Sulfur quantum dot fluorescent probe for sunset yellow detection and preparation method thereof
Through the preparation of sulfur quantum dot fluorescent probes, the problem of cumbersome operation and slow response speed of sunset yellow detection method is solved, and the rapid and sensitive detection of sunset yellow is achieved, with good linear range and low detection limits, and it is simple and easy Preparation conditions and long-term effectiveness at room temperature.
Patent Information
- Application Number
- CN202411417677.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-11
- Publication Date
- 2025-01-10
AI Technical Summary
The existing sunset yellow detection methods are cumbersome, have slow response speed, long detection period, and have no reports on the detection method using sulfur quantum dots as fluorescent probes.
Using sulfur quantum dot fluorescent probe, sulfur quantum with spherical structure, excellent water dispersion and photostability were prepared by completely dissolving sodium thiosulfate and β-cyclodextrin in ultrapure water and undergoing high-temperature and high-pressure reaction. Point, used for sensitive detection of sunset yellow.
It realizes fast and sensitive detection of sunset yellow, has good linear range and low detection limits, and is simple and easy to prepare, with long-term effectiveness and anti-interference ability at room temperature.
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Figure CN119286509A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of fluorescence analysis, and particularly relates to a sulfur quantum dot fluorescent probe for sunset yellow detection and a preparation method thereof. Background Art
[0002] Sunset yellow (SY) is one of the common synthetic azo dyes in food coloring. Due to its azo (N@N) functional group and aromatic ring structure, excessive intake of SY is harmful to human health. Therefore, sensitive and quantitative analysis of sunset yellow in food is of great practical significance.
[0003] At present, the methods for detecting sunset yellow include: immunoassay, high performance liquid chromatography (HPLC), electrochemistry, capillary electrophoresis and spectrophotometry. These detection methods not only require complex sample pretreatment, but also have the disadvantages of cumbersome operation, slow response speed and long detection cycle. Compared with other detection methods, fluorescent probes have been widely used in the fields of environment, biomedicine, etc. due to their advantages such as convenient operation and rapid response. On the one hand, sulfur quantum dots, as a new type of non-metallic fluorescent probe, not only have considerable environmental friendliness, but also have good optical properties. Most of the sulfur quantum dots reported use sublimated sulfur powder as a reaction precursor. The insoluble nature of sublimated sulfur powder leads to low synthesis efficiency of sulfur quantum dots. The sulfur quantum dots prepared using sodium thiosulfate as a precursor effectively improve the synthesis efficiency. On the other hand, up to now, there has been no report on the method of using sulfur quantum dots as fluorescent probes for sunset yellow detection. Summary of the invention
[0004] In view of the problems of complicated operation, slow response speed and long detection cycle of current sunset yellow detection methods, the present invention utilizes the luminescence characteristics of sulfur quantum dots to provide a sulfur quantum dot fluorescent probe for sunset yellow detection and a preparation method thereof. The preparation operation is convenient and fast, and the prepared sulfur quantum dots have excellent water dispersibility and light stability, which can realize sensitive detection of sunset yellow in beverages.
[0005] In order to achieve the above object, the present invention adopts the following technical solutions: A sulfur quantum dot fluorescent probe for sunset yellow detection, wherein the sulfur quantum dot fluorescent probe has a spherical structure, a particle size distribution between 1.1 nm and 2.5 nm, and an average particle size of 2.1±0.37 nm.
[0006] Furthermore, the sulfur quantum dot fluorescent probe has a lattice fringe of 0.212 nm.
[0007] Furthermore, the optimal excitation wavelength of the sulfur quantum dot fluorescent probe is at 330 nm, and the optimal emission peak is at 445 nm.
[0008] Furthermore, the linear range of the sulfur quantum dot fluorescent probe for detecting sunset yellow is 0.10 µM~140 µM, and the LOD is as low as 0.0510 μmol / L.
[0009] An efficient preparation method for a fluorescent probe for sunset yellow detection comprises the following steps: adding sodium thiosulfate and beta-cyclodextrin into ultrapure water, completely dissolving the mixture by ultrasound, transferring the mixture to a polytetrafluoroethylene reactor for high temperature and high pressure reaction, filtering and freeze drying, and obtaining the sulfur quantum dots.
[0010] Furthermore, the mass ratio of sodium thiosulfate to β-cyclodextrin is (2-3):(1-1.3).
[0011] Furthermore, the ultrasonic time is 10 min to 15 min.
[0012] Furthermore, the high temperature and high pressure reaction time is 400 min, and the reaction temperature is 170°C.
[0013] Furthermore, the specific step of filtering is: filtering with a 0.22 μm microporous filter membrane.
[0014] Furthermore, the freeze-drying time is 24 h.
[0015] A fluorescent probe for sunset yellow detection is prepared according to the above preparation method.
[0016] The present invention also provides the use of the fluorescent probe in the detection of sunset yellow. Sunset yellow can effectively quench the fluorescence emission of sulfur quantum dots, and sensitive analytical detection of sunset yellow can be achieved according to the change of the fluorescence intensity of the system.
[0017] Furthermore, it is used for the detection of sunset yellow in beverages.
[0018] Compared with the prior art, the present invention has the following advantages: The sulfur quantum dot fluorescent probe provided by the present invention uses sodium thiosulfate as the sulfur source, and the preparation conditions are mild, simple, easy, time-saving and efficient. β-cyclodextrin is used as a passivator for sulfur quantum dots, and its unique cavity structure provides a guarantee for the photostability of sulfur quantum dots. The prepared sulfur quantum dots can still effectively detect sunset yellow after being stored at room temperature for 6 months. The quantitative detection method not only has good sensitivity, but also has considerable anti-interference ability. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a TEM image of the sulfur quantum dots prepared in Example 1 of the present invention.
[0020] Figure 2 This is the XPS graph of the sulfur quantum dots prepared in Example 1 of the present invention.
[0021] Figure 3 The ultraviolet absorption spectrum and fluorescence emission spectrum of the sulfur quantum dots prepared in Example 1 of the present invention.
[0022] Figure 4 This is a fluorescence emission spectrum of the sulfur quantum dots prepared in Example 1 of the present invention detecting sunset yellow.
[0023] Figure 5 This is a linear relationship diagram between the sunset yellow concentration and the fluorescence intensity change of the detection system.
[0024] Figure 6 These are the results of the selectivity and interference evaluation of sulfur quantum dot fluorescent probes. DETAILED DESCRIPTION
[0025] In order to gain a deeper understanding of the present invention, we will provide a comprehensive and detailed description of the present invention. However, the present invention has multiple implementations and is not limited to the specific examples listed herein. The presentation of these examples is intended to deepen the comprehensive understanding of the disclosure of the present invention.
[0026] Example 1 Preparation of sulfur quantum dots 1.0 g of sodium thiosulfate was dissolved in 25.0 mL of ultrapure water, and then 0.50 g of β-cyclodextrin was added. The mixture was stirred until it was clear and transparent, and finally ultrasonicated for 15 min. The mixed solution was transferred to a polytetrafluoroethylene reactor and reacted at a constant temperature of 170 ° C in an oven for 400 min to obtain a brown sulfur quantum dot solution. The sulfur quantum dot stock solution obtained by the above reaction was filtered with a 0.22 μm microporous filter membrane to obtain a light brown sulfur quantum dot solution, which was freeze-dried for 24 h to obtain a sulfur quantum dot fluorescent probe. The quantum yield (based on 0.10 M quinine sulfate) was 0.073.
[0027] Characterization test: The morphology and size of sulfur quantum dot fluorescent probes were analyzed by transmission electron microscopy. Figure 1 The results show that the sulfur quantum dot fluorescent probe prepared by the above method presents spherical particles with good dispersion, and the particle size distribution is between 1.1 nm and 2.5 nm, the average particle size is 2.1±0.37 nm, and the lattice fringes are 0.212 nm. Figure 2 It is shown that the sulfur quantum dots contain four elements: S, C, O, and Na. The peaks at 161.68 eV, 162.88 eV, and 164.08 eV in the high-resolution X-ray photoelectron spectrum of sulfur are characteristic peaks of sulfur, while the characteristic peaks at 167.48 eV, 168.48 eV, and 169.58 eV are attributed to the signal peaks of sulfur oxide species. It can be seen that the sulfur quantum dots are mainly composed of zero-valent sulfur and surface sulfonate and sulfite groups. Figure 3The results show that the ultraviolet absorption peak of the sulfur quantum dots prepared by the above method at 216 nm is the n-σ* transition caused by surface heteroatoms (O, S). Under the excitation of 330 nm, the maximum emission peak appears at 445 nm. In addition, with quinine sulfate (0.10 mol / L H2SO4) solution as a reference, the quantum yield of the sulfur quantum dots is 0.073.
[0028] Example 2 Application of sulfur quantum dots in sunset yellow detection Sunset yellow solutions of different concentrations were added to the sulfur quantum dots prepared in Example 1, and the reaction was carried out at room temperature for 10 min. The fluorescence spectrum thereof was tested under 330 min excitation.
[0029] Depend on Figure 4 It can be seen that with the continuous addition of sunset yellow, the fluorescence emission of the sulfur quantum dots prepared in Example 1 at 445 nm is gradually quenched. Figure 5 It can be seen that the linear range of the sulfur quantum dots prepared in Example 1 for detecting sunset yellow is 0.10-140 μM, and the detection sensitivity is 51 nM.
[0030] Example 3
[0031] The sample beverage containing sunset yellow pigment in the ingredient list was placed in an ultrasonic bath for 15 min to completely extract the colorant, and then the sample solution was filtered through a 0.22 μmol / L microporous filter membrane and the filtrate was collected in a 50 mL volumetric flask. The pretreated beverage was taken as the sample to be tested, and the detection of sunset yellow in the beverage was carried out according to the steps described in Example 2. Subsequently, different concentrations of sunset yellow were added to the treated beverage sample solution, and a spike recovery test was performed. The results are shown in Table 1. As can be seen from Table 1, the spike recovery rate of sunset yellow in the beverage sample was 97.6% to 105%, and the relative standard deviation was less than 2.16%. The above results show that the sulfur quantum dots can be used as a highly sensitive fluorescent probe for the analysis and detection of sunset yellow in beverages.
[0032] Table 1
[0033] Example 4
[0034] In order to explore the selectivity and interference of sulfur quantum dot fluorescent probe in detecting SY, a variety of cations and anions (K + , Ca 2+ 、Na + Mg 2+ 、Al 3+ 、Zn 2+ , Fe 3+ , Mn 2+ 、CO3 2- , Cl﹣ ), some common molecules (serine, asparagine, cysteine, leucine) and common pigments (β-carotene, chlorophyll, curcumin, lemon yellow) were evaluated as interfering species. The results showed that most of the above-mentioned interfering substances had almost no effect on the detection of sunset yellow, and only SY could cause a significant change in the fluorescence intensity of Ⅰ-β-SQDs; while detecting SY, the above-mentioned interfering substances were introduced into the detection system to verify the anti-interference ability of sulfur quantum dot fluorescent probe in detecting curcumin. Figure 6 As shown, (the concentrations of sunset yellow and other interferents are 30 μmol / L and 3 μM, respectively. The dark blue bar represents the response of the sensing system to specific interfering species. The light blue bar shows the response of the sensing system in the presence of 30 μmol / L sunset yellow and 3 μmol / L corresponding interferents) When the interfering substances coexist with SY, the effect of most of the interfering substances on the detection of SY by sulfur quantum dot fluorescent probe is negligible, which indicates that the sulfur quantum dot fluorescent probe has good selectivity and anti-interference ability in detecting sunset yellow.
[0035] The contents not described in detail in the specification of the present invention belong to the prior art known to the professional and technical personnel in the field. Although the illustrative specific embodiments of the present invention are described above to facilitate the understanding of the present invention by the technical personnel in the field, it should be clear that the present invention is not limited to the scope of the specific embodiments. For the ordinary technical personnel in the field, as long as various changes are within the spirit and scope of the present invention defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.
Claims
1. A sulfur quantum dot fluorescent probe for sunset yellow detection, characterized in that: The sulfur quantum dot fluorescent probe has a spherical structure, a particle size distribution between 1.1 nm and 2.5 nm, and an average particle size of 2.1±0.37 nm.
2. A sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 1, characterized in that: The sulfur quantum dot fluorescent probe has a lattice fringe of 0.212 nm.
3. The sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 1, characterized in that: The optimal excitation wavelength of the sulfur quantum dot fluorescent probe is at 330 nm, and the optimal emission peak is at 445 nm.
4. The sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 1, characterized in that: The linear range of the sulfur quantum dot fluorescent probe for detecting sunset yellow is 0.10 µM~140 µM, and the LOD is as low as 0.0510 μmol / L.
5. The method for preparing a sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 1, characterized in that: Sodium thiosulfate and β-cyclodextrin are added into ultrapure water, and after being completely dissolved by ultrasound, the mixed solution is transferred to a polytetrafluoroethylene reactor for high temperature and high pressure reaction, and the sulfur quantum dots are obtained after filtering and freeze drying.
6. The method for preparing a sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 5, characterized in that: The mass ratio of the sodium thiosulfate to β-cyclodextrin is (2-3):(1-1.3).
7. The method for preparing a sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 5, characterized in that: The ultrasonic time is 10 min to 15 min; the filtration is specifically carried out by filtering with a 0.22 μm microporous filter membrane; and the freeze-drying time is 24 h.
8. The method for preparing a sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 5, characterized in that: The high temperature and high pressure reaction time is 400 min, and the reaction temperature is 170°C.
9. Use of a sulfur quantum dot fluorescent probe for sunset yellow detection prepared according to the preparation method according to any one of claims 5 to 8 in sunset yellow detection.
10. The use of a sulfur quantum dot fluorescent probe for sunset yellow detection according to claim 9 in sunset yellow detection, characterized in that: Used for the detection of sunset yellow in beverages.