A method for rapid detection of sodium ions in cigarette paper using nanoenzyme laccase

Abstract

The present invention belongs to the technical field of chemical analysis and detection, and relates to a method for rapidly detecting sodium ions in cigarette paper using a nanoenzyme laccase. The method uses 2-aminoterephthalic acid, copper nitrate, and cerium nitrate as precursors, polyvinylpyrrolidone as a stabilizer, and a solvothermal method to synthesize a copper-cerium MOF-based nanoenzyme with laccase-like activity, namely, the Cu / Ce-BDC-NH2 nanoenzyme; the Cu / Ce-BDC-NH2 nanoenzyme oxidizes 2,4-dichlorophenol and 4-aminoantipyrine to obtain a red product, and the potassium pyroantimonate ligand is adsorbed on the Cu / Ce-BDC-NH2 surface, inhibiting the catalytic effect, resulting in a decrease in laccase-like activity and Na + The introduction of NH2-containing laccase reacts with potassium pyroantimonate to form a stable complex, thereby restoring the activity of Cu / Ce-BDC-NH2 laccase and deepening the red color of the solution. Based on this, the present invention establishes a new method for rapid colorimetric detection of sodium ions.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis and detection, and relates to a method for quickly detecting sodium ions in cigarette paper using a nanoenzyme laccase. Background Art

[0002] Cigarette paper properties directly impact the combustion performance, aroma, and flavor quality of cigarettes, as well as the release of harmful components in cigarette smoke. Calcium carbonate, as a filler in cigarette paper, affects its air permeability. Potassium citrate and sodium citrate are primary additives to cigarette paper, and potassium (K) and sodium (Na) are key quality indicators for evaluating cigarette paper's combustion performance. Therefore, rapid determination of K and Na content in cigarette paper is crucial for controlling its quality. Currently, the main methods for determining inorganic element content in tobacco include flame photometry, ion chromatography, atomic absorption spectrometry, and inductively coupled plasma mass spectrometry (ICP-MS). However, these methods often require cumbersome sample pretreatment, slow detection speeds, and complex instrumentation. Colorimetric methods hold a prominent position in detection technologies due to their simplicity, rapidity, and lack of the need for extensive instrumentation. However, colorimetric detection of sodium ions has been largely unreported. Summary of the Invention

[0003] In response to the above technical problems, the present invention discloses a method for rapidly detecting sodium ions in cigarette paper using nanoenzyme laccase.

[0004] In order to achieve the above technical objectives, the present invention provides the following technical solutions:

[0005] A method for rapidly detecting sodium ions in cigarette paper using nanoenzyme laccase, the method comprising the following steps:

[0006] (1) Using 2-aminoterephthalic acid, copper nitrate, and cerium nitrate as precursors and polyvinylpyrrolidone as a stabilizer, a copper-cerium MOF-based nanozyme with laccase-like activity, namely Cu / Ce-BDC-NH2 nanozyme, was synthesized by a solvothermal method.

[0007] (2) At different concentrations of Na + Potassium pyroantimonate was added to the standard solution for reaction, and then Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine were added to generate red oxidation products; the volume was fixed with MES buffer solution, shaken and allowed to stand, and the absorbance was measured to establish the absorbance and Na + The quantitative relationship of concentration was calculated, and the standard curve was drawn to obtain the regression equation;

[0008] (3) Treating the cigarette paper sample to obtain a sample solution; adding potassium pyroantimonate to the sample solution for reaction, and then adding Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate red oxidation products; using MES buffer solution to make up the volume, shaking, and letting it stand, and measuring the absorbance of the sample solution; substituting the absorbance of the sample solution into the regression equation of step (2) to obtain the Na content in the cigarette paper sample. + content.

[0009] The present invention uses Cu / Ce-BDC-NH2 nanozyme to oxidize 2,4-dichlorophenol and 4-aminoantipyrine to obtain a red product. The potassium pyroantimonate ligand can be adsorbed on the surface of the Cu / Ce-BDC-NH2 nanozyme, inhibiting the catalytic effect and resulting in a decrease in the activity of the laccase-like enzyme. + The introduction of Cu / Ce-BDC-NH2 reacts with potassium pyroantimonate to form a stable complex, thereby restoring the activity of Cu / Ce-BDC-NH2 laccase and deepening the red color of the solution. Based on this principle, the present invention establishes a new colorimetric rapid detection method for sodium ions. The method provided by the present invention can only selectively detect sodium ions without interference from other substances. It is used for the determination of sodium ions in cigarette paper and exhibits the characteristics of high sensitivity, strong specificity, simple operation, and rapidity.

[0010] Furthermore, step (1) specifically includes:

[0011] (1.1) Combine 2.0-2.5 mmol Cu(NO3)2.3H2O, 2.0-2.5 mmol Ce(NO3) 3· 6H2O was dissolved in 35-50 mL N,N-dimethylformamide (DMF), labeled as solution A;

[0012] (1.2) Dissolve 2.0-2.5 mmol of 2-aminoterephthalic acid in 35-50 mL of N,N-dimethylformamide (DMF) and stir until well combined. This is labeled solution B.

[0013] (1.3) Add 0.1-0.2 g of polyvinylpyrrolidone (PVP) to solution B and stir evenly to form a homogeneous solution;

[0014] (1.3) Solution A was added to the homogeneous solution and stirred for 30-40 min. The mixed solution was then transferred to a stainless steel reactor lined with polytetrafluoroethylene and heated to 120-140°C for 6-8 h. After cooling naturally, the precipitate was obtained by centrifugation. The precipitate was washed 3-4 times with N,N-dimethylformamide (DMF) and anhydrous ethanol, respectively. The collected product was then centrifuged and dried under vacuum to obtain the Cu / Ce-BDC-NH2 nanozyme. The introduction of cerium ions significantly enhanced the Cu + and Cu 2+ The electron transfer of Cu / Ce-BDC-NH2 enhanced the laccase-like activity of Cu / Ce-BDC-NH2.

[0015] Furthermore, in step (1.3), the centrifugation is performed at 8000-10000 r / min for 5-10 min.

[0016] Furthermore, step (2) specifically includes:

[0017] 100 μL of different concentrations of Na were added to different colorimetric tubes. + The standard solution and 100-150 μL of 100 μmol / L potassium pyroantimonate solution were reacted for 10-15 min, and 50-100 μL of 1 mg / mL Cu / Ce-BDC-NH2 nanozyme aqueous solution were added. Then, 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine were added to generate red oxidation products. The volume was adjusted to 3 mL with pH 6.8 MES buffer solution, shaken, and allowed to stand for 5-10 min. The absorbance was measured at a wavelength of 510 nm to establish the absorbance and Na + The quantitative relationship of concentration was calculated, and the standard curve was drawn to obtain the regression equation.

[0018] Furthermore, in step (3), the cigarette paper sample is processed to obtain a sample test solution, specifically by weighing 0.1000 g of the shredded cigarette paper sample into a 100 mL conical flask, adding 20 mL of a 0.1-0.15 mol / L hydrochloric acid solution, ultrasonically extracting for 25-35 min, centrifuging at 2000-4000 r / min for 10-20 min, filtering the supernatant through a 0.45 μm microporous filter membrane, and then adjusting the volume to a 50 mL volumetric flask to obtain the sample test solution.

[0019] Furthermore, in step (3), the method for determining the absorbance of the sample assay solution specifically includes: adding 100 μL of sample assay solution and 100-150 μL of 100 μmol / L potassium pyroantimonate solution into a colorimetric tube, reacting for 10-15 minutes, adding 50-100 μL of 1 mg / mL Cu / Ce-BDC-NH2 nanozyme solution, and then adding 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine to generate a red oxidation product, diluting to 3 mL with pH 6.8 MES buffer solution, shaking, standing for 5-10 minutes, and measuring the absorbance of the sample assay solution at a wavelength of 510 nm.

[0020] Furthermore, the detection limit of the method for sodium ions in the sample test solution is 3.46 μg / L.

[0021] Furthermore, the method measures Na + The recoveries of the spiked products were between 97.0% and 102.5%, and the relative standard deviations (RSDs) were between 1.52% and 2.69%.

[0022] Advantages and technical effects of the present invention:

[0023] The copper-cerium MOF-based nanozyme (Cu / Ce-BDC-NH2 nanozyme) prepared by the method provided by the present invention has a sparse and porous framework structure, exposing more active adsorption sites, which is conducive to the enrichment of potassium pyroantimonate; at the same time, the introduction of cerium ions significantly enhances the Cu + and Cu 2+ The electron transfer of Cu / Ce-BDC-NH2 increased the laccase-like activity, and potassium pyroantimonate was used as Na + The ligand can be adsorbed on the Cu / Ce-BDC-NH2 surface, inhibiting the catalytic effect and leading to the decrease of laccase-like activity, while Na + The introduction of , reacts with potassium pyroantimonate to form a stable complex, which restores the activity of Cu / Ce-BDC-NH2 laccase and deepens the red color of the solution. Based on this, the present invention establishes a new colorimetric rapid detection method for sodium ions.

[0024] The method provided by the present invention is a sodium ion colorimetric detection method, which has a wide linear range (8.33~6000 μg / L), high detection sensitivity (detection limit is 3.46 μg / L), and the coexistence of substances (Ba in cigarette paper) in the cigarette paper is relatively low. 2+ Cr 6+ 、Ni 2+ 、Bi 3+ NH4 + 、SO4 2- 、Cl- 、NO3 - 、Zn 2+ 、Al 3+ 、Cu 2+ 、Mn 2+ , Pb 2+ 、Fe 3+ Mg 2+ , Ca 2+ , K + ) does not interfere with the determination. The method has good selectivity and has a good recovery rate (97.0% to 102.5%) for the determination of sodium ions in cigarette paper. The results are consistent with those of the ICP-MS method. In addition, compared with ICP-MS determination, the method provided by the present invention has the advantages of simple and rapid sample pretreatment operation and low detection cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 TEM image of the Cu / Ce-BDC-NH2 nanozyme prepared in Example 1 of the present invention;

[0026] Figure 2 This is the XPS spectrum (Cu 2p) of the Cu / Ce-BDC-NH2 nanozyme in Example 1 of the present invention;

[0027] Figure 3 This is the XPS spectrum of the Cu / Ce-BDC-NH2 nanozyme in Example 1 of the present invention (Ce 3d);

[0028] Figure 4 For example 1, potassium pyroantimonate (PP), Na + and PP+Na + Effect on the activity of Cu / Ce-BDC-NH2 type laccase;

[0029] Figure 5 The effects of N2, O2 and air on the activity of Cu / Ce-BDC-NH2 laccase in Example 1;

[0030] Figure 6 Detection of Na in the 2,4-DCP+4-AAP+PP+Cu / Ce-BDC-NH2 system in Example 1 + UV absorption spectrum;

[0031] Figure 7 Detection of Na in the 2,4-DCP+4-AAP+PP+Cu / Ce-BDC-NH2 system in Example 1 + Linear equation of

[0032] Figure 8 The coexisting substance in Example 1 is Na + Impact of testing results. DETAILED DESCRIPTION

[0033] The technical solution of the present invention is further described below with reference to specific embodiments and accompanying drawings.

[0034] Example 1: A method for rapidly detecting sodium ions in cigarette paper using nanoenzyme laccase, the method comprising the following steps:

[0035] (1) Using 2-aminoterephthalic acid, copper nitrate, and cerium nitrate as precursors and polyvinylpyrrolidone as a stabilizer, a copper-cerium MOF-based nanozyme with laccase-like activity, namely Cu / Ce-BDC-NH2 nanozyme, was synthesized by a solvothermal method.

[0036] (2) At different concentrations of Na + Potassium pyroantimonate was added to the standard solution for reaction, and then Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine were added to generate red oxidation products; the volume was fixed with MES buffer solution, shaken and allowed to stand, and the absorbance was measured to establish the absorbance and Na + The quantitative relationship of concentration was calculated, and the standard curve was drawn to obtain the regression equation;

[0037] (3) Treating the cigarette paper sample to obtain a sample solution; adding potassium pyroantimonate to the sample solution for reaction, and then adding Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate red oxidation products; using MES buffer solution to make up the volume, shaking, and letting it stand, and measuring the absorbance of the sample solution; substituting the absorbance of the sample solution into the regression equation of step (2) to obtain the Na content in the cigarette paper sample. + content.

[0038] In this embodiment, step (1) specifically includes:

[0039] (1.1) Combine 2.0-2.5 mmol Cu(NO3)2.3H2O, 2.0-2.5 mmol Ce(NO3) 3· 6H2O was dissolved in 35-50 mL of N,N-dimethylformamide, labeled as solution A;

[0040] (1.2) Dissolve 2.0-2.5 mmol of 2-aminoterephthalic acid in 35-50 mL of N,N-dimethylformamide and stir well. This is labeled solution B.

[0041] (1.3) Add 0.1-0.2 g of polyvinyl pyrrolidone to solution B and stir evenly to form a homogeneous solution;

[0042] (1.3) Solution A is added to the homogeneous solution and stirred for 30-40 min. The mixed solution is then transferred to a stainless steel reactor lined with polytetrafluoroethylene and heated to 120-140°C for 6-8 h. After natural cooling, a precipitate is obtained by centrifugation. The precipitate is washed 3-4 times with N,N-dimethylformamide and anhydrous ethanol, respectively, and centrifuged. The collected product is vacuum dried to obtain the Cu / Ce-BDC-NH2 nanozyme; wherein the centrifugation is performed at 8000-10000 r / min for 5-10 min.

[0043] Figure 1 This is the TEM image of the prepared Cu / Ce-BDC-NH2 nanozyme, which shows a two-dimensional sheet structure. Figure 2-Figure 3 The high-resolution Cu 2p and Ce 3d XPS spectra of Cu / Ce-BDC-NH2 nanozyme are shown in Figure 2. Figure 2 As shown, there are two binding energies at 933.2 and 952.9 eV, which are attributed to Cu 2+ , and there are satellite peaks at 940.3 and 960.1 eV, which are Cu 2+ The characteristic peaks of Ce 3d XPS spectrum are as follows: Figure 3 As shown, the peak at 901.1 eV can be attributed to Ce 3+ The peaks at 882.4, 886.2 and 905.9 eV are attributed to Ce. 4+ , proved that Ce in Cu / Ce-BDC-NH2 3+ and Ce 4+ coexistence, and at the same time, Ce 3+ Favorable for Cu 2+ transformation.

[0044] Evaluation of Cu / Ce-BDC-NH2 nanozyme activity: 2,4-dichlorophenol and 4-aminoantipyrine were used as catalytic reaction substrates to evaluate its laccase-like activity. Figure 4 The results showed that in the presence of Cu / Ce-BDC-NH2 nanozyme, 2,4-dichlorophenol (2,4-DCP) and 4-aminoantipyrine (4-AAP) were oxidized to generate corresponding red products with a maximum absorption peak at 510 nm. Compared with Cu / Ce-BDC-NH2, the absorption spectrum of potassium pyroantimonate (PP) decreased, indicating that PP inhibited the laccase-like activity of the system, while the addition of Na + To evaluate the laccase-like activity of Cu / Ce-BDC-NH2, the absorbance decreased significantly when air was replaced by N2, while the absorbance increased significantly when O2 was introduced, indicating that Cu / Ce-BDC-NH2 has laccase-like activity (e.g. Figure 5 shown).

[0045] In this embodiment, step (2) specifically includes:

[0046] 100 μL of different concentrations of Na were added to different colorimetric tubes. + The standard solution and 100-150 μL of 100 μmol / L potassium pyroantimonate solution were reacted for 10-15 min, and 50-100 μL of 1 mg / mL Cu / Ce-BDC-NH2 nanozyme aqueous solution were added. Then, 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine were added to generate red oxidation products. The volume was adjusted to 3 mL with pH 6.8 MES buffer solution, shaken, and allowed to stand for 5-10 min. The changes in the UV absorption spectrum in the range of 400-750 nm were measured. Figure 6 ; with Na + The concentration is the horizontal axis, and the absorbance A measured at a wavelength of 510 nm is the vertical axis. The standard curves are drawn and the regression equations are obtained. Figure 7 The regression equation, correlation coefficient, relative standard deviation, linear range, etc. are shown in Table 1.

[0047] Table 1 Linear equation, correlation coefficient, relative standard deviation, and linear range

[0048]

[0049] Method specificity investigation: The common coexisting ion pairs were investigated to determine Na + The relative error is within ±10%, Na + The concentration is 250 μg / L, such as Figure 8 As shown, the results show that: 100 times Ba 2+ Cr 6+ 、Ni 2+ 、Bi 3+ NH4 + 、SO4 2- 、Cl - 、NO3 - , 50 times Zn 2+ 、Al 3+ 、Cu 2+ 、Mn 2+ , Pb 2+ , 10 times Fe 3+ Mg 2+ , Ca 2+ , K + To Na + Therefore, the method can determine the Na +Has good selection specificity.

[0050] In step (3) of this embodiment, the cigarette paper sample is processed to obtain a sample test solution. The specific method is as follows: 0.1000 g of the shredded cigarette paper sample is weighed into a 100 mL conical flask, 20 mL of hydrochloric acid (1+99) solution is added, ultrasonic extraction is performed for 30 min, and the mixture is centrifuged at 3000 r / min for 15 min. The supernatant is filtered through a 0.45 μm microporous filter membrane and then fixed to volume in a 50 mL volumetric flask to obtain the sample test solution.

[0051] In step (3) of this embodiment, the method for determining the absorbance of the sample solution specifically includes: adding 100 μL of sample solution and 100-150 μL of potassium pyroantimonate solution with a concentration of 100 μmol / L to a 5 mL colorimetric tube, reacting for 10-15 minutes, adding 50-100 μL of Cu / Ce-BDC-NH2 nanozyme solution with a concentration of 1 mg / mL, and then adding 50-100 μL of 2,4-dichlorophenol solution with a concentration of 1 mg / mL and 50-100 μL of 4-aminoantipyrine with a concentration of 1 mg / mL to generate a red oxidation product, diluting to 3 mL with pH 6.8 MES buffer solution, shaking, standing for 5-10 minutes, and measuring the absorbance of the sample solution at a wavelength of 510 nm. Substituting the absorbance of the sample solution into the regression equation described in step (2), the Na + In this embodiment, the Na content in a cigarette paper is obtained. + The content is 0.25%.

[0052] Recovery and precision experiment: Three different concentrations of Na were added to three samples. + Standard solution; each concentration was measured three times in parallel, the spiked recovery was calculated, and the relative standard deviation RSD was calculated. The results are shown in Table 2; Na + The spiked recoveries ranged from 97.0% to 102.5%, with RSDs of 1.52% to 2.69%, demonstrating the excellent accuracy and precision of the method provided by the present invention. Furthermore, the method provided by the present invention was compared with an ICP-MS method, which employed microwave digestion (5 mL of concentrated HNO₃ + 1 mL of H₂O₂) followed by constant volume and then ICP-MS analysis. The results showed no significant differences between the two methods. Furthermore, compared with ICP-MS analysis, the method provided by the present invention offers advantages such as simple and rapid sample pretreatment and low detection costs.

[0053] Table 2 Sample spike recovery and RSD (n = 3)

[0054]

[0055] The present invention establishes a method for rapid detection of sodium ions in cigarette paper by nanoenzyme laccase + The determination has the advantages of fewer processing steps, shorter time, lower processing cost, easier operation, and no need for large-scale instruments and equipment, which has great advantages in actual detection.

[0056] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. For ordinary technicians in this field, they can still modify or improve the technical solutions described above, which all fall within the scope of protection of the present invention.

Claims

1. A method for rapid detection of sodium ions in cigarette paper using nanozyme laccase, characterized in that: The method comprises the following steps: (1) Using 2-aminoterephthalic acid, copper nitrate, and cerium nitrate as precursors and polyvinylpyrrolidone as a stabilizer, a copper-cerium MOF-based nanozyme with laccase-like activity, namely Cu / Ce-BDC-NH2 nanozyme, was synthesized by a solvothermal method. (2) At different concentrations of Na + Potassium pyroantimonate was added to the standard solution for reaction, and then Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine were added; the volume was fixed with MES buffer solution, shaken and allowed to stand, and the absorbance was measured to establish the absorbance and Na + The quantitative relationship of concentration was calculated, and the standard curve was drawn to obtain the regression equation; (3) Treating the cigarette paper sample to obtain a sample solution; adding potassium pyroantimonate to the sample solution for reaction, and then adding Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine; using MES buffer solution to make up the volume, shaking, and letting it stand, and measuring the absorbance of the sample solution; substituting the absorbance of the sample solution into the regression equation obtained in step (2) to obtain the Na content in the cigarette paper sample. + content; Step (1) specifically includes: (1.1) Combine 2.0-2.5mmol Cu(NO3)2.3H2O, 2.0-2.5 mmol Ce(NO3) 3· 6H2O was dissolved in 35-50 mL N,N-dimethylformamide and labeled as solution A; (1.2) Dissolve 2.0-2.5 mmol of 2-aminoterephthalic acid in 35-50 mL of N,N-dimethylformamide and stir well. This is labeled solution B. (1.3) Add 0.1-0.2 g of polyvinyl pyrrolidone to solution B and stir evenly to form a homogeneous solution; (1.4) Solution A was added to the homogeneous solution and stirred for 30-40 min. The mixed solution was then transferred to a stainless steel reactor lined with polytetrafluoroethylene and heated to 120-140°C for 6-8 h. After natural cooling, a precipitate was obtained by a first centrifugation. The precipitate was washed 3-4 times with N,N-dimethylformamide and anhydrous ethanol, respectively, and centrifuged a second time. The collected product was vacuum dried to obtain the Cu / Ce-BDC-NH2 nanozyme.

2. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: In step (1.3), the conditions of the first centrifugation and the second centrifugation are both: 8000-10000 r / min for 5-10 min.

3. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: Step (2) specifically includes: 100 μL of different concentrations of Na were added to different colorimetric tubes. + The standard solution and 100-150 μL of 100 μmol / L potassium pyroantimonate solution were reacted for 10-15 min, and 50-100 μL of 1 mg / mL Cu / Ce-BDC-NH2 nanozyme aqueous solution were added. Then, 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine were added to generate red oxidation products. The volume was adjusted to 3 mL with MES buffer solution of pH 6.8, shaken, and allowed to stand for 5-10 min. The absorbance was measured at a wavelength of 510 nm to establish the absorbance and Na + The quantitative relationship of concentration was calculated, and the standard curve was drawn to obtain the regression equation.

4. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: In step (3), the cigarette paper sample is processed to obtain a sample test solution. The specific method is as follows: 0.1000 g of the shredded cigarette paper sample is weighed and placed in a 100 mL conical flask, 20 mL of a 0.1-0.15 mol / L hydrochloric acid solution is added, ultrasonic extraction is performed for 25-35 min, and the sample is centrifuged at 2000-4000 r / min for 10-20 min. The supernatant is filtered through a 0.45 μm microporous filter membrane and then diluted to a 50 mL volumetric flask to obtain the sample test solution.

5. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: In step (3), the method for determining the absorbance of the sample assay solution specifically includes: adding 100 μL of sample assay solution and 100-150 μL of 100 μmol / L potassium pyroantimonate solution into a colorimetric tube, reacting for 10-15 min, adding 50-100 μL of 1 mg / mL Cu / Ce-BDC-NH2 nanozyme solution, and then adding 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine to generate a red oxidation product, diluting to 3 mL with pH 6.8 MES buffer solution, shaking, standing for 5-10 min, and measuring the absorbance of the sample assay solution at a wavelength of 510 nm.

6. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: The linear range of the method for detecting sodium ions in the sample solution is 8.33~6000 μg / L.

7. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: The detection limit of the method for sodium ions in the sample solution was 3.46 μg / L.

8. The method for rapid detection of sodium ions in cigarette paper using nanozyme laccase according to claim 1, characterized in that: The method measured Na + The recoveries of the spiked products were between 97.0% and 102.5%, and the relative standard deviations (RSDs) were between 1.52% and 2.69%.

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