Tetraphenylethylene derivatives, methods of preparation and use as fluorescent probes for perfluorooctane sulfonate

Abstract

The application discloses a tetraphenyl ethylene derivative, a preparation method and application as a perfluorooctyl sulfonate fluorescent probe, and the tetraphenyl ethylene derivative is characterized by a formula II. The tetraphenyl ethylene derivative has obvious aggregation-induced emission effect, excellent luminescence performance, and can realize 'on' detection of perfluorooctane sulfonate. The preparation method of the perfluorooctane sulfonate fluorescent probe of the tetraphenyl ethylene derivative is simple, the reaction condition is mild, is conducive to environmental protection, and meets the characteristics of green chemistry. The prepared tetraphenyl ethylene derivative fluorescent probe has excellent chemical stability, high sensitivity and good anti-interference ability, can realize rapid and efficient detection of perfluorooctyl sulfonate, and is expected to realize industrialization and on-site application.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent probe technology, specifically relating to a tetraphenylethylene derivative, its preparation method, and its use as a perfluorooctane sulfonate fluorescent probe. Background Technology

[0002] Perfluorooctane sulfonate (PFOS), an important chemical product, has wide applications in industrial production and consumer goods. However, PFOS is a highly toxic chemical; exposure to PFOS can affect reproductive health, cause endocrine disorders, damage the liver, and even lead to cancer. Furthermore, PFOS is a major polyfluoroalkyl compound contributing to water pollution internationally. PFOS is extremely difficult to degrade and metabolize, and tends to accumulate in the environment and human body. Therefore, researching accurate, rapid, and practically applicable methods for the detection of PFOS is of significant value and importance.

[0003] To date, various methods for detecting perfluorooctane sulfonate have been developed, among which fluorescent probes have become an ideal choice due to their advantages of low cost, rapid response, and ease of operation compared to traditional methods. Tetraphenylethylene (TPE), as a typical fluorescent molecule with AIE effect, has become one of the popular fluorescent molecular probe materials due to its high solid-state luminescence efficiency, high thermal stability, and ease of modification and synthesis.

[0004] To date, there are few reports on the detection of perfluorooctane sulfonate using fluorescent probes. Furthermore, many traditional methods for detecting perfluorooctane sulfonate, such as liquid chromatography-tandem mass spectrometry, nuclear magnetic resonance spectroscopy, polarography, and enzyme-linked immunosorbent assay (ELISA), are largely limited in application due to expensive equipment and complex operation. Therefore, the development of "on" tetraphenylethylene derivative fluorescent probes with good selectivity, high sensitivity, and simple operation is of significant application value for the rapid quantitative detection of perfluorooctane sulfonate. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a tetraphenylethylene derivative.

[0006] A second objective of this invention is to provide a method for preparing tetraphenylethylene derivatives.

[0007] A third object of the present invention is to provide the use of tetraphenylethylene derivatives as fluorescent probes for perfluorooctane sulfonate.

[0008] The technical solution of this invention is summarized as follows:

[0009] Tetraphenylethylene derivatives, characterized by the use of Formula II:

[0010]

[0011] Where X is -CH3, -CH2CH3 or -H;

[0012] R - For I - , Br - or ClO4 - .

[0013] The preparation method of tetraphenylethylene derivatives includes the following steps:

[0014] Compound I was added to acetonitrile and ultrasonically dispersed until uniform. The resulting dispersion was placed in a dark environment, R' was added, and the mixture was stirred until uniform. The mixture was heated to 30-50℃ and reacted for 24-48 hours. The precipitate was collected by centrifugation, washed with dichloromethane, filtered to obtain a yellow powder, and dried under vacuum to obtain tetraphenylethylene derivative (II).

[0015] Reaction equation:

[0016]

[0017] Where X is -CH3, -CH2CH3 or -H;

[0018] R - For I - , Br - or ClO4 - ;

[0019] R' is CH3I, CH3CH2Br, or Fe(ClO4)3·nH2O; n is 6, 9, or 10.

[0020] The ratio of compound I to acetonitrile is 200 mg: 30-50 mL.

[0021] The molar ratio of compound I to R' is 1:4-6.

[0022] The use of tetraphenylethylene derivatives as fluorescent probes for perfluorooctane sulfonate.

[0023] The beneficial effects of this invention are:

[0024] (1) The tetraphenylethylene derivative of the present invention has an obvious aggregation-induced emission effect and excellent luminescence performance, which can realize the "open" detection of perfluorooctane sulfonate.

[0025] (2) The method for preparing the tetraphenylethylene derivative perfluorooctane sulfonate fluorescent probe of the present invention is simple and the reaction conditions are mild, which is beneficial to environmental protection and meets the characteristics of green chemistry. The prepared tetraphenylethylene derivative fluorescent probe has excellent chemical stability, high sensitivity and good anti-interference ability, and can realize rapid and efficient detection of perfluorooctane sulfonate, which is expected to be industrialized and applied in the field. Attached Figure Description

[0026] Figure 1 For compound II-1 1 H NMR;

[0027] Figure 2 For compound II-1 13 C NMR;

[0028] Figure 3 The UV-Vis absorption spectra of fluorescent probe II under different ratios of poor solvent / good solvent are shown.

[0029] Figure 4 The fluorescence spectra of fluorescent probe II under different ratios of unfavorable solvent / good solvent are shown.

[0030] Figure 5 The UV-Vis absorption spectra of fluorescent probe II under different PFOS concentrations are shown.

[0031] Figure 6 The fluorescence spectra of fluorescent probe II under different PFOS concentrations are shown.

[0032] Figure 7 The graph shows the relationship between the maximum emission intensity change (I / I0) of fluorescent probe II and the PFOS concentration.

[0033] Figure 8 The fluorescence spectra of fluorescent probe II after adding different interfering substances to the aqueous solution;

[0034] Figure 9 The fluorescence spectrum of fluorescent probe II after simultaneous addition of PFOS and different interfering substances to an aqueous solution;

[0035] Figure 10 The bar chart shows the fluorescence intensity of fluorescent probe II under the action of different interfering substances and under the simultaneous action of PFOS and different interfering substances.

[0036] Figure 11 The fluorescence spectra of fluorescent probe II at different pH values;

[0037] Figure 12 The fluorescence spectra of fluorescent probe II at different pH values ​​after the addition of PFOS.

[0038] Figure 13 The Zeta potential diagram for fluorescent probe II;

[0039] Figure 14 The figure shows the zeta potential of fluorescent probe II under PFOS.

[0040] Figure 15 SEM images of the solution particles before and after the addition of fluorescent probe II to PFOS;

[0041] Figure 16 The fluorescence spectra of fluorescent probe II in sodium chloride solutions of different concentrations after the addition of PFOS. Detailed Implementation

[0042] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0043] The following embodiments are intended to further illustrate and demonstrate specific implementations within the scope of this invention. Therefore, these embodiments should be understood as being used only to illustrate the invention in more detail, and not to limit the scope of the invention in any way.

[0044] The following examples further illustrate preferred embodiments within the scope of the present invention. These examples are merely illustrative and not intended to limit the scope of the invention, as many variations can be made to the invention without departing from its essence and scope.

[0045] The products were detected using a Bruker AVANCE III HD 400MHz fully digital superconducting nuclear magnetic resonance spectrometer. 1 HNMR and 13 C NMR was performed using deuterated dimethyl sulfoxide (DMSO-d6) as the solvent and tetramethylsilane (TMS) as the internal standard.

[0046] The ultraviolet absorption spectrum of the product was determined using a PerkinElmer Lambda 750 ultraviolet spectrophotometer, with a 1×1cm quartz cuvette used as the sample cell.

[0047] The fluorescence spectrum of the product was determined using an F-2500 fluorescence spectrophotometer manufactured by Hitachi, Japan. A 1×1cm quartz cuvette was used as the sample cell, the excitation wavelength was 355nm, and the test and collection wavelength range was 400-700nm. All solvents used in the fluorescence spectroscopy test were of chromatographic purity.

[0048] The zeta potential of the product was determined using a Zetasizer Nano ZS Zeta potential analyzer manufactured by Malvern Instruments Ltd.

[0049] The morphology of the aggregated nanoparticles was analyzed using an S-4800 field emission scanning electron microscope manufactured by Hitachi, Japan.

[0050] The perfluorooctane sulfonate (PFOS) in the various embodiments of the present invention is potassium perfluorooctane sulfonate.

[0051] Example 1

[0052] The preparation method of tetraphenylethylene derivatives includes the following steps:

[0053] Weigh 200 mg (0.31 mmol) of tetra(4-pyridinebiphenyl)ethylene (I), add 30 mL of acetonitrile, and sonicate until homogeneous. Place the resulting dispersion in a dark environment, add 171.14 mg (1.24 mmol) of iodomethane, stir until homogeneous, heat to 40 °C, react for 48 h, centrifuge, collect the precipitate, wash three times with dichloromethane and filter to obtain a yellow powder, which is dried under vacuum to obtain compound II-1, abbreviated as TPE-py, with a yield of 85%.

[0054] Reaction equation:

[0055]

[0056] The molecular weight of TPE-py is 1028.55. The chemical structure of TPE-py was characterized by 1H NMR and 1C NMR spectroscopy. 1 H NMR (400MHz, DMSO-d6), δ (ppm): 8.58 (d, J = 6.6Hz, 8H), 8.0 (d, J = 6.7Hz, 8H), 7.6 (d, J = 8.3H, 8H), 7.3 (d, J = 8.3Hz, 8H), 4.21 (s, 12H), see Figure 1 ; 13 C NMR (400MHz, DMSO-d6), δ (ppm): 153.55, 146.34, 146.0, 141.46, 132.57, 128.45, 124.26, 47.59, see [reference needed] Figure 2 .

[0057] This demonstrates that the reaction produced TPE-py(II-1).

[0058] Example 2:

[0059] Photophysical properties determination of tetraphenylethylene derivative (II-1) prepared in Example 1

[0060] The tetraphenylethylene derivative (II-1) prepared in Example 1 was dissolved in deionized water to prepare a solution with a concentration of 1×10⁻⁶. -4 M, 2×10 -4The solution of M was used as stock solutions I and II. Six 0.5 mL portions of stock solution I were taken, and 4.5, 3.5, 2.5, 1.5, 0.5, and 0 mL of deionized water were added respectively. The volume was then adjusted to 5 mL with dioxane (DOX) to prepare solutions with undesirable solvent volume fractions of 0%, 20%, 40%, 60%, 80%, and 90%. One 0.25 mL portion of stock solution II was taken, and 4.75 mL of dioxane was added to prepare a solution with an undesirable solvent volume fraction of 95%. The UV-absorbing and fluorescence spectra of the seven solutions were measured. (See attached image). Figure 3 and Figure 4 .from Figure 3 The UV-absorbing spectra show that as the proportion of undesirable solvent in the solvent system increases, the UV absorption initially strengthens and then weakens. Furthermore, when the undesirable solvent content reaches 95%, the peak shape of the UV absorption changes significantly, with the full width at half maximum (FWHM) widening. Figure 4 It can be seen that when the content of the undesirable solvent in the system varies between 0% and 80%, the fluorescence emission generally shows an increasing trend, but the change is very slow and the fluorescence emission is relatively weak. When the content of the undesirable solvent increases to 90%, the fluorescence emission intensity increases significantly. When the content of the undesirable solvent is 95%, the fluorescence emission intensity continues to increase, and the maximum fluorescence intensity can reach as much as 16 times the initial intensity. This demonstrates that the tetraphenylethylene derivative (II-1) synthesized in Example 1 has obvious aggregation-induced emission properties, a large Stokes shift, and low background interference, making it suitable for fluorescence detection.

[0061] Example 3

[0062] Determination of UV-Vis and fluorescence spectra of the tetraphenylethylene derivative (II-1) prepared in Example 1 under different PFOS concentrations.

[0063] The tetraphenylethylene derivative (II-1) prepared in Example 1 was dissolved in water to prepare a solution with a concentration of 1×10⁻⁶. -5 The solution of M is used as stock solution I (also known as fluorescent probe II); potassium perfluorooctane sulfonate is dissolved in deionized water to prepare a solution of 1×10⁻⁶. -3 The solution of M was used as stock solution II. Nine 0.5 mL aliquots of stock solution I were taken, and different volumes of stock solution II were added to eight of these aliquots. The volume was then brought to 5 mL with deionized water to prepare aqueous solutions of PFOS with concentrations of 0, 5, 10, 15, 20, 25, 30, 35, and 40 μM. The UV-absorbing and fluorescence spectra were measured. (See attached table). Figure 5 and Figure 6 .from Figure 5 The UV-Vis absorption spectrum shows that when the PFOS concentration varies from 0 to 40 μM, the absorption wavelength is around 355 nm, and the peak at 355 nm gradually decreases as PFOS is gradually added. Figure 6The fluorescence spectrum shows that the maximum fluorescence emission intensity continuously increases with the addition of PFOS, reaching its maximum when the PFOS concentration is 20 μM. Afterward, further addition of PFOS does not significantly change the fluorescence intensity. Figure 7 As shown, when the concentration of PFOS in the fluorescence spectrum is in the range of 0-20 μM, the fluorescence intensity of the solution exhibits a good linear relationship with the PFOS concentration (R0). 2 =0.9889), the detection limit is 0.11 μM. Figure 7 The illustration shows a comparison of solutions without PFOS and solutions with 150 μM PFOS under a UV lamp. This demonstrates that the tetraphenylethylene derivative (II-1) synthesized in Example 1 can be used for the quantitative detection of PFOS in solution, and has the advantages of rapid response, high sensitivity, and visual detection.

[0064] Example 4

[0065] Selectivity characterization of tetraphenylethylene derivative (II-1) for PFOS detection

[0066] The tetraphenylethylene derivative (II-1) prepared in Example 1 was dissolved in deionized water to prepare a solution with a concentration of 1×10⁻⁶. -5 The solution of M is used as stock solution I; 13 aliquots of stock solution I, each 0.5 mL in volume, are used as stock solution I. 150 μL of a 1×10⁻⁶ solution is added to 12 of these aliquots. -3 The following solutions were added as interfering agents: NaCl aqueous solution, AgNO3 aqueous solution, KI aqueous solution, NaF aqueous solution, K2CO3 aqueous solution, K3PO4 aqueous solution, K2SO4 aqueous solution, potassium perfluorobutyl sulfonate (PFOA) aqueous solution, sodium octyl sulfonate (SO) aqueous solution, perfluorooctanoic acid (PFO) aqueous solution, sodium dodecyl sulfonate (SDS) aqueous solution, and sodium dodecyl sulfate (AS) aqueous solution. Finally, 150 μL of stock solution II from Example 3 was added, and the volume was brought to 5 mL with deionized water. The changes in fluorescence of the solution under UV light were observed, and the fluorescence emission spectrum was measured. See [link to relevant documentation]. Figure 8 .

[0067] Take 12 aliquots of stock solution I, each with a volume of 0.5 mL, and then add 150 μL of a 1×10⁻⁶ solution to each aliquot. -3The solutions were prepared as follows: NaCl aqueous solution, AgNO3 aqueous solution, KI aqueous solution, NaF aqueous solution, K2CO3 aqueous solution, K3PO4 aqueous solution, K2SO4 aqueous solution, potassium perfluorobutyl sulfonate (PFOA) aqueous solution, sodium octyl sulfonate (SO) aqueous solution, perfluorooctanoic acid (PFO) aqueous solution, sodium dodecyl sulfonate (SDS) aqueous solution, sodium dodecyl sulfate (AS) aqueous solution, and 150 μL of stock solution II from Example 3. All solutions were then brought to a final volume of 5 mL with deionized water. The fluorescence changes of the solutions were observed under a UV lamp, and their fluorescence emission spectra were measured. See [link to relevant documentation]. Figure 9 .exist Figure 8 The fluorescence spectrum shows that, compared to adding only PFOS, the fluorescence intensity of the probe solution did not change significantly when other interfering substances were added, indicating that these other interfering substances are unlikely to cause changes in the fluorescence of the probe solution. Figure 9 The comparison of fluorescence spectra shows that, when equal amounts of PFOS and interfering agents are present, the fluorescence intensity does not change significantly compared to the case where only PFOS is present. Similarly, from... Figure 10 The fluorescence intensity bar graph more clearly shows the changes in fluorescence intensity of the solution. This demonstrates that the tetraphenylethylene derivative (II-1) synthesized in Example 1 is specific for the detection of perfluorooctyl sulfonate and still has good detection performance in complex environments.

[0068] Example 5:

[0069] Tetraphenylethylene derivative (II-1) and its characterization for PFOS detection at different pH levels

[0070] Different masses of sodium hydroxide were dissolved in deionized water to prepare blank solutions with pH values ​​of 12, 11, 10, 9, and 8, respectively; different volumes of concentrated hydrochloric acid were dissolved in deionized water to prepare blank solutions with pH values ​​of 3, 4, 5, 6, and 7, respectively; the tetraphenylethylene derivative (II-1) prepared in Example 1 was dissolved in solutions with pH values ​​of 3-12 to prepare solutions with a concentration of 1×10⁻⁶. -5 The probe solution of M was used as a series of stock solutions. 0.5 mL of each stock solution was taken, and the volume was brought to 5 mL with blank solution of the corresponding pH. The fluorescence spectra were then measured. (See attached image). Figure 11 Take 0.5 mL of each of the stock solutions in this series, add 150 μL of stock solution II from Example 3, and bring the volume to 5 mL with blank solution of the corresponding pH. Measure the fluorescence spectrum. See [link to sample]. Figure 12 .like Figure 11 As shown, the fluorescence intensity of the probe solution remained essentially unchanged within a pH range of 3-12. Figure 12As shown, after adding PFOS, the fluorescence intensity did not change significantly compared to the neutral aqueous solution environment under different pH conditions, and it did not affect the actual detection effect. This demonstrates that the tetraphenylethylene derivative (II-1) synthesized in Example 1 has good acid-base stability as a fluorescent probe, and can still effectively detect perfluorooctane sulfonate over a wide pH range.

[0071] Example 6

[0072] Determination of the PFOS detection mechanism of tetraphenylethylene derivative (II-1)

[0073] Take two portions of stock solution I from Example 3, 0.5 mL each. Add 150 μL of stock solution II from Example 3 to one portion, and finally bring both portions to 5 mL with deionized water. Perform Zeta potential tests on each portion (see...). Figure 13 and Figure 14 ) and SEM testing (see Figure 15 Prepare 1×10⁻⁶ solutions respectively. -3 1×10 -2 1×10 -1 The tetraphenylethylene derivative (II-1) prepared in Example 1 was dissolved in sodium chloride solutions of different concentrations (1M, 0M) to prepare a solution with a concentration of 1×10⁻⁶. -5 The probe solution of M was used as a series of stock solutions. Then, 0.5 mL of each stock solution was taken and added to 150 μL of stock solution II from Example 3, and then brought to a total of 5 mL with the corresponding salt solution. The fluorescence spectra were then measured. (See attached image). Figure 16 .from Figure 13 It can be seen that the Zeta potential of the blank solution is 0.153 mV. From... Figure 14 It can be seen that the Zeta potential of the solution changes by -4.09 mV after the addition of PFOS. This change in Zeta potential demonstrates the electrostatic interaction between the tetraphenylethylene derivative (II-1) and PFOS. Figure 15 Scanning electron microscopy (SEM) images before and after the addition of PFOS also revealed that the particle size in the blank solution was approximately 30-70 nm, while after the addition of PFOS, the particle size in the solution system increased rapidly, with the widest particles reaching approximately 350-460 nm. The particle morphology changed significantly, from spherical to olive-shaped, more clearly demonstrating that PFOS can induce the aggregation of tetraphenylethylene derivative (II-1) upon interaction with PFOS. Figure 16The fluorescence spectrum also revealed that as the salt concentration in the system increased, the fluorescence emission gradually weakened, approaching the fluorescence emission intensity of the blank solution. It can be inferred that the high concentration of salt solution disrupted the electrostatic interaction between the tetraphenylethylene derivative (II-1) and PFOS, leading to the dissociation of the aggregates formed by the two, and the tetraphenylethylene derivative (II-1) returned to a near-monodisperse state. This demonstrates that the tetraphenylethylene derivative (II-1) synthesized in Example 1 is used to detect perfluorooctane sulfonate based on electrostatic interactions and aggregation-induced emission properties.

[0074] Example 7

[0075] The preparation method of tetraphenylethylene derivative (Ⅱ-2) includes the following steps:

[0076] Weigh 200 mg (0.31 mmol) of tetra(4-pyridinebiphenyl)ethylene (I), add 40 mL of acetonitrile, and sonicate until homogeneous. Place the resulting dispersion in a dark environment, add CH3CH2Br (168.90 mg, 1.55 mmol), stir until homogeneous, heat to 50 °C, react for 24 h, centrifuge, collect the precipitate, wash three times with dichloromethane and filter to obtain a yellow powder, which is then dried under vacuum to obtain compound II-2 with a yield of 95%.

[0077] Reaction equation:

[0078]

[0079] Example 8

[0080] The preparation method of tetraphenylethylene derivative (Ⅱ-3) includes the following steps:

[0081] Weigh 200 mg (0.31 mmol) of tetra(4-pyridinebiphenyl)ethylene (I), add 50 mL of acetonitrile, and ultrasonically disperse until homogeneous. Add 960.11 mg (1.86 mmol) of Fe(ClO4)3·9H2O to the resulting dispersion, stir until homogeneous, heat to 30 °C, react for 36 h, centrifuge, collect the precipitate, wash three times with dichloromethane and filter to obtain a yellow powder, which is then vacuum dried to obtain compound II-3 with a yield of 80%.

[0082] Reaction equation:

[0083]

[0084] Experiments have shown that compounds II-2 and II-3 are similar to compound II-1 in their fluorescence detection of potassium perfluorooctyl sulfonate.

Claims

1. Use of tetraphenylethylene derivatives as fluorescent probes for perfluorooctane sulfonate, wherein the tetraphenylethylene derivative is represented by formula (II): （Ⅱ）； in: X is -CH3, -CH2CH3, or -H; R - For I - , Br - or ClO4 - .

2. The use according to claim 1, characterized in that: Includes the following steps: Tetraphenylethylene derivative (II) was dissolved in water to prepare a solution with a concentration of 1×10⁻⁶. -5 A solution of M is used as stock solution I, also known as fluorescent probe II; perfluorooctyl sulfonate is dissolved in deionized water to prepare a 1×10⁻⁶ solution. -3 The solution of M is used as stock solution II; nine 0.5 mL aliquots of stock solution I are taken, and different volumes of stock solution II are added to eight of them respectively. Finally, deionized water is used to make up to 5 mL, thus preparing aqueous solutions of perfluorooctyl sulfonate with concentrations of 0, 5, 10, 15, 20, 25, 30, 35, and 40 μM, wherein the concentration of fluorescent probe II is 1 × 10⁻⁶. -6 M was used to measure its fluorescence spectrum. When the concentration of perfluorooctyl sulfonate in the fluorescence spectrum was in the range of 0-20 μM, the fluorescence intensity of the solution showed a good linear relationship with the concentration of perfluorooctyl sulfonate. 2 =0.9889.

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