Colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior and application thereof

Abstract

The invention discloses a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior and application of the colorimetric-luminescent probe / carbonate binary system in uranyl ion detection, a probe in the colorimetric-luminescent probe / carbonate binary system is cyanic acid isocyanato (4 '-methyl-terpyridyl) platinum (II), and the probe has good water solubility; and after uranyl ions are added into the probe / carbonate binary system solution, the binary system solution is changed from yellow to red and from non-luminescence to strong red luminescence. In the process, the uranyl ions are sensitively, quickly and intuitively detected by inducing the probe to generate a supramolecular self-assembly behavior by utilizing a complex anion obtained after the uranyl ions are coordinated with carbonate in a binary system in the detection process so as to cause violent changes of ultraviolet-visible absorption and luminescence; meanwhile, the method has the advantages of high detection selectivity, good anti-interference performance and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical sensing and relates to a colorimetric-luminescent terpyridine platinum salt probe / carbonate binary system for uranyl ion detection. Background Art

[0002] With the continuous development of the nuclear industry, radionuclides will inevitably be released into the environment during the research and utilization of nuclear energy, such as wastewater generated during the preparation of nuclear fuel, nuclear weapon explosions, nuclear leakage accidents, etc., which will pollute the environment and threaten human health. Radionuclides can produce ionizing radiation to destroy biological tissues and induce mutations in genetic information, thereby causing diseases such as malignant tumors and genetic effects such as congenital malformations. Therefore, the high-sensitivity detection of radionuclides in the environment is of great significance to ensure public health safety and human health.

[0003] At present, the detection methods of radionuclides include atomic absorption (ASS) / emission spectroscopy (AES), spectrophotometry, high performance liquid chromatography (HPLC), inductively coupled plasma mass spectrometry (ICPMS), electrochemical method and optical detection method. Among the many detection technologies, optical detection based on luminescence change or colorimetric change is considered to be one of the most promising detection technologies due to its many advantages such as high sensitivity, fast detection speed, simple operation and visualization. However, a large number of traditional optical probe materials have disadvantages such as high cost, poor stability, low sensitivity and long response time, which limit the practical application of optical detection in radionuclide detection. Therefore, it is imperative to develop new probe materials with excellent performance to solve these problems.

[0004] Compared with traditional inorganic or organic materials, coordination polymers composed of metal ions and organic ligands have become one of the most popular materials due to their simple synthesis, adjustable properties, and stable structure. However, most studies on coordination polymers focus on their porous structure and luminescence properties, while few studies have used them as probes to monitor radionuclides.

[0005] With d 8Platinum (II) complexes with electronic configuration and square planar structure are an important class of metal complexes. Due to their rich photophysical and photochemical properties, they are widely used in OLEDs, photocatalysis, luminescent probes and cell imaging. Among them, terpyridine platinum (II) complexes have rich luminescence properties and polymorphism, which have attracted great research interest in recent decades. The rich photophysical properties of terpyridine platinum (II) complexes mainly come from Pt-Pt and π-π interactions, and the magnitude and degree of their interaction determine the photophysical properties of the complex. In addition, Pt-Pt and π-π interactions are very sensitive to the environment. Changes in factors such as anions, solvent components, pH, polyelectrolytes, and temperature can cause changes in Pt-Pt and π-π interactions, thereby producing changes in absorption or emission spectra, making them have broad application prospects in the field of photochemical sensing. The existence form of radionuclides in aqueous solutions will also be affected by anions in the environment. For example, the form of uranyl ions is highly dependent on the presence of coordinating anions in the surrounding medium. Uranyl ions can react with Cl - 、NO3 - 、C2O4 2- 、CO3 2- 、CH3COO - PO4 3- 、F - and SO4 2- A variety of coordination ions, including uranyl, form stable complex anions. Previous studies have shown that anions show excellent performance in inducing self-assembly of terpyridine platinum (II) complexes to achieve sensitive, rapid and specific detection of target anions. Therefore, uranyl detection has great application potential in inducing supramolecular aggregation of platinum (II) complexes through uranyl coordination anions. Summary of the invention

[0006] The invention aims to provide a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior in view of the shortcomings in the current uranyl ion detection. The probe in the binary system is cyanocyanate·(4'-methyl-terpyridine) platinum (II). The colorimetric-luminescent probe has good water solubility, and its aqueous solution is light yellow and non-luminescent. Then, an appropriate amount of carbonate solution having a strong coordination ability with the uranyl ions is added thereto, so that a non-luminescent light yellow terpyridine platinum (II) complex probe / carbonate binary system solution is obtained. When the uranyl ions are added, the uranyl ions are first coordinated with the carbonate to form a coordinated anion, and then the coordinated anion and the terpyridine platinum (II) complex monomer form an anion-cation pair through ion association, and then the ion pair undergoes self-assembly aggregation behavior, so that the solution color turns red and generates obvious red luminescence, thereby realizing visual detection of the uranyl ions. The drastic changes in UV-visible absorption and luminescence caused by the supramolecular self-assembly behavior of the probe / carbonate binary system during uranyl detection are utilized to achieve sensitive, rapid and intuitive detection of uranyl ions, while also having the advantages of high detection selectivity and good anti-interference.

[0007] The present invention discloses a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior, wherein the chemical name of the probe is cyanoisocyanate·(4'-methyl-terpyridine) platinum (II), and its structural formula (1) is:

[0008]

[0009] The use of the colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior in detecting uranyl ions.

[0010] The present invention discloses a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior and its use, wherein the preparation method of the colorimetric-luminescent probe / carbonate binary system is:

[0011] a. Add 1g of potassium tetrachloroplatinate to a 250mL three-necked flask, then add 20mL of deionized water to completely dissolve it, then add 24mL of glacial acetic acid and 2.4mL of 1,5-cyclooctadiene in sequence, heat the mixed solution to 80-90°C, stir and react for 3h, and finally cool the reaction solution to room temperature to obtain a gray-bright solid precipitate. Filter the gray-bright solid precipitate, then wash it with water, ethanol and ether in sequence, and then dry it in an oven at 40°C for 30min to obtain 1,5-cyclooctadiene platinum (II) dichloride.

[0012] b. Add 0.8 g of 1,5-cyclooctadiene platinum (II) dichloride obtained in step a into a 100 mL single-necked flask, then add 40 mL of deionized water to completely dissolve it, then add 0.534 g of 4'-methyl-2,2':6',2"-terpyridine, heat the mixed solution to 40-50°C, and stir to react for 1 hour. Filter the cooled reaction solution to remove unreacted 1,5-cyclooctadiene platinum (II) dichloride, and use rotary evaporation to obtain chlorochloride·(4'-methyl-terpyridine) platinum (II) solid, then wash the solid three times with ether, and finally dry it in air.

[0013] c. Dissolve 0.4 g of chloro(4'-methyl-terpyridine)platinum(II) obtained in step b in 20 mL of deionized water, then add excess sodium cyanate and stir at room temperature until an orange precipitate is produced.

[0014] d. Add deionized water to the orange precipitate obtained in step c to completely dissolve the orange precipitate, then obtain a yellow solid by rotary evaporation, then dissolve the obtained yellow solid in as little glacial acetic acid as possible, and then slowly add ethyl acetate to produce an orange precipitate, filter the precipitate and dry it in an oven at 60° C. for 1 h to finally obtain isocyanato-(4'-methyl-terpyridine)platinum(II) purified by recrystallization.

[0015] e. Prepare the isocyanate-(4'-methyl-terpyridine) platinum (II) obtained in step d into a 1 mM probe aqueous solution, add 0.5 mL of 100 mM sodium carbonate solution to 3 mL of the 1 mM probe solution, and obtain the colorimetric-luminescent probe / carbonate binary system.

[0016] The advantages and beneficial effects of the present invention are:

[0017] The present invention discloses a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior and its application in uranyl ion detection. The uranyl ions are coordinated with excess carbonate ions in the binary system to form tricarbonate uranyl coordinated anions. The coordinated anions and probe ions form ion pairs through ion association, and then the ion pairs undergo self-assembly aggregation behavior to achieve efficient optical detection of uranyl ions. The probe molecule has good water solubility. When uranyl ions are added to the probe / carbonate binary system, the ternary supramolecular self-assembly behavior can be induced, so that the color of the binary system solution changes from light yellow to red, and changes from non-luminescence to strong red luminescence. Other common metal cations and common anions basically cannot change the color and luminescence of the binary system solution, but the mixing of common metal cations and common anions with uranyl ions will not significantly interfere with the detection of uranyl ions. Therefore, the binary system has a fast response speed for uranyl ion detection, high detection sensitivity, good selectivity, good anti-interference ability, and its colorimetric and luminescence dual-mode detection method improves its detection reliability under complex environmental conditions.

[0018] The present invention discloses a colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior and its application in uranyl ion detection. The probe in the colorimetric-luminescent probe / carbonate binary system is isocyanate·(4'-methyl-terpyridine) platinum (II), which has good water solubility. When uranyl ions are added to the probe / carbonate binary system solution, the color of the binary system solution changes from yellow to red, and from non-luminescence to strong red luminescence. This is because the coordinated anion of uranyl tricarbonate can statically associate with the platinum (II) complex through electrostatic interaction, and induce the platinum (II) complex to self-assemble under metal-metal and π-π interactions. The colorimetric-luminescent probe / carbonate binary system of the present invention has a fast detection response speed for uranyl ions; high detection sensitivity, with a detection limit of 0.0641 μM; good selectivity; and good anti-interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The selectivity of the colorimetric-luminescent probe / carbonate binary system of isocyanate·(4'-methyl-terpyridine) platinum (II) / carbonate for detecting uranyl ions of the present invention, a is a picture of color development under a fluorescent lamp, and b is a picture of color development under a 365nm ultraviolet lamp;

[0020] Figure 2 The anti-interference performance of the colorimetric-luminescent probe / carbonate binary system cyanate isocyanate·(4'-methyl-terpyridine) platinum (II) / carbonate on uranyl ion detection of the present invention is expressed by the UV-visible absorption peak intensity at 550nm;

[0021] Figure 3 The anti-interference performance of the colorimetric-luminescent probe / carbonate binary system cyanoisocyanate·(4'-methyl-terpyridine) platinum(II) / carbonate for uranyl ion detection of the present invention is expressed by the emission peak intensity at 670nm and excited by 365nm light;

[0022] Figure 4 The colorimetric-luminescent probe / carbonate binary system of the present invention isocyanate·(4'-methyl-terpyridine) platinum (II) / carbonate for detecting the change of the ultraviolet absorption spectrum of uranyl ions along with the content thereof;

[0023] Figure 5 The colorimetric-luminescent probe / carbonate binary system of the present invention isocyanate·(4'-methyl-terpyridine) platinum (II) / carbonate for detecting the change of the luminescence intensity of uranyl ions with their content;

[0024] Figure 6 The colorimetric-luminescent probe / carbonate binary system of the present invention isocyanate·(4'-methyl-terpyridine)platinum(II) / carbonate to detect changes in the UV-visible absorption peak intensity at 550nm and the emission peak intensity at 670nm of uranyl ions at different initial pH values;

[0025] Figure 7 The colorimetric-luminescent probe / carbonate binary system of the present invention isocyanate·(4'-methyl-terpyridine)platinum(II) / carbonate to detect changes in the ultraviolet-visible absorption peak intensity at 550nm and the emission peak intensity at 670nm of uranyl ions of different concentrations under different solution environmental conditions;

[0026] The present invention is further described below by means of specific examples, but the invention is not limited to these examples.

[0027] Example 1

[0028] This example verifies that the isocyanate·(4'-methyl-terpyridine) platinum (II) probe in the colorimetric / luminescent probe / carbonate binary system of the present invention has good water solubility:

[0029] At room temperature, 0.0105g, 0.0210g, 0.0316g, 0.0421g, 0.0526g and 0.0631g of isocyanato-(4'-methyl-terpyridine)platinum(II) were added to a beaker, and then the volume was adjusted to 50ml with a volumetric flask, and the concentrations of the detection reagents were 0.4mM, 0.8mM, 1.2mM, 1.6mM, 2.0mM and 2.4mM, respectively. These reagents were all light yellow solutions and did not emit light under a 365nm ultraviolet lamp. The ultraviolet absorption spectra of the probe solutions of different concentrations were tested, and their ultraviolet absorption values ​​at 400nm were linearly fitted. The results showed that the linear fit at this point was very high, with a correlation of up to 0.9994, and the solution concentration in the range of 0.4-2.4mM conformed to the Lambert-Beer law, indicating that it had good solubility.

[0030] Example 2

[0031] In this example, the detection performance of the colorimetric-luminescent probe / carbonate binary system of isocyanate cyanate·(4'-methyl-terpyridine) platinum(II) / carbonate for uranyl ions was verified. Figure 1 As shown:

[0032] Take 3mL of 1mM isocyanate·(4'-methyl-terpyridine)platinum(II) solution in a test tube, then add 0.5mL of 100mM sodium carbonate solution, and then add 180μL of 5mM uranyl solution dropwise. A red precipitate is produced in the test tube within 1 minute, and the precipitate emits bright red light under a 365nm ultraviolet lamp, indicating the presence of uranyl ions.

[0033] Example 3

[0034] In this example, the selectivity of the colorimetric-luminescent probe / carbonate binary system of the present invention, isocyanate·(4'-methyl-terpyridine) platinum(II) / carbonate, for detecting uranyl ions was verified. Figure 1 As shown:

[0035] At room temperature, take several 3mL portions of 1mM isocyanate·(4'-methyl-terpyridine)platinum(II) solution in a test tube, then add 0.5mL of 100mM sodium carbonate solution, and then add 45μL of 100mM common cations such as calcium ion, cadmium ion, magnesium ion, zirconium ion, nickel ion, cobalt ion, aluminum ion, copper ion, zinc ion, thorium ion, lithium ion and chromium ion, and 45μL of 100mM common anions such as iodate, phosphate, sulfate, fluoride, bromate, nitrate, oxalate, nitrite, thiocyanate, bromide, iodide, acetate and chloride. In fact, most of these ions cannot effectively induce the occurrence of self-assembly behavior. Even if they can induce the occurrence of self-assembly behavior, such as thorium and zirconium ions, the color of the orange self-assembled aggregates induced by them can be well distinguished from the color of the red aggregates induced by uranyl ions, indicating that the probe / carbonate binary system has good selectivity for uranyl.

[0036] Example 4

[0037] In this example, the anti-interference ability of the colorimetric-luminescent probe / carbonate binary system cyanate isocyanate·(4'-methyl-terpyridine) platinum(II) / carbonate in detecting uranyl ions was verified. Figure 2 and Figure 3 As shown:

[0038] At room temperature, several 3mL portions of 1mM isocyanato-(4'-methyl-terpyridine)platinum(II) solution were taken into test tubes, followed by the addition of 0.5mL 100mM sodium carbonate solution, and then 80μL 5mM uranyl solution and 45μL 100mM common cations such as calcium ion, cadmium ion, magnesium ion, zirconium ion, nickel ion, cobalt ion, aluminum ion, copper ion, zinc ion, thorium ion, lithium ion and chromium ion, as well as 45μL 100mM common anions such as iodate ion, phosphate ion, sulfate ion, fluoride ion, bromate ion, nitrate ion, oxalate ion, nitrite ion, thiocyanate ion, bromide ion, iodide ion, acetate ion and chloride ion were added simultaneously. The presence of these ions had no obvious effect on the colorimetric and luminescent responses of uranyl ion, indicating that it has good anti-interference ability for uranyl ion detection.

[0039] Example 5

[0040] In this example, the sensitivity of the colorimetric-luminescent probe / carbonate binary system of isocyanate cyanate·(4'-methyl-terpyridine) platinum(II) / carbonate to detect uranyl ions was verified. The UV titration experiment was as follows: Figure 4 As shown, the luminescence titration experiment is as follows Figure 5 As shown:

[0041] At room temperature, after adding uranyl solution with concentrations of 0-245μM to the binary system solution of cyanoisocyanate·(4'-methyl-terpyridine)platinum(II) (3mL 1mM) / carbonate (0.5mL 100mM), a new absorption peak appeared at 550nm, and the absorption peak continued to increase with the increase of uranyl ion concentration. The inset is the change of ultraviolet absorption at 550nm under different uranyl ion concentrations. It can be seen that: when the uranyl ion concentration is 0-139μM, the absorption peak is linearly correlated with the uranyl ion concentration. Based on the detection limit calculation formula 3σ / k, where σ is the standard deviation of 11 blank samples and k is the slope of the fitting line, the detection limit of ultraviolet absorption is calculated to be 0.26μM; similarly, in the luminescence titration experiment, at room temperature, in the binary system of cyanoisocyanate·(4'-methyl-terpyridine)platinum(II) (3mL 1mM) / carbonate (0.5mL 100mM), the absorption peak was 0.26μM. After adding 0-245 μM uranyl solutions to the binary system solution of 100 mM (247 nm), an emission peak appeared at 670 nm with light excitation at 365 nm, and the emission peak continued to increase with the increase of uranyl ion concentration. The inset shows the change of emission peak intensity at 670 nm under different uranyl concentrations. It can be seen that when the uranyl ion concentration is 0-166 μM, the emission peak is linearly correlated with the uranyl ion concentration. Based on the detection limit calculation formula 3σ / k, where σ is the standard deviation of 11 blank samples and k is the slope of the fitting line, the detection limit of luminescence is calculated to be 0.0641 μM.

[0042] Example 6

[0043] In this example, the detection performance of the colorimetric-luminescent probe / carbonate binary system of the present invention, isocyanate·(4'-methyl-terpyridine) platinum(II) / carbonate, for uranyl ions under different initial pH conditions was verified:

[0044] First, the pH of the uranyl solution (1mM) was adjusted to a range of 1-11 by using dilute hydrochloric acid and sodium carbonate, and then 200μL of the uranyl solution under different pH conditions was added dropwise to the binary system solution of isocyanate cyanate·(4'-methyl-terpyridine)platinum(II) (3mL1mM) / carbonate (0.5mL 100mM), and red precipitates were generated in all solutions within 1 minute, and the precipitates emitted bright red light under a 365nm ultraviolet lamp. Subsequently, the UV-visible absorption and emission spectra of the binary system solutions of the uranyl solution under different initial pH conditions were measured, and it was found that there was no obvious difference in the absorption peak intensity at 550nm and the emission peak intensity at 670nm, indicating that it can detect uranyl ions in a wide pH range.

[0045] Example 7

[0046] In this example, the detection performance of the colorimetric-luminescent probe / carbonate binary system of isocyanate·(4'-methyl-terpyridine) platinum(II) / carbonate for uranyl ions under different solution environment conditions was verified. The results are as follows Figure 7 As shown:

[0047] First, uranyl solutions with a concentration of 5mM were prepared using ultrapure water, seawater and tap water as solvents, and then 50μL, 100μL and 200μL of uranyl solutions under different solution conditions were added dropwise to the binary system solution of isocyanate·(4'-methyl-terpyridine)platinum(II) (3mL 1mM) / carbonate (0.5mL 100mM), and red precipitates were generated in all solutions within 1 minute, and the precipitates emitted bright red light under a 365nm ultraviolet lamp. Subsequently, the ultraviolet-visible absorption and luminescence spectra of the binary system solutions after adding uranyl solutions of different concentrations under different solution environments were measured, and it was found that the absorption peak intensity at 550nm and the emission peak intensity at 670nm after adding uranyl solutions with seawater and tap water as solvents were not significantly different from those after adding uranyl solutions with ultrapure water as solvent, indicating that it can detect uranyl ions under different solution environment conditions.

Claims

1. A colorimetric-luminescent probe / carbonate binary system based on supramolecular self-assembly behavior, wherein the chemical name of the probe is isocyanate·(4'-methyl-terpyridine) platinum (II), and its structural formula (1) is:

2. The method for preparing the colorimetric-luminescent probe / carbonate binary system according to claim 1 is as follows: a. Add 1g of potassium tetrachloroplatinate to a 250mL three-necked flask, then add 20mL of deionized water to completely dissolve it, then add 24mL of glacial acetic acid and 2.4mL of 1,5-cyclooctadiene in sequence, heat the mixed solution to 80-90°C, stir and react for 3h, and finally cool the reaction solution to room temperature to obtain a gray-bright solid precipitate. Filter the gray-bright solid precipitate, then wash it with water, ethanol and ether in sequence, and then dry it in an oven at 40°C for 30min to obtain 1,5-cyclooctadiene platinum (II) dichloride. b. Add 0.8 g of 1,5-cyclooctadiene platinum (II) dichloride obtained in step a into a 100 mL single-necked flask, then add 40 mL of deionized water to completely dissolve it, then add 0.534 g of 4'-methyl-2,2':6',2"-terpyridine, heat the mixed solution to 40-50°C, and stir to react for 1 hour. Filter the cooled reaction solution to remove unreacted 1,5-cyclooctadiene platinum (II) dichloride, and use rotary evaporation to obtain chlorochloride·(4'-methyl-terpyridine) platinum (II) solid, then wash the solid three times with ether, and finally dry it in air. c. Dissolve 0.4 g of chloro(4'-methyl-terpyridine)platinum(II) obtained in step b in 20 mL of deionized water, then add excess sodium cyanate and stir at room temperature until an orange precipitate is produced. d. Add deionized water to the orange precipitate obtained in step c to completely dissolve the orange precipitate, then obtain a yellow solid by rotary evaporation, then dissolve the obtained yellow solid in as little glacial acetic acid as possible, and then slowly add ethyl acetate to produce an orange precipitate, filter the precipitate and dry it in an oven at 60° C. for 1 h to finally obtain isocyanato-(4'-methyl-terpyridine)platinum(II) purified by recrystallization. e. Prepare the isocyanate·(4'-methyl-terpyridine)platinum(II) obtained in step d into an aqueous solution of a probe with a concentration of 1 mM, add 0.5 mL of 100 mM sodium carbonate solution to 3 mL of the 1 mM probe solution, and the colorimetric-luminescent probe / carbonate binary system described in claim 1 can be obtained.

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