A coumarin-based fluorescent probe, preparation method, and application in detecting water content and iodide ions in organic solvents

Abstract

The present invention provides a coumarin fluorescent probe, a preparation method and application thereof in detecting the water content and iodide ions in organic solvents, belonging to the technical field of fluorescent probe preparation and analytical detection. In the present invention, a coumarin fluorescent probe is synthesized based on a coumarin derivative, and the preparation method of the coumarin fluorescent probe is simple. The coumarin fluorescent probe can be used for the quantitative and qualitative detection of constant water and trace water in organic solvents, and has the characteristics of high detection sensitivity. The coumarin fluorescent probe can also be used for the qualitative and quantitative detection of iodide ions, and has the advantages of high selectivity and strong anti-interference ability. The probe has wide application value in the detection of iodide ions in natural environments, water bodies and organisms.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent probe preparation and ion detection, and particularly relates to a coumarin-based fluorescent probe, a preparation method and application in detecting the water content of organic solvents and iodide ions. Background Art

[0002] Determination of water content in organic solvents is crucial in various fields of chemistry and industrial processes. Currently, water content in various substances (such as common solvents, petroleum products, foods, and pharmaceuticals) is typically determined using methods such as Karl-Fischer titration, gas chromatography, and nuclear magnetic resonance titration. However, these conventional analytical techniques are inconvenient to operate and require high instrumentation. Optical methods offer advantages over these conventional analytical techniques, particularly fluorescence spectroscopy, which is widely used due to its fast response speed and high test sensitivity.

[0003] In recent years, various functional dye molecules have been used in optical sensing systems to measure the water content in organic solvents, including mercuric cyanide, flavonoids, chalcone, 3-hydroxychromone, naphthalimide, and indole derivatives. However, these have been primarily used to measure trace amounts of water and have not been able to measure the water content of a wide range of solvents. Therefore, there is a need for a fluorescent probe that can be used for both trace and normal water determination.

[0004] In addition, iodide ions (I - ) is a typical halide ion and a trace nutrient necessary for human growth and health. In the human body, iodine is used by the thyroid gland to synthesize thyroid hormones, which are the basis of nervous system activity, body metabolism and thyroid function. According to the World Health Organization (WHO), the daily intake of iodine is certain, and too much or too little will have adverse effects on human health. Iodine deficiency can cause a variety of diseases, such as goiter, hypothyroidism, thyroid cancer, cretinism and many other diseases. However, excessive intake of iodine can also lead to certain thyroid diseases, including hyperthyroidism and hypothyroidism. Therefore, I in the natural environment and water bodies is high. - A specific and simple detection method is very important.

[0005] In recent years, there have been many - Fluorescent probes have been developed, but most of them are made by combining fluorescent materials with heavy metal ions (such as Hg 2+ and Ag + The strong coordination ability of iodide ions is used to make complexes, or the fluorescence of the probe is quenched by heavy metals and then detected by I - The fluorescence of heavy metals, especially Hg, can be determined by reverse titration. 2+The use of highly toxic heavy metals not only makes waste liquid treatment difficult, but also easily causes environmental pollution problems, especially limiting the application of such probes in organisms. - Therefore, the development of non-transition metal fluorescent probes using I - The interaction between the probe molecules is of great significance for the high-specificity real-time monitoring and quantitative analysis of iodide ions in the natural environment, water bodies and organisms. Summary of the Invention

[0006] In response to some of the shortcomings of the prior art, the present invention provides a coumarin-based fluorescent probe, a preparation method, and its application in the detection of water content and iodide ions in organic solvents. In the present invention, a coumarin-based fluorescent probe is synthesized based on a coumarin derivative. The preparation method of the coumarin-based fluorescent probe is simple. The coumarin-based fluorescent probe can be used for the quantitative and qualitative detection of both constant and trace water in organic solvents, and has the characteristics of high detection sensitivity. The coumarin-based fluorescent probe can also be used for the qualitative and quantitative detection of iodide ions, and has the advantages of high selectivity and strong anti-interference ability. It has wide application value in the detection of iodide ions in natural environments, water bodies, and organisms.

[0007] The present invention first provides a coumarin-based fluorescent probe, which is a reddish-brown solid and has the structural formula:

[0008]

[0009] The present invention also provides a method for synthesizing the above-mentioned coumarin-based fluorescent probe, which specifically comprises the following steps:

[0010] Dissolving a coumarin derivative, 4-bromomethylphenylboronic acid pinacol ester and cesium carbonate in N,N-dimethylformamide and stirring for reaction, quenching the reaction after the reaction is completed, precipitating a solid, filtering under reduced pressure, washing, and drying to obtain the coumarin-based fluorescent probe;

[0011] Wherein, the structural formula of the coumarin derivative is:

[0012]

[0013] Preferably, the usage ratio of the coumarin derivative, 4-bromomethylphenylboronic acid pinacol ester, cesium carbonate and N,N-dimethylformamide is: 1 mmol: 1-1.5 mmol: 1.5-2 mmol: 30-40 mL.

[0014] Preferably, the reaction is carried out under stirring at room temperature for 7 to 10 hours.

[0015] Preferably, saturated saline is used to quench the reaction, and the amount of saturated saline used is 50 to 70 mL.

[0016] Preferably, anhydrous ethanol / water (V / V, 2:1) mixed solvent is used for washing three times, with a dosage of 10 mL per time.

[0017] The present invention also provides the use of the coumarin-based fluorescent probe in qualitatively or quantitatively detecting the water content of an organic solvent.

[0018] Preferably, the organic solvent comprises dioxane and tetrahydrofuran (THF);

[0019] The qualitative detection is to observe the fluorescence color change of the organic solvent to be detected under ultraviolet light, and to achieve qualitative detection of the organic solvent based on the fluorescence color change.

[0020] The steps of the quantitative detection are:

[0021] (1) Adding coumarin-based fluorescent probes to organic solvent sample solutions with different water contents, measuring the fluorescence spectra respectively, and obtaining standard working curves;

[0022] (2) Add the coumarin-based fluorescent probe solution to the solution to be tested, measure the fluorescence spectrum, substitute it into the standard working curve in step (1), and calculate the water content in the organic solvent.

[0023] Another object of the present invention is to provide the use of the above-mentioned coumarin-based fluorescent probe in the quantitative or qualitative detection of iodide ions.

[0024] Preferably, the qualitative detection is to observe the fluorescence color change of the organic solvent to be detected under ultraviolet light, and to achieve qualitative detection of iodide ions based on the fluorescence color change.

[0025] Preferably, the quantitative detection is:

[0026] (1) Add the coumarin-based fluorescent probe to sample solutions containing different iodide ion concentrations, place in the dark, and then measure the fluorescence spectra at an excitation wavelength of 370 nm to obtain a standard working curve;

[0027] (2) Add the coumarin-based fluorescent probe solution to the solution to be tested, place it away from light, and then measure the fluorescence spectrum with an excitation wavelength of 370 nm. Substitute it into the standard working curve in step (1) to calculate the amount of iodide ions.

[0028] Preferably, when the iodide ion concentration ranges from 0 to 280 μM, the fluorescence intensity of the fluorescent probe solution at 530 nm in a PBS / dioxane (2 / 8, V / V, pH=7.4, 20 mM) test system is linearly related to the iodide ion concentration.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] This invention constructs a novel coumarin-based fluorescent probe based on a coumarin derivative and pinacol borate, and uses it to detect water content and iodide ions in organic solvents. Pinacol borate is an electron-withdrawing group that forms a D-π-A structure with the N,N-diethyl group at the coumarin site. This probe exhibits strong fluorescence emission in the solvent, and the strong polarity and polarizability of water and iodide ions are exploited to modulate the fluorescence emission of the fluorescent probe, enabling efficient detection of these ions.

[0031] In this invention, a novel coumarin-based fluorescent probe was designed and synthesized, which can realize the fluorescence detection of water content in dioxane and tetrahydrofuran. When the water content in dioxane is between 0% and 10%, the water content and the fluorescence intensity of the probe have a good linear relationship (R 2 =0.99058), and the detection limit calculated according to the detection limit formula LOD=3σ / K (σ=5.53) is as low as 0.055%; when the water content in dioxane is between 10% and 50%, the fluorescence intensity also has a good linear relationship with the water content (R 2 =0.99154). Therefore, using the standard curve, the detection of constant and trace water content in dioxane within the range of 0% to 50% can be achieved; in addition, when the water content in tetrahydrofuran is between 10% and 70%, the fluorescence intensity and water content also show a good linear relationship (R 2 =0.99627), the water content in tetrahydrofuran can also be calculated using the standard curve.

[0032] The fluorescent probe in the present invention exhibits different colors under a 365nm ultraviolet lamp as the water content in the solvent increases. Therefore, the solution color change can be used to quickly and visually detect the water content in the solvent. Similarly, in a PBS / dioxane (2 / 8, v / v, pH = 7.4, 20mM) buffer solution, the probe emits bright yellow fluorescence. As the iodide ion concentration increases, the fluorescence gradually disappears. This obvious color change can be used to detect iodide ions with the naked eye.

[0033] The fluorescent probe of the present invention has good selectivity for detecting iodide ions in a PBS / dioxane (2 / 8, V / V, pH=7.4, 20 mM) test system and has good anti-interference ability for 16 common anions.

[0034] The present invention utilizes the interaction between the fluorescent probe and the iodide ion to realize its detection, avoiding the common detection method using the coordination effect between the iodide ion and the transition metal, and avoiding the transition metal, especially Hg 2+ The use of highly toxic transition metals such as chlorinated bicarbonate can effectively prevent waste from polluting the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the synthetic route of coumarin-based fluorescent probes.

[0036] Figure 2 This is the fluorescence spectrum of the coumarin-based fluorescent probe when the water content in the dioxane-H2O test system is 0-10%.

[0037] Figure 3 This is a linear relationship diagram between the fluorescence intensity of the coumarin-based fluorescent probe at 490 nm and the water content (0-10%) in the dioxane-H2O test system.

[0038] Figure 4 The following are fluorescence spectra of the coumarin-based fluorescent probe in a dioxane-H2O test system with a water content ranging from 0% to 100%. The following are fluorescence images of the coumarin-based fluorescent probe in a dioxane-H2O test system with a water content ranging from 0% to 90% under 365nm handheld UV light illumination.

[0039] Figure 5 This is a linear relationship diagram between the fluorescence intensity of the coumarin-based fluorescent probe at 518 nm and the water content (10-50%) in the dioxane-H2O test system.

[0040] Figure 6 These are fluorescence images of the fluorescent probe in the dioxane-H2O test system with different water content ratios under 365nm ultraviolet light.

[0041] Figure 7 This is the fluorescence spectrum of the coumarin-based fluorescent probe when the water content in the THF (tetrahydrofuran)-H2O test system is 0-100%.

[0042] Figure 8 This is a linear relationship diagram between the fluorescence intensity of the coumarin-based fluorescent probe at 520 nm and the water content (10-70%) in the THF-H2O test system.

[0043] Figure 9 Coumarin-based fluorescent probe solution with I - Fluorescence spectra with increasing concentration (0-60 equiv). The inset is a photograph of the probe solution under a 365 nm handheld UV lamp before and after the addition of iodine ions.

[0044] Figure 10 is the fluorescence emission intensity of the coumarin-based fluorescent probe at 530 nm and I - The linear relationship between the concentration (0 ~ 280μM).

[0045] Figure 11 This is the selective fluorescence spectrum of the coumarin-based fluorescent probe for anions.

[0046] Figure 12 Coumarin-based fluorescent probe and excess I- The fluorescence intensity at 530 nm after adding other anions to the solution system.

[0047] Figure 13 I was added to the coumarin-based fluorescent probe solution at different pH values. - Graph of fluorescence emission intensity at 530 nm before and after. DETAILED DESCRIPTION

[0048] To facilitate understanding of the present invention, the present invention will be described in detail and comprehensively below with reference to the accompanying drawings. However, the present invention can be implemented in various forms, and the embodiments described herein are merely some of the embodiments of the present invention. Rather, these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0049] Example 1:

[0050] The synthetic route of the coumarin-based fluorescent probe of the present invention is as follows: Figure 1 As shown, the specific steps are as follows: a coumarin derivative (181 mg, 0.5 mmol), 4-bromomethylphenylboronic acid pinacol ester (193 mg, 0.65 mmol) and cesium carbonate (325 mg, 1 mmol) were weighed and dissolved in 20 mL of N,N-dimethylformamide, and reacted under magnetic stirring at room temperature for 8 hours. After the reaction, 30 mL of saturated saline was added to quench the reaction. The precipitated solid was filtered under reduced pressure and then washed three times with a mixed solvent of anhydrous ethanol / water (V / V, 2:1) at a dosage of 5 mL / time. The solid was then vacuum dried to obtain 258 mg of a reddish-brown solid, which is the coumarin-based fluorescent probe.

[0051] Among them, the synthesis method of coumarin derivative 1 refers to the literature (J.-h.Zhu, H.Zhang, Y.Liao, J.-j.Liu, Z.-j.Quan, X.-c.Wang, A multifunctional fluorescent probe for highly selective detection of hydrazine and discovering the interplay between AIEand ICT, Dyes and Pigments, 175(2020)108111.).

[0052] The coumarin-based fluorescent probe 1H NMR (600 MHz, CDCl3) δ 8.53 (s, 1H), 8.03 (d, J = 15.6 Hz, 1H), 7.81 (m, 3H), 7.62 (d, J = 8.7 Hz, 2H), 7.42 (m, 3H), 6.97 (d, J = 8.7 Hz, 2H), 6.61 (dd, J = 8.9, 2.3 Hz, 1H), 6.48 (d, J = 2.3 Hz, 1H), 5.11 (d, J = 23.0 Hz, 2H), 3.45 (q, J = 7.1 Hz, 4H), 1.34 (s, 12H), 1.24 (t, J = 7.1 Hz, 6H). This indicates the successful preparation of the coumarin-based fluorescent probe.

[0053] Example 2:

[0054] A coumarin derivative (181 mg, 0.5 mmol), 4-bromomethylphenylboronic acid pinacol ester (148 mg, 0.5 mmol), and cesium carbonate (244 mg, 0.5 mmol) were weighed and dissolved in 10 mL of N,N-dimethylformamide and reacted at room temperature under magnetic stirring for 8 hours. After the reaction, 30 mL of saturated brine was added to quench the reaction. The precipitated solid was filtered under reduced pressure and then washed three times with a mixed solvent of anhydrous ethanol / water (v / v, 2:1) at a rate of 5 mL per wash. The solid was then dried under vacuum to obtain 205 mg of a reddish-brown solid, which was the coumarin-based fluorescent probe.

[0055] Example 3:

[0056] In this example, the coumarin-based fluorescent probe prepared in Example 1 was investigated for the detection of constant water or trace water in an organic solvent. In this example, the organic solution system was a dioxane-H2O test system. The specific investigation steps are as follows:

[0057] (1) Preparation of coumarin-based fluorescent probe stock solution

[0058] Accurately weigh 28.9 mg of the coumarin-based fluorescent probe and place it in a 50 mL volumetric flask. Dose dioxane to make the volume constant to obtain a 1.0 mM coumarin-based fluorescent probe stock solution, which is then stored in a -4°C refrigerator for later use.

[0059] (2) Detection of H2O content in dioxane

[0060] Into stoppered test tubes, 30 μL of coumarin-based fluorescent probe stock solution was added, followed by 2.970 mL of dioxane-H2O mixed solvent with water contents of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100%, respectively. The fluorescence spectra were measured with an excitation wavelength of 370 nm.

[0061] Figure 2 This is the fluorescence spectrum of the coumarin-based fluorescent probe when the water content in the dioxane-H2O test system is 0-10%. Figure 3 The linear relationship diagram of the fluorescence intensity of the coumarin-based fluorescent probe at 490 nm and the water content (0-10%) in the dioxane-H2O test system. Figure 2 and Figure 3 It can be seen that when the water content in the dioxane solvent increases from 0 to 10%, the fluorescence spectrum of the coumarin-based fluorescent probe red-shifts, and the fluorescence intensity at 490 nm shows a good linear relationship with the water content (R 2 =0.99058), and the resulting standard working curve is: y = 5646.54545 - 300.10909 * x, where x represents the volumetric water content (V / V, %) in dioxane, and y represents the fluorescence intensity of the coumarin-based fluorescent probe at 490 nm in the mixed solvent. The minimum detection limit calculated using the limit of detection formula (LOD) = 3σ / K is 0.055%. When the water content is within this range, the volumetric water content in dioxane can be calculated using the standard working curve.

[0062] Figure 4 This is the fluorescence spectrum of the coumarin-based fluorescent probe when the water content in the dioxane-H2O test system is 0% to 100%. Figure 5 The linear relationship diagram of the fluorescence intensity of the coumarin-based fluorescent probe at 518 nm and the water content (10-50%) in the dioxane-H2O test system is shown in FIG. Figure 4 and Figure 5 It can be seen that when the water content increases from 10% to 50%, the maximum emission intensity of the coumarin-based fluorescent probe undergoes a red shift and gradually decreases. The fluorescence intensity at 518 nm shows a good linear relationship with the water content (R 2 =0.99154), and the resulting standard working curve is: y = 6280.21111 - 113.30333 * x, where x represents the volumetric water content (V / V, %) in dioxane and y represents the fluorescence intensity of the probe at 518 nm in the mixed solvent. When the water content is within the range of 10-50%, the water content can be determined using the standard working curve.

[0063] (3) Visual detection of water content in dioxane:

[0064] Figure 6The figure shows the fluorescence photographs of the coumarin-based fluorescent probe under 365nm handheld UV lamp when the water content in the dioxane-H2O test system is 0% to 90%. As can be seen from the figure, as the water content in the dioxane increases, the solution changes from yellow-green to orange-yellow. Therefore, based on the fluorescence color of the test system, the water content in the dioxane can be visually and qualitatively detected.

[0065] Example 4:

[0066] In this example, the coumarin-based fluorescent probe prepared in Example 1 was used to detect the water content in a tetrahydrofuran (THF)-H2O test system. The specific investigation steps are as follows:

[0067] (1) Preparation of coumarin-based fluorescent probe stock solution

[0068] Accurately weigh 28.9 mg of the coumarin-based fluorescent probe and place it in a 50 mL volumetric flask. Dose the flask with tetrahydrofuran (THF) to obtain a 1.0 mM coumarin-based fluorescent probe mother solution, which is then stored in a -4°C refrigerator for later use.

[0069] (2) Detection of H2O content in tetrahydrofuran

[0070] Into stoppered test tubes, 30 μL of coumarin-based fluorescent probe stock solution was added, followed by 2.970 mL of THF-H2O mixed solvent with water contents of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and 100%, respectively. The fluorescence spectra were measured with an excitation wavelength of 370 nm.

[0071] Figure 7 The fluorescence spectrum of the coumarin-based fluorescent probe in the THF-H2O test system with a water content of 0 to 100% is shown in Figure 2. Figure 8 The linear relationship between the fluorescence intensity of the coumarin-based fluorescent probe at 520 nm and the water content (10-70%) in the THF-H2O test system is shown in FIG. Figure 7 and 8 It can be seen that when the water content in tetrahydrofuran solvent increases from 0 to 70%, the fluorescence spectrum of the probe undergoes an obvious red shift. When the water content in tetrahydrofuran is between 10% and 70%, the fluorescence intensity of the probe solution at 520 nm shows a good linear relationship with the water content. The obtained standard working curve is: y = 3941.14286-39.53214*x(R 2=0.99627) wherein: x represents the volume content of water in tetrahydrofuran (V / V, %), and y represents the fluorescence intensity of the probe at 520 nm in the mixed solvent. When the water content ratio is within the range, the volume content of water can be calculated according to the standard working curve.

[0072] In summary, the fluorescent probe provided by the present invention can not only quantitatively detect trace water in solvents, but also be used for quantitative detection of constant water in solvents. At the same time, with the help of ultraviolet light, visual qualitative detection of water content in solvents can also be achieved.

[0073] Example 5:

[0074] In this example, the detection of iodide ions by the coumarin-based fluorescent probe prepared in Example 1 was investigated. The specific investigation steps are as follows:

[0075] 30 μL of the coumarin-based fluorescent probe mother solution prepared in Example 3 and 2.970 mL of PBS / dioxane (2 / 8, V / V, pH=7.4, 20 mM) buffer solution were added to a stoppered test tube to obtain a probe solution with a concentration of 10 μM. 0.01 M iodide ions were then added to the solution to make the concentration of iodine ions 0.01 M. - The concentration (0-60 equiv) was changed gradually, and after being placed in the dark for 13 minutes, the fluorescence spectra were tested with 370 nm as the excitation wavelength.

[0076] Figure 9 Coumarin-based fluorescent probe solution with I - The fluorescence spectra of the probe solution with increasing concentration gradient (0-60 equiv) are shown in the inset. The inset is a photo of the probe solution before and after adding iodine ions under a 365 nm handheld UV lamp. As can be seen from the figure, in the concentration range of 0-600 μM, as I - With the increase of concentration, the fluorescence emission intensity of the probe gradually decreased. At the same time, under 365nm ultraviolet light, the solution changed from bright yellow-green to colorless, as shown in the inset. This significant color change indicates that the probe can be used for I - naked eye recognition.

[0077] Figure 10 is the fluorescence emission intensity of the coumarin-based fluorescent probe at 530 nm and I - The linear relationship between the concentration (0-280 μM) and the fluorescence intensity at 530 nm is shown in the figure. - The concentration showed a good linear relationship (R 2 =0.99431). The linear equation is y=4157.91667-9.6744*x. According to the detection limit formula LOD=3σ / K (σ=5.53), the lowest detection limit calculated is 1.71 μM.

[0078] Example 6:

[0079] In this example, the selectivity of the coumarin-based fluorescent probe prepared in Example 1 for common anions was investigated. The specific investigation steps are as follows:

[0080] Prepare SO4 with ultrapure water 2- 、SO3 2- 、SCN - 、S2O3 2- PO4 3- 、NO3 - 、NO2 - 、HPO4 2- 、HCO3 - 、H2PO4 - , H2O2, CO3 2- 、ClO3 - 、Cl - Br - 、F - and I - The final concentration of the potassium salt analyte stock solution was 0.01M.

[0081] 30 μL of the coumarin-based fluorescent probe stock solution prepared in Example 3 and 2.970 mL of PBS / dioxane (2 / 8, V / V, pH = 7.4, 20 mM) buffer solution were added to a stoppered test tube to obtain a probe solution with a concentration of 10 μM. 100 equiv of SO4 was then added to the solution. 2- 、SO3 2- 、SCN - 、S2O3 2- PO4 3- 、NO3 - 、NO2 - 、HPO4 2- 、HCO3 - 、H2PO4 - , H2O2, CO3 2- 、ClO3 - 、Cl - Br - 、F - and I - The potassium salt analyte stock solution was placed in the dark for 13 minutes, and then its fluorescence spectrum was tested at 370 nm as the excitation wavelength.

[0082] Figure 11 The selective fluorescence spectrum of the coumarin-based fluorescent probe for anions is shown in the figure. It can be seen from the figure that only I - With the addition of SO4 2- 、SO32- 、SCN - 、S2O3 2- PO4 3- 、NO3 - 、NO2 - 、HPO4 2- 、HCO3 - 、H2PO4 - , H2O2, CO3 2- 、ClO3 - 、Cl - Br - and F - The addition of has little effect on the fluorescence intensity of the coumarin-based fluorescent probe, indicating that the probe of the present invention has a good effect on the fluorescence intensity of the coumarin-based fluorescent probe. - The detection has good selectivity.

[0083] Example 8:

[0084] In this example, the anti-interference ability of the coumarin-based fluorescent probe prepared in Example 1 for iodide ion detection was investigated. The specific investigation steps are as follows:

[0085] 30 μL of the coumarin-based fluorescent probe stock solution prepared in Example 3 and 2.970 mL of PBS / dioxane (2 / 8, V / V, pH = 7.4, 20 mM) buffer solution were added to a stoppered test tube to obtain a probe solution with a concentration of 10 μM. 100 equiv of iodide ions and 100 equiv of SO4 were then added to the solution. 2- 、SO3 2- 、SCN - 、S2O3 2- PO4 3- 、NO3 - 、NO2 - 、HPO4 2- 、HCO3 - 、H2PO4 - , H2O2, CO3 2- 、ClO3 - 、Cl - Br - 、F - and I - The potassium salt analyte stock solution was placed in the dark for 13 minutes, and then its fluorescence spectrum was tested at 370 nm as the excitation wavelength.

[0086] Figure 12 Coumarin-based fluorescent probe and excess I -Fluorescence intensity at 530 nm after adding other anions to the solution system. As can be seen from the figure, the addition of other anions has almost no effect on the fluorescence intensity of the probe solution at 530 nm. This demonstrates that the coumarin-based fluorescent probe prepared in the present invention has strong anti-interference ability for the detection of iodide ions.

[0087] Example 9:

[0088] In this example, the acid-base stability of the coumarin-based fluorescent probe prepared in Example 1 was investigated. The specific investigation steps are as follows:

[0089] 30 μL of the coumarin-based fluorescent probe stock solution prepared in Example 3 and 2.970 mL of PBS / dioxane (2 / 8, v / v, pH = 7.4, 20 mM) buffer solutions of varying pH values ​​were added to stoppered test tubes to obtain test solutions with a concentration of 10 μM. The fluorescence spectra of the test solutions were measured at an excitation wavelength of 370 nm. 100 equiv of iodide ions were then added to the test solutions, which were then incubated in the dark for 20 minutes before the fluorescence emission spectra were measured.

[0090] Figure 13 I was added to the coumarin-based fluorescent probe solution at different pH values. - The fluorescence emission intensity at 530nm before and after the experiment is shown in the figure. It can be seen from the figure that the fluorescence intensity of the coumarin-based fluorescent probe remains stable in the range of pH = 5 to 11, indicating that the coumarin-based fluorescent probe provided by the present invention has good acid-base stability. - The detection can be carried out in the range of pH = 3 to 9 and is less affected by changes in acidity and alkalinity.

[0091] In summary, the fluorescent probe provided by the present invention has good selectivity and anti-interference ability for iodide ions and can quantitatively detect iodide ions in a wide pH range.

[0092] The embodiments described are preferred implementations of the present invention, but the present invention is not limited to the above implementations. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention are within the scope of protection of the present invention.

Claims

1. A method for synthesizing a coumarin fluorescent probe, characterized in that: include: Dissolving a coumarin derivative, 4-bromomethylphenylboronic acid pinacol and cesium carbonate in N,N-dimethylformamide and stirring for reaction, quenching the reaction after the reaction is completed, precipitating a solid, filtering under reduced pressure, washing, and drying to obtain the coumarin fluorescent probe; Wherein, the structural formula of the coumarin derivative is: ； The usage ratio of the coumarin derivative, 4-bromomethylphenylboronic acid pinacol ester, cesium carbonate and N,N-dimethylformamide is: 1 mmol: 1-1.5 mmol: 1.5-2 mmol: 30-40 mL; The reaction conditions are as follows: stirring the reaction at room temperature for 7 to 10 hours.

2. The method for synthesizing a coumarin fluorescent probe according to claim 1, wherein The quenching reaction is carried out using saturated saline, and the volume ratio of the saturated saline to N,N-dimethylformamide is 50-70 mL:30-40 mL.

3. The coumarin fluorescent probe prepared by the method according to any one of claims 1 or 2, characterized in that The coumarin fluorescent probe is a reddish-brown solid, and the structural formula of the coumarin fluorescent probe is: 。 4. Use of the coumarin fluorescent probe according to claim 3 in qualitatively or quantitatively detecting the water content of an organic solvent; the water content is constant water or trace water.

5. The use according to claim 4, characterized in that The organic solvents are dioxane and tetrahydrofuran.

6. Use of the coumarin fluorescent probe according to claim 1 in the qualitative or quantitative detection of iodide ions.

7. The use according to claim 6, characterized in that The applications are: (1) Add the coumarin fluorescent probe mother solution to the sample solution containing different iodide ion concentrations, place it in the dark, and then measure the fluorescence spectrum at 370 nm as the excitation wavelength to obtain the standard working curve; (2) Add the coumarin fluorescent probe solution to the solution to be tested, place it away from light, and then measure the fluorescence spectrum with an excitation wavelength of 370 nm. Substitute it into the standard working curve in step (1) to obtain the amount of iodide ions.

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