Fluorescent probe for rapidly detecting acetylene and preparation method thereof

Abstract

The invention discloses a fluorescent probe for rapidly detecting acetylene, the fluorescent probe is a metal nanocluster solution, and the metal nanocluster solution has a fluorescence emission peak and is used for being in contact with acetylene to generate static fluorescence quenching. The invention further discloses a preparation method, the problems that an existing gas chromatography technology for detecting acetylene is long in consumed time, high in operation specialty and high in cost are solved, and the glutathione modified copper nanocluster solution has high sensitivity and linear response, can detect acetylene in a low concentration range (such as 0.26 nL / L-26000 mu L / L) and has a good linear relation. The stability of the GSH-Cu NCs solution is good, the probe solution can be stored for a long time, and the fluorescence lifetime is stable. The glutathione modified copper nanocluster solution has strong anti-interference capability, and the GSH-Cu NCs solution has the advantages of high detection speed, simple and convenient acetylene detection operation, low cost and no need of complex instruments, and is suitable for field use.

Description

Technical Field

[0001] This invention relates to the field of rapid acetylene detection technology, specifically to a fluorescent probe for rapid detection of acetylene and its preparation method. Background Technology

[0002] Acetylene ( It is a key gas in transformer oil that indicates high-energy discharge faults. Its concentration ≥1μL / L can trigger an early warning, which is crucial for the safe operation of the power grid.

[0003] Currently, commonly used detection methods include traditional analytical techniques such as gas chromatography (GC). For example, Chinese invention patent application number CN201711164435.X discloses a method for determining trace amounts of propadiene and acetylene in MTO products using gas chromatography. In this method, trace amounts of acetylene in the MTO sample are completely separated from an unknown component, ensuring that the determination of acetylene is not interfered with and guaranteeing the accuracy of the detection results.

[0004] However, while this method is accurate, it has the following obvious shortcomings: long time consumption: a complete GC analysis usually takes about 2 hours, making it impossible to achieve real-time or rapid on-site detection; complex equipment: it relies on large instruments, requires highly specialized operation, and is not suitable for rapid on-site diagnosis; cumbersome sample processing: it requires multiple steps such as gas extraction and sample injection, making the process complex; and high cost: the cost of instrument maintenance and consumables is high, which is not conducive to large-scale or frequent use.

[0005] Therefore, there is a need to develop a fluorescent probe and preparation method that can quickly detect acetylene to deal with sudden transformer failures, and that is simple to operate and has low cost. Summary of the Invention

[0006] The technical problem to be solved by the present invention is that the existing gas chromatography technology for detecting acetylene is time-consuming, requires high professional expertise and is costly. The purpose is to provide a fluorescent probe for rapid detection of acetylene and its preparation method.

[0007] This invention is achieved through the following technical solution: In a first aspect, the present invention provides a fluorescent probe for rapid detection of acetylene, characterized in that the fluorescent probe is a metal nanocluster solution, the metal nanocluster solution having a fluorescence emission peak and being used to induce static fluorescence quenching upon contact with acetylene.

[0008] In some alternative embodiments, the metal nanocluster solution is a glutathione-modified copper nanocluster solution.

[0009] Secondly, a method for preparing a fluorescent probe for rapid detection of acetylene includes the following steps: Prepare reducing aqueous solutions; Preparation of aqueous solutions of transition metals; The reducing aqueous solution, the transition metal aqueous solution, and the pH buffer solution were mixed and reacted, and the mixture was stirred at 55°C for 5 hours to obtain a metal nanocluster solution with a fluorescence emission peak.

[0010] In some optional embodiments, the reducing aqueous solution is a GSH aqueous solution, the transition metal aqueous solution is a copper nitrate aqueous solution, and the pH buffer solution is a potassium hydrogen phthalate buffer solution.

[0011] Thirdly, the present invention provides a method for rapid detection of acetylene, using the above-described fluorescent probe or the fluorescent probe prepared above, comprising the following steps: The gas sample to be tested is brought into contact with a certain amount of the fluorescent probe solution in a sealed container and then shaken to mix. Let the reaction stand for a period of time; Detect the fluorescence intensity of the solution after the reaction; The concentration of acetylene in the gas sample to be tested is quantitatively determined based on the degree of quenching of the fluorescence intensity.

[0012] In some alternative implementations, the gas sample to be tested includes headspace gas extracted from transformer insulating oil.

[0013] In some alternative implementations, the settling time does not exceed 3 minutes.

[0014] In fact, the inventors have demonstrated through experiments that the reaction time for static fluorescence quenching between GSH-Cu NCs solution and acetylene is very short. The 3-minute setting in this application can ensure that GSH-Cu NCs solution and acetylene react fully.

[0015] In some alternative implementations, the detectable acetylene concentration range is 0.26 nL / L–26000 μL / L.

[0016] Fourthly, the present invention provides the use of the above-described fluorescent probe or the fluorescent probe prepared therefrom in the preparation of reagents or kits for detecting transformer faults.

[0017] Fifthly, the present invention provides an application of the above-described fluorescent probe or the fluorescent probe prepared above in the detection of acetylene.

[0018] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The fluorescent probe for rapid detection of acetylene provided by the present invention has high sensitivity and linear response, and can detect acetylene in a low concentration range (e.g., 0.26 nL / L–26000 μL / L) with good linearity.

[0019] 2. The fluorescent probe for rapid detection of acetylene provided by this invention exhibits strong anti-interference capabilities. Experiments have demonstrated that this fluorescent probe is highly resistant to interference. CO , , , Common gases showed no significant response.

[0020] 3. Good stability of probe solution: The probe solution can be stored for a long time and the fluorescence lifetime is stable.

[0021] 4. The probe solution offers fast detection speed and simple operation for acetylene detection. It is low-cost and requires no complex instruments, making it suitable for field use.

[0022] The technical principle of this invention is as follows: Using acetylene as a quencher and glutathione-modified copper nanoclusters solution as a fluorescent probe, fluorescence quenching is achieved through the specific interaction between acetylene and GSH-Cu NCs solution. The quenching mechanism is static quenching.

[0023] Quantification was then achieved through the linear relationship between fluorescence intensity change (quenching rate) and acetylene concentration. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the exemplary embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of the present invention and should not be considered as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is a linear regression curve obtained by reacting the copper nanocluster solution of the present invention with acetylene at different concentrations; Figure 2 The fluorescence spectra of the copper nanocluster solution of the present invention reacted with acetylene at different concentrations. Figure 3 This is a comparison chart of the quenching rates obtained by reacting various interfering gases with copper nanocluster solutions according to the present invention; Figure 4 This is a fluorescence intensity decay diagram after the copper nanocluster solution of the present invention interacts specifically with acetylene; Figure 5 This is a fluorescence lifetime curve of the copper nanocluster solution of the present invention before and after the reaction with acetylene; Figure 6 This is a fluorescence lifetime fitting curve of the copper nanocluster solution of the present invention before and after the reaction with acetylene; Figure 7This is the ultraviolet absorption spectrum of the copper nanocluster solution after reacting with acetylene according to the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0026] Throughout this specification, references to "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "an embodiment," "an example," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described herein, as well as the features of those different embodiments or examples.

[0027] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60–120 and 80–110 are listed for a specific parameter, it is understood that ranges of 60–110 and 80–120 are also expected. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1–3, 1–4, 1–5, 2–3, 2–4, and 2–5. In this application, unless otherwise stated, the numerical range "a–b" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0~5" indicates that all real numbers between "0~5" have been listed in this article; "0~5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0028] Example 1: Preparation of Fluorescent Probe This invention provides a fluorescent probe for rapid detection of acetylene, wherein the fluorescent probe is a metal nanocluster solution, the metal nanocluster solution having a fluorescence emission peak and being used to induce static fluorescence quenching upon contact with acetylene.

[0029] Static quenching relies on the ground-state specific binding of fluorescent molecules to quenchers. Only substances that can form ground-state complexes with fluorescent molecules can trigger quenching; non-specific substances (such as irrelevant ions and impurities) cannot trigger it.

[0030] In addition, the fluorescence intensity decreases with the increase of quencher concentration (acetylene concentration in this example), but the fluorescence lifetime remains basically unchanged (because the free fluorescent molecules in the excited state are not affected, their decay kinetics are still normal, only their number decreases).

[0031] Furthermore, the metal nanocluster solution is a glutathione-modified copper nanocluster solution (GSH-Cu NCs).

[0032] Regarding the preparation of fluorescent probes: Prepare a 25 mg / mL GSH aqueous solution; Prepare a 1 mmol / L copper nitrate aqueous solution; Mix 25 mL of GSH aqueous solution with 2.5 mL of copper nitrate solution, add 22 mL of potassium hydrogen phthalate buffer solution with a pH of 4.003; stir the reaction at 55 °C for 5 hours to obtain a GSH-Cu NCs solution with fluorescent properties.

[0033] As can be seen, the synthesis method of fluorescent probes is simple, the raw materials are readily available and the preparation cost is low, and the amount of sample required for detection is small, making them suitable for rapid detection of acetylene and possessing great market potential.

[0034] Based on the specific interaction between GSH-Cu NCs solution and acetylene, GSH-Cu NCs solution can also be used in the preparation of reagents or kits for detecting transformer faults. Specifically, the glutathione (GSH) on the surface of GSH-Cu NCs contains thiol (-SH) and amino groups (-SH). Functional groups such as ) can react with acetylene ( The unsaturated carbon bonds in the nanoclusters form π-π stacking or coordination, leading to changes in the electronic structure of the nanoclusters and significant quenching of fluorescence intensity (mainly static quenching, with essentially no change in fluorescence lifetime); while nitrogen gas normally present in transformer oil ( ),oxygen( No response ensures specificity of the test. The GSH-Cu NCs test kit covers three core scenarios: routine inspection of transformers, fault diagnosis, and aging assessment, providing technical support for the safe operation of power systems. Example 2

[0035] This embodiment was used to verify the high sensitivity and linear response of the GSH-Cu NCs solution. The concentration range of acetylene was selected as 0.26 nL / L-26000 μL / L, specifically 0.00026 ppm acetylene (concentration of 0.26 nL / L), 0.0026 ppm acetylene, 0.026 ppm acetylene, 0.26 ppm acetylene, 2.6 ppm acetylene, 26 ppm acetylene, 260 ppm acetylene, 2600 ppm acetylene, and 26000 ppm acetylene.

[0036] The specific operation process is as follows: Add 1 mL of the GSH-Cu NCs solution prepared in Example 1 to the headspace vial and cap it.

[0037] Add acetylene gas or blank gas (pure nitrogen or argon) of different concentrations to the headspace vial using a microsyringe. After shaking and mixing, let stand for 3 minutes to ensure a complete reaction.

[0038] Pour the completed reaction solution into a cuvette and detect its fluorescence value using a fluorescence spectrophotometer.

[0039] Specifically, a fluorescence spectrophotometer is used to detect fluorescence intensity, providing continuous wavelengths of excitation light covering the estimated excitation peak range, with the scan range set to 420-520 nm. For example... Figure 2 As shown, the final fluorescence spectra of GSH-CuNCs solution and GSH-CuNCs solution with different concentrations of acetylene under fluorescence quenching were obtained, with wavelength as the x-axis and fluorescence intensity as the y-axis. The graph shows that the fluorescence emission peak is strongest at 450 nm. Under the same wavelength conditions, the higher the acetylene concentration, the lower the fluorescence intensity. Furthermore, the GSH-CuNCs solution still exhibits detection capability at an acetylene concentration of 0.26 nL / L, demonstrating the high sensitivity of the GSH-CuNCs solution.

[0040] The method for quantifying acetylene concentration by the degree of fluorescence quenching is as follows: A fluorescence standard curve was plotted using the changes in fluorescence intensity at different acetylene concentrations. Stable fluorescence values ​​were recorded at each concentration at a wavelength of 450 nm. A linear regression function was plotted with acetylene concentration on the x-axis and the corresponding fluorescence value on the y-axis, as shown below. Figure 1 As shown, the standard curve exhibits good linearity. >0.99.

[0041] This function allows for the quantitative calculation of acetylene concentration in the sample by measuring the final fluorescence intensity. Example 3

[0042] This embodiment is used to verify the high selectivity and anti-interference properties of GSH-Cu NCs solution. Hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane and propylene gases were selected as comparisons to investigate whether the above gases would cause fluorescence quenching with GSH-Cu NCs solution.

[0043] The operation process in this embodiment is as follows: Add 1 mL of the GSH-Cu NCs solution prepared in Example 1 to the headspace vial and cap it.

[0044] Using a microsyringe, add hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, propylene, or acetylene gas to the headspace vial, shake to mix, and let stand for 3 minutes to react.

[0045] Pour the completed reaction solution into a cuvette and detect the fluorescence value using a fluorescence spectrophotometer.

[0046] Specifically, the fluorescence value (reflecting fluorescence intensity) of the original GSH-Cu NCs solution was first measured using a fluorescence spectrophotometer. Then, following the steps, different gases of the same concentration were introduced into the headspace flask clock, and the stable fluorescence values ​​F after the different gases reacted with the GSH-Cu NCs solution were recorded. The fluorescence quenching rate Q was calculated according to the formula: Q = ( - F) / × 100%.

[0047] like Figure 3 As shown, the quenching rates of gases such as hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, and propylene are all close to 1. Therefore, it can be concluded that the GSH-Cu NCs solution has no significant response to gases such as hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, and propylene, but exhibits a specific interaction with acetylene, resulting in significant fluorescence quenching. This also demonstrates that the GSH-Cu NCs solution has high selectivity for acetylene and no response to interfering factors such as hydrogen, carbon monoxide, carbon dioxide, methane, ethane, ethylene, propane, and propylene, exhibiting strong anti-interference properties. Example 4

[0048] This embodiment compares with traditional detection methods to verify the reliability of the data.

[0049] Specifically, the method for detecting acetylene concentration in this embodiment is as follows: 5 mL of nitrogen gas was added to 40 mL of insulating oil as a balance gas, and the mixture was shaken at 50 °C for 30 min. The shaken gas was then collected and used as the gas to be tested.

[0050] Add 1 mL of the GSH-Cu NCs solution prepared in Example 1 to the headspace vial and cap it.

[0051] Inject 1 mL of the gas to be tested using a microsyringe. The gas to be tested is divided into three groups: sample 1, sample 2 and sample 3. Shake and let stand for 3 min.

[0052] The reacted solution was poured into a cuvette, and the fluorescence values ​​were measured using a fluorescence spectrophotometer. The final acetylene concentration was determined based on the linear regression function obtained in Example 2.

[0053] The existing methods for detecting acetylene concentration are as follows: 1 mL of shaken gas was injected into a standard gas chromatograph (GC) for detection. The standard CC concentrations of samples 1, 2 and 2 were all 0.2 μL / L. The final results are shown in Table 1.

[0054] Table 1 Comparison of detection concentrations between standard gas chromatography and this embodiment

[0055] The two methods were compared. A t-test was performed, which essentially assesses the reliability of the difference by quantifying the difference between the means of the two sets of data and the degree of fluctuation in the data itself. Ultimately, no significant difference was found between the standard gas chromatography and the detection methods of this embodiment. This demonstrates that the method described in this embodiment is feasible for the quantitative detection of acetylene concentration. Example 5

[0056] This embodiment is used to verify the stability of the GSH-Cu NCs solution. It should be noted that in Examples 2-4, the reaction time for both the gas and the GSH-Cu NCs solution was set to 3 minutes to ensure sufficient reaction. However, the inventors found during the experiment that the specific interaction time between acetylene and the GSH-Cu NCs solution was very short, therefore the following stability test was conducted.

[0057] The specific operation process is as follows: Add 1 mL of the LGSH-Cu NCs solution prepared in Example 1 to the headspace vial and cap it.

[0058] Timing was then started, and acetylene gas was injected through a micro-syringe at 15 seconds. Fluorescence values ​​were measured every 15 seconds to determine its stability.

[0059] like Figure 4As shown, after the fluorescence quenching of acetylene by the GSH-Cu NCs solution, the fluorescence value fluctuates only slightly and remains essentially unchanged for a period of time (data was measured every 15 seconds in this example, up to 300 seconds). This demonstrates the good stability of the GSH-Cu NCs solution, allowing the probe solution to be stored for a long time and ensuring accurate detection of acetylene concentration.

[0060] In addition, this example compares the fluorescence lifetime before and after the reaction, and uses professional software to perform exponential fitting on the decay curves, such as... Figure 5 and Figure 6 As shown, the fluorescence lifetime curves of GSH-Cu NCs and GSH-Cu NCs+ can be observed. The fluorescence lifetime follows an exponential decay law, indicating that the fluorescence lifetime is good before and after the reaction. Example 6

[0061] This embodiment is used to determine the type of fluorescence quenching by studying the ultraviolet spectra before and after the reaction.

[0062] Figure 7 The UV absorption spectra of GSH solution, copper nitrate solution, GSH-Cu solution, and GSH-Cu solution after the addition of acetylene are shown. The spectra reveal that the UV absorption of both substances is very low before synthesis. After the synthesis of GSH-Cu, the UV absorption at 280 nm increases significantly. Upon reaction with acetylene, the UV absorption decreases significantly.

[0063] The above experiments further demonstrate that the GSH-Cu NCs solution has a specific effect on acetylene upon contact, leading to static quenching rather than dynamic quenching.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fluorescent probe for rapid detection of acetylene, characterized in that, The fluorescent probe is a metal nanocluster solution, which has a fluorescence emission peak and is used to induce static fluorescence quenching upon contact with acetylene.

2. The fluorescent probe for rapid detection of acetylene according to claim 1, characterized in that, The metal nanocluster solution is a glutathione-modified copper nanocluster solution.

3. A method for preparing a fluorescent probe for rapid detection of acetylene, characterized in that, Includes the following steps: Prepare reducing aqueous solutions; Preparation of aqueous solutions of transition metals; The reducing aqueous solution, the transition metal aqueous solution, and the pH buffer solution were mixed and reacted, and the mixture was stirred at 55°C for 5 hours to obtain a metal nanocluster solution with a fluorescence emission peak.

4. The method for preparing a fluorescent probe for rapid detection of acetylene according to claim 3, characterized in that, The reducing aqueous solution is a GSH aqueous solution, the transition metal aqueous solution is a copper nitrate aqueous solution, and the pH buffer solution is a potassium hydrogen phthalate buffer solution.

5. A method for rapid detection of acetylene, characterized in that, The application of the fluorescent probe according to claim 1 or 2, or the fluorescent probe prepared according to claim 3 or 4, includes the following steps: The gas sample to be tested is brought into contact with a certain amount of the fluorescent probe solution in a sealed container and then shaken to mix. Let the reaction stand for a period of time; Detect the fluorescence intensity of the solution after the reaction; The concentration of acetylene in the gas sample to be tested is quantitatively determined based on the degree of quenching of the fluorescence intensity.

6. The method for rapid detection of acetylene according to claim 5, characterized in that, The gas sample to be tested includes headspace gas extracted from transformer insulating oil.

7. The method for rapid detection of acetylene according to claim 5, characterized in that, The reaction time should not exceed 3 minutes.

8. The method for rapid detection of acetylene according to claim 5, characterized in that, The detectable concentration range of acetylene is 0.26 nL / L–26000 μL / L.

9. Use of a fluorescent probe according to claim 1 or 2, or a fluorescent probe prepared according to claim 3 or 4, in the preparation of a reagent or kit for detecting transformer faults.

10. The use of a fluorescent probe according to claim 1 or 2, or a fluorescent probe prepared according to claim 3 or 4, in the detection of acetylene.

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