Method for rapidly detecting sodium ions in cigarette paper by nano-enzyme laccase

Abstract

The invention belongs to the technical field of chemical analysis and detection, and relates to a method for rapidly detecting sodium ions in cigarette paper by nano-enzyme laccase. According to the method, 2-aminoterephthalic acid, copper nitrate and cerous nitrate are taken as precursors, polyvinylpyrrolidone is taken as a stabilizer, and a solvothermal method is adopted to synthesize the copper-cerium-containing MOF-based nano-enzyme with laccase-like activity, namely Cu / Ce-BDC-NH2 nano-enzyme; cu / Ce-BDC-NH2 nano-enzyme oxidizes 2, 4-dichlorophenol and 4-aminoantipyrine to obtain a red product, the potassium pyroantimonate ligand is adsorbed on the surface of Cu / Ce-BDC-NH2 to inhibit catalytic action, so that laccase-like activity is reduced, Na < + > is introduced to react with potassium pyroantimonate to generate a stable complex, the activity of Cu / Ce-BDC-NH2 laccase is recovered, and the red color of a solution is deepened. The invention establishes a novel colorimetric rapid detection method for sodium ions.

Description

Technical Field

[0001] 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 by using nanozyme laccase. Background Art

[0002] The properties of cigarette paper directly affect the combustion performance, aroma and taste quality of cigarettes, and also affect the release amount of harmful components in cigarette smoke. Calcium carbonate, as a filler for cigarette paper, can affect the air permeability of cigarette paper; while potassium citrate and sodium citrate are the main additives for cigarette paper, and potassium (K) and sodium (Na) are the main quality indicators for evaluating the combustion performance of cigarette paper. Therefore, rapid determination of the K and Na contents in cigarette paper is of great significance for controlling the quality of cigarette paper. At present, the methods for determining the content of inorganic elements in tobacco mainly include flame photometry, ion chromatography, atomic absorption spectrometry and inductively coupled plasma mass spectrometry (ICP-MS), etc. However, these methods often have cumbersome sample pretreatment operations, slow detection speed and require complex instrument equipment. Colorimetry occupies an important position in detection technology because of its simple and rapid operation and the need for no large-scale instrument equipment, but the colorimetric detection of sodium ions has rarely been reported. Summary of the Invention

[0003] In view of the above technical problems, the present invention discloses a method for rapidly detecting sodium ions in cigarette paper by using nanozyme laccase.

[0004] In order to achieve the above technical objectives, the present invention provides the following technical solutions: A method for rapidly detecting sodium ions in cigarette paper by using nanozyme laccase, the method comprising the following steps: (1) Using 2-aminoterephthalic acid, copper nitrate and cerium nitrate as precursors and polyvinylpyrrolidone as a stabilizer, synthesizing a copper-cerium MOF-based nanozyme with laccase-like activity, namely Cu / Ce-BDC-NH2 nanozyme, by a solvothermal method; (2) Adding potassium pyroantimonate to react in different concentrations of Na + standard solutions, then adding Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate a red oxidation product; diluting to a constant volume with MES buffer solution, shaking well and standing still, measuring the absorbance, establishing a quantitative relationship between the absorbance and the Na + concentration, plotting a standard curve and obtaining a regression equation; (3) Treat the cigarette paper sample to obtain a sample determination solution; add potassium pyroantimonate to the sample determination solution for reaction, then add the Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate a red oxidation product; make up the volume with MES buffer solution, shake well and stand still, and measure the absorbance of the sample determination solution; substitute the absorbance of the sample determination solution into the regression equation in step (2) to obtain Na in the cigarette paper sample + content.

[0005] Among them, 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 to inhibit the catalytic effect, resulting in a decrease in laccase-like activity. The introduction of Na + reacts with potassium pyroantimonate to form a stable complex, restoring the laccase-like activity of Cu / Ce-BDC-NH2 and deepening the red color of the solution. Based on this principle, the present invention has established 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, and is used for the determination of sodium ions in cigarette paper, showing the characteristics of high sensitivity, strong specificity, simple operation and rapidity.

[0006] Further, step (1) specifically includes: (1.1) Dissolve 2.0 - 2.5 mmol of Cu(NO3)2·3H2O and 2.0 - 2.5 mmol of Ce(NO3) 3· 6H2O in 35 - 50 mL of N,N-dimethylformamide (DMF), and label it as solution A; (1.2) Dissolve 2.0 - 2.5 mmol of 2-aminoterephthalic acid in 35 - 50 mL of N,N-dimethylformamide (DMF), stir evenly, and label it as solution B; (1.3) Add 0.1 - 0.2 g of polyvinylpyrrolidone (PVP) to the solution B, stir evenly to form a homogeneous solution; (1.3) Add solution A to the homogeneous solution, stir for 30 - 40 min, then transfer the mixed solution into a stainless steel reaction kettle lined with polytetrafluoroethylene, heat to 120 - 140 °C, keep for 6 - 8 h, naturally cool, and obtain a precipitate by centrifugation. Wash the precipitate 3 - 4 times with N,N-dimethylformamide (DMF) and absolute ethanol respectively, centrifuge, and vacuum dry the collected product to obtain Cu / Ce-BDC-NH2 nanozyme. Among them, the introduction of cerium ions significantly enhances Cu + and Cu 2+The electron transfer improves the laccase-like activity of Cu / Ce-BDC-NH2.

[0007] Further, in step (1.3), the centrifugation is carried out at 8000 - 10000 r / min for 5 - 10 min.

[0008] Further, step (2) specifically includes: Add 100 μL of Na + standard solutions with different concentrations, 100 - 150 μL of potassium pyroantimonate solution with a concentration of 100 μmol / L in different colorimetric tubes, react for 10 - 15 min, add 50 - 100 μL of an aqueous solution of Cu / Ce-BDC-NH2 nanozyme with a concentration of 1 mg / mL, then add 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, dilute to 3 mL with pH 6.8 MES buffer solution, shake well, stand for 5 - 10 min, measure the absorbance at a wavelength of 510 nm, establish the quantitative relationship between the absorbance and the Na + concentration, draw a standard curve, and obtain a regression equation.

[0009] Further, in step (3), the cigarette paper sample is processed to obtain a sample determination solution. The specific method is: Weigh 0.1000 g of the shredded cigarette paper sample into a 100 mL Erlenmeyer flask, add 20 mL of hydrochloric acid solution with a concentration of 0.1 - 0.15 mol / L, ultrasonically extract for 25 - 35 min, centrifuge at 2000 - 4000 r / min for 10 - 20 min, filter the supernatant through a 0.45 μm microporous filter membrane, and then dilute and fix the volume in a 50 mL volumetric flask to obtain the sample determination solution.

[0010] Further, in step (3), the method for measuring the absorbance of the sample determination solution specifically includes: Add 100 μL of the sample determination solution, 100 - 150 μL of potassium pyroantimonate solution with a concentration of 100 μmol / L in a colorimetric tube, react for 10 - 15 min, add 50 - 100 μL of Cu / Ce-BDC-NH2 nanozyme solution with a concentration of 1 mg / mL, then add 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, dilute to 3 mL with pH 6.8 MES buffer solution, shake well, stand for 5 - 10 min, and measure the absorbance of the sample determination solution at a wavelength of 510 nm.

[0011] Further, the detection limit of sodium ions in the sample determination solution by the method is 3.46 μg / L.

[0012] Further, the method measures Na + with a spike recovery rate ranging from 97.0% to 102.5% and a relative standard deviation RSD ranging from 1.52% to 2.69%.

[0013] Advantages and technical effects of the present invention: The copper-cerium MOF-based nanozyme (Cu / Ce-BDC-NH2 nanozyme) prepared by the method provided by the present invention has a sparse porous framework structure, exposing more active adsorption sites, which is beneficial to the enrichment of potassium antimonate; at the same time, the introduction of cerium ions significantly enhances the electron transfer between Cu + and Cu 2+ , improving the laccase-like activity of Cu / Ce-BDC-NH2. Potassium antimonate, as a ligand of Na + , can adsorb on the surface of Cu / Ce-BDC-NH2, inhibiting the catalysis and resulting in a decrease in laccase-like activity. However, the introduction of Na + reacts with potassium antimonate to form a stable complex, restoring the laccase-like activity of Cu / Ce-BDC-NH2 and deepening the red color of the solution. Based on this, the present invention establishes a new colorimetric rapid detection method for sodium ions.

[0014] The method provided by the present invention is a colorimetric detection method for sodium ions, with a wide linear range (8.33 - 6000 μg / L), high detection sensitivity (detection limit of 3.46 μg / L), and the coexisting substances (Ba 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 + ) in cigarette paper do not interfere with the determination. This method has good selectivity and is used for the determination of sodium ions in cigarette paper, with good recovery rates (97.0% - 102.5%), consistent with the results of the ICP-MS method. Moreover, compared with the ICP-MS determination, the method provided by the present invention has the advantages of simple and rapid sample pretreatment operation and low detection cost. Description of the drawings

[0015] Figure 1 TEM image of the Cu / Ce-BDC-NH2 nanozyme prepared in Example 1 of the present invention; Figure 2 XPS spectrum (Cu 2p) of the Cu / Ce-BDC-NH2 nanozyme in Example 1 of the present invention; Figure 3 XPS spectrum (Ce 3d) of the Cu / Ce-BDC-NH2 nanozyme in Example 1 of the present invention; Figure 4 is for potassium pyroantimonate (PP), Na + and PP+Na + Influence on the laccase-like activity of Cu / Ce-BDC-NH2; Figure 5 is for the influence of N2, O2 and air on the laccase-like activity of Cu / Ce-BDC-NH2 in Example 1; Figure 6 is for the ultraviolet absorption spectrum of the 2,4-DCP+4-AAP+PP+Cu / Ce-BDC-NH2 system to detect Na + ; Figure 7 is for the linear equation of the 2,4-DCP+4-AAP+PP+Cu / Ce-BDC-NH2 system to detect Na + ; Figure 8 is for the influence result of coexisting substances on the detection of Na + ; Detailed implementation manners

[0016] The technical solution of the present invention will be further described below in conjunction with specific embodiments and the accompanying drawings.

[0017] Example 1: A method for rapidly detecting sodium ions in cigarette paper by a nanozyme laccase, the method comprising 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, is synthesized by a solvothermal method; (2) React potassium pyroantimonate in standard solutions of different concentrations of Na + , then add a Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate a red oxidation product; dilute to a constant volume with MES buffer solution, shake well, stand still, measure the absorbance, establish the quantitative relationship between the absorbance and the concentration of Na + , draw a standard curve, and obtain a regression equation; (3) Treat the cigarette paper sample to obtain a sample determination solution; add potassium pyroantimonate to the sample determination solution for reaction, then add the Cu / Ce-BDC-NH2 nanozyme solution, 2,4-dichlorophenol and 4-aminoantipyrine to generate a red oxidation product; make up the volume with MES buffer solution, shake well and stand still, and measure the absorbance of the sample determination solution; substitute the absorbance of the sample determination solution into the regression equation in step (2) to obtain the Na in the cigarette paper sample + content.

[0018] In this embodiment, step (1) specifically includes: (1.1) Dissolve 2.0 - 2.5 mmol of Cu(NO3)2·3H2O and 2.0 - 2.5 mmol of Ce(NO3) 3· 6H2O in 35 - 50 mL of N,N-dimethylformamide, and label it as solution A; (1.2) Dissolve 2.0 - 2.5 mmol of 2-aminoterephthalic acid in 35 - 50 mL of N,N-dimethylformamide, stir evenly, and label it as solution B; (1.3) Add 0.1 - 0.2 g of polyvinylpyrrolidone to solution B and stir evenly to form a homogeneous solution; (1.3) Add solution A to the homogeneous solution, stir for 30 - 40 min, then transfer the mixed solution into a stainless steel reaction kettle with a polytetrafluoroethylene lining, heat to 120 - 140 °C, keep for 6 - 8 h, cool naturally, obtain a precipitate by centrifugation, wash the precipitate 3 - 4 times with N,N-dimethylformamide and absolute ethanol respectively, centrifuge, and vacuum dry the collected product to obtain Cu / Ce-BDC-NH2 nanozyme; wherein, the centrifugation is carried out at 8000 - 10000 r / min for 5 - 10 min.

[0019] Figure 1 Figure 0 is the TEM image of the prepared Cu / Ce-BDC-NH2 nanozyme, which shows a two-dimensional sheet structure. Figures 2 - 3 Figure 1 is the high-resolution Cu 2p and Ce 3d XPS spectra of the Cu / Ce-BDC-NH2 nanozyme. The Cu 2p XPS spectrum is as Figure 2 shown, with two binding energies at 933.2 and 952.9 eV, attributed to Cu 2+ , and at the same time, satellite peaks are present at 940.3 and 960.1 eV, which are the characteristic peaks of Cu 2+ ; the Ce 3d XPS spectrum is as Figure 3 shown, and the peak at 901.1 eV can be attributed to Ce 3+, the peaks located at 882.4, 886.2 and 905.9 eV are attributed to Ce 4+ , demonstrating Ce in Cu / Ce-BDC-NH2 3+ and Ce 4+ coexistence. Meanwhile, Ce 3+ is beneficial to the conversion of Cu 2+ .

[0020] Evaluation of the nanozyme activity of Cu / Ce-BDC-NH2: Using 2,4-dichlorophenol and 4-aminoantipyrine as catalytic reaction substrates to evaluate its laccase-like activity, Figure 4 it shows that in the presence of the Cu / Ce-BDC-NH2 nanozyme, 2,4-dichlorophenol (2,4-DCP) and 4-aminoantipyrine (4-AAP) are oxidized to form corresponding red products, and a maximum absorption peak appears at 510 nm. Compared with Cu / Ce-BDC-NH2, the addition of potassium pyroantimonate (PP) reduces the absorption spectrum, indicating that PP inhibits the laccase-like activity of the system. After adding Na + , the laccase-like activity is restored. To evaluate the laccase-like activity of Cu / Ce-BDC-NH2, N2 is used to replace air, and the absorbance decreases significantly. When O2 is introduced, the absorbance increases significantly, indicating that Cu / Ce-BDC-NH2 has laccase oxidase-like activity (as Figure 5 shown).

[0021] In this embodiment, step (2) specifically includes: Add 100 μL of Na + standard solutions with different concentrations, 100 - 150 μL of potassium pyroantimonate solution with a concentration of 100 μmol / L in different colorimetric tubes, react for 10 - 15 min, add 50 - 100 μL of an aqueous solution of Cu / Ce-BDC-NH2 nanozyme with a concentration of 1 mg / mL, then add 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 red oxidation products, dilute to 3 mL with pH 6.8 MES buffer solution, shake well, and let stand for 5 - 10 min; Measure the changes in the ultraviolet absorption spectrum in the range of 400 - 750 nm, see Figure 6 ; Take the Na + concentration as the abscissa and the absorbance A measured at a wavelength of 510 nm as the ordinate, and draw standard curves respectively to obtain the regression equation, see Figure 7 ; The regression equation, correlation coefficient, relative standard deviation, linear range, etc. are shown in Table 1.

[0022] Table 1 Linear equation, correlation coefficient, relative standard deviation, linear range Method specificity investigation: The interference of common coexisting ions on the determination of Na + was investigated, and the relative error was within ±10%. The concentration of Na + was 250 μg / L. As Figure 8 shown, the results indicated that 100-fold Ba 2+ , Cr 6+ , Ni 2+ , Bi 3+ , NH4 + , SO4 2- , Cl - , NO3 - , 50-fold Zn 2+ , Al 3+ , Cu 2+ , Mn 2+ , Pb 2+ , 10-fold Fe 3+ , Mg 2+ , Ca 2+ , K + had no interference on the SERS determination of Na + . Therefore, the method for determining Na + had good selective specificity.

[0023] In step (3) of this example, the cigarette paper sample was processed to obtain a sample determination solution. The specific method was as follows: Weigh 0.1000 g of the shredded cigarette paper sample into a 100 mL Erlenmeyer flask, add 20 mL of hydrochloric acid (1+99) solution, extract by ultrasonic for 30 min, centrifuge at 3000 r / min for 15 min, filter the supernatant through a 0.45 μm microporous filter membrane, and then make up the volume to 50 mL in a volumetric flask to obtain the sample determination solution.

[0024] In step (3) of this example, the method for measuring the absorbance of the sample determination solution specifically included: Add 100 μL of the sample determination solution, 100 - 150 μL of potassium antimonate solution with a concentration of 100 μmol / L into a 5 mL colorimetric tube, react for 10 - 15 min, add 50 - 100 μL of Cu / Ce-BDC-NH2 nanozyme solution with a concentration of 1 mg / mL, then add 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. Dilute to 3 mL with pH 6.8 MES buffer solution, shake well, let stand for 5 - 10 min, and measure the absorbance of the sample determination solution at a wavelength of 510 nm. Substitute the absorbance of the sample determination solution into the regression equation described in step (2) to obtain the content of Na + ; In this example, the Na content in a certain cigarette paper was obtained+ The content is 0.25%.

[0025] Recovery and precision experiments: Three different concentrations of Na standard solutions were added to three samples respectively; each concentration was determined in parallel 3 times, the spike recovery rate was calculated, and the relative standard deviation RSD was calculated. The results are shown in Table 2; the spike recovery rate of Na was measured to be between 97.0% and 102.5%, and the RSD was between 1.52% and 2.69%, indicating that the method provided by the present invention has good accuracy and precision. At the same time, the method provided by the present invention was compared with the ICP-MS method. The ICP-MS method was digested by microwave with (5 mL concentrated HNO3 + 1 mL H2O2) and then made up to volume, and then ICP-MS determination was carried out. The results showed that there was no obvious difference between the two methods, and compared with the ICP-MS determination, the method provided by the present invention has the advantages of simple and rapid sample pretreatment operation, low detection cost, etc. + +

[0026] Table 2 Spike recovery rate and RSD of samples (n = 3) When the method for rapidly detecting sodium ions in cigarette paper by nanozyme laccase established by the present invention is used for Na determination, it has the advantages of fewer treatment steps, shorter time used, lower treatment cost, simple operation, and does not require large-scale instrument equipment, and has strong advantages in actual detection. +

[0027] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those of ordinary skill in the art, they can still modify or deform and improve the previously described technical solutions, and these all belong to the protection scope 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, draw the standard curve and 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.

2. According to claim 1, a method for rapid detection of sodium ions in cigarette paper using nanozyme laccase, characterized in that: Step (1) specifically includes: (1.1) Combine 2.0-2.5mmol Cu(NO3)2.3H2O, 2.0-2.5 mmol Ce(NO3) 3· 6H2O is dissolved in 35-50 mL N,N-dimethylformamide and is labeled as solution A; (1.2) Dissolve 2.0-2.5 mmol 2-aminoterephthalic acid in 35-50 mL N,N-dimethylformamide and stir well. This is called solution B. (1.3) Add 0.1-0.2 g of polyvinyl pyrrolidone to the solution B and stir evenly to form a homogeneous solution; (1.4) Solution A is added to the homogeneous solution and stirred for 30-40 min. The mixed solution is then transferred into 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 the first centrifugation. The precipitate is washed 3-4 times with N,N-dimethylformamide and anhydrous ethanol, respectively, and a second centrifugation is performed. The collected product is vacuum dried to obtain Cu / Ce-BDC-NH2 nanozyme.

3. According to claim 2, a method for rapid detection of sodium ions in cigarette paper using nanozyme laccase, 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.

4. 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: Add 100 μL of different concentrations of Na into 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, followed by 50-100 μL of 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of 1 mg / mL 4-aminoantipyrine to generate red oxidation products. The product was diluted to 3 mL with MES buffer solution at 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.

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 cigarette paper sample is processed to obtain a sample test solution. The specific method is as follows: weigh 0.1000 g of the shredded cigarette paper sample into a 100 mL conical flask, add 20 mL of a 0.1-0.15 mol / L hydrochloric acid solution, ultrasonically extract for 25-35 min, centrifuge at 2000-4000 r / min for 10-20 min, filter the supernatant through a 0.45 μm microporous filter membrane, and then make up the volume in a 50 mL volumetric flask to obtain a sample test solution.

6. 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 the sample assay solution and 100-150 μL of a 100 μmol / L potassium pyroantimonate solution into a colorimetric tube, reacting for 10-15 min, adding 50-100 μL of a 1 mg / mL Cu / Ce-BDC-NH2 nanozyme solution, and then adding 50-100 μL of a 1 mg / mL 2,4-dichlorophenol solution and 50-100 μL of a 1 mg / mL 4-aminoantipyrine to generate a red oxidation product, diluting the volume to 3 mL with a pH 6.8 MES buffer solution, shaking well, standing for 5-10 min, and determining the absorbance of the sample assay solution at a wavelength of 510 nm.

7. 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.

8. 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 is 3.46 μg / L.

9. 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 recovery of spiked samples was between 97.0% and 102.5%, and the relative standard deviation (RSD) was between 1.52% and 2.69%.

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