A method for fluorescent detection of inorganic selenium

Abstract

The application discloses a kind of inorganic selenium (such as sodium selenite) fluorescence detection methods containing SeO3 2 Including the following steps: S1 nitrogen boron co-doped carbon quantum dot powder is matched into solution D, and its fluorescence intensity F0 is tested;S2: after different concentrations of SeO3 2 Solution is mixed with the D solution to obtain mixed solution, fluorescence test is carried out, and the fluorescence intensity value F of each mixed solution is obtained;S3: with the concentration of SeO3 2 As abscissa, fluorescence growth rate is ordinate, linear fitting is carried out, and regression equation y=kx+b is obtained;S4: the solution to be measured containing SeO3 2 With D solution is mixed to obtain the mixed solution of sample to be measured, fluorescence test is carried out, and the concentration of SeO3 2 Is calculated by substituting linear regression equation y=kx+b.The application uses nitrogen, boron-doped carbon quantum dots as fluorescent probe to realize the rapid and accurate detection of SeO3 2 Content, overcome other SeO3 2 Detection method equipment cost is high, and the problems such as operation complex.

Description

Technical Field

[0001] This invention relates to the field of health product testing technology, and in particular to a fluorescence detection method for inorganic selenium. Background Technology

[0002] Selenium, an essential nutrient for the human body, is widely distributed in various organs, tissues, and body fluids. It typically exists in the body as antioxidant enzymes and selenoproteins, significantly enhancing immunity and antioxidant capacity. However, appropriate selenium concentrations are beneficial; exceeding safe limits can lead to selenium poisoning symptoms, including liver cancer, tooth loss, and paralysis. Selenium primarily exists as selenates and selenites (containing SeO3). 2- Selenium exists in various forms, including organic and selenium-containing compounds. Among these, selenite is the most toxic when ingested in excess. Studies have confirmed that most selenium poisoning from drinking water or food is caused by selenite, and millions of people have suffered from selenium poisoning due to the use of water contaminated with selenite. Therefore, accurate detection of SeO3 in water is crucial. 2- Its content is of great significance in environmental science, medical science and nutritional science.

[0003] Currently, the detection of trace SeO3 2- Methods include atomic absorption spectrometry, mass spectrometry, electrochemical techniques, and chromatography. These methods generally possess good selectivity and high sensitivity, meeting basic detection needs. However, the high cost of detection equipment, the relatively complex detection process, and the long processing time limit their widespread application. Fluorescent sensors have attracted widespread attention due to their simplicity, economy, high sensitivity, intuitiveness, and rapid response. Various fluorescent probes relying on organic dye molecules, metal nanoparticles, and semiconductor quantum dots (QDs) have emerged. However, most of these probes suffer from drawbacks such as toxicity, low sensitivity, poor selectivity, and susceptibility to bleaching. Carbon quantum dots (CQDs), with their good solubility, low toxicity, good biocompatibility and environmental friendliness, as well as good sensitivity and selectivity, have been widely used in a wide range of fields, including bioimaging, catalysis, and sensors. However, the detection of trace amounts of SeO3 remains a challenge. 2- The content of trace SeO3 is still under investigation, and currently there are no carbon quantum dots (CQDs) with improved surface functionalization / passivation or heteroatom doping to detect trace SeO3. 2- The method. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings of existing technologies by providing a fluorescence detection method for inorganic selenium, employing nitrogen-boron-doped carbon quantum dots as fluorescent probes to detect SeO3. 2- Rapid and accurate detection of SeO3 content overcomes the limitations of other methods. 2- The testing methods and equipment are expensive and the operation is complicated.

[0005] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0006] An inorganic selenium (containing SeO3) 2- The fluorescence detection method includes the following steps:

[0007] S1: Dissolve nitrogen-boron co-doped carbon quantum dot powder in ultrapure water to prepare a solution D of a certain concentration, and test its fluorescence intensity, which is recorded as F0;

[0008] S2: Different concentrations of SeO3 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0009] S3: SeO3 2- Using the concentration as the x-axis and the fluorescence growth rate as the y-axis, a linear fit was performed to obtain the regression equation y = kx + b, where y is the fluorescence growth rate, the fluorescence growth rate is F / F0⁻¹, and x is the concentration of SeO₃. 2- The concentration, k is the slope, and b is the intercept;

[0010] S4: The test sample containing SeO3 2- The solution of D is mixed with the solution of the sample to be tested. Fluorescence testing is then performed to obtain the fluorescence intensity value of the sample to be tested. The fluorescence growth rate of the sample to be tested is calculated and substituted into the linear regression equation y = kx + b to calculate the SeO3. 2- The concentration.

[0011] Preferably, the mass concentration of solution D in step S1 is 0.1-1.0 mg / ml, and more preferably, it can be 0.15, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or 1.0 mg / ml.

[0012] Preferably, the different SeO3 mentioned in step S2 2- The concentration is 25-125 μM, preferably 50-100 μM.

[0013] Preferably, the nitrogen-boron co-doped carbon quantum dot powder is prepared from a carbon source, a nitrogen source, and a boron source according to the following steps:

[0014] 1) Dissolve the carbon source citric acid, the nitrogen source 2-amino-3-hydroxypyridine, and the boron source boron-containing compound in pure water in sequence to obtain solution A;

[0015] 2) Transfer solution A to a polytetrafluoroethylene liner, then place it in a stainless steel reactor and react at 150-180℃ for 90-300 min to obtain solution B;

[0016] 3) Transfer solution B to pure water and dialyze for 24-72 hours to obtain solution C. Filter solution C and freeze-dry it to obtain powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs), which are then stored for later use.

[0017] Preferably, the amount of carbon source citric acid is 0.84-1.16 g, the amount of nitrogen source 2-amino-3-hydroxypyridine is 0.113-0.5 g, and the amount of boron source boron-containing compound is 0.08-0.3 g; further, the amount of carbon source citric acid can be 0.84, 0.9, 1.0, 1.05, 1.1, 1.12, or 1.16 g; the amount of nitrogen source 2-amino-3-hydroxypyridine can be 0.113, 0.12, 0.2, 0.22, 0.3, 0.33, 0.4, 0.44, or 0.5 g; and the amount of boron source boron-containing compound can be 0.08, 0.1, 0.15, 0.2, 0.25, or 0.3 g.

[0018] Preferably, the boron source compound is at least one of sodium borohydride, boric acid, or borax. Preferably, the nitrogen source can also be a compound with 2-amino-3-hydroxypyridine as its core.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] 1. The fluorescence detection method for inorganic selenium of this invention uses nitrogen-boron-doped carbon quantum dots as fluorescent probes to detect SeO3. 2- Rapid and accurate detection of SeO3 content overcomes the limitations of other methods. 2- Content detection methods suffer from problems such as high equipment costs and complex operation.

[0021] 2. This invention utilizes nitrogen-boron-doped carbon quantum dots (N,B-CQDs) containing pyridine rings to adsorb SeO3. 2- The fluorescence intensity was significantly enhanced and the position of the maximum emission peak redshifted, making it suitable as a fluorescent probe. The surface of doped carbon quantum dots contains a large number of functional groups such as hydroxyl, carboxyl, and pyridine rings, which can interact with inorganic SeO3. 2- The interaction causes a significant enhancement in the fluorescence of a solution containing N,B-CQDs of a certain concentration, and a red shift in the position of the maximum emission peak. This property can be used to detect the fluorescence of SeO3. 2- This fluorescent probe offers highly efficient detection, effectively distinguishing other anions and organic selenium (such as the selenium-containing amino acid Se-Met). It is a rapid, efficient, and highly selective method for detecting inorganic SeO3. 2- The method.

[0022] 3. This invention is based on the principle of fluorescence enhancement effect and redshift of the maximum emission peak position for detection. This is based on SeO3 doped carbon quantum dots. 2-The content detection method has advantages such as high sensitivity, low spectral interference, and low cost. It is completely different from most methods on the market that detect heavy metal ions based on the fluorescence quenching effect of carbon quantum dots. The doped carbon quantum dot fluorescent probe can selectively detect inorganic SeO3. 2- It has significant economic and social value.

[0023] The above is an overview of the invention's technical solution. The invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0024] Figure 1 This embodiment describes the doped carbon quantum dots and their adsorption of SeO3. 2- NMR spectroscopy;

[0025] Figure 2 This is a schematic diagram illustrating the effect of different anions and organic selenium on the fluorescence intensity of N,B-CQDs aqueous solution in Example 1.

[0026] Figure 3 In this Example 1, N,B-CQDs and different concentrations of SeO3 were present in an aqueous solution. 2- A schematic diagram of the fluorescence emission spectrum;

[0027] Figure 4 The fluorescence intensity change of N,B-CQDs in Example 1 and SeO3 2- A diagram illustrating the relationship between concentrations. Detailed implementation method:

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0029] Example 1: The fluorescence detection method for inorganic selenium provided in this example utilizes nitrogen-boron-doped carbon quantum dots as fluorescent probes to detect SeO3 by fluorescence spectroscopy. 2- The content of [something] is determined through the following steps:

[0030] 1) Powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) were dissolved in ultrapure water to prepare a 0.1 mg / mL solution D, and its fluorescence intensity was tested and denoted as F0;

[0031] 2) Selenite ions (SeO3) at concentrations of 25 μM, 30 μM, 35 μM, 40 μM, 45 μM, 50 μM, 55 μM, 65 μM, 75 μM, 87.5 μM, 100 μM, and 125 μM were added. 2-The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0032] 3) With SeO3 2- Using the selenite ion concentration as the x-axis and the fluorescence growth rate (F / F0-1) as the y-axis, a linear fit was performed to obtain the regression equation y = kx + b, where y is the fluorescence growth rate and x is the SeO3 ion concentration. 2- The concentration of selenite ions, k is the slope, and b is the intercept;

[0033] 4) The sample containing selenite ions (SeO3) is to be tested. 2- The solution of ) was mixed with solution D to obtain a mixed solution of SeO32--N,B-CQDs, and then fluorescence testing was performed to obtain a solution containing SeO32--N,B-CQDs. 2- Substituting the fluorescence intensity values ​​of the N,B-CQDs mixed solution into the linear regression equation y=kx+b, the SeO3 was calculated. 2- To determine the concentration of selenite ions. The excitation wavelength for fluorescence in the fluorescence assay used was 360 nm.

[0034] This embodiment uses the above-described fluorescence spectroscopy method to detect SeO3. 2- The solution D (a water-soluble brown powder D(N,B-CQDs)) obtained in this embodiment of the invention was prepared to a suitable concentration and used for the detection of SeO3 by fluorescence spectroscopy. 2- The content of [specific substance] is shown in the attached [document / record]. Figure 2 , Figure 3 , Figure 4 .

[0035] The above-mentioned powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) were prepared by the following method:

[0036] 1) Dissolve 0.84 g of citric acid, 0.5 g of 2-amino-3-hydroxypyridine, and 0.08 g of sodium borohydride in 30 mL of pure water to obtain solution A;

[0037] 2) Transfer solution A to a polytetrafluoroethylene liner, then place it in a stainless steel reactor and react at 180°C for 150 min to obtain solution B;

[0038] 3) Transfer solution B to a 1000D dialysis bag and dialyze for 48 hours to obtain solution C;

[0039] 4) Filter solution C through a 0.45 μm organic filter membrane, then freeze at -60 °C for 4 h, and vacuum dry for 12 h to obtain water-soluble brown powder D(N,B-CQDs), which is stored at 0 °C for later use.

[0040] Comparative Example 1: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that the preparation method of carbon quantum dots is the same as in Example 1. The total amount of the reaction raw materials mcitric acid + m2-amino-3-hydroxypyridine remains unchanged, but the ratio is changed accordingly. The specific steps are as follows:

[0041] 1) Dissolve 1g of citric acid, 0.343g of 2-amino-3-hydroxypyridine, and 0.08g of sodium borohydride in 30mL of pure water to obtain solution A;

[0042] 2) Transfer solution A to a polytetrafluoroethylene liner, then place it in a stainless steel reactor and react at 180°C for 150 min to obtain solution B;

[0043] 3) Transfer solution B to a 1000D dialysis bag and dialyze for 48 hours to obtain solution C;

[0044] 4) Filter solution C through a 0.45 μm organic filter membrane, then freeze at -60 °C for 4 h, and vacuum dry for 12 h to obtain brown powder D(N,B-CQDs), which is stored at 0 °C for later use.

[0045] Comparative Example 2: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that the preparation method of carbon quantum dots is the same as in Example 1. The total amount of the reaction raw materials mcitric acid + m2-amino-3-hydroxypyridine remains unchanged, but the ratio is changed accordingly. The specific steps are as follows:

[0046] 1) Dissolve 1.16 g of citric acid, 0.183 g of 2-amino-3-hydroxypyridine, and 0.08 g of sodium borohydride in 30 mL of pure water to obtain solution A;

[0047] 2) Transfer solution A to a polytetrafluoroethylene liner, then place it in a stainless steel reactor and react at 180°C for 150 min to obtain solution B;

[0048] 3) Transfer solution B to a 1000D dialysis bag and dialyze for 48 hours to obtain solution C;

[0049] 4) Filter solution C through a 0.45 μm organic filter membrane, then freeze at -60 °C for 4 h, and vacuum dry for 12 h to obtain brown powder D(N,B-CQDs), which is stored at 0 °C for later use.

[0050] Example 4: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that: 1) powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are dissolved in ultrapure water to prepare a 0.15 mg / mL D solution, and its fluorescence intensity is tested and recorded as F0;

[0051] 2) Selenite ions (SeO3) at concentrations of 25 μM, 30 μM, and 35 μM were added. 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0052] Example 5: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that: 1) powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are dissolved in ultrapure water to prepare a 0.2 mg / mL D solution, and its fluorescence intensity is tested and recorded as F0;

[0053] 2) Selenite ions (SeO3) at concentrations of 50 μM, 55 μM, and 65 μM were added. 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0054] Example 6: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that: 1) powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are dissolved in ultrapure water to prepare a 0.5 mg / mL D solution, and its fluorescence intensity is tested and recorded as F0;

[0055] 2) Selenite ions (SeO3) at concentrations of 75 μM and 87.5 μM were added. 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0056] Example 7: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that: 1) powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are dissolved in ultrapure water to prepare a 0.7 mg / mL solution D, and its fluorescence intensity is tested and recorded as F0;

[0057] 2) Selenite ions (SeO3) at concentrations of 40 μM and 45 μM were added. 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0058] Example 8: The fluorescence detection method for inorganic selenium provided in this example is basically the same as that in Example 1, except that: 1) powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are dissolved in ultrapure water to prepare a 0.9 mg / mL solution D, and its fluorescence intensity is tested and recorded as F0;

[0059] 2) Selenite ions (SeO3) at concentrations of 100 μM and 125 μM were added. 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F.

[0060] A comprehensive comparison of the fluorescence intensity of aqueous solutions of solution D (a water-soluble brown powder D(N,B-CQDs)) of the same concentration obtained from Example 1, Comparative Examples 1 and 2 revealed that Example 1 exhibited the best performance, with a fluorescence quantum yield as high as 21%. 2- It has a strong response.

[0061] The present invention provides a fluorescence detection method for inorganic selenium that utilizes nitrogen-boron-doped carbon quantum dots (N,B-CQDs) containing pyridine rings to adsorb SeO3. 2- The fluorescence intensity was significantly enhanced and the position of the maximum emission peak redshifted, making it suitable as a fluorescent probe. The surface of doped carbon quantum dots contains a large number of functional groups such as hydroxyl, carboxyl, and pyridine rings, which can interact with inorganic SeO3. 2- The interaction significantly enhances the fluorescence of N,B-CQDs solutions of a certain concentration and causes a red shift in the position of the maximum emission peak. The corresponding NMR test results are shown in the appendix. Figure 1 This characteristic can be used to achieve the processing of SeO3. 2- This fluorescent probe offers highly efficient detection, effectively distinguishing other anions and organic selenium, making it a rapid, efficient, and highly selective method for detecting inorganic SeO3. 2- This method differs significantly from most commercially available methods for detecting heavy metal ions based on the fluorescence quenching effect of carbon quantum dots. This invention utilizes the fluorescence enhancement of carbon quantum dots to selectively detect inorganic SeO3, thereby detecting selenium. 2- It has advantages such as high sensitivity, less spectral interference, and low cost, and has significant economic and social value.

[0062] Based on the disclosure and teachings of the foregoing specification, those skilled in the art can make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and some modifications and changes to the invention should also fall within the protection scope of the claims of the present invention.

Claims

1. A fluorescence detection method for inorganic selenium, characterized in that, Includes the following steps: S1: Dissolve nitrogen-boron co-doped carbon quantum dot powder in ultrapure water to prepare a solution D of a certain concentration, and test its fluorescence intensity, which is recorded as F0; S2: Different concentrations of SeO3 2- The solution was mixed with solution D to obtain mixed solutions. The fluorescence intensity of each mixed solution was measured and recorded as F. S3: SeO3 2- Using the concentration as the x-axis and the fluorescence growth rate as the y-axis, a linear fit was performed to obtain the regression equation y = kx + b, where y is the fluorescence growth rate, the fluorescence growth rate is F / F0 - 1, and x is the concentration of SeO3. 2- The concentration, k is the slope, and b is the intercept; S4: The test sample containing SeO3 2- The solution was mixed with solution D to obtain the test sample mixture solution. Fluorescence testing was then performed to obtain the fluorescence intensity value of the test sample mixture solution. The fluorescence growth rate of the test sample mixture solution was calculated and substituted into the linear regression equation y = kx + b to calculate the SeO3 content. 2- The concentration; The nitrogen-boron co-doped carbon quantum dot powder is synthesized in one step by a hydrothermal method using a carbon source, a nitrogen source, and a boron source, and is prepared according to the following steps: 1) Dissolve the carbon source citric acid, the nitrogen source 2-amino-3-hydroxypyridine, and the boron source boron-containing compound in pure water in sequence to obtain solution A; 2) Transfer solution A to a polytetrafluoroethylene liner, then place it in a stainless steel reactor and react at 150-180 ℃ for 90-300 min to obtain solution B; 3) Transfer solution B to pure water and dialyze for 24-72 hours to obtain solution C. After filtering and freeze-drying solution C, powdered nitrogen-boron co-doped carbon quantum dots (N,B-CQDs) are obtained and stored for later use.

2. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, In step S1, the mass concentration of solution D is 0.1-1 mg / ml.

3. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, The different SeO3 mentioned in step S2 2- The concentration is 25-125 μM.

4. The fluorescence detection method for inorganic selenium as described in claim 3, characterized in that, In step S2, SeO3 2- The concentration is 50-100 uM.

5. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, The amount of citric acid, the carbon source, used is 0.84-1.16 g.

6. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, The amount of the nitrogen source 2-amino-3-hydroxypyridine used is 0.113-0.50 g.

7. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, The amount of the boron source boron-containing compound used is 0.08-0.30 g.

8. The fluorescence detection method for inorganic selenium as described in claim 1 or 7, characterized in that, The boron source boron-containing compound is at least one of sodium borohydride, boric acid, or borax.

9. The fluorescence detection method for inorganic selenium as described in claim 1, characterized in that, The nitrogen source is a compound with 2-amino-3-hydroxypyridine as its parent nucleus.

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