A near-infrared fluorescence analysis method for rapid detection of iodine ions

Abstract

The invention discloses a near-infrared fluorescence analysis method for rapid detection of iodine ions, comprising: S100, preparation of compound CyN, S200, construction of probe CyN-Cu, S300, spectral detection, S400, selective experiment, S500, detection of iodine ions, S600, detection of actual samples. The invention has the beneficial effect that the invention constructs a near-infrared fluorescent probe CyN-Cu. According to the redox reaction between iodine ions and copper ions, copper ions are separated from CyN, and the fluorescence intensity of the system is significantly restored, thus establishing an "off-on" type near-infrared fluorescence enhanced detection method. ‑ Method, I ‑ The concentration is linearly related to the change of the fluorescence intensity of the system in the range of 0.1μmol / L to 5mmol / L, and the fitting equation is y=2.3621x+1.1471, R2=0.9987, and the detection limit is 65nmol / L. Compared with other methods, this method has the advantages of simple synthesis, fast response rate (<100s), high selectivity and near-infrared emission. The probe response is not interfered by other anions and has been successfully applied to I ‑ Rapid testing.

Description

Technical Field

[0001] The invention relates to the technical field of iodine ion detection, in particular to a near-infrared fluorescence analysis method for rapidly detecting iodine ions. Background Art

[0002] Iodine is an essential trace element in life and the main raw material for synthesizing thyroid hormones. It plays an irreplaceable role in nerve function activity. Normally, the iodine content in the body is in a dynamic equilibrium state. Excessive iodine intake can cause hyperthyroidism, while too little iodine intake can cause serious diseases such as dementia and hypothyroidism. However, the ingested iodine is excreted into urine and blood through metabolism. Therefore, it is of great significance to use a simple and rapid method to detect the iodine content in food, environmental and biological samples.

[0003] At present, fluorescence spectroscopy has the advantages of low detection limit, high sensitivity, high selectivity, less interference, real-time analysis and simple operation, and has received widespread attention. Due to the heavy atom effect of iodine, most iodine ion fluorescent probes are quenched, resulting in a low signal-to-noise ratio and easy to produce false positive signals. However, most enhanced iodine ion fluorescent probes are metal ion coordination type, such as mercury ions, which are prone to environmental pollution and limit their practical application. In addition, the enhanced iodine ion fluorescent probes have a high detection limit and an emission peak below 650nm, which limits their detection in biological samples, especially in cells, blood and other biological samples. The interference of autofluorescence. Therefore, it is of great significance to develop an iodine ion fluorescent probe with near-infrared excitation and near-infrared emission.

[0004] As we all know, heptamethine cyanine dye is a fluorophore with near-infrared emission and has been widely used in the field of fluorescence detection. In addition, there are literature reports that pyridone groups can react with metal ions (Cd 2+ ,Cu 2+ and Ni 2+ ) has a specific chelating effect, thereby quenching the fluorescence of the fluorophore (Sensor.Actuat.B-Chem.2009,138,637; Eur.J.Org.Chem.2008,2,481). Interestingly, iodine ions can undergo a redox reaction with copper ions, thereby destroying the coordination effect between the pyridone group and the copper ion, thereby causing the recovery of fluorescence (Sensor.Actuat.B-Chem.2009,138,637). In view of this, in-depth research was conducted on the above issues, resulting in this case. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems, and a near-infrared fluorescence analysis method for rapid detection of iodine ions is designed to solve the problems mentioned in the background technology.

[0006] To achieve the above-mentioned purpose, the technical solution of the present invention is: a near-infrared fluorescence analysis method for rapid detection of iodine ions, comprising: S100, preparation of compound CyN, S200, construction of probe CyN-Cu, S300, spectral detection, S400, selective experiment, S500, detection of iodine ions, and S600, detection of actual samples.

[0007] Preferably, the S100 comprises: weighing 0.357 g of benzindole quaternary ammonium salt, 0.361 g of N-[3-(anilinomethylene)-2-chloro-1-cyclohexyl-1-yl)methylene]aniline hydrochloride and 0.1817 g of 2-acetylpyridine, dissolving them in 20 mL of ethanol, setting the oil bath temperature, and reflux reaction; after the reaction is completed, cooling, adding 100 mL of ether, filtering to obtain a dark blue solid, washing with saturated brine, extracting with dichloromethane three times, combining the organic phases, drying over anhydrous magnesium sulfate, filtering, evaporating the solvent with a rotary evaporator, vacuum drying to obtain a blue solid, separating by column chromatography, using methanol / dichloromethane (v / v, 1:16) as the developing solvent, obtaining 0.1723 g of a dark green solid with a yield of 32.14%, and storing the solid in a sealed refrigerator for standby use.

[0008] Preferably, the temperature of the S100 oil bath is 80° C., and the reflux reaction time of the S100 is 8 hours.

[0009] Preferably, the S200 comprises: compound CyN is prepared into a 50 mmol / L solution with DMF, anhydrous copper sulfate is prepared into a 100 mmol / L solution with deionized water, 2.5 μL of 10 mmol / L CyN solution is added to a 1 mL cuvette, and 100 mmol / L Cu is gradually added. 2+ solution, 25 μL Tris-HCl buffer (50 mmol / L, pH = 6.0), mixed well and diluted to 500 μL with DMF, reacted for 20 min, then, the changes in fluorescence signals were recorded with a fluorescence spectrophotometer, and the probe CyN-Cu mother solution was obtained when the quenching effect was optimal.

[0010] Preferably, the S300 includes:

[0011] UV-visible absorption spectrum detection: 5.0 μL of the above CyN-Cu mother solution and 50 μL Tris-HCl buffer were taken in a cuvette, mixed evenly and diluted to 1 mL with DMF. The UV-visible absorption spectrum of CyN-Cu was measured, and then 1 μL of 200 mmol / L I - Solution, react for 3 minutes, and then measure the CyN-Cu and I - The UV-visible absorption spectrum after action;

[0012] For the detection of fluorescence emission spectrum, take the above 2.5 μL CyN-Cu in 25 μL Tris-HCl buffer (50 mmol / L, pH = 6.0), then add iodine ion solution of different concentrations, mix well, dilute to 500 μL with DMF, react for 3 minutes, and measure its fluorescence emission spectrum. The detection conditions are as follows: excitation wavelength 650 nm, excitation slit width 10.0 nm, emission slit width 10.0 nm, voltage 700 V.

[0013] Preferably, the S400 includes:

[0014] Use deionized water to prepare different ions into 200mmol / L solution for use, take 2.5μL CyN-Cu in 25μL Tris-HCl buffer (50mmol / L, pH=6.0), mix well and dilute to 500μL with DMF, then add equal amounts of different anion solutions, after the reaction, use a fluorescence spectrophotometer to record the changes in fluorescence signals, detection conditions: excitation wavelength 650nm, excitation slit width 10.0nm, emission slit width 10.0nm, voltage 700V.

[0015] Preferably, the S400 reaction is performed for 3 minutes.

[0016] Preferably, the S500 includes:

[0017] Take 2.5 μL CyN-Cu in 25 μL tris-HCl buffer (50 mmol / L, pH = 6.0), mix well and dilute to 500 μL with DMF, measure its fluorescence emission spectrum, then add different concentrations of - solution, react for 3 minutes, and record the changes in fluorescence signal with a fluorescence spectrophotometer. Repeat the test 3 times for detection.

[0018] Preferably, the S500 detection conditions are an excitation wavelength of 650 nm, an excitation slit width of 10.0 nm, an emission slit width of 10.0 nm, and a voltage of 700 V.

[0019] Preferably, the S600 includes:

[0020] Accurately weigh 10g of raw dark tea and 10g of Jinhua dark tea, soak them in 100mL of boiling water for 10min respectively, soak the residue in boiling water for two more times, combine the filtrate and concentrate it to 20mL, add the concentrate to a 50mL volumetric flask, dilute to the scale with distilled water, set aside, add CyN-Cu solution and a certain amount of dark tea reserve solution to the cuvette, record the changes in fluorescence signal with a fluorescence spectrophotometer, test three times in parallel, and the detection conditions are as follows: excitation wavelength 650nm, excitation slit width 10.0nm, emission slit width 10.0nm, voltage 700V.

[0021] A near-infrared fluorescence analysis method for rapid detection of iodine ions prepared by the technical solution of the present invention has the following beneficial effects:

[0022] 1. The present invention constructs a near-infrared fluorescent probe CyN-Cu. According to the redox reaction between iodine ions and copper ions, copper ions are separated from CyN, and the fluorescence intensity of the system is significantly restored, thus establishing an "off-on" type near-infrared fluorescence enhanced detection I - Method, I - The concentration is linearly related to the change of the fluorescence intensity of the system in the range of 0.1μmol / L to 5mmol / L, and the fitting equation is y=2.3621x+1.1471, R2=0.9987, and the detection limit is 65nmol / L. Compared with other methods, this method has the advantages of simple synthesis, fast response rate (<100s), high selectivity and near-infrared emission. The probe response is not interfered by other anions and has been successfully applied to I - Rapid testing;

[0023] 2. The present invention uses 2-chloro-3-(hydroxymethylene)-1-cyclohexene-1-carboxaldehyde as a raw material, and sequentially reacts with N-ethylbenzindole and 2-acetylpyridine to obtain a cyanine derivative (CyP), which is then coordinated with copper ions to obtain a fluorescent probe (CyP-Cu). The iodide ion (I - ) can induce a significant enhancement in the fluorescence signal of CyN-Cu, and the change in fluorescence signal intensity is related to the iodine ion (I - ) concentration, has a good linear relationship, has the advantages of fast response rate (<100s), high specific recognition, low detection limit (65nM), wide response range (0-5mM), and is not interfered by common ions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the S100 structure of a near-infrared fluorescence analysis method for rapid detection of iodine ions described in the present invention.

[0025] Figure 2 This is a schematic diagram of the S200 structure of a near-infrared fluorescence analysis method for rapid detection of iodine ions described in the present invention.

[0026] Figure 3 This is a schematic diagram of the construction of the probe CyP-Cu for the near-infrared fluorescence analysis method for rapid detection of iodine ions described in the present invention and its spectral characterization structure.

[0027] Figure 4 The solvent type of the near-infrared fluorescence analysis method for rapid detection of iodine ions according to the present invention is I - Schematic diagram of the impact structure of the detection.

[0028] Figure 5The present invention provides a method for rapid detection of iodide ions by near-infrared fluorescence analysis of Tris-HCl buffer solutions of different pH values. - Schematic diagram of the impact structure of the detection.

[0029] Figure 6 The present invention provides a near-infrared fluorescence analysis method for rapid detection of iodine ions with different solvent ratios. - Schematic diagram of the impact structure of the detection.

[0030] Figure 7 The probe CyN-Cu and I - Schematic diagram of the kinetic curve structure of the action.

[0031] Figure 8 This is a schematic diagram of the ion-selective structure of the near-infrared fluorescence analysis method for rapid detection of iodine ions described in the present invention.

[0032] Fig. 9 The present invention is a schematic diagram of the detection structure of the iodine ion concentration of the near-infrared fluorescence analysis method for rapid detection of iodine ions. DETAILED DESCRIPTION

[0033] The present invention will be described in detail below in conjunction with the accompanying drawings. Figure 1-9 As shown, a near-infrared fluorescence analysis method for rapid detection of iodide ions.

[0034] Example

[0035] A near-infrared fluorescence analysis method for rapid detection of iodine ions comprises: S100, preparation of compound CyN, S200, construction of probe CyN-Cu, S300, spectrum detection, S400, selective experiment, S500, detection of iodine ions, and S600, detection of actual samples.

[0036] As a preferred embodiment, further, S100 includes: weighing 0.357g (1.5mmol) of benzindole quaternary ammonium salt, 0.361g (1mmol) of N-[3-(anilinomethylene)-2-chloro-1-cyclohexyl-1-yl)methylene]aniline hydrochloride and 0.1817g (1.5mmol) of 2-acetylpyridine, dissolving in 20mL of ethanol, setting the oil bath temperature, and reflux reaction; after the reaction is completed, cooling, adding 100mL of ether, filtering to obtain a dark blue solid, washing with saturated brine, extracting three times with dichloromethane, combining the organic phases, drying over anhydrous magnesium sulfate, filtering, and evaporating the solvent with a rotary evaporator, vacuum drying to obtain a blue solid, column chromatography separation, the developing solvent is methanol / dichloromethane (v / v, 1:16), and 0.1723g of a dark green solid is obtained, with a yield of 32.14%, and the solid is sealed and stored in a refrigerator for standby use.

[0037] As a preferred embodiment, further, the temperature of the S100 oil bath is 80° C., and the reflux reaction time of S100 is 8 hours.

[0038] As a preferred embodiment, further, S200 includes: compound CyN is prepared into a 50 mmol / L solution with DMF, anhydrous copper sulfate is prepared into a 100 mmol / L solution with deionized water, 2.5 μL of 10 mmol / L CyN solution is added to a 1 mL cuvette, 100 mmol / L Cu2+ solution and 25 μL Tris-HCl buffer (50 mmol / L, pH = 6.0) are gradually added, mixed evenly, diluted to 500 μL with DMF, reacted for 20 minutes, and then, the changes in the fluorescence signal are recorded with a fluorescence spectrophotometer, and the probe CyN-Cu mother solution is obtained when the quenching effect is optimal.

[0039] As a preferred solution, further, S300 includes:

[0040] UV-visible absorption spectrum detection: 5.0 μL of the above CyN-Cu mother solution and 50 μL Tris-HCl buffer were taken in a cuvette, mixed evenly and diluted to 1 mL with DMF, and the UV-visible absorption spectrum of CyN-Cu was measured. Then 1 μL of 200 mmol / L I- solution was added and reacted for 3 min, and then the CyN-Cu and I- were measured. - The UV-visible absorption spectrum after action;

[0041] For the detection of fluorescence emission spectrum, take the above 2.5 μL CyN-Cu in 25 μL Tris-HCl buffer (50 mmol / L, pH = 6.0), then add iodine ion solution of different concentrations, mix well, dilute to 500 μL with DMF, react for 3 minutes, and measure its fluorescence emission spectrum. The detection conditions are as follows: excitation wavelength 650 nm, excitation slit width 10.0 nm, emission slit width 10.0 nm, voltage 700 V.

[0042] As a preferred solution, further, S400 includes:

[0043] Use deionized water to prepare different ions into 200mmol / L solution for use, take 2.5μL CyN-Cu in 25μL Tris-HCl buffer (50mmol / L, pH=6.0), mix well and dilute to 500μL with DMF, then add equal amounts of different anion solutions, after the reaction, use a fluorescence spectrophotometer to record the changes in fluorescence signals, detection conditions: excitation wavelength 650nm, excitation slit width 10.0nm, emission slit width 10.0nm, voltage 700V.

[0044] As a preferred embodiment, further, S400 is reacted for 3 minutes.

[0045] As a preferred solution, further, S500 includes:

[0046] Take 2.5 μL CyN-Cu in 25 μL tris-HCl buffer (50 mmol / L, pH = 6.0), mix well and dilute to 500 μL with DMF, measure its fluorescence emission spectrum, then add different concentrations of I-solution, react for 3 minutes, and record the changes in fluorescence signal with a fluorescence spectrophotometer. Repeat the test 3 times for detection.

[0047] As a preferred solution, further, the S500 detection conditions are: an excitation wavelength of 650nm, an excitation slit width of 10.0nm, an emission slit width of 10.0nm, and a voltage of 700V.

[0048] As a preferred solution, further, S600 includes:

[0049] Accurately weigh 10g of raw dark tea and 10g of Jinhua dark tea, soak them in 100mL boiling water for 10min respectively, soak the residue in boiling water for 2 more times, combine the filtrate and concentrate it to 20mL, take the concentrate and add it to a 50mL volumetric flask, dilute it to the mark with distilled water, set aside, add CyN-Cu solution and a certain amount of dark tea reserve solution to the cuvette, record the change of fluorescence signal with a fluorescence spectrophotometer, test it 3 times in parallel, the detection conditions are: excitation wavelength 650nm, excitation slit width 10.0nm, emission slit width 10.0nm, voltage 700V

[0050] According to Cu 2+ The compound CyN was coordinated with Cu2+ to construct the probe CyN-Cu, and the interaction between CyN and Cu was investigated. 2+ The concentration ratio is as follows Figure 3 shown.

[0051] Figure 3 (a). CyN, CyN-Cu 2+ and CyN-Cu 2+ +I - Ultraviolet fluorescence emission spectra before and after the reaction. (b) Compound CyN and Cu 2+ Fluorescence emission spectra before and after the reaction. (c) Fluorescence intensity change of the fluorescence spectrum of compound CyN and Cu 2+ (d) Probe CyN-Cu and I - Fluorescence emission spectrum of the effect.

[0052] like Figure 3 As shown in (a), the compound CyN and Cu2+ After the action, the absorption peak at 670nm decreased, and the absorbance of the absorption peak at 500nm was significantly enhanced. Figure 3 As shown in (b) and (c), as Cu 2+ With the increase of Cu concentration, the fluorescence intensity of compound CyN at 700nm gradually weakened. 2+ When the concentration is 200umol / L, the fluorescence quenching effect reaches the minimum and maintains equilibrium. 2+ The complexation ratio is about 1:1. Figure 3 (a) shows that the probe CyN-Cu and I - After the action, the absorption peak intensity at 670nm was significantly enhanced, and the absorption peak at 500nm disappeared. Figure 3 (d) shows that the probe CyN-Cu produces a weak fluorescence signal at 700 nm, which is consistent with I - After the reaction, the fluorescence intensity was significantly enhanced. The change in the spectral signal shows that the probe CyN-Cu and I - The fluorescence "off-on" process was shown before and after the action, and its fluorescence emission peak was at 700nm, which belongs to the near-infrared fluorescence enhanced type I - Fluorescent probes.

[0053] Under the conditions of iodine ion concentration of 5mmol / L and CyN-Cu concentration of 200umol / L, DMF, methanol, ethanol, acetonitrile and DMSO were selected as solvents to investigate the effect of solvent type on I - The impact of the test, the results are as follows Figure 4 shown.

[0054] Depend on Figure 4 (a) It can be seen that the probe exhibits a stronger fluorescence signal in ethanol and a weaker fluorescence intensity in other solvents. - After that, the system showed a weaker fluorescence signal in DMSO. Figure 4 (b) shows that when ethanol and DMSO are used as solvents, the system - The change of fluorescence peak before and after can be ignored; when DMF is used as solvent, adding I - The fluorescence peak value before and after the change is quite obvious, increasing by 10.05 times; acetonitrile and methanol are used as solvents, and the probe CyN-Cu and I - The fluorescence intensity before and after the action increased by 4 times and 2.2 times, respectively. - The system selected a mixed solution of DMF and Tris-HCl buffer solution as the solvent.

[0055] Under the conditions of iodide ion concentration of 5mmol / L, CyN-Cu of 200umol / L, and Tris-HCl / DMF buffer solution (50mmol / L, v / v, 1:19), the effect of Tris-HCl buffer solution with different pH on I- detection was investigated. The results are as follows: Figure 5 shown.

[0056] Depend on Figure 5 As shown in (a), in the pH range of 5.0-8.0, the probe CyN-Cu exhibited a weak fluorescence signal. In the pH range of 5.0-6.0, the probe CyN-Cu and I - After the reaction, a strong fluorescence signal was displayed; in the pH range of 6.0-8.0, as the pH increased, the probe CyN-Cu and I - The fluorescence signal was significantly weakened after the action. Figure 5 (b) shows that in the pH range of 5.0-7.0, the probe CyN-Cu and I - The fluorescence intensity increased 4-6 times after the reaction. However, when the pH was 8.0, the addition of I - The fluorescence signal before and after is almost unchanged, which may be due to Cu 2+ Under alkaline conditions, Cu(OH)2 is formed, which reduces its interaction with I - The redox reaction occurred, which hindered the recovery of the fluorescence signal of the system. Therefore, Tris-HCl with pH 6.0 was selected as the best buffer solvent in subsequent experiments.

[0057] In Tris-HCl / DMF buffer solution (50 mmol / L, pH=6.0), I - Under the condition of 5mmol / L concentration, the effect of different solvent ratios on I - The impact of the test, the results are as follows Figure 6 shown.

[0058] Depend on Figure 6 As shown in (a), in a mixed solution of Tris-HCl and DMF, with the increase of DMF content, the initial fluorescence intensity of the probe CyN-Cu gradually weakened and then slightly enhanced, while the fluorescence signal of the probe CyN-Cu after interacting with I- was significantly enhanced. Figure 3 .4(b) shows that when the ratio of Tris-HCl to DMF is in the range of 1:1 to 1:19, as the content of DMF increases, the fluorescence intensity of the system increases significantly, from 1 to 10 times. When the ratio of Tris-HCl to DMF is 1:24, the fluorescence intensity of CyN-Cu and I - The fluorescence intensity before and after the action only increased by 5.5 times. Therefore, in subsequent experiments, Tris-HCl / DMF buffer solution (50mmol / L, pH=6.0, v / v, 1:19) was selected as the optimal detection condition.

[0059] In Tris-HCl / DMF buffer solution (50 mmol / L, pH=6.0, v / v, 1:19), the probe CyN-Cu concentration was 200 umol / L. - Under the action of - The response after the action is as follows: Figure 7 shown.

[0060] like Figure 7 As shown in the figure, after the fluorescence signal of the probe CyN-Cu becomes stable, different concentrations of I - At the emission wavelength of 700 nm, the fluorescence intensity of the probe CyN-Cu increases rapidly. - When the highest concentration was 5mmol / L, the fluorescence intensity reached the maximum value in about 100s and remained basically constant. - It has a good effect and reacts quickly, thus achieving I - Rapid detection.

[0061] In Tris-HCl / DMF buffer solution (50 mmol / L, pH=6.0, v / v, 1:19), the concentration of probe CyN-Cu was 200 umol / L. To verify the activity of probe CyN-Cu on I - High selectivity, selecting I with the same concentration - and other common anions as the recognition objects, and the changes in fluorescence intensity before and after their interaction with CyN-Cu and when other common anions coexist with iodine ions were investigated. The results are as follows Figure 8 shown.

[0062] Figure 8 (a) shows that the fluorescence intensity enhancement of CyN-Cu by some common anions is negligible, while the halogen elements have a significant effect on the fluorescence intensity of the probe CyN-Cu, and the degree of influence is F - >Br - In sharp contrast, I - The addition of α-Cu significantly increased the fluorescence intensity of the detection system, indicating that the probe CyN-Cu was used for I - The detection has a good specific response. Especially I - When coexisting with other anions, the probe CyN-Cu has a strong affinity for I - Still showing strong anti-interference ability, the results are as follows Figure 6 (b) Therefore, the probe CyN-Cu has high selectivity and anti-interference ability.

[0063] In Tris-HCl / DMF buffer solution (50mmol / L, pH=6.0, v / v, 1:19), the concentration of probe CyN-Cu was 200umol / L, and the interaction between probe CyN-Cu and I - The fluorescence emission spectra before and after the action are as follows Fig. 9 shown.

[0064] like Fig. 9 As shown in Figure 2, the probe CyN-Cu exhibits a weak fluorescence signal at 700 nm. - As the concentration increases, the fluorescence intensity gradually increases. - The concentration ranged from 0.1 μmol / L to 5 mmol / L, and the fluorescence intensity of the probe CyN-Cu showed a good linear relationship. The linear regression equation obtained by fitting was y=2.3621x+1.1471 (R2=0.9987), and the detection limit was 65 nmol / L.

[0065] The probe CyP-Cu was further studied for the detection of iodine ions in iodized black tea, serum, urine, tap water and food, as shown in the following table. The results showed a good recovery rate, proving that the probe CyP-Cu can achieve the detection of actual samples.

[0066] Table 1. Actual sample testing

[0067]

[0068] The above technical solutions only reflect the preferred technical solutions of the technical solutions of the present invention. Some changes that may be made to certain parts thereof by technicians in this technical field all reflect the principles of the present invention and fall within the protection scope of the present invention.

Claims

1. A near-infrared fluorescence analysis method for rapid detection of iodine ions, characterized in that: include: S100, preparation of compound CyN, S200, construction of probe CyN-Cu, S300, spectral detection, S400, selectivity experiment, S500, detection of iodide ions, S600, detection of actual samples; The S100 comprises: weighing 0.357g of benzindole quaternary ammonium salt, 0.361g of N-[3-(anilinomethylene)-2-chloro-1-cyclohexyl-1-yl)methylene]aniline hydrochloride and 0.1817g of 2-acetylpyridine, dissolving in 20mL of ethanol, setting the oil bath temperature, and reflux reaction; after the reaction is completed, cooling, adding 100mL of ether, filtering to obtain a dark blue solid, washing with saturated brine, extracting with dichloromethane three times, combining the organic phases, drying with anhydrous magnesium sulfate, filtering, evaporating the solvent with a rotary evaporator, vacuum drying to obtain a blue solid, separating by column chromatography, using methanol / dichloromethane as the developing solvent, and a volume ratio of 1:16, to obtain 0.1723g of a dark green solid with a yield of 32.14%, and storing in a sealed refrigerator for standby use; The S200 method comprises: preparing a 50 mmol / L solution of the compound CyN with DMF, preparing a 100 mmol / L solution of anhydrous copper sulfate with deionized water, adding 2.5 µL of the 10 mmol / L CyN solution to a 1 mL cuvette, and gradually adding 100 mmol / L Cu 2+ Solution, 25 µL Tris-HCl buffer, wherein the buffer concentration is 50 mmol / L, pH = 6.0, after mixing evenly, diluted with DMF to 500 µL, react for 20 min, then, record the change of fluorescence signal with a fluorescence spectrophotometer, and obtain the probe CyN-Cu mother solution when the best quenching effect is obtained.

2. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The temperature of the S100 oil bath is 80° C., and the reflux reaction time of the S100 is 8 hours.

3. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S300 includes: UV-visible absorption spectrum detection: 5.0 µL of the above CyN-Cu mother solution and 50 µL Tris-HCl buffer were taken into a cuvette, mixed evenly and diluted to 1 mL with DMF. The UV-visible absorption spectrum of CyN-Cu was measured, and then 1 µL of 200 mmol / L I - The solution was reacted for 3 minutes, and then the UV-visible absorption spectrum of CyN-Cu and I- was measured; For the detection of fluorescence emission spectrum, 2.5 µL of the above CyN-Cu was dissolved in 25 µL Tris-HCl buffer solution with a buffer concentration of 50 mmol / L and pH = 6.0, and then different concentrations of iodine ion solution were added. After mixing evenly, the mixture was diluted to 500 µL with DMF. After reacting for 3 minutes, the fluorescence emission spectrum was measured. The detection conditions were as follows: excitation wavelength 650 nm, excitation slit width 10.0 nm, emission slit width 10.0 nm, and voltage 700 V.

4. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S400 includes: Use deionized water to prepare 200 mmol / L solutions of different ions for later use. Take 2.5 µL of CyN-Cu in 25 µL Tris-HCl buffer, where the buffer concentration is 50 mmol / L and pH = 6.

0. Mix well and dilute to 500 µL with DMF. Then add equal amounts of different anion solutions. After the reaction, use a fluorescence spectrophotometer to record the changes in fluorescence signals. The detection conditions are as follows: excitation wavelength 650 nm, excitation slit width 10.0 nm, emission slit width 10.0 nm, voltage 700 V.

5. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S400 reaction was carried out for 3 min.

6. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S500 includes: Take 2.5 µL CyN-Cu in 25 µL tris-HCl buffer, where the buffer concentration is 50 mmol / L, pH = 6.0, mix well and dilute to 500 µL with DMF, measure its fluorescence emission spectrum, and then add different concentrations of I - The solution was reacted for 3 minutes, and the changes in fluorescence signals were recorded using a fluorescence spectrophotometer. The test was repeated 3 times in parallel for detection.

7. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S500 detection conditions are as follows: an excitation wavelength of 650 nm, an excitation slit width of 10.0 nm, an emission slit width of 10.0 nm, and a voltage of 700 V.

8. A near-infrared fluorescence analysis method for rapid detection of iodine ions according to claim 1, characterized in that: The S600 includes: Accurately weigh 10g of raw dark tea and 10g of Jinhua dark tea, soak them in 100mL boiling water for 10 min respectively, soak the residue in boiling water for two more times, combine the filtrate and concentrate it to 20mL, add the concentrate to a 50mL volumetric flask, dilute to the mark with distilled water for later use, add CyN-Cu solution and a certain amount of dark tea reserve solution to the cuvette, record the changes in fluorescence signal with a fluorescence spectrophotometer, and test three times in parallel. The detection conditions are as follows: excitation wavelength 650nm, excitation slit width 10.0nm, emission slit width 10.0nm, voltage 700V.

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