Fluorescent probe molecule and fluorescent nanocellulose film and application thereof

Abstract

This invention discloses a fluorescent probe molecule, a fluorescent cellulose nanoparticle membrane, and their applications. The fluorescent probe molecule uses methylene blue as the fluorophore and allyl groups as the recognition sites. The fluorescent cellulose nanoparticle membrane is prepared by uniformly mixing the fluorescent probe molecule with cellulose diacetate to form a spinning solution, and then using electrospinning technology to obtain a flexible fluorescent sensing film. The resulting flexible fluorescent sensing film is a fluorescent cellulose nanoparticle membrane for carbon monoxide detection. The prepared fluorescent probe molecule has advantages such as simple operation, low cost, high selectivity, rapid response, and real-time monitoring, making it suitable for detecting carbon monoxide in the ecological environment. The combination of the cellulose diacetate membrane and the fluorescent probe molecule not only improves the detection performance and application range but also reduces costs and environmental impact, demonstrating broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of carbon monoxide detection technology, and particularly relates to a fluorescent probe molecule, a fluorescent nanocellulose membrane, and its application. Background Technology

[0002] In industry, carbon monoxide is commonly used as a product of incomplete combustion of fuels in steel manufacturing, chemical production, and power generation. Due to its flammability and reducing properties, carbon monoxide also plays an important role in chemical synthesis. While carbon monoxide is a harmful gas in the environment, it is also an important endogenous gaseous neurotransmitter molecule that plays a crucial role in normal physiological and pathological processes in living organisms. Therefore, it is essential to monitor the carbon monoxide levels in the environment and within the body.

[0003] Currently, commonly used methods for carbon monoxide detection include microbial fuel cell methods, electrochemical sensor methods, gas chromatography, and non-spectral infrared techniques. However, these methods have drawbacks such as complex equipment, high cost, poor anti-interference capabilities, and long response times. Summary of the Invention

[0004] To address the aforementioned technical problems, one objective of this invention is to provide a fluorescent probe molecule that is easy to prepare and has high sensitivity.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows: a fluorescent probe molecule, wherein the fluorescent probe molecule uses methylene blue as the fluorophore and allyl group as the recognition site; the structural formula of the fluorescent probe is as follows:

[0006]

[0007] The preparation method of the fluorescent probe molecule described in the above technical solution is as follows:

[0008] A first mixed solution is obtained by mixing methylene blue, sodium carbonate, deionized water and dichloromethane. The first mixed solution is heated and refluxed at 38-42℃. When the reflux phenomenon is observed, an aqueous solution of sodium dithionite is added to the first mixed solution until the first mixed solution turns yellow and separates into layers. The first mixed solution is then cooled to room temperature, and the dichloromethane organic phase of the reduced methylene blue intermediate is separated from the first mixed solution.

[0009] A second mixed solution was obtained by mixing dichloromethane organic phase of methylene blue reduced intermediate, N,N-diisopropylethylamine and dichloromethane. Allyl chloroformate was added to the second mixed solution under ice-water bath conditions and stirred at room temperature for 12-24 h to obtain crude product. The crude product was purified to obtain fluorescent probe molecule.

[0010] In the above technical solution, the volume ratio of deionized water to dichloromethane in the first mixed solution is 4:5, the concentrations of methylene blue and sodium carbonate in the first mixed solution relative to deionized water are 0.21-0.22 mol / L and 0.88-0.89 mol / L, respectively, the concentration of the aqueous solution of sodium dithionate is 1-1.1 mol / L, and the molar ratio of methylene blue to sodium dithionate is 5:20-21.

[0011] In the above technical solution, the molar ratio of N,N-diisopropylethylamine to methylene blue in the second mixed solution is 1-1.1:1; the volume ratio of N,N-diisopropylethylamine to dichloromethane in the second mixed solution is 1:20; and the volume ratio of N,N-diisopropylethylamine to allyl chloroformate in the second mixed solution is 5:6.

[0012] The purification process described in the above technical solution is carried out by column chromatography. The silica gel used in the column chromatography is soaked in petroleum ether mixed with N,N-diisopropylethylamine for 6-12 hours before use. The eluent used is prepared by petroleum ether and dichloromethane in a volume ratio of 1.5-3:1.

[0013] The second objective of this invention is to provide a fluorescent nanocellulose membrane prepared using the above-mentioned fluorescent probe molecules, which can be used in the detection of carbon monoxide.

[0014] To achieve the above objectives, the technical solution of the present invention is as follows: a fluorescent nanocellulose membrane, wherein fluorescent probe molecules as described above are mixed uniformly with cellulose diacetate to form a spinning solution, and a flexible fluorescent sensing film is prepared by electrospinning technology, and the obtained flexible fluorescent sensing film is a fluorescent nanocellulose membrane for carbon monoxide detection.

[0015] The method for preparing the spinning solution described in the above technical solution is to add dried cellulose diacetate and fluorescent probe molecules to the spinning solvent, wherein the concentrations of cellulose diacetate and fluorescent probe molecules in the spinning solution are 0.098 g / mL and 0.05 g / mL, respectively.

[0016] The spinning solvent described in the above technical solution is prepared by mixing acetone, DMAc and deionized water in a mass ratio of 6:3:1.

[0017] The receiver used in the electrospinning process described in the above technical solution is silicone paper.

[0018] A third objective of this invention is to provide an application of the fluorescent nanocellulose membrane described above for the detection of carbon monoxide.

[0019] The beneficial effects of this invention are as follows: the prepared fluorescent probe molecules have advantages such as simple operation, low price, high selectivity, rapid response, real-time monitoring, and convenient portability, making them suitable for the detection of carbon monoxide in the environment and organisms; the fluorescent nanocellulose membrane prepared by combining cellulose diacetate membrane with fluorescent probe molecules not only improves the detection performance and application range, but also reduces cost and environmental impact, showing broad application prospects; cellulose diacetate retains the basic properties of cellulose, such as good film-forming properties and heat resistance, which make cellulose diacetate have extremely strong application prospects in the fields of ecological environment and biomedicine. Attached Figure Description

[0020] Figure 1 MB-CO, MB-CO+Pd 2+ MB-CO+Pd 2+ Figure 1. Absorbance results of CORM-3 and MB at different UV wavelengths in UV response experiment;

[0021] Figure 2 MB-CO, MB-CO+Pd 2+ MB-CO+Pd 2+ +CORM-3 and MB fluorescence intensity results at different UV wavelengths in UV response experiments;

[0022] Figure 3 The image shows the results of the UV titration experiment of MB-CO.

[0023] Figure 4 The graph shows the relationship between the UV absorbance of MB-CO at 665 nm and the CORM-3 concentration ratio.

[0024] Figure 5 The graph shows the linear relationship between the UV absorbance of MB-CO at 665 nm and the concentration of CORM-3.

[0025] Figure 6 The image shows the results of the MB-CO fluorescence titration experiment.

[0026] Figure 7 The graph shows the relationship between the fluorescence absorbance of MB-CO at 684 nm and the CORM-3 concentration ratio.

[0027] Figure 8 The graph shows the linear relationship between the fluorescence absorbance of MB-CO at 684 nm and the concentration of CORM-3.

[0028] Figure 9 Images of the kinetic experiment of MB-CO in a cuvette (25 μM);

[0029] Figure 10Images of the kinetic experiment of MB-CO in a cuvette (50 μM);

[0030] Figure 11 The image shows the results of the UV kinetics test of MB-CO.

[0031] Figure 12 The graph shows the results of the fluorescence kinetics test of MB-CO;

[0032] Figure 13 The graph shows the results of the UV selectivity test for MB-CO.

[0033] Figure 14 The image shows the results of the fluorescence selectivity test for MB-CO.

[0034] Figure 15 The graph shows the results of the MB-CO anti-interference test.

[0035] Figure 16 The graph shows the results of the pH test for MB-CO.

[0036] Figure 17 Scanning electron microscope images of the fluorescent cellulose nanofilm before and after the reaction;

[0037] Figure 18 This is a graph showing the UV changes of the fluorescent cellulose nanofiber membrane.

[0038] Figure 19 This is a graph showing the fluorescence changes of the fluorescent cellulose nanofilm. Detailed Implementation

[0039] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. The invention is described more specifically in the following paragraphs by way of example with reference to the accompanying drawings. The advantages and features of the invention will become clearer from the following description and claims. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of the invention.

[0040] Explanation of abbreviation:

[0041] MB: Methylene Blue;

[0042] MB-CO: Fluorescent probe molecule;

[0043] CDA: Cellulose diacetate powder;

[0044] DMAc: Dimethylacetamide;

[0045] MB-CO-CDA: Fluorescent cellulose nanofilm (i.e., cellulose nanofilm loaded with fluorescent probe molecules);

[0046] DMSO: Dimethyl sulfoxide;

[0047] CORM-3: Potassium tricarbonyl ruthenium(II) chloride;

[0048] D IPEA: N,N-diisopropylethylamine.

[0049] The structural formula of the fluorescent probe molecule (MB-CO) provided in this embodiment is as follows:

[0050]

[0051] The specific synthesis process is as follows:

[0052]

[0053] The method for synthesizing fluorescent probe molecules in this embodiment includes the following steps:

[0054] Step 1: Mix methylene blue (1g, 2.6 mmol), sodium carbonate (1.12g, 10.6 mmol), deionized water (12mL), and dichloromethane (15mL) to obtain a first mixed solution. Place the solution in a 100mL double-necked flask (equipped with a condenser for reflux). Stir at 40°C for about 10 minutes and observe reflux. Dissolve sodium dithionate (1.84g, 10.6 mmol) in deionized water (10mL) and add it to the first mixed solution until the solution turns yellow and separates into layers. Then cool to room temperature and separate the dichloromethane organic phase of the reduced methylene blue intermediate.

[0055] Step 2: The isolated methylene blue reduced intermediate was rapidly added to a 100 mL double-necked flask containing DIPEA (0.5 mL, 2.76 mmol) and dichloromethane (10 mL) to form a second mixed solution. Allyl chloroformate (0.6 mL, 5.2 mmol) was added to the second mixed solution under ice-water bath conditions. The reaction mixture was stirred at room temperature for 12-24 h and concentrated under reduced pressure to obtain the crude product. The crude product was purified by column chromatography to obtain the fluorescent probe molecule (MB-CO).

[0056] The NMR data of the above fluorescent probe molecules are as follows: 1H NMR(400MHz,CDC l3) δ7.36(d,J=8.7Hz,2H),6.66(d,J=2.6Hz,2H),6.61(dd,J=8.9,2.6Hz,2H),5.93(ddt,J=16.0, 10.5, 5.2Hz, 1H), 5.27 (d, J = 17.1Hz, 1H), 5.18 (d, J = 10.4Hz, 1H), 4.72-4.61 (m, 2H), 2.92 (s, 12H). 13 CNMR (101MHz, CDC l 3) δ 153.26, 147.76, 131.75, 131.51, 127.25, 125.94, 116.41, 110.03, 109.31, 65.61, 39.68. HRMS(ESI):ca l cu l ated for([M]+H) + (C 20 H 24 N3O2S + )370.1595, found 370.1600.

[0057] The method for preparing the flexible fluorescent cellulose nanofilm in this embodiment includes the following steps:

[0058] Cellulose diacetate powder (CDA) was dried in a vacuum drying oven at 60°C for 10 hours. A spinning solvent was prepared by mixing acetone, DMAc (dimethylacetamide), and deionized water in a mass ratio of 6:3:1. The dried CDA (0.98 g) and fluorescent probe molecules (0.5 g) were gradually added to the spinning solvent (10 g), and stirred for 6-12 hours until completely dissolved to obtain the spinning solution.

[0059] The spinning solution was drawn into a 5 mL syringe. A No. 20 needle was used as the syringe needle. After standing for 5 minutes with the needle tip facing upwards, air bubbles were expelled. The syringe was installed on the electrospinning machine frame and fixed in place. The distance between the needle tip and the receiver was 15 cm. Electrospinning was carried out under the conditions of injection speed of 0.4 mL / min and voltage of 30 kV. Silicone paper was used as a collector. After the prepared fluorescent nanocellulose membrane (MB-CO-CDA) was allowed to stand and dry, it was cut into rectangles (1.5*2.0 cm).

[0060] The fluorescent cellulose nanofiber membrane was used to detect carbon monoxide using the following method: The cut fluorescent cellulose nanofiber membrane was placed in a petri dish and then placed on Pd... 2+After 4 minutes in the solution and CORM-3 solutions of different concentrations, the samples were transferred to clean petri dishes to air dry. The test was repeated at least three times. Images were captured using a mobile phone and a laser confocal instrument, and the RGB values ​​of the images were obtained (via a smartphone app).

[0061] The optical and physical properties of the synthesized fluorescent probe molecules were tested using the following methods:

[0062] (1) Preparation of solution

[0063] To avoid the direct use of the toxic gas carbon monoxide, CORM-3 (an existing carbon monoxide-releasing molecule) is used instead of carbon monoxide gas (mainly due to its advantages such as stability, safety, high efficiency, specificity and low toxicity, which make CORM-3 an ideal tool for studying the biological functions of carbon monoxide and developing new drugs).

[0064] Preparation of stock solution:

[0065] A fluorescent probe stock solution (0.5 mM) was prepared by adding fluorescent probe molecules to DMSO (dimethyl sulfoxide). Pd was then added to the DMSO. 2+ Get Pd 2+ The stock solution (1mM) can be diluted with PBS buffer solution before use.

[0066] Mother liquor preparation:

[0067] CORM-3 was added to deionized water to obtain a CORM-3 stock solution (concentration 5 mM), similar to the preparation of glutathione stock solution, homocysteine ​​stock solution, cysteine ​​stock solution, and S stock solution at concentrations of 5 mM. 2- Ion mother liquor, SO3 2- Ion mother liquor, S2O3 - Ion mother liquor, SO4 2- Ion mother liquor, NO3 - Ion mother liquor, NO2 - Ion mother liquor, Na + Ion mother liquor, K + Ion mother liquor, Ca 2+ Ion mother liquor, Mg 2+ Ion mother liquor, Fe 2+ Ion mother liquor, Fe 3+ Ion mother liquor, Pb 2+ Ion mother liquor, Hg 2+ Ion mother liquor, ClO - Ion mother liquor, H2O2 mother liquor, ONOO - ion mother liquor, ·OH ion mother liquor and O2 - Ion mother liquor; the above mother liquors can be diluted to obtain sample solutions of different concentrations during use.

[0068] (2) Optical response test of fluorescent probe molecules to carbon monoxide

[0069] This embodiment investigates the responsiveness of fluorescent probe molecules to carbon monoxide through optical response experiments. For example... Figure 1 As shown, under UV conditions, fluorescent probe molecule stock solution (1 vol 1%) and Pd were added to PBS buffer solution (10 mM, pH = 7.4). 2+ The stock solution (1 vol 1%) shows a significant absorption peak at 665 nm for the fluorescent probe molecules. Figure 2 As shown, under fluorescent conditions, fluorescent probe molecule stock solution (1 vol 1%) and Pd were added to PBS buffer solution (10 mM, pH = 7.4). 2+ The stock solution (1 vol%) shows a significant absorption peak at 684 nm for the fluorescent probe molecules.

[0070] (3) Concentration dependence test of fluorescent probe molecules on carbon monoxide

[0071] Add 1 vol% fluorescent probe molecule stock solution and Pd to PBS buffer solution (10 mM, pH = 7.4). 2+ The stock solution (1 vol 1%) was then used, followed by a fluorescent titration experiment to evaluate the sensitivity of the fluorescent probe molecules to carbon monoxide, such as... Figure 3 As shown, the fluorescent probe molecule stock solution and Pd were added. 2+ After excitation at 620 nm with PBS buffer solution of the original solution, different concentrations of CORM-3 sample solution were added. As the concentration of the sample solution increased (0-50 μM), the absorption peak of the fluorescent probe molecule at 665 nm continuously increased, gradually reaching equilibrium at a CORM-3 sample solution concentration of 25 μM. Simultaneously, a significant color change was observed in the solution, from colorless to blue, thus achieving preliminary detection of carbon monoxide by the naked eye (e.g., ...). Figure 4 ).like Figure 6 As shown, the fluorescent probe molecule stock solution and Pd were added. 2+ After excitation at 620 nm, different concentrations of CORM-3 sample solution were added to the PBS buffer solution of the stock solution. As the concentration of the sample solution increased (0-50 μM), the fluorescence absorption peak of the fluorescent probe molecule at 684 nm continuously increased, gradually reaching equilibrium at a CORM-3 sample solution concentration of 25 μM. Simultaneously, significant changes in the fluorescence of the solution were observed, thus achieving preliminary fluorescence detection of carbon monoxide (e.g., ...). Figure 7 ).

[0072] in, Figure 3 and Figure 6The fifteen curves correspond to concentrations of 0 μM, 1 μM, 2 μM, 3 μM, 4 μM, 5 μM, 6 μM, 7.5 μM, 10 μM, 12.5 μM, 15 μM, 20 μM, 25 μM, 35 μM, and 50 μM, respectively. Figure 3 and Figure 6 The concentration-increasing arrows in the diagram are used to distinguish the peaks of the fifteen curves (the fifteen curves do not intersect at their peaks).

[0073] Furthermore, the UV-Vis intensity change of the fluorescent probe molecule (5 μM) at 665 nm showed a good linear correlation with the CORM-3 sample concentration in the range of 0–7.5 μM (R0). 2 =0.9984)(e.g. Figure 5 As shown in the figure, the detection limit was 42.7 nM. Meanwhile, the fluorescence intensity change showed a good linear correlation with the CORM-3 sample concentration in the range of 0-15 μM (R0). 2 =0.9988)(e.g. Figure 8 As shown in the figure, the detection limit is 9.8 nM, indicating that the fluorescent probe molecule has high sensitivity to carbon monoxide and is suitable for the detection of carbon monoxide.

[0074] (4) Kinetics of fluorescent probe molecules on carbon monoxide

[0075] Add 1 vol mol% fluorescent probe molecule stock solution and Pd to PBS buffer solution (10 mM, pH = 7.4). 2+ The stock solution (1 vol 1%) was used to conduct titration tests to investigate the kinetics of the fluorescent probe molecules to different concentrations of CORM-3 sample solutions (0, 5, 10, 25, 50 μM) in order to explore the time response capability of the fluorescent probe molecules (e.g., ...). Figure 9 and 10 (As shown). Within 4 minutes, the UV-Vis light intensity and fluorescence intensity of the fluorescent probe molecule showed a rapid increase followed by a stabilization trend, reaching equilibrium at 8 minutes (as shown). Figure 11 and Figure 12 As shown), a significant color change in the solution can be observed (e.g. Figure 9 and Figure 10 , Figure 9 and Figure 10 (The color deepens sequentially in the middle), therefore, 8 minutes was chosen as the testing time for subsequent in vitro UV-Vis and fluorescence tests.

[0076] (5) pH dependence test of fluorescent probe molecules on carbon monoxide

[0077] Add 1 vol mol% fluorescent probe molecule stock solution and Pd to PBS buffer solution (10 mM, pH = 7.4). 2+Stock solution (1 vol 1%), pH dependence of fluorescent probe molecules on carbon monoxide (e.g. Figure 16 (As shown). The results indicate that the fluorescent probe molecule exhibits good physiological adaptability within a pH range of 2-12 and can serve as a reliable indicator for detecting carbon monoxide. The above-mentioned stock solution containing the fluorescent probe molecule and Pd... 2+ After treatment with CORM-3 (25 μM) in the PBS buffer solution of the original solution, the fluorescent probe molecules were approximately stable in the pH range of 6-9 and exhibited optimal response under physiological conditions (e.g., Figure 16 As shown in the figure, this indicates that fluorescent probe molecules can be used for monitoring carbon monoxide in living organisms.

[0078] (6) Test of the selectivity and anti-interference properties of fluorescent probe molecules for carbon monoxide

[0079] To evaluate the specificity of the fluorescent probe molecules, this example tested the fluorescence response of the fluorescent probe molecules to different samples (analytes). The fluorescent probe molecule stock solution (1 vol 1%) and Pd were added to PBS buffer solution (10 mM, pH = 7.4). 2+ Stock solution (1 vol 1%) contains fluorescent probe molecules and Pd 2+ The PBS buffer solution of the stock solution was mixed with CORM-3 sample solution, glutathione sample solution, homocysteine ​​sample solution, cysteine ​​sample solution, and S... 2- Ionic sample solution, SO3 2- Ion sample solution, S2O3 - Ionic sample solution, SO4 2- Ionic sample solution, NO3 - Ionic sample solution, NO2 - Ion sample solution, Na + Ion sample solution, K + Ion sample solution, Ca 2+ Ionic sample solution, Mg 2+ Ion sample solution, Fe 2+ Ion sample solution, Fe 3+ Ion sample solution, Pb 2+ Ion sample solution, Hg 2+ Ion sample solution, ClO - Ion sample solution, H2O2 sample solution, ONOO - Ionic sample solution, ·OH ion sample solution and O2 - During incubation with ion-containing sample solutions (all sample solutions were diluted to 50 μM), only the CORM-3 sample solution caused significant changes in UV-Vis and fluorescence signals (e.g., Figure 13 and Figure 14 (As shown). The results indicate that the influence of other related analytes is negligible.

[0080] This embodiment also investigated the anti-interference experiment of the fluorescent probe molecule in different analytes, such as Figure 15 As shown, the UV-Vis and fluorescence intensity of the fluorescent probe molecule to carbon monoxide are almost unaffected by any amino acids, reactive oxygen species, metal cations, and anions, and exhibit a stronger optical response when CORM-3 is used as an interfering analyte. These test results indicate that the fluorescent probe molecule has an extremely high response to carbon monoxide, and the test results are reliable.

[0081] in, Figures 13-15 The horizontal axis numbers correspond to different sample solutions. Horizontal axis numbers 1-24 represent the blank group (deionized water), glutathione sample solution, homocysteine ​​sample solution, cysteine ​​sample solution, and S... 2- Ionic sample solution, SO3 2- Ion sample solution, S2O3 - Ionic sample solution, SO4 2- Ionic sample solution, NO3 - Ionic sample solution, NO2 - Ion sample solution, Na + Ion sample solution, K + Ion sample solution, Ca 2+ Ionic sample solution, Mg 2+ Ion sample solution, Fe 2+ Ion sample solution, Fe 3+ Ion sample solution, Pb 2+ Ion sample solution, Hg 2+ Ion sample solution, ClO - Ion sample solution, H2O2 sample solution, ONOO - Ionic sample solution, ·OH ionic sample solution, O2 - Ion sample solution - [and CORM-3 sample solution]

[0082] The performance testing method for fluorescent nanocellulose membrane (MB-CO-CDA) is as follows:

[0083] This embodiment uses scanning electron microscopy (SEM) to observe the morphology of the fluorescent nanocellulose membrane before and after contact with CORM-3 sample solution (25 μM). Figure 17 As shown, Figure 17 In Chinese, "before" indicates before contact, and "after" indicates after contact. Figure 18 The fluorescent cellulose nanofiber membrane exhibits uniform and randomly arranged fibers with a smooth surface free of droplets, demonstrating an ideal morphology. Its diameter is 0.42204 ± 0.06427 μm. The fluorescent cellulose nanofiber membrane, when combined with Pd... 2+After the solution (10 μM) and the CORM-3 sample solution (25 μM) were fully contacted, the fiber diameter of the fluorescent cellulose nanofiber membrane was observed to increase to 1.04548 ± 0.22936 μM (e.g., ...). Figure 17 (As shown in the figure). These results indicate that the fluorescent cellulose nanofilm can respond to the CORM-3 sample solution.

[0084] Fluorescent cellulose nanofiber membranes were observed sequentially on Pd using laser confocal microscopy. 2+ Fluorescence changes before and after immersion in the solution (10 μM) and CORM-3 sample solution (25 μM) were studied. The results showed that the fluorescent cellulose nanofiber membrane exhibited weak red fluorescence before the reaction, while strong red fluorescence was observed after the reaction. The concentration of the CORM-3 sample solution could be gradually increased from 0 to 50 μM. With increasing CORM-3 sample solution concentration (0 μM, 25 μM, and 50 μM, respectively), Pd... 2+ With the solution concentration kept constant at 10 μM, the red fluorescence emitted by the fluorescent cellulose nanofilm gradually increased. These findings indicate that the fluorescent probe molecules have good compatibility with the cellulose diacetate membrane, and that the fluorescent cellulose nanofilm exhibits good adhesion to Pd... 2+ The solution and CORM-3 solution exhibit good responsiveness, with colorimetric-fluorescence dual-mode detection, and hold promise for the quantitative detection of carbon monoxide in real-world environments (specifically as follows). Figure 18 and Figure 19 As shown, Figure 19 In this context, "Red Channel" represents the red channel; "Bright" represents the bright field channel; and "Merged" represents the mixed channel.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Those skilled in the art can readily implement the present invention based on the accompanying drawings and the above description. However, any modifications, alterations, or variations made by those skilled in the art without departing from the scope of the present invention, utilizing the disclosed technical content, are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, or variations made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the present invention.

Claims

1. A fluorescent cellulose nanofilm, characterized in that, The following method was used to prepare the flexible fluorescent sensing film: fluorescent probe molecules were mixed with cellulose diacetate to form a spinning solution, and a flexible fluorescent sensing film was prepared by electrospinning technology. The resulting flexible fluorescent sensing film is a fluorescent nanocellulose film for carbon monoxide detection. The fluorescent probe molecule uses methylene blue as the fluorophore and allyl group as the recognition site; the structural formula of the fluorescent probe is as follows: 。 2. The fluorescent cellulose nanofilm according to claim 1, characterized in that, The spinning solution is prepared by adding dried cellulose diacetate and fluorescent probe molecules to the spinning solvent. The concentrations of cellulose diacetate and fluorescent probe molecules in the spinning solution are 0.098 g / mL and 0.05 g / mL, respectively.

3. The fluorescent cellulose nanofilm according to claim 1, characterized in that, The spinning solvent is prepared by mixing acetone, DMAc and deionized water in a mass ratio of 6:3:

1.

4. The fluorescent cellulose nanofilm according to claim 1, characterized in that, The receiver used in the electrospinning process is silicone paper.

5. An application of the fluorescent cellulose nanofilm as described in any one of claims 1-4, characterized in that, Used to detect carbon monoxide.

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