Fluorescence probe micro-plastic fluorescence detection method based on boron-fluorine dipyrrole

Abstract

The invention discloses a fluorescent probe microplastic fluorescence detection method based on boron-fluorine dipyrrole, and relates to the technical field of fluorescence detection. The invention discloses a double-targeting ratio type fluorescent probe micro-plastic fluorescence detection method based on boron-fluorine dipyrrole, and relates to rhodamine spirolactam boron-fluorine dipyrrole organic fluorescent molecules as a fluorescent color developing agent combined with micro-plastics, and the fluorescent color developing agent can rapidly detect polyester and polystyrene micro-plastics in a water phase and an organic phase. The method is easy and convenient to operate, does not need complex pretreatment, has the advantages of being high in detection sensitivity, high in anti-interference performance and high in function integration degree, and is suitable for rapid detection and risk assessment of environment water samples and food contact material migration liquid.

Description

Technical Field

[0001] This invention relates to the field of fluorescence detection technology, specifically to a fluorescence detection method for microplastics based on boron-fluorine dipyrrole fluorescent probes. Background Technology

[0002] Microplastics (plastic particles with a diameter of <5 mm), as a new type of environmental pollutant, are widely found in water bodies, soil, and even food. Due to their large specific surface area and strong hydrophobicity, microplastics readily adsorb heavy metal ions (such as Pb²⁺ and Cd²⁺) and persistent organic pollutants from the environment, forming complex pollution that poses a serious threat to ecosystems and human health. Therefore, the detection of microplastics has become a major public health issue.

[0003] Microplastics are characterized by their diverse types and low concentrations in water, making quantitative detection difficult using current methods such as micro-infrared spectroscopy, Raman spectroscopy, and pyrolysis-gas chromatography / mass spectrometry. Therefore, researchers have explored more advanced methods, attempting to detect microplastics using fluorescence spectroscopy. Fluorescence spectroscopy is widely used across various industries due to its sensitivity, simple equipment, and lack of complex sample processing requirements. Chinese invention patent CN202311217373.X relates to using fluorescence response to screen and separate microplastics in water. Another patent, CN202311291167.3, uses fluorescence colorimetry to analyze microplastics in marine fish. However, these technologies struggle to detect microplastics made of different polymers. For rapid differentiation and identification of materials such as polyethylene terephthalate (PET), PS, and PE, they only detect the microplastics themselves and cannot simultaneously reflect their environmental risks as pollutant carriers.

[0004] Among numerous microplastics, polyethylene terephthalate (PET) is closely related to the human body. PET is found in everyday items such as beverage bottles, food containers, temporary packaging bags for fruits and vegetables, towels, and clothing. A statistical study published by Heather A. Leslie et al. found PET in 50% of the subjects' blood samples, making it the most prevalent type of plastic in the samples. PET and other microplastics can trigger oxidative stress in liver cells, damage mitochondrial structure, and even induce apoptosis. Therefore, developing a qualitative and quantitative analytical method for PET microplastics is particularly important and urgent. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a fluorescent detection method for microplastics based on boron-fluorine dipyrrole fluorescent probes.

[0006] The present invention proposes a technical solution to solve the above-mentioned technical problems: a fluorescent detection method for microplastics based on boron-fluorine dipyrrole, which involves adding a solution of a fluorescent colorimetric agent to a solution of the polyethylene terephthalate microplastic to be tested into the solution of the fluorescent colorimetric agent, and then detecting the fluorescence intensity by fluorescence emission spectroscopy.

[0007] Preferably, the fluorescent colorimetric agent uses a boron-fluorine dipyrrole derivative as the fluorescent core, and integrates the microplastic targeting module into one unit through covalent bonds; the microplastic targeting module includes catechol borate ester units and pyrene ring units.

[0008] Preferably, the boron-fluorine dipyrrole derivative contains a borate group, a vinyl group, and a hydroxyl group, and its structural formula is: .

[0009] Preferably, the borate group is connected to the catechol borate unit via a five-membered ring borate bond; the vinyl group is connected to the pyrene ring unit via π-π conjugation; and the hydroxyl group is connected to the rhodamine spironolactam derivative via an ether bond.

[0010] Preferably, the specific step is to prepare the fluorescent colorimetric reagent with a concentration of 1×10⁻⁶. -9 mol / L ~ 1×10 -6 A solution of the polyethylene terephthalate microplastic to be tested was added to a solution prepared with a fluorescent colorimetric reagent, and the fluorescence intensity was detected by fluorescence emission spectroscopy.

[0011] Preferably, the diethylene terephthalate (PTP) microplastics of different concentrations are first detected using an aqueous solution of the fluorescent colorimetric reagent, and the content curve of the standard is plotted. Then, the PTP microplastic sample solution is detected using an aqueous solution of the fluorescent colorimetric reagent, and the PTP microplastic content in the aqueous solution is calculated using the standard curve method.

[0012] Preferably, the solvent for the solution made from the fluorescent colorimetric agent is water or ethanol.

[0013] Preferably, the concentration of the solution prepared by the fluorescent colorimetric reagent is 1×10⁻⁶. -9 mol / L ~ 1×10 -6 mol / L.

[0014] Preferably, the concentration is 1×10 -8 mol / L ~ 5×10 -8 mol / L.

[0015] Preferably, the fluorescence intensity is detected by fluorescence emission spectroscopy at 473 nm excitation and 568 nm measurement.

[0016] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention not only simplifies pretreatment, enabling direct detection in aqueous phases without the need for cumbersome steps such as digestion and centrifugation, but also reduces detection time from several hours to within 5 minutes, significantly improving detection efficiency. Furthermore, it enhances material differentiation capabilities by utilizing both polar and non-polar recognition units to simultaneously target PET microplastics, achieving visual differentiation between PET microplastics and other microplastics, filling a gap in existing technology. Moreover, it exhibits excellent analytical performance, with high sensitivity (microplastic detection limit down to 0.1 ng / L) and strong anti-interference capabilities, making it suitable for detecting complex real-world samples. Attached Figure Description

[0017] Figure 1 , Figure 2 This is a synthetic route diagram for fluorescent colorimetric reagents.

[0018] Figure 3 This is the MALDI-TOF mass spectrum of the fluorescent chromogenic reagent.

[0019] Figure 4 The fluorescence titration diagrams of PET microplastics at different concentrations were detected using a target fluorescent chromogenic agent.

[0020] Figure 5 Standard curve of fluorescence detection method for PET microplastics in Example 1. Detailed Implementation

[0021] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those skilled in the art.

[0022] Example 1: Detection of PET microplastics in aqueous solution using fluorescent colorimetric reagents A 1×10⁻⁶ fluorescent colorimetric reagent was prepared. -8 The concentration of the fluorescent reagent was mol / L aqueous solution. Different standard concentrations of PET microplastics were added, and the emission peak intensity was measured at 568 nm. Then, a standard curve was prepared. Figure 5 The standard curve obtained was y = 0.027x + 0.0149, with an R-value of 0.9939, indicating a good linear relationship. This shows that the fluorescence intensity in aqueous solution is linearly proportional to the PET microplastic content.

[0023] Example 2: Detection of PET microplastics in ethanol solution using fluorescent colorimetric reagents A 1×10⁻⁶ fluorescent colorimetric reagent was prepared. -7A mol / L ethanol solution was prepared with a fluorescent reagent concentration of [missing value]. Different standard concentrations of PET microplastics (2, 5, 10, 20, 50, 100, 200 ng / L) were added, and the emission peak intensity was measured at 568 nm. A standard curve was then constructed, yielding the curve y = 0.026x + 0.039 with an R-value of 0.9915, indicating a good linear relationship. This demonstrates that the fluorescence intensity in the ethanol solution is linearly proportional to the PET microplastic content.

[0024] Example 3: Verification of the probe's ability to identify and differentiate microplastics of different materials The detection method for PET microplastics in this application example was used to perform fluorescence detection on solutions containing PET microplastics and PP, PE, PS, and PVC. The concentrations of PP, PE, PS, and PVC microplastics in the solution were all 1 mng / L, while the concentration of PET microplastics was 100 ng / L. Experimental results demonstrated that these coexisting particles did not interfere with the fluorescence detection of PET microplastics at 568 nm.

[0025] Obviously, the above embodiments are merely examples to clearly illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, these obvious variations or modifications derived from the spirit of the present invention are still within the protection scope of the present invention.

Claims

1. A method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe, characterized in that: The fluorescent colorimetric reagent solution is added to the solution of the polyethylene terephthalate microplastic to be tested, and the fluorescence intensity is detected by fluorescence emission spectroscopy.

2. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 1, characterized in that, The fluorescent colorimetric agent uses a boron-fluorine dipyrrole derivative as the fluorescent core, and integrates the microplastic targeting module into one unit through covalent bonds; the microplastic targeting module includes catechol borate ester unit and pyrene ring unit.

3. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 1, characterized in that, The boron-fluorine dipyrrole derivative contains a borate group, a vinyl group, and a hydroxyl group, and its structural formula is as follows: 。 4. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 2, characterized in that, The borate group is connected to the catechol borate unit via a five-membered ring borate bond; the vinyl group is connected to the pyrene ring unit via π-π conjugation; and the hydroxyl group is connected to the rhodamine spironolactam derivative via an ether bond.

5. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 2, characterized in that, The specific steps involve preparing the fluorescent colorimetric reagent to a concentration of 1×10⁻⁶. -9 mol / L ~ 1×10 -6 A solution of the polyethylene terephthalate microplastic to be tested was added to a solution prepared with a fluorescent colorimetric reagent, and the fluorescence intensity was detected by fluorescence emission spectroscopy.

6. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 5, characterized in that: The solvent for the solution prepared by the fluorescent colorimetric agent is water or ethanol.

7. The fluorescence detection method for microplastics based on boron-fluorine dipyrrole fluorescent probes according to claim 5, characterized in that: The concentration of the solution prepared with the fluorescent colorimetric reagent is 1×10⁻⁶. -9 mol / L ~ 1×10 -6 mol / L.

8. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 5, characterized in that: The concentration is 1×10 -8 mol / L ~ 5×10 -8 mol / L.

9. The method for detecting fluorescence in microplastics using a boron-fluorine dipyrrole-based fluorescent probe according to claim 5, characterized in that, The fluorescence intensity was detected by fluorescence emission spectroscopy at 473 nm excitation and 568 nm measurement.

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