toluene (TOL) are shown. Because the maximum absorption peaks of the fluorescent probe QWF in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) differ significantly from those in the other solvents, the fluorescence emission spectra of the probes in all solvents except these two were measured under an excitation condition of 410 nm. The fluorescence emission spectra of DMSO and DMF were measured at 465 nm and 500 nm, respectively.

[0030] Figure 5 The fluorescence spectra of DMSO under 465 nm excitation and DMF under 500 nm excitation are shown.

[0031] Figure 6 This is a Job's Plot curve showing the binding of the fluorescent probe QWF to BPA.

[0032] Figure 7 The image shows the fluorescence intensity of the fluorescent probe QWF against BPA in DMSO / H2O (1 / 9, v / v) solution at different reaction times.

[0033] Figure 8 The graph shows the fluorescence spectrum changes of the fluorescent probe QWF before and after the addition of BPA.

[0034] Figure 9 This is a schematic diagram showing the change in fluorescence intensity of the fluorescent probe QWF in DMSO / H2O (1 / 9, v / v) solution as a function of BPA concentration.

[0035] Figure 10 I in DMSO / H2O (1 / 9, v / v) solution of fluorescent probe QWF 562nm Linear relationship between intensity and BPA concentration.

[0036] Figure 11 This is a bar chart showing the fluorescence intensity of the fluorescent probe QWF in detecting BPA under various metal ion interferences.

[0037] Figure 12I in urine samples for the fluorescent probe QWF 562nm Working curves showing the relationship between strength and different BPA concentrations (0-80 μM) (urine sample 1).

[0038] Figure 13 I in urine samples for the fluorescent probe QWF 562nm Working curves showing the relationship between strength and different BPA concentrations (0-80 μM) (urine sample 2).

[0039] Figure 14 I in urine samples for the fluorescent probe QWF 562nm Working curves showing the relationship between strength and different BPA concentrations (0-80 μM) (urine sample 3).

[0040] Figure 15 For fluorescent probe QWF 1 1H NMR spectrum, using DMSO-d6 as solvent.

[0041] Figure 16 For fluorescent probe QWF 13 C10 NMR spectra were obtained using DMSO-d6 as the solvent.

[0042] Figure 17 This is a high-resolution mass spectrum of the fluorescent probe QWF. Detailed Implementation

[0043] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0044] Example 1: Synthesis of the fluorescent probe QWF

[0045] Synthetic routes such as Figure 1 As shown, at room temperature, I₂ (0.8 g) was preferentially added to a three-necked flask, dissolved in 10 mL of methanol, followed by the sequential addition of 1 g of 4-methoxysalicylaldehyde (6.57 mmol) and 1.23 g of 2-aminobenzenethiol (9.86 mmol), forming a solid. The mixture was stirred at room temperature for 24 h, and the reaction was confirmed to be complete by TLC. After cooling to room temperature, the mixture was filtered to obtain a pale yellow solid, 2-(2-benzothiazolyl)-4-methoxyphenol (0.7 g). The yield was 41.39%. 1H NMR (400MHz, DMSO-d6) δ11.02(s,1H),8.16-8.09(m,1H),8.06(d,J=8.1Hz,1H),7.71(d,J=2.4Hz,1H) ,7.53(ddd,J=8.3,7.1,1.3Hz,1H),7.44(ddd,J=8.2,7.2,1.2Hz,1H),7.07-7.00(m,2H),3.80(s,3H).

[0046] 0.5 g (1.94 mmol) of 2-(2-benzothiazolyl)-4-methoxyphenol was dissolved in 15 mL of AcOH, and 1.3 g (9.27 mmol) of utrolidine was added. The mixture was heated under reflux for 24 h. The reaction was confirmed to be complete by TLC. The reaction solution was cooled to room temperature and poured into 100 mL of 2 M hydrochloric acid. The mixture was stirred, and a solid was formed. The residue was collected by vacuum filtration, and the crude product was purified by column chromatography (DCM:PE = 1:1). The solvent was removed by vacuum distillation to obtain the purified product 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde (200 mg). The yield was 36.07%. 1 HNMR (400MHz, DMSO-d6) δ12.34(s,1H),10.34(s,1H),8.21(d,J=8.0Hz,1H),8.14(d,J=8 .1Hz,1H),7.97(d,J=3.2Hz,1H),7.60(t,J=7.3Hz,1H),7.56-7.45(m,2H),3.88(s,3H).

[0047] To a 5 mL ethanol solution containing 50 mg of 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde (0.17 mmol), 34 μL of 2-hydrazidepyridine (0.298 mmol) was added and the mixture was refluxed and stirred for 6 hours. The reaction solution was cooled to room temperature, washed with ethanol, and filtered to give a yellow solid product, QWF (44 mg, 0.12 mmol), in 70.5% yield. 1 H NMR (400MHz, DMSO-d6) δ12.55(s,1H),11.27(s,1H),8.37(s,1H),8.19(d,J=7.0Hz,2H),8.11(d,J=8.0Hz,1H),7.68(d,J=3.1Hz, 2H),7.58(ddd,J=8.3,7.2,1.3Hz,1H),7.53-7.45(m,1H),7.43(s,1H),7.08(d,J=8.4Hz,1H),6.84(t,J=6.1Hz,1H),3.86(s,3H). 13C NMR(101MHz,DMSO-d6)δ165.15,156.35,152.64,151.74,149.77,148.57,138.61,138.29,134.76,127.14,125.88 ,123.19,122.76,122.61,119.66,116.54,116.03,113.17,107.03,56.27.HRMS(ESI-TOF):m / z[M+H]+calculated for C 20 H 17 N4O2S + :377.0989; found:377.1072.

[0048] Example 2: Study of UV absorption and fluorescence spectra of probe molecules in solvents with different polarities

[0049] (1) Dissolve QWF (3.76 mg) in 10 mL of DMSO to prepare QWF test stock solution (1 mM). The stock solution is stored in a refrigerator at 4 °C away from light and has a shelf life of 3 months.

[0050] (2) Add 1.98 mL of dimethyl sulfoxide (DMSO), water (H2O), dichloromethane (DCM), acetonitrile (ACN), N,N-dimethylformamide (DMF), ethanol (EtOH), ethyl acetate (EA), tetrahydrofuran (THF), phosphate buffered saline (PBS), 4-hydroxyethylpiperazine ethanesulfonic acid (Hepes), and toluene (TOL) to a 3.5 mL four-sided transparent quartz cuvette, and add 40 μL of probe stock solution to obtain a test solution with a concentration of 20 μM.

[0051] (3) Place the working solution into the scanned baseline UV-Vis absorption spectrum, set the scan range to 250–800 nm, and obtain the UV-Vis absorption spectra of QWF in different solutions. Read the absorbance at the maximum absorption peak of QWF in different solvents; the spectra are as follows. Figure 3 As shown.

[0052] (4) Place the working solution into a fluorescence spectrometer, set the excitation wavelength to 410 nm, and the scanning range to 430 nm–800 nm. Obtain the fluorescence spectra of QWF in different solutions. The spectra are as follows: Figure 4 and Figure 5 As shown in the table. The relevant absorption and emission parameters are shown in Table 1.

[0053] Table 1. Absorption and emission of probe molecules in different solvents

[0054] Tol DCM EA THF EtOH DMF ACN DMSO <![CDATA[λ ab / nm]]> 314 / 399 309 / 398 311 / 397 312 / 399 310 / 395 294 / 498 309 / 395 297 / 468 <![CDATA[λ em / nm]]> 660 660 670 520 640 580 565 540

[0055] Example 3: Job's Plot Study of Probe Molecules Binding to BPA

[0056] The complexation ratio of probe QWF to BPA was determined by measuring the Job's Plot curve of probe QWF binding to BPA. The specific procedure is as follows:

[0057] (1) Dissolve QWF (3.76 mg) in 10 mL of DMSO to prepare QWF test stock solution (1 mM). The stock solution is stored in a refrigerator at 4 °C away from light and has a shelf life of 3 months.

[0058] (2) Different concentrations of probe and analyte BPA were added to 2 mL of DMSO solution in 11 3.5 mL four-sided transparent quartz cuvettes, respectively, maintaining a total concentration of 40 μM for both probe and BPA. The ratio of fluorescent probe QWF to BPA concentration was varied. The cuvettes were placed in a fluorescence spectrometer. The excitation wavelength was set to 410 nm, and the detection wavelength range was 430 nm to 800 nm. The fluorescence spectra of the probes were obtained.

[0059] (3) Record the fluorescence intensity of the above fluorescence spectrum at 562 nm to obtain a series of I values ​​related to BPA concentration. 562nm The fluorescence intensity. Using this value as the ordinate and [BPA] / ([BPA]+[QWF]) as the abscissa, a Job's Plot curve is obtained, as shown below. Figure 6 As shown.

[0060] (4) Figure 6 This indicates that when [BPA] / ([BPA]+[HBI]) is 0.47, I 562nm The fluorescence intensity reached its maximum, indicating that the complexation ratio of the fluorescent probe QWF to BPA was 1:1.

[0061] Example 4: Kinetic Study of Probe Molecules on BPA

[0062] To determine the optimal reaction time for the probe molecule to detect BPA, the changes in fluorescence intensity of the probe molecule and BPA at different time points were investigated. The specific procedures are as follows:

[0063] (1) Dissolve BPA (41 mg) in 10 mL of deionized water with pH 9-10 to prepare BPA test stock solution (20 mM). The stock solution is stored in a refrigerator at 4°C away from light and has a shelf life of 3 days.

[0064] (2) Add 40 μL of probe stock solution to 2 mL of DMSO / H2O (1 / 9, v / v) solution in two 3.5 mL four-sided transparent quartz cuvettes to obtain a test solution with a concentration of 20 μM.

[0065] (3) Add 10 μL of BPA stock solution to each of the two cuvettes to obtain a test solution with a BPA concentration of 0.1 mM.

[0066] (4) Place the working solution into a fluorescence spectrometer, set the excitation wavelength to 410 nm, the scanning range to 430 nm–800 nm, and the temperature to 25 °C. Obtain the fluorescence intensity of probe QWF at 562 nm after the addition of BPA over time. Record the fluorescence intensity of probe QWF at 562 nm, expressed as I... 562nm A line graph is plotted with the vertical axis representing the input and the horizontal axis representing the reaction time. The results are as follows: Figure 7 As shown.

[0067] (5) Experimental results show that at 25℃, within 1 minute of adding BPA, I 562nm The fluorescence intensity at that location was significantly enhanced. After 10 minutes, the fluorescence intensity still retained approximately 84% of its peak value.

[0068] Example 5: Study on the fluorescence intensity changes of probe molecules under different concentrations of BPA

[0069] To test the fluorescence response characteristics of the probe molecule to different concentrations of BPA, the experimental procedure is described in detail using a DMSO / H2O (1 / 9, v / v) solution as an example.

[0070] (1) Place 2 mL of DMSO / H2O (1 / 9, v / v) solution into a 3.5 mL four-sided transparent quartz cuvette. Add 40 μL of QWF stock solution (1 mM) to the cuvette and mix well. Place the cuvette in a fluorescence spectrometer. Set the excitation wavelength to 410 nm and the detection wavelength range to 430 nm–800 nm. Obtain the initial fluorescence spectrum of the probe (e.g., ...). Figure 8 (As shown).

[0071] (2) Add 1, 2, 3, 4, 5, 6, and 7 μL of BPA stock solution (20 mM) to cuvettes, respectively, to obtain test solutions containing 10, 20, 30, 40, 50, 60, and 70 μM BPA. Measure the fluorescence spectra of the above test solutions (e.g., Figure 8 and 9 (As shown).

[0072] (3) Record the fluorescence intensity of the above fluorescence spectrum at 562 nm to obtain a series of I values ​​related to BPA concentration. 562nm The value. A scatter plot of this value against BPA concentration, such as... Figure 10 As shown.

[0073] (4) Figure 10Linear fitting was performed within the linear range (0–70 μM), and the detection limit of probe QWF in DMSO / H2O (1 / 9, v / v) solution was determined based on 3σ / k.

[0074] (5) Experimental results show that the fluorescence intensity of probe QWF is significantly enhanced after the addition of BPA, indicating that the fluorescence intensity of probe QWF is in an "on" state, and the fluorescence intensity of probe QWF increases linearly with the increase of BPA concentration. 562nm The value showed a good linear relationship with the concentration of BPA, and the detection limit was 0.18 μM.

[0075] Example 6: Selectivity study of probe molecules for BPA

[0076] To test the selectivity of the probe molecule for BPA, the fluorescence response of the probe molecule to different types of metal ions was tested. The tested ions included Na. + K + Ca 2+ Mg 2+ Fe 2+ Fe 3+ Co 2+ Zn 2+ Cd 2+ Al 3+ Cu 2+ The detection concentration of metal ions is 0.2 mM, and the working concentration of the probe molecules is 20 μM. The specific operating procedure is as follows:

[0077] (1) Prepare a 20mM metal ion stock solution. Weigh the corresponding amount of the substance and put it into a 5mL volumetric flask. Add about 4mL of deionized water to dissolve it, and then add more deionized water to the mark of the volumetric flask. Shake well and store in the refrigerator for later use.

[0078] (2) Place 2 mL of DMSO / H₂O (1 / 9, v / v) solution into a 3.5 mL four-sided transparent quartz cuvette. Add 40 μL of QWF stock solution (1 mM) to the cuvette and mix well. Place the cuvette in a fluorescence spectrometer. Set the excitation wavelength to 410 nm and the detection wavelength range to 430–800 nm. Obtain the initial fluorescence spectrum of the probe and record the fluorescence intensity at 562 nm.

[0079] (3) Add 10 μL of each metal ion to the cuvette in (2) to obtain a series of test solutions containing 0.2 mM of metal ions. Test the fluorescence spectrum of the above test solutions.

[0080] (4) Record the fluorescence intensity at 562 nm in the above fluorescence spectrum to obtain the IF of the probe QWF in various interfering environments. 562nmThe value (I) is taken as 100% of the fluorescence intensity. The I value for each sample is then obtained. 562nm The results of creating a bar chart from the numerical values ​​are as follows: Figure 11 As shown.

[0081] (5) Experimental results show that: Fe 3+ Fe 2+ CO 2+ Cu 2+ These metals can cause fluorescence quenching. However, considering Fe... 3+ Fe 2+ CO 2+ Cu 2+ The concentration of these metal ions in the human body is extremely low, so their influence is negligible. Therefore, the QWF probe exhibits good selectivity and anti-interference properties for BPA.

[0082] Example 7: Detection of BPA by probe molecules in actual urine samples

[0083] The QWF probe allows for direct testing after a 10-fold dilution of urine samples (from 3 healthy individuals). The specific testing protocol is as follows:

[0084] (1) Take 0.2 mL of urine sample diluted 10 times and 1.8 mL of DMSO and place them in a 3.5 mL four-sided transparent quartz cuvette. Add 40 μL of QWF stock solution (1 mM) to the cuvette and shake well. Place the cuvette in a fluorescence spectrometer. Set the excitation wavelength to 410 nm and the detection wavelength to 430–800 nm. Obtain the initial fluorescence intensity of the probe at 562 nm in the urine sample.

[0085] (2) Add 0, 2, 4, 6 and 8 μL of BPA stock solution (20 mM) to cuvettes to obtain test solutions of 0, 20, 40, 60 and 80 μM BPA. Measure the fluorescence intensity of the above test solutions at 562 nm.

[0086] (3) Record the fluorescence intensity at 562 nm in the above fluorescence spectrum to obtain a series of I values ​​related to BPA concentration. 562nm The linear relationship. With I 562nm A scatter plot is created with BPA concentration on the x-axis and P(BPA concentration) on the y-axis, as shown below. Figure 12 , 13 As shown in Figure 14.

[0087] (4) Figure 12 Linear fitting was performed on the linear interval (0–80 μM) to obtain the standard curve equation; Figure 13 Linear fitting was performed on the linear interval (0–80 μM) to obtain the standard curve equation; Figure 14Linear fitting was performed on the linear interval (0–80 μM) to obtain the standard curve equation.

[0088] (5) Add BPA standard solutions of known concentrations (30, 50, and 70 μM) to urine samples that have been diluted 10 times, and record probe I. 562nm The fluorescence intensity was measured, and the BPA content in the actual urine was determined according to the standard linear equation. This step was repeated three times. The test results are shown in Table 2.

[0089] Table 2. Detection of BPA in urine by probe molecules.

[0090]

[0091] As can be seen from the table, the calculated BPA concentration in the actual sample is in good agreement with the concentration of added BPA, with a recovery rate in the range of 93.14% to 99.09% and an RSD in the range of 0.26% to 2.54%.

[0092] Finally, it should be noted that the above description of the embodiments is intended to enable those skilled in the art to understand and use them. Those skilled in the art will readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above-described embodiments, and any improvements made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A benzothiazole fluorescent molecule, characterized in that, The structural formula is shown in equation (1):

2. The method for preparing a benzothiazole fluorescent molecule according to claim 1, characterized in that the step... include: 1) At room temperature, 2-aminobenzylthiol and 4-methoxysalicylaldehyde are added to a methanol solution containing I2 to react and give 2-(2-benzothiazolyl)-4-methoxyphenol. 2) 2-(2-benzothiazolyl)-4-methoxyphenol reacts with hexamethylenetetramine under reflux in acetic acid to give 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde; 3) 3-(2-benzothiazolyl)-2-hydroxy-5-methoxybenzaldehyde and 2-hydrazine were reacted by heating and reflux in ethanol to obtain QWF as shown in formula (1).

3. The benzothiazole fluorescent molecule of claim 1 can be used for the detection of boron-containing compounds, or for the preparation of products for the detection of boron-containing compounds.

4. A product for detecting boron-containing compounds, characterized in that, The product contains a benzothiazole fluorescent molecule as described in claim 1.

5. The product for detecting boron-containing compounds according to claim 4, characterized in that, The product is at least one of reagents, reagent kits, components, devices, or equipment.

6. The product for detecting boron-containing compounds according to claim 4, characterized in that, The boron-containing compounds include at least one of boron oxyacids and their salts, boron hydrides, metal borides, organoborides, and other functional boron compounds.

7. A method for detecting boron-containing compounds, characterized in that the steps include... include: Using a benzothiazole fluorescent molecule as described in claim 1 as a probe, a detection system is formed by mixing it with the sample to be tested. The system is then scanned in the range of 430 nm to 800 nm at an excitation wavelength of 410 nm to perform qualitative and / or quantitative determination of boron-containing compounds in the sample.

8. The detection method according to claim 7, characterized in that, Using the concentration of boron-containing compounds and the fluorescence intensity of a benzothiazole fluorescent molecule as described in claim 1 at 562 nm as the x and y axes, the qualitative and / or quantitative determination of boron-containing compounds in the sample is performed using the external standard method, internal standard method, or standard addition method.

9. The detection method according to claim 7, characterized in that, The solvents used in the detection system include any one or any combination of dimethyl sulfoxide, N,N-dimethylformamide, a mixed solvent of dimethyl sulfoxide and water, and a mixed solvent of N,N-dimethylformamide and water.

10. The detection method according to claim 7, characterized in that, The boron-containing compounds include at least one of boron oxyacids and their salts, boron hydrides, metal borides, organoborides, and other functional boron compounds.

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