P-coumarin imprinting fluorescence sensor and preparation method thereof
By using the fluorescent sensor of coumarin imprinting prepared using grapefruit leaf powder, the problem of complexity and cost of coumarin detection in the prior art is solved, and high sensitivity and specific detection is achieved, simplifying the detection process and reducing the cost.
Patent Information
- Application Number
- CN202411532601.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-30
- Publication Date
- 2025-02-07
AI Technical Summary
The detection methods of coumarin in the prior art have problems such as high cost, high complexity, long analysis time and low selectivity, and it is difficult to meet the needs of fast, accurate and reliable detection.
Using grapefruit leaf powder as carbon source, a fluorescent sensor for coumarin blot is prepared by mixing with dimethyl sulfoxide, ethyl orthosilicate and silane coupling agent. The sensor passes carbon quantum dots and porphyria The binding of linear substances enables specific detection of coumarin.
High sensitivity and specific detection of coumarin is achieved, background interference is avoided, strong stability and high accuracy are strong, and the lower detection limit can reach 0.5μg L-1, simplifying the detection process and reducing costs.
Smart Images
Figure CN119394989A_ABST
Abstract
Description
Technical Field
[0001] The present application belongs to the technical field of food safety, and in particular, relates to a coumarin imprinted fluorescent sensor and a preparation method thereof. Background Art
[0002] p-Coumarin (pCA) is a phenolic acid widely distributed in plants and has attracted increasing interest due to its diverse physiological effects (e.g., antioxidant, antimicrobial, anti-inflammatory, antitumor, mutagenic, anti-Alzheimer's, neuroprotective, UV protection) and wide applications (e.g., food, cosmetics, chemical, pharmaceutical industries). Therefore, there is a need to develop rapid, accurate, fast, and reliable analytical methods, as well as sensitive determination of pCA in real samples. So far, a variety of quantitative techniques have been developed, including liquid chromatography-diode array detection (HPLC-DAD), HPLC-mass spectrometry (HPLC-MS), HPLC-e electrochemical detection (HPLC-ECD), ECD, and surface-enhanced Raman spectroscopy (SERS). Although these methods are robust and effective, in some cases, expensive instrumentation, sample pretreatment, and other factors make the detection means complicated, the analysis time is long, and the selectivity is low, which limits their practicality and widespread use. Summary of the invention
[0003] The technical problem to be solved by the present invention is to solve the deficiencies in the prior art, thereby providing an environmentally friendly, low-cost and highly sensitive coumarin imprinted fluorescent sensor and a preparation method thereof.
[0004] The technical solution adopted by the present invention to solve its technical problem is:
[0005] A method for preparing a coumarin imprinted fluorescent sensor comprises the following steps:
[0006] S1: Mix the carbon source and dimethyl sulfoxide, heat and reflux in a dark place to obtain a carbon quantum dot solution, then dialyze and dry to obtain a carbon quantum dot solution, dialyze the carbon quantum dot solution in a dialysis bag under a water environment, and dry the dialysate to obtain carbon quantum dots;
[0007] S2: mixing the carbon quantum dots obtained in step S1 with tetraethyl orthosilicate, a silane coupling agent (aminopropyl triethoxysilane) and p-coumarin to form a carbon quantum dot mixed solution;
[0008] S3: Disperse the carbon quantum dot mixed solution obtained in step S2 in an ethanol solution, wash away the p-coumarin, and obtain a p-coumarin imprinted fluorescent sensor.
[0009] Preferably, in the method for preparing the coumarin imprinted fluorescent sensor of the present invention, in step S1, the carbon source is grapefruit leaf powder.
[0010] Preferably, in the method for preparing the p-coumarin imprinted fluorescent sensor of the present invention, the method for preparing grapefruit leaf powder is: clean the grapefruit leaves, dry them and grind them to obtain the grapefruit leaf powder.
[0011] Preferably, in the method for preparing the coumarin imprinted fluorescent sensor of the present invention, the ratio of the grapefruit leaf powder to dimethyl sulfoxide is 1 g:30-50 mL.
[0012] Preferably, in the method for preparing the p-coumarin imprinted fluorescent sensor of the present invention, the heating reflux environment in step S1 is a vacuum environment, the temperature is 80-90° C., and the time is more than 1 day.
[0013] Preferably, in the method for preparing the p-coumarin imprinted fluorescent sensor of the present invention, in step S2, the ratio of the volume of tetraethyl orthosilicate, the volume of the silane coupling agent 3-aminopropyltriethoxysilane and the mass of p-coumarin is 3:1-1.5:1-1.5, the reaction solvent environment is an ethanol-water mixed solution, and the reaction temperature is 25°C.
[0014] Preferably, in the method for preparing the p-coumarin imprinted fluorescent sensor of the present invention, in step S3, the p-coumarin is washed away by shaking at 40° C.-50° C., and monitored by ultraviolet spectroscopy until the p-coumarin is washed away.
[0015] Preferably, in the method for preparing the coumarin imprinted fluorescent sensor of the present invention, the dialysis in step S2 is performed in a dialysis bag of 500-1000 Da for 12-48 hours.
[0016] Preferably, in the method for preparing the coumarin imprinted fluorescent sensor of the present invention, the heating and reflux of the mixed solution of the carbon source and dimethyl sulfoxide is performed under an environment with a light intensity lower than 0.2 lux.
[0017] A p-coumarin imprinted fluorescent sensor of this embodiment is prepared by the above preparation method.
[0018] The beneficial effects of the present invention are:
[0019] (1) The coumarin imprinted fluorescent sensor of the present application has a specific detection function for coumarin, can effectively avoid background interference of the sample during the detection process, and has the advantages of strong stability and high accuracy.
[0020] (2) The preparation process of the coumarin imprinted fluorescent sensor of the present application uses grapefruit leaf powder as an environmentally friendly green carbon source. Compared with other chemical reagents as carbon sources, the scheme is simpler and more stable. The grapefruit leaf powder contains porphyrin substances that can form double emission peaks, with a small standard deviation and a lower detection limit of 0.5 μg L -1 .
[0021] (3) The present application solves the problems of the current chromatography, mass spectrometry and Raman spectroscopy in some cases, which are complicated detection methods, long analysis time and low selectivity due to expensive instruments, sample pretreatment and other factors. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The technical solution of the present application is further described below in conjunction with the accompanying drawings and embodiments.
[0023] Figure 1 This is the fluorescence spectrum of the coumarin imprinted fluorescent sensor of Example 1.
[0024] Figure 2 This is a fluorescence spectrum diagram of the p-coumarin imprinted fluorescent sensor of Example 1 after adding p-coumarin.
[0025] Figure 3 This is a linear equation diagram after adding p-coumarin to the p-coumarin imprinted fluorescent sensor of Example 1.
[0026] Figure 4 This is the spectrum diagram of the fluorescence sensor of Comparative Example 1. DETAILED DESCRIPTION
[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.
[0028] Example 1
[0029] This embodiment provides a method for preparing a coumarin imprinted fluorescent sensor, comprising the following steps:
[0030] S1: Mix the carbon source-grapefruit leaf powder (1 g) and dimethyl sulfoxide (40 mL) in a distillation flask, and use ultrasound to make the mixture more uniform; reflux by heating in a water bath in a dark room (light intensity is less than 0.2 lux, generally 0.02 lux-0.2 lux) under vacuum environment, heating temperature 85 ° C, reflux time 24h, to obtain a carbon quantum dot solution, and then place it in a 500Da dialysis bag in a water environment for 48h, and dry the dialysate to obtain carbon quantum dots (stored in the dark);
[0031] S2: The carbon quantum dots obtained in step S1 are mixed with tetraethyl orthosilicate, silane coupling agent-aminopropyltriethoxysilane and p-coumarin to form a carbon quantum dot mixed solution; 20 mg of the obtained carbon quantum dots, 120 μL of tetraethyl orthosilicate (TEOS), 40 μL of silane coupling agent 3-aminopropyltriethoxysilane (APTES) and 40 mg of p-coumarin (i.e., v:v:m=3:1:1) are added to 50 mL of a reaction solvent ethanol-water mixed solution for mixed reaction (ethanol: water, v:v=2:8), the reaction temperature is 25°C, and the reaction time is 5 hours (the content of the reaction product can be sampled to detect the reaction product to determine whether the reaction needs to be terminated);
[0032] S3: Ultrasonic dispersion of the carbon quantum dot mixed solution obtained in step S2 in 100% anhydrous ethanol, and washing away the p-coumarin by shaking at 45°C (monitoring the washing effect using ultraviolet spectroscopy) to obtain a p-coumarin imprinted fluorescent sensor - a fluorescent probe with p-coumarin-specific molecular imprinted micropores.
[0033] Example 2
[0034] This embodiment provides a method for preparing a coumarin imprinted fluorescent sensor, comprising the following steps:
[0035] S1: Mix the carbon source-grapefruit leaf powder (1 g) and dimethyl sulfoxide (30 mL) in a distillation flask, and use ultrasound to make the mixture more uniform; reflux by heating in a water bath in a dark room (light intensity is less than 0.2 lux, generally 0.02 lux-0.2 lux) under vacuum environment, heating temperature 80 ° C, reflux time 24h, to obtain a carbon quantum dot solution, and then place it in an 800Da dialysis bag under water environment for 12h, and dry the dialysate to obtain carbon quantum dots (stored in the dark);
[0036] S2: The carbon quantum dots obtained in step S1 are mixed with tetraethyl orthosilicate, silane coupling agent-aminopropyltriethoxysilane and p-coumarin to form a carbon quantum dot mixed solution; 20 mg of the obtained carbon quantum dots, 120 μL of tetraethyl orthosilicate (TEOS), 50 μL of silane coupling agent 3-aminopropyltriethoxysilane (APTES) and 50 mg of p-coumarin (i.e., v:v:m=3:1.25:1.25) are added to 55 mL of a reaction solvent ethanol-water mixed solution for mixed reaction (ethanol:water, v:v=2:8), the reaction temperature is 25°C, and the reaction time is 5 hours (the content of the reaction product can be sampled to detect the reaction product to determine whether the reaction needs to be terminated);
[0037] S3: Ultrasonic dispersion of the carbon quantum dot mixed solution obtained in step S2 in 100% anhydrous ethanol, and washing away the p-coumarin by shaking at 40°C (monitoring the washing effect using ultraviolet spectroscopy) to obtain a p-coumarin imprinted fluorescent sensor - a fluorescent probe with p-coumarin-specific molecular imprinted micropores.
[0038] Example 3
[0039] This embodiment provides a method for preparing a coumarin imprinted fluorescent sensor, comprising the following steps:
[0040] S1: Mix the carbon source-grapefruit leaf powder (1 g) and dimethyl sulfoxide (50 mL) in a distillation flask, and use ultrasound to make the mixture more uniform; reflux by heating in a water bath in a dark room (light intensity is less than 0.2 lux, generally 0.02 lux-0.2 lux) under vacuum environment, heating temperature 90 ° C, reflux time 24h, to obtain a carbon quantum dot solution, and then place it in a 1000Da dialysis bag in a water environment for 36h, and dry the dialysate to obtain carbon quantum dots (stored in the dark);
[0041] S2: The carbon quantum dots obtained in step S1 are mixed with tetraethyl orthosilicate, silane coupling agent-aminopropyltriethoxysilane and p-coumarin to form a carbon quantum dot mixed solution; 20 mg of the obtained carbon quantum dots, 120 μL of tetraethyl orthosilicate (TEOS), 60 μL of silane coupling agent 3-aminopropyltriethoxysilane (APTES) and 60 mg of p-coumarin (i.e., v:v:m=3:1.5:1.5) are added to 60 mL of a reaction solvent ethanol-water mixed solution for mixed reaction (ethanol: water, v:v=2:8), the reaction temperature is 25°C, and the reaction time is 5 hours (the content of the reaction product can be sampled to detect the reaction product to determine whether the reaction needs to be terminated);
[0042] S3: Ultrasonic dispersion of the carbon quantum dot mixed solution obtained in step S2 in 100% anhydrous ethanol, and washing away the p-coumarin by shaking at 50°C (monitoring the washing effect using ultraviolet spectroscopy) to obtain a p-coumarin imprinted fluorescent sensor - a fluorescent probe with p-coumarin-specific molecular imprinted micropores.
[0043] The preparation method of grapefruit leaf powder is as follows: the purchased dried grapefruit leaves (standard grade products of traditional Chinese medicine in Hunan Province) are dried twice at a temperature of 30-45° C., usually for 24 hours, and then ground into powder using a mortar.
[0044] Effect Example
[0045] The p-coumarin imprinted fluorescence sensor prepared by the preparation method of Example 1 was used to quantitatively determine the p-coumarin (p-coumarin had been added in a specific standard amount) in a kiwifruit juice sample. The excitation wavelength was set to 400 nm, the excitation and emission slit widths were both set to 5 nm, and the emission spectrum was set to 420-700 nm.
[0046] Table 1 Quantitative determination of p-coumarin in kiwifruit juice by the p-coumarin imprinted fluorescent sensor prepared in Example 1
[0047]
[0048] The above table shows that the spiked recovery of p-coumarin in kiwifruit juice samples is 97-105%, and the standard deviation is less than 5%, which shows the excellent detection characteristics of the above sensor. Figure 3 As shown, the linear range is 2-200 μg L -1 .
[0049] Comparative Example 1
[0050] The preparation method of the fluorescent sensor of Comparative Example 1 (without using the p-coumarin template label) comprises the following steps:
[0051] S1: Mix the carbon source-grapefruit leaf powder (1 g) and dimethyl sulfoxide (40 mL) in a distillation flask, and use ultrasound to make the mixture more uniform; reflux by heating in a water bath in a dark room (light intensity is less than 0.2 lux, generally 0.02 lux-0.2 lux) under vacuum environment, heating temperature 85 ° C, reflux time 24h, to obtain a carbon quantum dot solution, and then place it in a 500Da dialysis bag in a water environment for 48h, and dry the dialysate to obtain carbon quantum dots (stored in the dark);
[0052] S2: The carbon quantum dots in step S1 are mixed with tetraethyl orthosilicate, silane coupling agent-aminopropyltriethoxysilane and p-coumarin to form a carbon quantum dot mixed solution; 20 mg of the obtained carbon quantum dots, 120 μL of tetraethyl orthosilicate (TEOS), and 40 μL of silane coupling agent 3-aminopropyltriethoxysilane (APTES) (i.e., v:v=3:1) are added to 50 mL of a reaction solvent ethanol-water mixed solution for a mixed reaction (ethanol: water, v:v=2:8), the reaction temperature is 25°C, and the reaction time is 5 hours (the content of the reaction product can be sampled to detect so as to determine whether the reaction needs to be terminated);
[0053] S3: ultrasonically dispersing the carbon quantum dot mixed solution obtained in step S2 in 100% anhydrous ethanol to obtain a p-coumarin imprinted fluorescent sensor - a fluorescent probe having p-coumarin-specific molecular imprinted micropores.
[0054] The above-mentioned fluorescence sensor was used to perform spike recovery determination on p-coumarin in kiwifruit juice. As shown in Table 2, the fluorescence sensor is almost unable to specifically detect p-coumarin because it has no molecular imprinting sites.
[0055] Table 2 Quantitative determination of p-coumarin in kiwifruit juice by the fluorescence sensor of comparative example 1
[0056]
[0057] Comparative Example 2
[0058] According to Example 1, a p-coumarin imprinted fluorescent sensor was prepared. As a control, p-coumarin and molecules similar to p-coumarin were detected to verify the selectivity. As shown in Table 3, the target molecule can be targeted and selected in a mixed solution with a structure similar to p-coumarin and a high recovery rate of 97% can be achieved, indicating that the material prepared in Example 1 has excellent specific selectivity for p-coumarin.
[0059] Table 3 Quantitative determination of p-coumarin and its analogs in kiwifruit juice by p-coumarin imprinted fluorescence sensor
[0060]
[0061] Comparative Example 3
[0062] As comparative example 3, the purchased dried grapefruit peel powder (standard grade product of traditional Chinese medicine in Hunan Province) was used as the carbon source, and the other steps were the same as those in Example 1. The prepared single emission imprinted fluorescent sensor was used to detect the spiked recovery of p-coumarin in kiwi juice. The results are shown in Table 4. The spiked recovery value of the prepared single emission imprinted fluorescent sensor differed from the actual spiked value by more than 10%, and the spiked recovery rate was low, at 84.4-88.5%. In addition, the relative deviation during detection was 6.7-11.3%, indicating that the detection results were unstable during the detection process. In comparison, Example 1 of the present application exhibits better accuracy and stability.
[0063] Table 4 Quantitative determination of p-coumarin in kiwifruit juice by fluorescence sensor
[0064]
[0065] Based on the above ideal embodiments of this application, the relevant staff can make various changes and modifications without departing from the technical concept of this application through the above description. The technical scope of this application is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.
Claims
1. A method for preparing a coumarin imprinted fluorescent sensor, characterized in that: The following steps are involved: S1: Mix the carbon source and dimethyl sulfoxide, heat and reflux in a dark place to obtain a carbon quantum dot solution, then dialyze and dry to obtain a carbon quantum dot solution, dialyze the carbon quantum dot solution in a dialysis bag under a water environment, and dry the dialysate to obtain carbon quantum dots; S2: mixing the carbon quantum dots obtained in step S1 with tetraethyl orthosilicate, a silane coupling agent (aminopropyl triethoxysilane) and p-coumarin to form a carbon quantum dot mixed solution; S3: Disperse the carbon quantum dot mixed solution obtained in step S2 in an ethanol solution, wash away the p-coumarin, and obtain a p-coumarin imprinted fluorescent sensor.
2. The method for preparing the coumarin imprinted fluorescent sensor according to claim 1, characterized in that: In step S1, the carbon source is grapefruit leaf powder.
3. The method for preparing the coumarin imprinted fluorescent sensor according to claim 2, characterized in that: The preparation method of the grapefruit leaf powder is as follows: the grapefruit leaves are cleaned, dried and ground to obtain the grapefruit leaf powder.
4. The method for preparing the coumarin imprinted fluorescent sensor according to claim 3, characterized in that: The ratio of the grapefruit leaf powder to dimethyl sulfoxide is 1 g:30-50 mL.
5. The method for preparing the coumarin imprinted fluorescent sensor according to claim 1, characterized in that: In step S1, the heating reflux environment is a vacuum environment, the temperature is 80-90° C., and the time is more than 1 day.
6. The method for preparing the coumarin imprinted fluorescent sensor according to claim 1, characterized in that: In step S2, the ratio of the volume of tetraethyl orthosilicate, the volume of the silane coupling agent 3-aminopropyltriethoxysilane and the mass of p-coumarin is 3:1-1.5:1-1.5, the reaction solvent environment is an ethanol-water mixed solution, and the reaction temperature is 25°C.
7. The method for preparing the p-coumarin imprinted fluorescent sensor according to claim 1, characterized in that: In step S3, the p-coumarin is washed away by shaking at 40° C.-50° C., and monitored by ultraviolet spectroscopy until the p-coumarin is washed away.
8. The method for preparing the p-coumarin imprinted fluorescent sensor according to claim 1, characterized in that: The dialysis in step S2 is performed in a 500-1000Da dialysis bag for 12-48 hours.
9. The method for preparing the coumarin imprinted fluorescent sensor according to claim 1, characterized in that: The heating and reflux of the mixed solution of the carbon source and dimethyl sulfoxide is carried out in an environment where the light intensity is lower than 0.2 lux.
10. A p-coumarin imprinted fluorescent sensor, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 9.