Fluorescent sensor array and application thereof in rapid detection and dynamic monitoring of typical perfluorinated pollutants in fire extinguishing protection equipment

Abstract

The invention discloses a fluorescent sensor array and application thereof in rapid detection and dynamic monitoring of typical perfluorinated pollutants in fire-fighting and fire-extinguishing protection equipment. The fluorescent sensor array comprises luminescent metal organic frameworks (LMOFs) PCN-999 (at) RGH and Uio-67-NH2 (at) FR. When the two LMOFs interact with perfluoroalkyl compounds (PFASs), different fluorescence responses are shown, a five-channel fluorescence sensor array constructed by the two LMOFs and the perfluoroalkyl compounds (PFASs) are combined with a statistical analysis method, rapid distinguishing of the six PFASs can be achieved, the detection limit is low, and the synthesis path is simple. Tests show that the fluorescent array constructed by the method can be used for rapidly screening typical PFASs in complex matrixes such as fire extinguishing protection equipment and the like, quantitative pollution level data of the fire extinguishing protection equipment can be given in time, the accuracy is equivalent to that of a high performance liquid chromatography-mass spectrometry method, and a scientific basis and a technical support are provided for occupational exposure protection of firefighters.

Description

Technical Field

[0001] The present invention relates to the field of rapid detection and dynamic monitoring of typical perfluorinated compounds in fire-fighting and fire-extinguishing protective equipment, and in particular to a fluorescent sensor array and its application in rapid detection and dynamic monitoring of typical perfluorinated compounds in fire-fighting and fire-extinguishing protective equipment. Background Art

[0002] Perfluorinated and polyfluorinated compounds (PFASs) are widely used in firefighting foams and firefighting protective clothing for firefighters due to their excellent chemical stability, extremely high surface activity and unique hydrophobic and oleophobic properties. However, PFASs are a typical class of persistent organic pollutants that can be released into the air through smoke, and then contaminated, migrated and accumulated in firefighting protective equipment, seriously threatening the lives and health of firefighters.

[0003] PFASs can withstand strong ultraviolet light, heating, chemical and microbial effects and are extremely difficult to degrade. Toxicological studies have shown that PFASs can cause genetic, immunotoxicity and carcinogenicity to experimental animals, are highly bioaccumulative, persistent and mobile, and are difficult to be metabolized or excreted by the human body. A genome-wide association study of firefighters showed that DNA methylation was related to the length of service of firefighters or the concentration of PFASs in their blood. Firefighters will experience exposure to foam fire extinguishing agents containing PFASs and potential cumulative effects throughout their careers. Due to the lack of relevant detection and early warning mechanisms, this risk has not received enough attention. Therefore, it is urgent to develop a standardized, portable, low-cost rapid detection method to carry out qualitative and quantitative detection of typical PFASs in complex matrices such as fire-fighting protective equipment, and to obtain key information such as the types, physical and chemical properties and concentration distribution of PFASs in a timely manner, so as to provide important technical support for the performance maintenance and service life evaluation of firefighters' personal protective equipment, and provide guidance for the occupational health of firefighters.

[0004] At present, the detection of PFASs mainly relies on chromatography, mass spectrometry, electrophoresis and electrochemical methods. These detection methods require expensive equipment, complex sample preparation, harsh detection conditions, high costs, and require professional personnel to operate. They are not suitable as a normalized detection method throughout the life cycle of fire protection equipment. In addition, there are often multiple PFASs coexisting in actual test samples, and it is time-consuming and laborious to use different detection methods to detect different PFAS one by one. Therefore, it is particularly important to design a simple and effective high-throughput detection method that can detect multiple PFASs at the same time.

[0005] Fluorescence analysis technology is widely used in the field of sensing due to its advantages of simplicity, rapidity, high sensitivity and low cost. At present, some fluorescent sensors for detecting perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) have been developed and reported. However, most traditional fluorescent sensing systems usually only contain single-emission luminescent sensing elements and cannot achieve the distinguishing detection of a class of compounds with similar structures.

[0006] Sensor array technology uses a group of sensor elements to produce a special response pattern for each target, combining the signals of multiple sensor units, greatly improving the selectivity of the sensor array, thus overcoming the limitation of traditional luminescent sensors that cannot effectively distinguish highly similar analytes, and is particularly suitable for distinguishing compounds with similar structures. However, most existing reports require testing multiple sensors, and the analysis operation time is doubled.

[0007] As a type of porous crystalline material, luminescent metal organic frameworks (LMOFs) have been widely used in luminescence, gas storage and separation, catalysis, biomedicine, etc. due to their advantages such as high specific surface area, adjustable pore structure and easy surface modification. Through the pre-designed screening of ligands and metal nodes, and the effective regulation of pore size and pore shape, the target functional groups, pore microenvironment and optical properties of LMOFs molecules can be accurately and controllably prepared, making LMOFs an optimal platform for producing multi-dimensional luminescence. At the same time, the development of crystalline porous LMOFs fluorescence sensor arrays has brought new opportunities and development space for the high-specific identification research of trace or even trace PFASs, and also provided a good theoretical basis and technical support for the application research of high-sensitive detection of typical harmful carcinogenic pollutants PFASs in complex matrices such as fire extinguishing protective equipment.

[0008] In summary, constructing a fluorescent sensor array based on LMOFs is crucial to achieve high-throughput rapid detection and dynamic monitoring of typical perfluorinated compounds in complex matrices such as fire-fighting protective equipment. Summary of the invention

[0009] In view of this, the present invention proposes a fluorescent sensor array, and also provides the application of the fluorescent sensor array in the rapid detection and dynamic monitoring of typical perfluorinated pollutants in fire-fighting protective equipment. The rapid LMOFs fluorescent sensor array of the present invention can timely and accurately provide quantitative pollution level data of PFASs on protective equipment, which can provide scientific basis and technical support for occupational exposure protection of firefighters.

[0010] To achieve the above object, the present invention adopts the following technical solutions: The fluorescent sensor array of the present invention comprises two dye-encapsulated luminescent metal organic frameworks PCN-999@RGH and Uio-67-NH2@FR, wherein the PCN-999@RGH has two fluorescent channels and the Uio-67-NH2@FR has three fluorescent channels; PCN-999@RGH was prepared by ultrasonically dissolving the ligand L12, ZrCl4, rhodamine 6G derivative RGH and formic acid into N,N-diethylformamide, reacting at 110-130 °C under normal pressure, cooling to room temperature after the reaction, centrifuging, washing, drying, soaking in acetone after drying, and finally vacuum activating to obtain PCN-999@RGH; wherein the structural formulas of the ligand L12 and the rhodamine 6G derivative RGH are: Uio-67-NH2@FR was prepared by ultrasonically dissolving ZrCl4 and ligand H2BPDC-NH2, benzoic acid, fluorescein isothiocyanate, and Nile red in N,N-dimethylformamide, transferring them to an autoclave after they were completely dissolved, placing the autoclave at 110-130 °C for reaction, cooling to room temperature after the reaction, centrifuging, washing, drying, soaking in acetone after drying, and finally vacuum activating to obtain Uio-67-NH2@FR; wherein the structural formula of the ligand H2BPDC-NH2 is as follows: The construction of the fluorescent sensor array includes the following: PCN-999@RGH and Uio-67-NH2@FR were ultrasonically dispersed in deionized water to obtain suspensions of PCN-999@RGH and Uio-67-NH2@FR. The suspensions of PCN-999@RGH and Uio-67-NH2@FR were added to each sample to obtain a mixed probe. The mixed probe was incubated at room temperature and then subjected to fluorescence spectroscopy test to obtain a raw data matrix of sample number × 2 sensors × N parallel times.

[0011] Preferably, when preparing PCN-999@RGH and Uio-67-NH2@FR, they are washed three times with N,N-dimethylformamide and acetone respectively after centrifugation; after washing, they are vacuum dried at 80°C overnight; the soaking time in acetone is more than 36 hours, and the acetone is replaced every 12 hours during the soaking process; and the final vacuum activation temperature is 80°C.

[0012] Preferably, the ratio of the ligand L12, ZrCl4, rhodamine 6G derivative and formic acid is 20 mg: 40 mg: 15 mg: 1.2 mL; the ratio of ZrCl4, H2BPDC-NH2, benzoic acid, fluorescein isothiocyanate and Nile red is 60 mg: 64.3 mg: 940 mg: 10 mg: 5 mg.

[0013] The fluorescent sensor array described in the present invention is used in the rapid detection and dynamic monitoring of typical perfluorinated pollutants (PFASs) in fire-fighting protective equipment, wherein the PFASs include any one of perfluorooctanoic acid, perfluorooctane sulfonic acid, perfluorobutane sulfonic acid, perfluorohexane sulfonic acid potassium salt, perfluorononanoic acid and perfluorodecanoic acid, and a combination of two or more thereof.

[0014] The fluorescent sensor array is used for rapid identification and quantitative detection of PFASs in fire protection equipment, including the following: In the first step, an excess of barium chloride is added to the rinse liquid sample of the fire protection equipment, the precipitate is removed by centrifugation, and the supernatant is filtered with a filter membrane to obtain a pre-treated sample; The stock solutions of six PFASs were prepared with deionized water, each with a concentration of 300 μM; In the second step, PCN-999@RGH and Uio-67-NH2@FR powders were added to the pretreated sample, and PCN-999@RGH and Uio-67-NH2@FR were dispersed in the pretreated sample by ultrasound to obtain a suspension; In the third step, the suspension in the second step was added to the mother solution of each PFAS, and the fluorescence spectrum test was performed after incubation at room temperature; In the fourth step, the relative fluorescence intensity I0 / I was used to describe the different fluorescence responses of each channel to PFASs at a specific fluorescence emission wavelength, where I0 was the initial fluorescence intensity of the two probes and I was the fluorescence intensity of the mixed probe after the addition of PFASs in the third step. The data were processed by heat map, PCA and HCA to quickly screen and quantify PFASs in the rinse fluid of fire protection equipment.

[0015] Compared with the prior art, the advantages of the present invention are: The present invention combines luminescent metal organic frameworks (LMOFs) and sensor arrays to propose a new type of LMOFs sensor array that can be used for the rapid identification and detection of six perfluoroalkyl compounds. Specifically, PCN-999@RGH and Uio-67-NH2@FR of the present invention exhibit different fluorescence responses when interacting with perfluoroalkyl compounds. The sensor array constructed by these two LMOFs combined with statistical analysis methods can achieve rapid differentiation and screening of six PFASs with low detection limits (such as the LOD value of perfluorodecanoic acid as low as 29.92 nM) and a simple synthesis path.

[0016] Experiments have shown that the fluorescent array constructed by the present invention can be used for the rapid detection and dynamic monitoring of PFASs in complex matrices such as fire-fighting and fire-fighting protection equipment, and can timely obtain key information such as the type, physical and chemical properties and concentration distribution of PFASs in fire-fighting and fire-fighting protection equipment, and the accuracy is comparable to that of high-performance liquid chromatography-mass spectrometry, providing a scientific basis and technical support for the performance maintenance of firefighters' personal protective equipment, service life assessment and occupational exposure protection of firefighters, and providing guiding opinions for doing a good job in the occupational health of firefighters. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is the infrared spectrum of PCN-999@RGH in Example 1 of the present invention.

[0018] Figure 2 This is the infrared spectrum of Uio-67-NH2@FR in Example 1 of the present invention.

[0019] Figure 3 This is the XRD pattern of PCN-999@RGH in Example 1 of the present invention.

[0020] Figure 4 This is the XRD diagram of Uio-67-NH2@FR in Example 1 of the present invention.

[0021] Figure 5 (a) heat map, (b) PCA map and (c) HCA dendrogram of the fluorescence sensor array and the responses of six PFASs in Example 2 of the present invention.

[0022] Figure 6 3 is an anti-interference analysis diagram of the fluorescent sensor array in Example 3 of the present invention, wherein (a) is a PCA diagram, and (b) is a HCA dendrogram.

[0023] Figure 7 (a) PCA, (b) HCA dendrogram, and (c) heat map of the response of the fluorescent sensor array to six PFASs in Example 4 of the present invention. The final concentration of each PFAS was 0.5 μM.

[0024] Figure 8 (a) PCA, (b) HCA dendrogram, and (c) heat map of the response of the fluorescent sensor array to six PFASs in Example 4 of the present invention. The final concentration of each PFAS was 6 μM.

[0025] Fig. 9 (a) PCA, (b) HCA dendrogram, and (c) heat map of the response of the fluorescent sensor array to six PFASs in Example 4 of the present invention. The final concentration of each PFAS was 10 μM.

[0026] Fig.10 (a) PCA, (b) HCA dendrogram, and (c) heat map of the response of the fluorescent sensor array to six PFASs in Example 4 of the present invention. The final concentration of each PFAS was 20 μM.

[0027] Fig.11 (a) PCA graph of the response of the fluorescent sensor array to different concentrations of PFOA (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFOA concentration.

[0028] Fig.12 (a) PCA graph of the response of the fluorescent sensor array to different concentrations of PFOS (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFOS concentration.

[0029] Fig.13 (a) PCA graph of the response of the fluorescent sensor array to different concentrations of PFBS (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFBS concentration.

[0030] Fig.14 (a) PCA graph of the response of the fluorescence sensor array to different concentrations of PFHxSK (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFHxSK concentration.

[0031] Fig.15 (a) PCA graph of the response of the fluorescent sensor array to different concentrations of PFNA (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFNA concentration.

[0032] Fig.16 (a) PCA graph of the response of the fluorescent sensor array to different concentrations of PFDA (0.2-30 μM) in Example 4 of the present invention, and (b) linear relationship graph between factor 1 and PFDA concentration.

[0033] Fig.17(a) PCA score diagram and (b) HCA dendrogram of the fluorescence response of the fluorescence sensor array in Example 5 of the present invention to mixtures of PFOA and PFOS at different molar ratios.

[0034] Fig.18 (a) PCA score diagram and (b) HCA dendrogram of the fluorescence response of the fluorescence sensor array in Example 6 of the present invention to the fire retardant clothing rinsing liquid added with different PFAS.

[0035] Fig.19 (a) PCA score diagram of the fluorescence response of the fluorescence sensor array in Example 7 of the present invention to the mixture of PFOA and PFOS in different molar ratios in sample 1, (b) the final concentration of PFOA and PFOS in sample 1, and (c) quantitative analysis of the sample by the linear function of PFOA concentration and factor 1.

[0036] Fig. 20 (a) PCA score diagram of the fluorescence response of the fluorescence sensor array in Example 7 of the present invention to the mixture of PFOA and PFOS in different molar ratios of sample 2, (b) the final concentration of PFOA and PFOS in sample 2, and (c) quantitative analysis of the sample by the linear function of PFOA concentration and factor 1.

[0037] Fig.21 (a) PCA score diagram of the fluorescence response of the fluorescence sensor array in Example 7 of the present invention to the mixture of PFOA and PFOS in different molar ratios in sample 3, (b) the final concentration of PFOA and PFOS in sample 3, and (c) quantitative analysis of the sample by the linear function of PFOA concentration and factor 1. DETAILED DESCRIPTION

[0038] It should be pointed out that the chemical reagents used in the present invention are all existing commercially available reagents, the fluorescence spectrum test uses a fluorescence spectrometer, and the fluorescence test parameters are all adopted: the excitation wavelength of the fluorescence spectrum is set to 370 nm, the detection range is 400 nm-700nm, the slit is 5.0 nm×5.0 nm, and the scanning speed is 6000 nm / min.

[0039] It should be pointed out that the six PFASs in the embodiments of the present invention include perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), perfluorohexane sulfonic acid potassium salt (PFHxSK), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA).

[0040] The present invention proposes a fluorescent sensor array, which is constructed by using two dye-encapsulated multi-emission luminescent metal organic frameworks PCN-999@RGH and Uio-67-NH2@FR. PCN-999@RGH has two fluorescent channels, and Uio-67-NH2@FR has three fluorescent channels. Among them, the synthesis of PCN-999@RGH: ligand L12, ZrCl4, rhodamine 6G derivative (hereinafter referred to as "RGH"), and formic acid are ultrasonically dissolved in N, N-diethylformamide (ie, DEF), reacted at 110-130 ° C and normal pressure for 24 h-36 h, then cooled to room temperature, centrifuged, washed (with N, N-dimethylformamide and acetone, respectively), vacuum dried at 80 ° C overnight, and then soaked in acetone for more than 36 h after drying, and the acetone is replaced every 12 h, and finally vacuum activated at 80 ° C to obtain PCN-999@RGH; Synthesis of Uio-67-NH2@FR: ZrCl4 and ligand H2BPDC-NH2, benzoic acid, fluorescein isothiocyanate (FITC), and Nile Red (Nile Red) were ultrasonically dissolved in N,N-dimethylformamide (DMF), and then transferred to an autoclave and heated at 110-130 °C for 18-48 h. After the reaction, the autoclave was cooled to room temperature, centrifuged, washed (with N,N-dimethylformamide and acetone, respectively), and vacuum dried overnight. After drying, it was soaked in acetone for more than 36 h, and the acetone was replaced every 12 h. Finally, it was activated under vacuum conditions (80 °C) for 12 h to obtain Uio-67-NH2@FR. The structural formulas of the ligand L12, ligand H2BPDC-NH2 and RGH are: The construction of the fluorescent sensor array includes the following: S2.1, suspend PCN-999@RGH and Uio-67-NH2@FR in deionized water to obtain suspensions of PCN-999@RGH and Uio-67-NH2@FR, respectively, to obtain two probes; S2.2, add the suspension of PCN-999@RGH and Uio-67-NH2@FR to each PFAS solution, incubate at room temperature for 10 minutes, and then use a fluorescence spectrometer to detect fluorescence to obtain the original data array of six PFASs×5 channels×5 parallels; in addition, when each PFAS has N concentrations, the original matrix data of each PFAS is N (corresponding to N concentrations)×5 channels×5 parallels; when the PFASs solution is binary or multivariate, the original matrix data is M×5 channels×5 parallels of different ratios of the PFASs solution; Data analysis of the raw data array: The relative fluorescence intensity I0 / I is used to describe the different fluorescence responses of each channel to PFASs at a specific fluorescence emission wavelength, where I0 is the fluorescence intensity of the two probes, and I is the fluorescence intensity after adding PFASs to the two probes. It is further displayed by its corresponding heat map, and each I0 / I data point is represented by a color. The obtained I0 / I data are processed by principal component analysis PCA and hierarchical cluster analysis HCA; the above six PFASs include perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutane sulfonic acid (PFBS), perfluorohexane sulfonic acid potassium salt (PFHxSK), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA).

[0041] Example 1 Synthesis of two sensor materials in the fluorescence sensor array of the present invention 1. The construction of the fluorescent sensor array in the present invention uses two dye-encapsulated multi-emission luminescent metal organic frameworks PCN-999@RGH and Uio-67-NH2@FR as sensors. The synthesis methods of PCN-999@RGH and Uio-67-NH2@FR are as follows: 1. Synthesis of PCN-999@RGH: 20 mg of ligand L12, 40 mg of ZrCl4, 15 mg of RGH, and 1.2 mL of formic acid were ultrasonically dissolved (ultrasonication for 10 min) in 3.0 mL of DEF, reacted at 120 °C for 72 h, cooled to room temperature, centrifuged, washed three times with DMF and acetone respectively, dried overnight at 80 °C in vacuum, and then soaked in acetone for 48 h after drying. During the soaking process, acetone was replaced every 12 h, and finally vacuum activated at 80 °C to obtain PCN-999@RGH; 2. Synthesis of Uio-67-NH2@FR: 60 mg ZrCl4, 64.30 mg ligand H2BPDC-NH2, 940 mg benzoic acid, 10 mg FITC, and 5 mg Nile Red were ultrasonically dissolved in 10 mL DMF, then transferred to an autoclave and heated at 120 °C for reaction. After the reaction, it was cooled to room temperature and centrifuged. It was washed three times with DMF and acetone respectively, dried in vacuum at 80 °C overnight, and soaked in acetone for 48 h after drying. The acetone was replaced every 12 h during the soaking process. Finally, it was vacuum activated at 80 °C to obtain Uio-67-NH2@FR.

[0042] 2. Characterization of PCN-999@RGH and Uio-67-NH2@FR 1. IR spectra of PCN-999@RGH and Uio-67-NH2@FR are shown in Figure 1 and Figure 2 .Depend on Figure 1It can be seen that PCN-999 and PCN-999@RGH have -1 , 1600 cm -1 There are strong absorption peaks at , which belong to the stretching vibration peak of C=O and the asymmetric stretching vibration peak of OCO; Figure 2 It can be seen that 1237 cm -1 、3450-3350 cm -1 、1694 cm -1 、1598 cm -1 and 460 cm -1 The absorption peaks at the positions are respectively attributed to the stretching vibration peaks of CN, NH, C=O, OCO and Zr-O bonds. Compared with the infrared spectrum of PCN-999, no obvious characteristic peaks corresponding to RGH were observed in the infrared spectrum of PCN-999@RGH; compared with the infrared spectrum of Uio-67-NH2, no obvious characteristic peaks corresponding to FITC and Nile Red were observed in the infrared spectrum of Uio-67-NH2@FR. This indicates that most of the fluorescent dye molecules are encapsulated in the pores of PCN-999 and Uio-67-NH2, and their vibrations are hindered by the three-dimensional structure.

[0043] 2. XRD characterization of PCN-999@RGH and Uio-67-NH2@FR Figure 3 and Figure 4 .Depend on Figure 3 It can be seen that the characteristic peaks at 2θ angles of 2.57°, 3.52°, 5.12°, 6.55°, 7.30° and 8.35° confirm the successful synthesis and high crystallinity of PCN-999. Figure 4 It can be seen that the characteristic peaks at 2θ angles of 5.72°, 6.61°, 9.39°, 10.94°, 11.39°, 19.60° and 19.84° prove the successful preparation and high crystallinity of Uio-67-NH2. No characteristic diffraction peaks of dye molecules were observed in PCN-999@RGH and Uio-67-NH2@FR, indicating that the effect of dye encapsulation on the lattice of PCN-999@RGH and Uio-67-NH2@FR is negligible.

[0044] The recognition performance of the fluorescent sensor array constructed by the present invention is evaluated in combination with specific examples. It should be pointed out that in Examples 2-7 of the present invention, the relative fluorescence intensity I0 / I is used to describe the different fluorescence responses of each channel to PFASs at a specific fluorescence emission wavelength, I0 is the fluorescence intensity of the blank, I is the fluorescence intensity of the sample (such as a single PFAS, binary or multi-PFASs, actual sample and spiked sample, etc.) and the probe mixture, and the blank uses a suspension of PCN-999@RGH or Uio-67-NH2@FR without adding a sample. The final concentrations of PCN-999@RGH and Uio-67-NH2@FR in the blank are consistent with the final concentrations of PCN-999@RGH and Uio-67-NH2@FR in the mixed solution (i.e., a mixed solution of the sample and the two probes) in the embodiment, which are 20 mg / L and 80 mg / L respectively (of course, other concentration values ​​can also be used in actual detection, and are not limited to the concentrations in the embodiments of the present invention).

[0045] Example 2 Construction of fluorescence sensor array and feasibility analysis of six PFASs The fluorescent sensor array of the present invention includes two fluorescent probes, PCN-999@RGH and Uio-67-NH2@FR. PCN-999@RGH has two fluorescent channels, and Uio-67-NH2@FR has three fluorescent channels. Six PFASs are used as target analytes to investigate the recognition performance of the present invention for PFASs, which specifically includes the following contents: In the first step, the suspension of PCN-999@RGH and Uio-67-NH2@FR was prepared with deionized water (using ultrasonic dispersion for 10 min) to obtain two fluorescent probes, which were added to the analyte separately when used; the mother solution of each PFAS was prepared with deionized water, and the concentration of the mother solutions of the six PFASs was 100 μM; In the second step, the suspensions of the two materials (a total of 2960 μL) were added to each PFAS mother solution (40 μL) to obtain a mixed probe, so that the final concentrations of PCN-999@RGH and Uio-67-NH2@FR in the mixed probe were 20 mg / L and 80 mg / L, respectively, and the final concentration of each PFAS was 8 μM; In the third step, the mixed probes were incubated at room temperature for 10 min, and fluorescence spectra were tested after the incubation to obtain the original data array of 6 PFASs × 5 channels × 5 replicates; In the fourth step, the relative fluorescence intensity I0 / I was used to describe the different fluorescence responses of each channel to PFASs at a specific fluorescence emission wavelength, where I0 is the fluorescence intensity of the two probes and I is the fluorescence intensity after PFASs were added to the probes. The results were further displayed by their corresponding heat maps, with each I0 / I data point represented by a color. The obtained I0 / I data were processed using principal component analysis PCA and hierarchical cluster analysis HCA. The results are shown in Figure 5 ; The heat map results of the six PFASs are shown in Figure 5 a, where the response of each fluorescence channel to each PFAS is represented by a color, Figure 5 a As can be seen, different PFASs show unique color patterns. The results show that the fluorescent sensing array constructed by the present invention has the potential to distinguish six PFASs; PCA analysis was performed on the response data matrix to generate a two-dimensional score plot consisting of the two most important factors. The results are shown in Figure 5 b. By Figure 5 b It can be seen that the six PFASs are clustered into six separate groups without overlap, which indicates that the present invention can accurately distinguish these six PFASs; The HCA analysis results of the six PFASs are shown in Figure 5 c, Figure 5 c shows that the samples of each PFAS were correctly assigned to the corresponding groups without errors or misclassification.

[0046] The results show that the five-channel fluorescence sensor array constructed based on PCN-999@RGH and Uio-67-NH2@FR in the present invention has good recognition and discrimination capabilities for six PFASs (i.e., PFOA, PFOS, PFBS, PFHxSK, PFNA and PFDA).

[0047] Example 3 Anti-interference performance of the fluorescence sensor array constructed by the present invention In this example, metal ions and organic matter that may exist in the rinse fluid of firefighters' firefighting protective clothing were used as interfering substances, and PCN-999@RGH and Uio-67-NH2@FR suspensions incubated at room temperature for 10 min were used as blanks to investigate the anti-interference ability of the fluorescent sensor array constructed by the present invention for the detection of six PFASs, specifically including the following contents: In the first step, deionized water was used to prepare suspensions of PCN-999@RGH and Uio-67-NH2@FR (ultrasonic dispersion for 10 min) to obtain two fluorescent probes; deionized water was used to prepare the mother solution of each PFAS, with a concentration of 100 μM; deionized water was used to prepare common metal salt solutions (including magnesium salts, sodium salts, iron salts and copper salts, etc.), surfactants sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS), and standard solutions of perfluorobutyric acid (PFBA), perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA) that were not array-trained as interferents, with a concentration of 5000 μM for each standard solution; In the second step, 20 μL of interfering substances were taken, and 20 μL of the mother solution and 2960 μL of the PCN-999@RGH and Uio-67-NH2@FR suspensions were added to each interfering substance to obtain a mixed probe, so that the final concentrations of PCN-999@RGH and Uio-67-NH2@FR in the mixed solution were 20 mg / L and 80 mg / L, respectively. The final concentrations of the six PFOA, PFOS, PFBS, PFHxSK, PFNA and PFDA that had been trained by the array were 1 μM, and the final concentrations of other interfering substances were all 50 μM (the concentration of the interfering substance was 50 times that of the target analyte). The mixed probe was incubated at room temperature for 10 min and then subjected to fluorescence spectrometry test. In this step, each interfering substance was mixed one by one with each PFASs that had been trained by the array. In the third step, the fluorescence test data were analyzed, and I0 / I was used as the fluorescence response value, where I0 was the fluorescence intensity of the emission channel corresponding to the blank, and I was the fluorescence intensity of the emission channel after adding six PFASs and various interferents.

[0048] The linear discriminant analysis (PCA) and hierarchical cluster analysis (HCA) of the above mixed probes were performed as follows: Figure 6 As shown. Figure 6 As can be seen from a, the relevant PFASs and interfering substances are clearly separated without crosstalk. High concentrations of interfering substances have no significant effect on the fluorescence signal of the five-channel sensor array composed of two fluorescent probes. The results show that even the presence of high concentrations of interfering substances will not affect the identification and distinction of the six PFASs. Figure 6 b As can be seen, the samples of the six PFASs and interferents that had been trained on the array were correctly assigned to the corresponding groups without errors or misclassifications.

[0049] In summary, the five-channel sensor array constructed based on PCN-999@RGH and Uio-67-NH2@FR in the present invention has good recognition and differentiation capabilities and specificity for six PFASs (PFOA, PFOS, PFBS, PFHxSK, PFNA, and PFDA), and has strong anti-interference ability.

[0050] Example 4 Identification and differentiation capabilities of the fluorescent sensor array constructed by the present invention for six PFASs 1. The ability of the fluorescent sensor array to identify and distinguish six PFASs at the same concentration This example uses six PFASs as target analytes, and PCN-999@RGH and Uio-67-NH2@FR as fluorescent mixed probes (with five fluorescent channels) to investigate their ability to identify and distinguish the six PFASs at the same concentration, specifically including the following: In the first step, suspensions of PCN-999@RGH and Uio-67-NH2@FR were prepared with deionized water to obtain fluorescent probes. The mother solution of each PFAS was prepared with deionized water, and the concentration gradient of each PFAS was 25, 50, 100, 300, 500 and 1000 μM. In the second step, 2960 μL of suspension was added to the mother solution of each PFAS (40 μL) to make the final concentrations of PCN-999@RGH and Uio-67-NH2@FR 20 mg / L and 80 mg / L, respectively, and the final concentration gradient of each PFAS was 0.5, 1, 2, 6, 10, and 20 μM, respectively. After incubation at room temperature for 10 min, fluorescence spectrum test was performed to obtain the raw data array corresponding to each concentration, i.e., six PFASs × five channels × five parallels; The third step is to analyze the raw data array corresponding to each concentration. The results are shown in Figure 7-10 The PCA results of the six PFASs are shown in Figure 7 a-10a, the six PFASs corresponding to each concentration formed tight clusters, which were clearly separated from each other and had no overlap. The sensor array maintained 100% accuracy in accurately identifying the six PFASs; The HCA analysis results of the six PFASs are shown in Figure 7 b-10b, the figure shows that the six PFASs corresponding to each concentration have six different clusters without overlap; The fluorescence data heat map of the six PFASs is shown in Figure 7 c-10c, each data point is represented by a color, and the results show the differences among six different PFASs at the same concentration, which means that the sensor array constructed by the present invention has been successful in screening and distinguishing PFASs of the same concentration.

[0051] Depend on Figure 7-10It can be seen that the results of the six PFASs at a concentration of 0.5 μM are consistent with the results at concentrations of 1, 2, 6, 10, and 20 μM. The results show that the sensor array constructed by the present invention can effectively distinguish the six PFASs at a concentration as low as 0.5 μM, and exhibits good recognition ability for PFASs.

[0052] 2. The ability of the fluorescent sensor array to identify and distinguish the same PFASs at different concentrations This example uses mother solutions of different concentrations of each PFAS as the analysis object, and uses PCN-999@RGH and Uio-67-NH2@FR as mixed fluorescent probes to investigate the ability of the fluorescent sensor array to identify and distinguish the same PFASs at different concentrations, specifically including the following contents: In the first step, suspensions of PCN-999@RGH and Uio-67-NH2@FR were prepared with deionized water to obtain fluorescent probes, and the two suspensions were mixed to obtain a fluorescent mixed probe; The mother solution of each PFAS was prepared with deionized water, and the concentration gradient of each PFAS mother solution was 10, 25, 50, 100, 200, 300, 400, 500, 750, 1000, and 1500 μM; In the second step, the suspension of PCN-999@RGH and Uio-67-NH2@FR was added to the mother solution of each PFAS, so that the final concentrations of PCN-999@RGH and Uio-67-NH2@FR were 20 mg / L and 80 mg / L, respectively, and the final concentrations of PFASs in the mixed solution were 0.2, 0.5, 1, 2, 4, 6, 8, 10, 15, 20, and 30 μM, respectively; then incubated at room temperature for 10 min, and fluorescence spectrum test was performed to obtain the original data array of each PFAS, that is, 11 concentrations × 5 parallels, a total of 55 data points; In the third step, according to the fluorescence response values ​​(I0 / I) of the five fluorescence sensing channels to the six PFASs, a two-dimensional PCA standard score graph and standard curve were drawn for each PFAS. The results are shown in Figure 11-16 .

[0053] Depend on Fig.11 a-16a As can be seen, the 55 data points of each PFAS were correctly arranged in the concentration order of factor 1 and clearly clustered into 11 clusters respectively, and distinguished with 100% accuracy without any overlap, which shows that the sensor array can effectively identify multiple PFASs at different concentrations through PCA.

[0054] The present invention selects factor 1 to quantify the concentration of PFASs. Factor 1 shows a good linear relationship with the six PFASs in the range of 0.2-10 μM, and the LOD value (minimum detection limit) of the sensor array for perfluorodecanoic acid (PFDA) can be as low as 29.92 nM. The results show that the five-channel fluorescence sensor array constructed by the present invention is suitable for the differentiation and quantitative analysis of PFASs, and has a low detection limit, laying the foundation for the quantitative analysis of trace or even trace PFASs in complex matrix samples.

[0055] In summary, the fluorescent sensor array with five sensing channels constructed in the present invention exhibits excellent identification ability for PFASs and can be used for differentiation, identification and quantitative analysis of PFASs.

[0056] Example 5 Identification and differentiation capabilities of the fluorescent sensor array constructed by the present invention for binary PFASs This example uses binary PFASs composed of two compounds, PFOA and PFOS, as the analysis object to examine the ability of the fluorescent sensor array constructed by the present invention to identify and distinguish multiple PFASs, specifically including the following contents: In the first step, suspensions of PCN-999@RGH and Uio-67-NH2@FR were prepared with deionized water to obtain fluorescent probes, and the two suspensions were mixed to obtain a fluorescent mixed probe; Deionized water was used to prepare binary PFASs mother solutions with different molar ratios, and the molar ratios of PFOA / PFOS were 100 / 0, 80 / 20, 60 / 40, 40 / 60, 20 / 80, and 0 / 100 (a total of six molar ratios); the total concentration of PFOA and PFOS in multiple binary PFASs mother solutions was constant at 300 μM; In the second step, the suspension of PCN-999@RGH and Uio-67-NH2@FR was added to the binary PFASs mother solution, so that the final concentrations of PCN-999@RGH and Uio-67-NH2@FR were 20 mg / L and 80 mg / L, respectively, and the final concentration of the binary PFASs mother solution was 6 μM. After incubation at room temperature for 10 min, the fluorescence spectrum test was performed to obtain 6 molar ratios × five channels × five parallel raw data arrays; In the third step, according to the fluorescence response values ​​(I0 / I) of the five fluorescence sensing channels to binary PFASs, a two-dimensional PCA standard score graph and HCA graph were drawn. The results are shown in Fig.17 .

[0057] Depend on Fig.17 The PCA plot of a clearly shows that the binary PFASs at different molar ratios are completely separated without any overlap and are properly arranged in the order of molar ratio in the dimension of factor 1; Fig.17b As can be seen, the dendrogram generated by HCA clearly reveals six different clusters (one cluster represents a binary PFASs of one molar ratio). The results show that the fluorescent sensor array constructed by the present invention can completely distinguish each PFAS in the PFASs mixture, and has potential practical value for the analysis of PFASs components in complex actual samples.

[0058] Example 6 Application of the fluorescent sensor array of the present invention in the analysis of typical PFASs in complex matrices such as the rinse fluid of firefighters' firefighting protective clothing The fluorescent sensor array constructed by the present invention is used for the detection and analysis of typical PFASs in the rinse fluid of firefighters' firefighting protective clothing (of course, it can also be other complex matrices), specifically including the following contents: In the first step, excess barium chloride was added to the fireproof clothing rinse liquid sample to remove the surfactant sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), and possible sulfate, carbonate, hydrogen phosphate, and sulfite in the sample, and centrifuged at 10,000 rpm for 5 min. The supernatant was filtered three times with a 0.22 μm filter membrane to obtain a pretreated sample. The stock solutions of six PFASs (including PFOA, PFOS, PFBS, PFHxSK, PFNA, and PFDA) were prepared with deionized water, and the concentration of each PFAS was 300 μM; In the second step, PCN-999@RGH and Uio-67-NH2@FR powders were added to the pretreated samples and ultrasonicated for 10 min to disperse PCN-999@RGH and Uio-67-NH2@FR in the pretreated samples to obtain a suspension; In the third step, 2960 μL of the suspension in the second step was added to the mother solution of each PFAS (40 μL) to make the final concentration of each mixed probe 20 mg / L and 80 mg / L, respectively, and the final concentration of each PFAS was 6 μM; after incubation at room temperature for 10 min, the fluorescence spectrum test was performed. The fluorescence test results were sorted and analyzed as follows Fig.18 shown.

[0059] Two-dimensional PCA plot (i.e. Fig.18 a) shows that the six PFASs in the spiked sample of the rinse fluid present six independent clusters without overlap, and the sum of the two factors is 98.81%, indicating that the effective information of the original data is retained and is representative of the entire sample. The results show that the fluorescent sensor array constructed by the present invention can be used to distinguish and identify PFASs in complex matrix samples such as the rinse fluid of firefighters' firefighting protective clothing, and this method has the potential to analyze actual samples.

[0060] Example 7 Application of the fluorescent sensor array constructed by the present invention in quantitative analysis of PFASs in the rinse fluid of firefighters' firefighting protective clothing (i.e., actual complex matrix samples) The fluorescent sensor array constructed by the present invention is used for the quantitative analysis of PFASs in complex matrix samples such as the rinse fluid of firefighters' firefighting protective clothing, specifically including the following contents: In the first step, an excess of barium chloride was added to the actual sample, and then the insoluble impurities were removed by centrifugation at 10,000 rpm for 5 min. The supernatant was filtered three times with a 0.22 μm filter membrane to obtain a pretreated sample for later use; Deionized water was used to prepare binary PFASs mother solutions with different molar ratios. The molar ratios of PFOA / PFOS in the binary PFASs mother solutions were 100 / 0, 80 / 20, 60 / 40, 40 / 60, 20 / 80, and 0 / 100, respectively. The total concentration of PFOA and PFOS in the multiple binary PFASs mother solutions was kept constant at 300 μM for later use. In the second step, PCN-999@RGH and Uio-67-NH2@FR powders were added to the pretreated sample, and PCN-999@RGH and Uio-67-NH2@FR were uniformly dispersed by ultrasonic treatment for 10 min to obtain a sample suspension; wherein, sample 1 was the first rinse liquid of the firefighter's firefighting protective clothing, and the sample 1 suspension was obtained after adding the two probe powders; sample 2 was the second rinse liquid of the firefighter's firefighting protective clothing, and the sample 2 suspension was obtained after adding the two probe powders; and sample 3 was the third rinse liquid of the firefighter's firefighting protective clothing, and the sample 3 suspension was obtained after adding the two probe powders; In the third step, 40 μL of binary PFASs stock solution (each molar ratio was repeated five times) was taken, and 2960 μL of the sample suspension in the second step was added to each molar ratio of binary PFASs stock solution to obtain a standard solution set for each sample, which was used to construct a sample database; In the fourth step, different concentrations of PFOA and PFOS were added to the sample suspension in the second step as test samples, so that the final concentrations of PCN-999@RGH and Uio-67-NH2@FR in each test sample were 20 mg / L and 80 mg / L, respectively, and the final concentration of the binary PFASs mixed solution was 6 μM; Among them, each sample corresponds to three different molar ratios of PFOA and PFOS, and the final concentration molar ratios are 1 μM:5 μM, 2 μM:4 μM and 4.5 μM:1.5 μM respectively; Step 5: Incubate the standard solution in step 3 and the test sample in step 4 at room temperature for 10 min and then perform fluorescence spectrum test. The fluorescence response and standard curve of the standard solution and test sample of samples 1-3 are shown in Figure 19-21 The spiked recoveries of samples 1-3 are shown in Table 1.

[0061] Table 1 Comparison of the content of PFOA in actual samples determined by the present invention and HPLC-MS method Depend on Fig.19 a-21a shows that the standard solutions are regularly arranged in the order of molar ratio in the direction of factor 1, indicating that factor 1 can be used to quantify the concentration of PFASs in the mixture; the least squares method is used to linearly fit factor 1 and PFOA concentration ( Fig.19 c-21c), the concentration of PFOA in samples 1-3 was calculated according to the linear regression equation (see Table 1). As can be seen from Table 1, the determination results of the present invention are basically consistent with the test results of HPLC-MS, indicating that the multi-channel fluorescent sensor array constructed by the present invention can be used for qualitative and quantitative detection of PFASs in complex matrices such as firefighters' firefighting protective equipment.

[0062] In summary, the five-channel fluorescence array sensor constructed based on the dye-encapsulated metal organic framework in the present invention has excellent recognition and differentiation capabilities for the same type of PFASs with similar structures, and only requires incubation for 10 minutes for fluorescence spectrum testing, which is short in time and highly efficient. Its accuracy is comparable to that of high-performance liquid chromatography-mass spectrometry, and can achieve high-throughput rapid identification and analysis of PFASs in complex matrices such as firefighters' fire-fighting protective equipment, providing a simple and practical on-site rapid detection and real-time monitoring technology for firefighters' occupational exposure protection.

Claims

1. A fluorescence sensor array, characterized in that: The invention comprises two luminescent metal organic frameworks based on dye encapsulation, PCN-999@RGH and Uio-67-NH2@FR, wherein the PCN-999@RGH has two fluorescence channels and the Uio-67-NH2@FR has three fluorescence channels; PCN-999@RGH was prepared by ultrasonically dissolving the ligand L12, ZrCl4, rhodamine 6G derivative RGH and formic acid into N,N-diethylformamide, reacting at 110-130°C under normal pressure, cooling to room temperature after the reaction, centrifuging, washing, drying, soaking in acetone after drying, and finally vacuum activating to obtain PCN-999@RGH; wherein the structural formulas of the ligand L12 and rhodamine 6G derivative RGH are: Uio-67-NH2@FR was prepared by ultrasonically dissolving ZrCl4 and ligand H2BPDC-NH2, benzoic acid, fluorescein isothiocyanate, and Nile red in N,N-dimethylformamide, transferring them to an autoclave after they were completely dissolved, placing the autoclave at 110-130°C for reaction, cooling to room temperature after the reaction, centrifuging, washing, drying, soaking in acetone after drying, and finally vacuum activating to obtain Uio-67-NH2@FR; wherein the structural formula of the ligand H2BPDC-NH2 is as follows: The construction of the fluorescent sensor array includes the following: PCN-999@RGH and Uio-67-NH2@FR were ultrasonically dispersed in deionized water to obtain suspensions of PCN-999@RGH and Uio-67-NH2@FR respectively. The suspensions of PCN-999@RGH and Uio-67-NH2@FR were added to each sample to obtain a mixed probe. The mixed probe was incubated at room temperature and then subjected to fluorescence spectroscopy test to obtain a raw data matrix of number of samples × 2 sensors × N parallel times.

2. The fluorescence sensor array according to claim 1, characterized in that: In the preparation of PCN-999@RGH and Uio-67-NH2@FR, they were washed three times with N,N-dimethylformamide and acetone respectively after centrifugation; after washing, they were vacuum dried at 80°C overnight; the immersion time in acetone was more than 36 hours, and the acetone was replaced every 12 hours during the immersion process; the final vacuum activation temperature was 80°C.

3. The fluorescence sensor array according to claim 1, characterized in that: The ratio of the ligand L12, ZrCl4, rhodamine 6G derivative RGH and formic acid is 20 mg: 40 mg: 15 mg: 1.2 mL; The ratio of ZrCl4, H2BPDC-NH2, benzoic acid, fluorescein isothiocyanate and Nile red is 60mg:64.3mg:940mg:10mg:5mg.

4. Application of the fluorescent sensor array according to any one of claims 1 to 3 in the rapid detection and dynamic monitoring of typical perfluorinated pollutants PFASs in fire protection equipment, wherein: The PFASs include any one or a combination of two or more of perfluorooctanoic acid, perfluorooctane sulfonic acid, perfluorobutane sulfonic acid, perfluorohexane sulfonic acid potassium salt, perfluorononanoic acid and perfluorodecanoic acid.

5. The use according to claim 4, characterized in that: The fluorescent sensor array is used for qualitative and quantitative detection of typical PFASs in fire protection equipment, specifically including the following contents: In the first step, an excess of barium chloride is added to the rinse liquid sample of the fire protection equipment, the precipitate is removed by centrifugation, and the supernatant is filtered with a filter membrane to obtain a pre-treated sample; The stock solutions of six PFASs were prepared with deionized water, each with a concentration of 300 μM; In the second step, PCN-999@RGH and Uio-67-NH2@FR powders were added to the pretreated sample, and PCN-999@RGH and Uio-67-NH2@FR were dispersed in the pretreated sample by ultrasound to obtain a suspension; In the third step, the suspension in the second step was added to the mother solution of each PFAS, and the fluorescence spectrum test was performed after incubation at room temperature; In the fourth step, the relative fluorescence intensity I0 / I was used to describe the different fluorescence responses of each channel to PFASs at a specific fluorescence emission wavelength, where I0 was the initial fluorescence intensity of the two probes, and I was the fluorescence intensity of the mixed probe after the addition of PFASs in the third step. The data were processed by heat map, PCA and HCA to quickly screen and quantify PFASs in the rinse fluid of fire protection equipment.

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