CN114935562A - Fluorescent probe based on gold nanocluster supramolecular assembly and application of fluorescent probe in perfluorooctanesulfonic acid detection - Google Patents

Abstract

A fluorescent probe based on gold nano-cluster supramolecular assembly and its application in the detection of perfluorooctane sulfonic acid belong to the technical field of fluorescence detection. In the present invention, HAuCl ₄ ·3H ₂ O is used as Au source, cytidine-5' phosphate is used as stabilizer, and citric acid is used as reducing agent to prepare gold nano-clusters, and then the assembly formed by gold nano-clusters and CLD215 is used as fluorescence The probe, PFOS dissociates the assembly through competitive action, and then produces a fluorescence quenching response, and establishes a linear curve of fluorescence intensity-PFOS concentration of the fluorescence emission spectrum of AuNCs/CLD215, thereby realizing the detection of pollutant PFOS ( PFOS) high-sensitivity quantitative detection, with high sensitivity and wide detection range. In addition, this fluorescent probe successfully detected PFOS in mineral water and soil water with high recovery rate.

Description

A gold nanocluster supramolecular assembly-based fluorescent probe and its application in the detection of perfluorooctane sulfonic acid

technical field

The invention belongs to the technical field of fluorescence detection, and in particular relates to a fluorescence probe based on a gold nano-cluster supramolecular assembly and its application in the detection of perfluorooctane sulfonic acid.

Background technique

Perfluorinated compounds are synthetic fluorinated organic compounds that have been widely used in surfactants, dye protection products, adhesives, firefighting foams, pesticides and food packaging due to their unique hydrophobic and lipophobic properties. Since perfluorinated compounds have very strong CF bonds (485kJ·mol ^-1 ), they have very high thermal and chemical stability. Additionally, they are classified as persistent organic pollutants due to their toxicity and bioaccumulation.

In recent years, numerous reports have assessed the toxicity of perfluorinated compounds and their health risks to animals and humans. They can cause adverse damage to the kidneys, liver and immune system by binding to proteins. Due to the thermal and chemical stability of high-energy carbon-fluorine bonds, perfluorinated compounds have high environmental persistence. At the same time, it can be transferred, bioaccumulated and biomagnified along the food chain. Perfluorooctane sulfonic acid (PFOS) with a long chain (the carbon number of fluorine-containing bond ≥8) and a sulfonic acid group at the same time is easier to accumulate and enlarge in vivo. Therefore, among a large number of perfluorinated compounds, perfluorooctane sulfonic acid (PFOS) is the most representative persistent organic pollutant. It is currently found in oceans and rivers around the world, in the serum of many animals, in occupationally exposed workers and the general public. It is shown that these perfluorinated compounds are globally distributed, so monitoring PFOS in environmental systems is of great significance.

At present, common quantitative detection methods for PFOS include: high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), gas chromatography-mass spectrometry (GC/MS), surface-enhanced Raman scattering (SERS), resonance light scattering, electrochemical analysis, etc. Although these methods have certain advantages, they still have disadvantages such as complex synthesis process, complex sample preparation, expensive instrument requirements, and time-consuming procedures, which hinder their application in high-throughput monitoring of environmental samples. Fluorescence sensors have received more and more attention due to their high sensitivity, convenient operation, and non-destructive testing methods. However, fluorescent probes for PFOS detection are still very rare, such as upconverting nanoparticles, quantum dots, and organic conjugated materials. However, many materials are limited in application due to poor water solubility, high price and poor selectivity. Therefore, developing a simple, rapid, and cost-effective assay for PFOS remains a challenge.

On the other hand, metal nanoclusters have unique core-shell structures with discrete energy levels, which enable AuNCs to exhibit full-spectrum photoluminescence from blue to near-infrared. In addition, excellent photostability, long carrier lifetime and Stokes shift, low toxicity, and good biocompatibility provide excellent performance in analysis, sensing, and bioimaging. However, the luminescence of gold nanoclusters is generally weak, which severely limits its applicability in luminescence detection. In view of this, several strategies such as doping with metal ions (Ag and Cu), host-guest assembly and intercalation into polymer matrices, aggregation-induced luminescence enhancement, etc., have been employed to improve the luminescence performance. Aggregation-induced emission enhancement (AIEE) mainly refers to the reduction of intermolecular interactions by the accumulation of molecules, while greatly restricting the intramolecular rotation in the aggregated state, thereby strongly inhibiting the non-radiative inactivation process of single molecules, and finally leading to AIEE ( Aggregation-induced luminescence enhancement) The fluorescence intensity of the compound in the solid or aggregated state is much greater than its fluorescence intensity in dilute solution. Therefore, in this experiment, through the supramolecular assembly of amino-functionalized calix[4]arene, the metal nanoclusters are aggregated, so as to greatly enhance the luminescence intensity of metal nanoclusters.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a fluorescent probe based on gold nanocluster supramolecular assembly and its application in the detection of perfluorooctane sulfonic acid.

The invention enhances the fluorescence of gold nanoclusters through supramolecular assembly and is applied to the detection of PFOS in water medium. The gold nanoclusters were synthesized by a hydrothermal method, using cytidine-5' phosphate (5' CMP) as a ligand, the excitation wavelength was 370-380 nm, and the strongest emission wavelength was 570-590 nm. The gold nanoclusters have poor luminescence performance and low stability. Therefore, supramolecular assembly with amino-functionalized calix[4]arene (CLD215) can greatly increase the fluorescence emission intensity of the gold nanoclusters. This fluorescence enhancement is attributed to the supramolecular assembly of CLD215 with gold nanoclusters, which effectively increases the radiative transition rate while suppressing the non-radiative rate, thereby enhancing the luminescence intensity of metal nanoclusters. In the present invention, the assembly formed by the gold nanocluster and CLD215 is used as a fluorescent probe, and the perfluorooctane sulfonic acid dissociates the assembly through competition, thereby generating a fluorescence quenching response, and establishing the fluorescence intensity of AuNCs/CLD215 fluorescence emission spectrum-PFOS Concentration linear curve, so as to achieve highly sensitive quantitative detection of the pollutant perfluorooctane sulfonic acid (PFOS). The results showed that the linear range of PFOS detection was 0-100μM, and the detection limit was 5.1μM, with high sensitivity and wide detection range. In addition, this fluorescent probe successfully detected PFOS in mineral water and soil water with high recovery rate.

The gold nanocluster supramolecular assembly-based fluorescent probe of the present invention uses HAuCl ₄ ·3H ₂ O as Au source, cytidine-5' phosphate (5'CMP) as stabilizer, citric acid As a reducing agent; firstly, HAuCl ₄ ·3H ₂ O, cytidine-5'phosphoric acid, and citric acid-sodium citrate buffer solution with pH=4.5 were sequentially added to the ultrapure aqueous solution to form a mixed solution; in the mixed solution, HAuCl _4. The final concentration of 3H ₂ O is 8-15 μM, the final concentration of cytidine 5'-monophosphate is 25-35 μM, and the final concentration of sodium citrate is 200-300 μM; then the obtained mixed solution is heated at 95-105 ℃ Under the condition of hydrothermal reaction for 15-30 min, the nucleotide-protected gold nanocluster solution was obtained, which was centrifuged and freeze-dried into solid powder and prepared into AuNCs solution with MES-NaOH buffer solution; amino-functionalized cup was added to the AuNCs solution [ 4] Supramolecular assembly of aromatic hydrocarbons (CLD215), thereby obtaining fluorescent probe solutions based on gold nanocluster supramolecular assemblies through non-covalent bonds, namely electrostatic interactions; in AuNCs solution, the concentration of AuNCs is related to calix[4]arene. The ratio of the final concentration ranged from 0.1 mg/mL: 16 to 24 μM.

Description of drawings

Figure 1: (a) fluorescence excitation spectrum (left curve) and fluorescence emission spectrum (right curve) of AuNCs in aqueous solution, (b) transmission electron microscope (HR-TEM) image and grain size distribution (inset) of AuNCs; Corresponding to embodiment 1;

Figure 2: (a) Fluorescence emission spectra of AuNCs at different concentrations of CLD215, (b) a dot plot of the fluorescence intensity of the highest emission peak in the fluorescence emission spectrum of AuNCs with the concentration of CLD215; corresponding to Example 2;

Figure 3: (a) Transmission electron microscope (HR-TEM) image and grain size distribution of AuNCs/CLD215 (inset) (b) UV absorption spectra of AuNCs at different concentrations of CLD215; corresponding to Example 3;

Figure 4: (a) The fluorescence emission spectra of AuNCs under different PFOS concentrations, (b) the fluorescence intensity at 510 nm of the AuNCs fluorescence emission spectrum as a function of the concentration of PFOS; corresponding to Example 4;

Figure 5: Fluorescence emission spectra of AuNCs/CLD215 under different PFOS concentrations; corresponding to Example 4;

Figure 6: (a) Dot plot of fluorescence intensity at 510 nm of AuNCs/CLD215 fluorescence emission spectrum with the concentration of PFOS (0-180 μM), (b) fluorescence emission spectrum of AuNCs/CLD215 at 510 nm-PFOS concentration (0-100 μM) Linear curve; corresponding to Example 4;

Figure 7: (a) Transmission electron microscope (HR-TEM) and grain size distribution (inset) of AuNCs/CLD215+PFOS; (b) UV absorption spectra of AuNCs/CLD215 under different PFOS concentrations; corresponding to Example 5;

Figure 8: The selectivity (a) and anti-interference analysis (b) of the fluorescence response of AuNCs/CLD215 to PFOS; the ratio of fluorescence quenching intensity refers to the fluorescence intensity (I ₀ ) at 510 nm before adding PFOS and 510 nm after adding PFOS The ratio of the quenching difference (I ₀ -I) of the fluorescence intensity (I) and the fluorescence intensity (I ₀ ) at 510 nm before adding PFOS, namely (I ₀ -I)/I ₀ ; corresponding to Example 6;

By comparing the fluorescence emission positions of AuNCs in the literature ^[1] (Fig. 1a), it is preliminarily determined that AuNCs have been synthesized. Next, the morphology of the as-prepared AuNCs was characterized (Fig. 1b). The average grain size was found to be ~1.45 nm after particle size statistical analysis. Nucleotide-protected gold nanoclusters have been successfully synthesized by fluorescence spectroscopy and electron microscopy characterization.

As shown in Figure 2a,b, with the stepwise addition of different concentrations (0, 4, 8, 12, 16, 20, 24 μM) of calix[4]arene (CLD215) into the AuNCs solution, the fluorescence intensity of AuNCs has obvious Enhancement phenomenon, and there is a slight increase in lifetime (Table 1), fluorescence enhancement (~8 times), and accompanied by a certain degree of blue shift phenomenon (~60nm).

After that, the process was characterized to a certain extent. As shown in Figure 3a, the morphology of AuNCs/CLD215 was characterized. Through particle size statistics of about 200 particles, the final statistical result was 10.07 nm. Compared with AuNCs, the size of the assembly was The particle size increases, thus, indicating that CLD215 and AuNCs, through electrostatic interaction, undergo supramolecular assembly, which induces enhanced fluorescence emission after aggregation.

As shown in Fig. 4a,b, with the stepwise addition of PFOS with different concentrations (0, 20, 40, 80, 120, 200, 400 μM) into the AuNCs solution, the fluorescence intensity has no obvious quenching phenomenon, indicating that PFOS does not quench Quenching the fluorescence of the gold nanoclusters themselves. However, with the gradual addition of different concentrations (0-180 μM) of PFOS into the AuNCs/CLD215 solution, the fluorescence intensity was significantly quenched (Fig. 5), indicating that PFOS can quench the fluorescence of the gold nanoclusters and calixarene assemblies. . From Figure 6b, it can be seen that AuNCs showed a good linear response to PFOS in a wide range from 0 to 100 μM. As the concentration of PFOS increased, the fluorescence intensity of the fluorescent probe at 510 nm decreased, and finally at 180 μM reached the plateau (Fig. 6a). The linear relationship between the fluorescence intensity I at 510 nm and the PFOS concentration is shown in Fig. 6b, and the linear response for PFOS varies between 0 and 100 μM (R ² =0.995). And AuNCs/CLD215 was diluted with 20 μM MES-NaOH buffer solution (pH 6.5), and the detection limit of PFOS was calculated to be 5.1 μM.

In addition, the effects of other interfering substances such as PFOA, CTAB, n-octanoic acid, sodium 1-octane sulfonate, Na ₂ SO ₄ , KCl, MgCl ₂ , NaCl on AuNCs/CLD215 were also analyzed. None of the compounds caused significant changes in the fluorescence intensity of AuNCs/CLD215. Figure 8(a) shows that only PFOS can significantly quench the fluorescence of AuNCs/CLD215. Figure 8(b) shows that adding other interfering substances to the solution containing PFOS did not affect the fluorescence response of AuNCs/CLD215 to PFOS. Therefore, we believe that these interfering substances have no effect on the detection of PFOS by the fluorescent AuNCs/CLD215 probe, indicating that this method is an effective means to detect PFOS in practical applications.

Detailed ways

Cytidine 5'-monophosphate (CMP) used in the present invention was purchased from TCI (Shanghai) Development Co., Ltd. Chloroauric acid trihydrate (HAuCl ₄ ·3H ₂ O), sodium citrate and citric acid were purchased from Beijing Chemical Factory. Tetraethylammonium heptadecafluorooctanesulfonate (PFOS), sodium 1-octanesulfonate, and Marlene ethanesulfonic acid monohydrate (MES) were purchased from Shanghai Aladdin Reagent Company. Perfluorooctanoic acid sodium (PFOA), n-octanoic acid, and cetyltrimethylammonium bromide (CTAB) were purchased from Shanghai McLean Biochemical Technology Co., Ltd. Basic drugs such as sodium hydroxide (NaOH) were purchased from Tianjin Guangfu Reagent Company. All chemicals were of analytical grade and were not repurified. Ultrapure water was used throughout the experiment.

Example 1:

According to literature reports ^[1] , HAuCl ₄ ·3H ₂ O, cytidine 5'-monophosphate (CMP), citric acid-sodium citrate solution (pH=4.5) were added to 7 mL of ultrapure water in turn, HAuCl ₄ ·3H The final concentration of ₂ O was 10 μM, the final concentration of cytidine 5’-monophosphate was 30 μM, and the final concentration of sodium citrate was 250 μM; after that, the obtained mixture solution was put into a 20 mL autoclave, and the hydrothermal reaction was carried out at 100 °C. After cooling for 20 min, a nucleotide-protected gold nanocluster solution (AuNCs) was obtained.

The results show that the excitation wavelength of the AuNCs obtained in Example 1 is 370-380 nm, and the emission wavelength is 570-590 nm (Fig. 1a). The gold nanoclusters were successfully synthesized through the preliminary determination of the emission position of the fluorescence spectrum. Secondly, the morphology of the prepared AuNCs was characterized (Fig. 1b). It can be seen from the figure that the nanoparticles have high dispersibility and uniform particle size. The average grain size of about 200 AuNCs was found to be ∼1.45 nm, and the interplanar spacing of the grains of AuNCs (inset in Fig. 1b) was ∼0.24 nm.

Example 2:

The AuNCs obtained in Example 1 were centrifuged by the acetone precipitation method. After centrifugation, the AuNCs were lyophilized into solid powder, and the 1 mg/mL AuNCs mother solution was prepared with MES-NaOH solution; after being diluted ten times with MES-NaOH buffer solution, A 0.1 mg/mL solution of AuNCs was obtained. Take 7 parts of 500 μL, 0.1 mg/mL AuNCs solution, and add different amounts of CLD215 dropwise to them respectively, so that the final concentrations of CLD215 are 0, 4, 8, 12, 16, 20, and 24 μM, respectively (Fig. 2b). When the final concentration of calix[4]arene is 20 μM, the fluorescence intensity of gold nanoclusters increases to the strongest (it can be seen that when the concentration of AuNCs in AuNCs solution is 0.1 mg/mL, the more suitable calix[4]arene has the highest fluorescence intensity. AuNCs/CLD215 (0.1 mg/mL, 20 μM), a fluorescent probe based on gold nanocluster supramolecular assemblies, was obtained.

When CLD215 reached 20 μM, the fluorescence enhancement almost reached a plateau (Figure 2, and the lifetime was slightly enhanced (Table 1).

Table 1: Fluorescence lifetime measurement data of AuNCs, AuNCs/CLD215

Example 3:

A series of characterizations were performed on the fluorescence-enhanced assembly AuNCs/CLD215 (0.1 mg/mL, 20 μM) obtained in Example 2 to prove the binding mode between AuNCs and CLD215 and the mechanism of fluorescence enhancement. As shown in Figure 3a, the morphology of AuNCs/CLD215 was characterized, and the particle size statistical result was 10.07 nm. Therefore, the process of particle size growth from AuNCs to AuNCs/CLD215 (20 μM) indicated that the reason for the fluorescence enhancement was aggregation-induced Glow enhancement.

In addition, the changes in UV absorbance of calix[4]arene (CLD215) with different concentrations (0, 4, 8, 12, 16, 20, 24 μM) were gradually added to the AuNCs solution (3b). There is a certain degree of enhancement, which also indicates the supramolecular assembly of gold nanoclusters and calixarene to form luminescent aggregates.

The results showed that AuNCs and CLD215 interacted electrostatically, resulting in supramolecular assembly, increased particle size, and the formation of luminescent aggregates.

Example 4:

The fluorescence-enhanced assembly AuNCs/CLD215 (0.1 mg/mL, 20 μM) obtained in Example 2 was used as a fluorescent probe for the detection of PFOS. First, the feasibility of the experiment was tested. As shown in Figure 4a and b, with the gradual addition of PFOS of different concentrations (0, 20, 40, 80, 120, 200, 400 μM) to the AuNCs solution, the fluorescence intensity did not show any obvious quenching. extinction phenomenon (Figure 4a, b). The AuNCs/CLD215 (0.1 mg/mL, 20 μM) obtained in Example 2 was diluted twice with MES-NaOH buffer solution (at this time, the concentration of AuNCs in AuNCs/CLD215 was 50 μg/mL, and the concentration of CLD215 was 10 μM. According to the From the results of Example 2 and Example 4, when the concentration of AuNCs in the AuNCs solution was 50 μg/mL, the appropriate final concentration of calix[4]arene was 8-12 μM), taking 500 μL AuNCs/CLD215 (50 μg/mL, 10 μM) solution, into which PFOS of different concentrations (0-180 μM, all concentrations in the present invention are final concentrations) were gradually added, and the fluorescence intensity was obviously quenched (Fig. 5). It was shown that PFOS did not quench the gold nanocluster itself, but had a quenching effect on the assembly, so AuNCs/CLD215 (50 μg/mL, 10 μM) was used to detect PFOS.

The present invention is mainly for the detection of PFOS. It can be seen from Figure 6b that the AuNCs/CLD215 fluorescent probes have a good linear response to PFOS in a wide concentration range from 0 to 100 μM. As the concentration of PFOS increased, the fluorescence intensity of the fluorescent probe at 510 nm decreased, and finally reached a plateau at 180 μM (6a). The linear relationship between the fluorescence intensity at 510 nm and the concentration of PFOS is shown in Figure 6b, and the linear response range for PFOS is 0-100 μM (Y=3.01X+447.256, R ² =0.995, where Y is the fluorescence intensity at 510 nm, X is the PFOS concentration). And after AuNCs/CLD215 was diluted with 20 μM MES-NaOH buffer solution (pH 6.5), the detection limit of AuNCs/CLD215 for PFOS was calculated to be 5.1 μM ^[2] . The results showed that AuNCs/CLD215 had a wide detection range and better detection limit for the detection of PFOS, and could be used as a fluorescent probe for the detection of PFOS.

Example 5:

The process of detecting PFOS by AuNCs/CLD215 in Example 4 was characterized. The morphology of AuNCs/CLD215-PFOS was firstly characterized (Fig. 7a). It can be seen from the figure that the dispersibility of the nanoparticles is relatively high and the particle size is relatively uniform. The average grain size was found to be -6.45 nm by particle size statistical analysis of approximately 200 grains. Compared with the AuNCs/CLD215 particle size (10.07nm), it can be found that the process from the assembly to the addition of PFOS is a depolymerization process. In addition, the UV absorption spectrum analysis (Fig. 7b) also found that, contrary to the rising trend of UV absorption formed by the assembly, the UV absorption of AuNCs/CLD215 gradually decreased with the increase of PFOS concentration after the dropwise addition of PFOS, which also proved to be depolymerization. The process is consistent with the electron microscope results. From Table 2, it can be found that the fluorescence lifetime of AuNCs/CLD215 is almost unchanged compared with that of AuNCs/CLD215-PFOS, indicating that the fluorescence quenching mechanism of AuNCs/CLD215-PFOS is static quenching.

Table 2: Fluorescence lifetime measurement data of AuNCs/CLD215, AuNCs/CLD215+PFOS

Example 6:

To study the selectivity of AuNCs/CLD215 for PFOS. A certain amount (200 μM) of PFOS, PFOA, CTAB, n-octanoic acid, sodium octane sulfonate, Na ₂ SO ₄ , KCl, MgCl ₂ , NaCl was added to AuNCs/CLD215 diluted with MES-NaOH buffer solution (pH 6.5) solution, mix quickly. All fluorescence tests were performed at room temperature. The results showed that PFOS quenched the fluorescence of AuNCs/CLD215 to the greatest extent, and the others hardly quenched or quenched the fluorescence of the assemblies to a lesser extent. This indicates that the AuNCs/CLD215 fluorescent probe can effectively detect PFOS (Fig. 8a)

The method of interference test is to add PFOS (200 μM) to the AuNCs/CLD215 solution diluted by MES-NaOH buffer solution (pH 6.5) and incubate for five minutes, and then add a series of interfering substances (200 μM) (CTAB, n-octanoic acid) respectively. , sodium octane sulfonate, Na ₂ SO ₄ , KCl, MgCl ₂ , NaCl), and then the fluorescence spectrum test was performed. The results showed that the addition of other interfering substances to the solution containing PFOS did not affect the fluorescence response of AuNCs/CLD215 to PFOS (Fig. 8b).

Example 7:

The detection of mineral water samples is mainly to take 100 μL of mineral water and add the same concentration of AuNCs/CLD215 solution, and then add three different final concentrations of PFOS (66 μM, 83 μM, 100 μM) to the above solutions (denoted as 1#~3#) . After incubation for 2 min, fluorescence spectroscopy was performed. The results showed that the recoveries ranged from 97.5% to 104.1%, and the relative standard deviations (RSDs) were lower than 5%, indicating that AuNCs/CLD215 could be used in physical detection (Table 3).

Table 3: Measurement data of PFOS in mineral water

The soil water sample detection method was first modified according to the literature ^[3] , the soil was treated, and the soil (0.1g, obtained by the Yanhu Lake of Jilin University) was dispersed in 100mL MES-NaOH buffer solution (20mM, pH=6.5) , ultrasonic extraction (10min); then the sample was heated to boiling, cooled to room temperature, centrifuged (8000rpm, 10min); finally filtered through a 0.22 μm filterable membrane, and measured under the same conditions. The results showed that the recoveries ranged from 95.6% to 104.8%, and the relative standard deviations (RSDs) were all lower than 5%, indicating that AuNCs/CLD215 could be used in physical detection (Table 4).

Table 4: Measurement data of PFOS in soil water samples

It should also be noted that the specific embodiments of the present invention are only used for illustrative description, and do not limit the protection scope of the present invention in any way. Those skilled in the art can improve or change according to the above descriptions, but all these Improvements and changes should all belong to the protection scope of the claims of the present invention.

references

[1] Zhang Chunxia, Wang Yu, Wu Yuqing, Li Hongwei, etc.; Development of cytidine 5'-monophosphate-protected gold nanoclusters via aggregation-induced emission enhancement as direct luminescent substrates for ratiometric determination of alkaline phosphatase and Inhibitor Evaluation [J], Colloids and Surfaces A: Physical Chemistry and Engineering Aspects, 640(2022), 128423;

[2] Zheng Zhe, Geng Wenchao, Gao Jie, Mu Yijiang, Guo Dongsheng; Differential calixarene receptors produce a mode of distinguishing glycosaminoglycans [J], Introduction to Organic Chemistry, 2018, 5, 2685-2691;

[3] Zhang Qiaojuan, Liao Mengyu, Yao Yizhi, etc.; A water-soluble fluorescent probe based on perynediimide for perfluorooctane sulfonate in 100% aqueous medium [J], sensor and actuator : B. Chemical Substances, 350 (2022) 130851.

Claims (3)

1. A fluorescent probe based on gold nanocluster supramolecular assemblies is characterized in that: is HAuCl ₄ ·3H ₂ Taking O as an Au source, cytidine-5' phosphate as a stabilizer and citric acid as a reducing agent; firstly, HAuCl is added ₄ ·3H ₂ Sequentially adding O, cytidine-5' phosphoric acid and citric acid-sodium citrate buffer solution with the pH value of 4.5 into the ultrapure water solution to form a mixed solution; in a mixed solution of HAuCl ₄ ·3H ₂ The final concentration of O is 8-15 mu M, the final concentration of cytidine 5' -monophosphate is 25-35 mu M, and the final concentration of sodium citrate is 200-300 mu M; then carrying out hydrothermal reaction on the obtained mixed solution at the temperature of 95-105 ℃ for 15-30 min to obtain a gold nanocluster solution protected by nucleotide, carrying out centrifugal freeze-drying to obtain solid powder, and preparing the solid powder into an AuNCs solution by using MES-NaOH buffer solution; then adding the amino functionalized cup [4] into the AuNCs solution]Aromatic hydrocarbon is subjected to supramolecular assembly, so that a fluorescent probe solution based on the gold nanocluster supramolecular assembly is obtained through non-covalent bonds, namely electrostatic interaction; concentration of AuNCs in AuNCs solution with cup [4]]The ratio range of the final concentration of the aromatic hydrocarbon is 0.1 mg/mL: 16 to 24 μ M.

2. The use of the gold nanocluster supramolecular assembly-based fluorescent probe according to claim 1 in perfluorooctanesulfonic acid detection.

3. The application of the gold nanocluster supramolecular assembly-based fluorescent probe in perfluorooctanesulfonic acid detection, according to claim 3, is characterized in that: when the concentration of AuNCs in the AuNCs solution is 0.05mg/mL and the final concentration of calix [4] arene is 10 mu M, the linear response range of the fluorescent probe to the concentration of the perfluorooctanesulfonic acid is 0-100 mu M, and the detection limit is 5.1 mu M.

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