Preparation method of ureidopyrimidone / rosin fluorescent film for phytic acid detection

Abstract

The invention discloses a method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection, which uses rosin A and ureidopyrimidone as carbon sources to prepare fluorescent carbon dots, then uses rosin B as a building block, and the fluorescent carbon dots as sensing active sites, and constructs a ureidopyrimidone / rosin-based fluorescent film under the mediation of ureidopyrimidone molecules. The preparation method of the invention is simple, easy to operate, has abundant raw material sources, is low in price, and the prepared ureidopyrimidone / rosin fluorescent film has good stability, and can be detected by Cd 2+ The fluorescence can be adjusted in an “on-off-on” mode to detect phytic acid with high sensitivity and good selectivity.

Description

Technical Field

[0001] The invention belongs to the field of natural product detection, and in particular relates to a method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection. Background Art

[0002] Phytic acid has a six-membered ring and a polyhydroxy structure, and contains 12 hydroxyl groups and 6 phosphate groups on its end groups. It can form complexes with heavy metal ions, and the phosphate group of phytic acid has a strong ability to chelate heavy metal ions. However, since phytic acid is water-soluble, phytates entering the environment can easily lead to eutrophication of water bodies. On the other hand, phytic acid and phytates are difficult to be absorbed by organisms, which will affect the bioavailability of trace elements and the absorption of protein, fat, and starch. In view of the important impact of phytic acid on the environment and organisms, accurate detection of phytic acid is particularly important.

[0003] Commonly used methods for phytic acid detection include nuclear magnetic resonance, high performance liquid chromatography, inductively coupled plasma mass spectrometry, and Raman spectroscopy. However, the nuclear magnetic resonance method has a long detection time, poor selectivity, and high cost; the high performance liquid chromatography instrument is expensive; the sample pretreatment of inductively coupled plasma mass spectrometry is complicated; and the Raman spectroscopy method has low accuracy. Fluorescence analysis shows great potential in phytic acid detection due to its good selectivity, high sensitivity, and short response time, but homogeneous fluorescence sensing is easy to contaminate the system to be tested and cannot be reused. Therefore, the key problem that needs to be solved in phytic acid fluorescence detection is how to design the composition and structure of the fluorescent film to achieve high sensitivity and high responsiveness detection of phytic acid. Summary of the invention

[0004] In order to solve the shortcomings of the existing phytic acid detection method, the present invention provides a method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection. The method uses rosin as a building block, introduces ureidopyrimidone as a control unit into rosin, and uses fluorescent carbon dots as sensing units to construct a fluorescent film rich in molecular channels and effective sensing sites. The fluorescent film can achieve high sensitivity and high selectivity detection of phytic acid.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection comprises the following steps:

[0007] (1) dissolving rosin A in ethanol to form a uniform rosin ethanol solution, then adding ureidopyrimidone, heating and reacting for a certain period of time in an airtight condition, and then filtering, dialyzing and concentrating the reaction product to obtain fluorescent carbon dots;

[0008] (2) Rosin B is dissolved in dichloroethane to form a rosin dichloroethane solution, and ureidopyrimidone and the fluorescent carbon dots prepared in step (1) are added respectively. After condensation reflux reaction under nitrogen atmosphere, the reaction product is injection molded and refrigerated, and then subjected to freeze-thaw cycles to form a ureidopyrimidone / rosin fluorescent film.

[0009] Furthermore, the rosin A in step (1) is any one of hydrogenated rosin and disproportionated rosin; the concentration of the formed rosin ethanol solution is 0.1wt%-1wt%, and the mass ratio of the ureidopyrimidone to the rosin ethanol solution is 1:30-1:90.

[0010] Furthermore, the heating reaction in step (1) is carried out at a temperature of 200-230° C. and for a time of 6-12 hours.

[0011] Furthermore, the rosin B in step (2) is any one of maleic rosin and polymerized rosin; the concentration of the formed rosin dichloroethane solution is 1.5wt%-3wt%, the mass ratio of the ureidopyrimidone to the rosin dichloroethane solution is 1:20-1:50, and the mass ratio of the fluorescent carbon dots to the rosin dichloroethane solution is 1:50-1:100.

[0012] Furthermore, the temperature of the condensation reflux reaction in step (2) is 100-130° C. and the time is 3-5 hours.

[0013] Furthermore, the freeze-thaw cycle in step (2) is first freezing at -20°C for 6-8 h, then thawing at 3-8°C for 6-8 h, and repeating this process 3-5 times.

[0014] The fluorescent carbon dots in the fluorescent film contain carboxyl groups on their surface, which can react with Cd 2+ Photoinduced electron transfer occurs between the two, resulting in fluorescence quenching of the fluorescent film, while phytic acid and Cd 2+ The interaction can inhibit Cd 2+ The light-induced electron transfer process between the fluorescent carbon dots and the fluorescent film can restore the fluorescence, and the degree of fluorescence recovery increases with the increase of phytic acid concentration. Therefore, phytic acid can be used to treat Cd 2+ The strong complexation of the fluorescent film restores the fluorescence, thereby achieving highly selective and sensitive detection of phytic acid.

[0015] The detection includes the following steps:

[0016] 1) The ureidopyrimidone / rosin fluorescent film is placed in a Cd(NO3)2 solution for 20 minutes to quench its fluorescence, and then a series of phytic acid solutions of known concentrations are added, mixed evenly and placed for 20 minutes, and the fluorescence intensity before and after the addition of the phytic acid solution is measured by a fluorescence spectrophotometer, and a relationship curve between the relative change value of the fluorescence intensity ((P0-P) / P) and the concentration of the phytic acid solution is plotted;

[0017] 2) The ureidopyrimidone / rosin fluorescent film is placed in the same Cd(NO3)2 solution for 20 minutes, and then the phytic acid solution to be tested is added, mixed evenly and allowed to stand for 20 minutes, and the fluorescence intensity before and after the addition of the phytic acid solution is measured using a fluorescence spectrophotometer, and the phytic acid content in the solution is calculated using the relationship curve between the relative change value of the fluorescence intensity obtained in step 1) and the concentration of the phytic acid solution.

[0018] The significant advantages of the present invention are:

[0019] The invention efficiently prepares fluorescent carbon dots based on ureidopyrimidone and rosin, and uses the hydrophobic tricyclic phenanthrene rigid structure of rosin as a building block, the fluorescent carbon dots as a sensing unit, and the ureidopyrimidone as a regulating assembly unit to prepare a ureidopyrimidone / rosin fluorescent film. The preparation method of the invention is simple, easy to operate, and has abundant raw material sources and low prices. The prepared ureidopyrimidone / rosin fluorescent film has good stability, high detection sensitivity and good selectivity for phytic acid. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 An atomic force microscope image of the fluorescent carbon dots prepared in Example 1;

[0021] Figure 2 This is a scanning electron microscope image of the ureidopyrimidone / rosin fluorescent film prepared in Example 1;

[0022] Figure 3 This is a curve showing the change in relative fluorescence intensity ((P0-P) / P) of the ureidopyrimidone / rosin fluorescent film prepared in Example 3 to different concentrations of phytic acid (P represents the fluorescence intensity before adding phytic acid, and P0 represents the fluorescence intensity after adding phytic acid). DETAILED DESCRIPTION

[0023] A method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection comprises the following steps:

[0024] (1) dissolving rosin A in ethanol to form a uniform rosin ethanol solution with a concentration of 0.1wt%-1wt%, then adding ureidopyrimidone at a mass ratio of 1:30-1:90 to the rosin ethanol solution, and transferring to a high-pressure reactor, heating at 200-230°C for 6-12h in an air-tight condition, and then filtering, dialyzing, and concentrating the reaction product to obtain fluorescent carbon dots;

[0025] (2) Rosin B is dissolved in dichloroethane to form a rosin dichloroethane solution with a concentration of 1.5 wt% to 3 wt%, and ureidopyrimidone and the fluorescent carbon dots prepared in step (1) are added in a mass ratio of 1:20 to 1:50 and 1:50 to 1:100 to the rosin dichloroethane solution, respectively. The reaction is refluxed at 100 to 130° C. for 3 to 5 hours under a nitrogen atmosphere, and the reaction product is injection molded and refrigerated, and then subjected to a freeze-thaw cycle to form a ureidopyrimidone / rosin fluorescent film.

[0026] Wherein, the rosin A is any one of hydrogenated rosin and disproportionated rosin; and the rosin B is any one of maleated rosin and polymerized rosin.

[0027] The freeze-thaw cycle described in step (2) is to first freeze at -20°C for 6-8 h, then thaw at 3-8°C for 6-8 h, and repeat this process 3-5 times.

[0028] In order to make the contents of the present invention easier to understand, the technical solution of the present invention is further described below in conjunction with specific implementation methods, but the present invention is not limited thereto.

[0029] Example 1

[0030] (1) 3 g of disproportionated rosin was dissolved in 500 mL of ethanol to form a uniform disproportionated rosin solution. Then 60 g of the disproportionated rosin solution was added with 2 g of ureidopyrimidone and transferred to a high-pressure reactor. The reaction was carried out at 200 °C for 12 h under air-tight conditions. The reaction product was taken out for filtration, dialysis and concentration to obtain fluorescent carbon dots.

[0031] (2) Dissolve 3 g of maleic rosin in 140 mL of dichloroethane, then take out 20 g, add 1 g of ureidopyrimidone and 0.3 g of fluorescent carbon dots, and reflux at 100 °C for 5 h under nitrogen atmosphere. The reaction product is injection molded and refrigerated, and then cyclic freeze-thaw cycles are used to form a ureidopyrimidone / rosin fluorescent film.

[0032] Figure 1 This is an atomic force microscope image of the fluorescent carbon dots prepared in this example. Figure 1 As shown, the obtained fluorescent carbon dots are spherical nanoparticles which are evenly dispersed.

[0033] Figure 2This is a scanning electron microscope image of the ureidopyrimidone / rosin fluorescent film prepared in this example. Figure 2 As shown, the internal pore structure of the obtained fluorescent film is well developed and forms a uniform three-dimensional network structure.

[0034] Example 2

[0035] (1) 2 g of hydrogenated rosin was dissolved in 260 mL of ethanol to form a uniform hydrogenated rosin solution. Then 90 g of the hydrogenated rosin solution was added with 1 g of ureidopyrimidone and transferred to a high-pressure reactor. The reaction was carried out at 230 ° C for 6 h under air-tight conditions. The reaction product was taken out for filtration, dialyzation and concentration to obtain fluorescent carbon dots.

[0036] (2) 6 g of polymerized rosin was dissolved in 200 mL of dichloroethane. Then 100 g of the polymerized rosin was taken, 2 g of ureidopyrimidone and 1 g of fluorescent carbon dots were added, and the mixture was refluxed at 130 °C for 3 h under a nitrogen atmosphere. The reaction product was injection molded and refrigerated, and then a ureidopyrimidone / rosin fluorescent film was formed through a freeze-thaw cycle.

[0037] Example 3

[0038] (1) 1.5 g of disproportionated rosin was dissolved in 500 mL of ethanol to form a uniform disproportionated rosin solution. Then 75 g of the disproportionated rosin solution was added with 1.5 g of ureidopyrimidone and transferred to a high-pressure reactor. The reaction was carried out at 210 °C for 10 h under air-tight conditions. The reaction product was taken out and filtered, dialyzed and concentrated to obtain fluorescent carbon dots.

[0039] (2) Dissolve 4 g of polymerized rosin in 150 mL of dichloroethane, then take out 45 g, add 1.5 g of ureidopyrimidone and 0.6 g of fluorescent carbon dots, and reflux at 120 °C for 4 h under nitrogen atmosphere. The reaction product is injection molded and refrigerated, and then cyclic freeze-thaw cycles are used to form a ureidopyrimidone / rosin fluorescent film.

[0040] The ureidopyrimidone / rosin fluorescent film prepared in this example was placed in a quartz cuvette containing Tris buffer, 100 μM Cd(NO3)2 solution was added and allowed to stand for 20 min, and then the fluorescence intensity was measured using a fluorescence spectrophotometer. Phytic acid solutions of different concentrations (0-70 μM) were then added, mixed evenly and allowed to stand for 20 min, and then the fluorescence intensity was measured using a fluorescence spectrophotometer. A relative fluorescence intensity ((P0-P) / P) change curve of the mixed system was drawn. The results are shown in Figure 3 .

[0041] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A method for preparing a ureidopyrimidone / rosin fluorescent film for phytic acid detection, characterized in that: The following steps are involved: (1) dissolving rosin A in ethanol to form a uniform rosin ethanol solution, then adding ureidopyrimidone, heating and reacting for a certain period of time in an airtight condition, and then filtering, dialyzing and concentrating the reaction product to obtain fluorescent carbon dots; (2) separately dissolving rosin B in dichloroethane to form a rosin dichloroethane solution, and adding ureidopyrimidone and the fluorescent carbon dots prepared in step (1) respectively, and after condensation reflux reaction under a nitrogen atmosphere, injection molding the reaction product for cold storage, and performing a freeze-thaw cycle to form a ureidopyrimidone / rosin fluorescent film; In step (1), the rosin A is any one of hydrogenated rosin and disproportionated rosin; the concentration of the formed rosin ethanol solution is 0.1wt%-1wt%, and the mass ratio of the ureidopyrimidone to the rosin ethanol solution is 1:30-1:90; The heating reaction temperature in step (1) is 200-230°C and the time is 6-12h; In step (2), the rosin B is any one of maleated rosin and polymerized rosin; the concentration of the formed rosin dichloroethane solution is 1.5wt%-3wt%, the mass ratio of the ureidopyrimidone to the rosin dichloroethane solution is 1:20-1:50, and the mass ratio of the fluorescent carbon dots to the rosin dichloroethane solution is 1:50-1:100; The temperature of the condensation reflux reaction in step (2) is 100-130°C, and the time is 3-5h; the freeze-thaw cycle is first frozen at -20°C for 6-8h, then thawed at 3-8°C for 6-8h, and repeated 3-5 times.

2. An application of the ureidopyrimidone / rosin fluorescent film prepared by the method of claim 1 in phytic acid detection, characterized in that: The detection includes the following steps: 1) First, the ureidopyrimidone / rosin fluorescent film is placed in a Cd(NO3)2 solution for 20 minutes, and then a series of phytic acid solutions of known concentrations are added, mixed evenly and then placed for 20 minutes, and the fluorescence intensity before and after the addition of the phytic acid solution is measured by a fluorescence spectrophotometer, and a relationship curve between the relative change value of the fluorescence intensity and the concentration of the phytic acid solution is plotted; 2) The ureidopyrimidone / rosin fluorescent film is placed in the same Cd(NO3)2 solution for 20 minutes, and then the phytic acid solution to be tested is added, mixed evenly and allowed to stand for 20 minutes, and the fluorescence intensity before and after the addition of the phytic acid solution is measured using a fluorescence spectrophotometer, and the phytic acid content in the solution is calculated using the relationship curve between the relative change value of the fluorescence intensity obtained in step 1) and the concentration of the phytic acid solution.

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