Perovskite paper-based reactor capable of being used for detecting mercury ions in wastewater and preparation method of perovskite paper-based reactor

Abstract

The invention discloses a perovskite paper-based reactor capable of being used for detecting mercury ions in wastewater and a preparation method, and belongs to the technical field of detection. Comprising the following steps: dispersing CsBr and PbBr2 in N, N-dimethylformamide, heating and dissolving, adding oleic acid and oleylamine into the dissolved product, adding the obtained product into ethyl acetate, and obtaining the perovskite quantum dots by using a saturated solution crystallization method; re-suspending the perovskite quantum dots in normal hexane, adding phospholipid and aminated cholesterol, and obtaining a water-soluble perovskite nanoparticle solution by using a film dispersion method; the method comprises the following steps: uniformly coating absorbent paper with a water-soluble perovskite nanoparticle solution, and obtaining a perovskite paper-based reactor through a freeze-drying technology; the perovskite paper-based reactor can be used for detecting the concentration of mercury ions in wastewater, and has the advantages of good sensitivity, high selectivity, simplicity and convenience in operation and the like.

Description

Technical Field

[0001] The invention belongs to the field of detection technology, and in particular relates to a perovskite paper-based reactor that can be used to detect mercury ions in wastewater and a preparation method thereof. Background Art

[0002] With the rapid development of global industrialization and the rapid growth of population, people's demand and consumption for energy are increasing day by day. The demand for nuclear energy and traditional fossil fuels has increased dramatically, but radioactive wastewater and heavy metals are inevitably produced during their operation. Mercury ions, as the main heavy metal pollutant in wastewater, are easily enriched in aquatic organisms and enter the human body through the food chain. Mercury ions are highly toxic and can damage the human digestive system and central nervous system, posing a serious threat to human health. Therefore, the rapid qualitative and quantitative detection of mercury ions is of great significance to multidisciplinary fields such as chemistry, environmental science, and biomedicine.

[0003] Traditional detection technologies for mercury ions include atomic absorption spectroscopy, high performance liquid chromatography, atomic fluorescence spectroscopy, plasma mass spectrometry, and enzyme-linked immunosorbent assay. Although these technologies can achieve sensitive and accurate detection of mercury ions, their operation process is complicated, the required instruments are expensive, and the portability is low, which is not conducive to the detection of Hg. 2+ Paper-based reactors have shown great application potential in the field of biological detection and diagnosis due to their portability, ease of operation, rapid response, high sensitivity, and ease of functionalization and integration. They are especially suitable for instant detection and outdoor use, providing an effective solution for rapid, economical, and environmentally friendly medical diagnosis.

[0004] Traditional organic fluorescent molecules have defects such as poor photostability and low quantum efficiency, making it difficult to achieve sensitive and accurate mercury ion detection. Summary of the invention

[0005] In view of the above technical problems, the present invention proposes a perovskite paper-based reactor and a preparation method that can be used to detect mercury ions in wastewater. Perovskite quantum dots have been widely used in in vitro diagnostic fields such as biosensing, bioimaging, and early diagnosis of tumors due to their advantages such as high quantum efficiency, adjustable luminescence characteristics, high sensitivity, and low cost. The present invention cleverly combines perovskite quantum dots with paper-based reactors and uses them for the detection of mercury ions in wastewater, which can significantly improve the sensitivity and portability of mercury ion detection.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] Technical purpose 1: A method for preparing a perovskite paper-based reactor, comprising the following steps:

[0008] CsBr and PbBr 2Dispersing in N,N-dimethylformamide, heating and dissolving to obtain a first product;

[0009] adding oleic acid and oleylamine to the first product to obtain a second product;

[0010] The second product is added to ethyl acetate to obtain perovskite quantum dots using a saturated solution crystal method;

[0011] The perovskite quantum dots are resuspended in n-hexane, and phospholipids and amino cholesterol are added to obtain a water-soluble perovskite nanoparticle solution by a thin film dispersion method;

[0012] The water-soluble perovskite nanoparticle solution is evenly coated on absorbent paper, and a perovskite paper-based reactor is obtained by freeze-drying technology.

[0013] Furthermore, the CsBr and PbBr 2 The molar ratio is 1:1;

[0014] The volume ratio of oleic acid, oleylamine and N,N-dimethylformamide is 2.5:1:50;

[0015] The volume ratio of the first product to ethyl acetate is 1:100;

[0016] The molar ratio of the phospholipid to the amino cholesterol is 5:2.

[0017] Furthermore, the reaction time required to obtain the first product was 1.5 h, the stirring speed was 200 rpm, and the temperature was 80 °C;

[0018] The reaction time required to obtain the second product is 0.5h;

[0019] The reaction conditions of the saturated solution crystallization method are: reaction time is 0.5h, stirring speed is 700rpm;

[0020] The reaction conditions of the thin film dispersion method are: ultrasonic time is 2 minutes, and ultrasonic power is 320W.

[0021] Furthermore, the absorbent paper is pure white filter paper made of pure plant fiber through a special process, which is existing technology and was purchased from Shanghai Jinbiao Biotechnology Co., Ltd. with a model number of CH27.

[0022] Technical purpose two: A perovskite paper-based reactor prepared using the above preparation method.

[0023] Furthermore, the diameter of the perovskite paper-based reactor is 1.5 cm.

[0024] Technical purpose three: Application of the perovskite paper-based reactor in detecting mercury ions in wastewater. Mercury ion-specific recognition molecules are surface ligands of water-soluble perovskite nanoparticles.

[0025] The reaction principle of the present invention is that mercury ions form a high coordination effect with nitrogen atoms in the oleylamine ligands on the surface of perovskite, resulting in changes in the electron transfer path and the generation of non-radiative recombination, causing changes in the fluorescence signal. The high quantum efficiency of perovskite and the specific binding of its abundant surface ligands to mercury ions improve its sensitivity and specificity for mercury ion detection.

[0026] Compared with the prior art, the present invention has the following advantages and technical effects:

[0027] The invention develops a method for preparing a perovskite paper-based reactor, which has the advantages of high photoluminescence quantum yield, narrow emission spectrum and photostability, and can detect the mercury ion concentration of wastewater with high sensitivity and specificity. At the same time, the perovskite paper-based reactor can realize economical, portable and real-time detection of mercury ion concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0029] Figure 1 This is a physical picture of the water-soluble perovskite nanoparticle solution prepared in Example 1;

[0030] Figure 2 This is a transmission electron microscopy image of the water-soluble perovskite nanoparticle solution prepared in Example 1;

[0031] Figure 3 Elemental analysis results of the water-soluble perovskite nanoparticle solution prepared in Example 1;

[0032] Figure 4 This is a physical picture of the perovskite paper-based reactor prepared in Example 1;

[0033] Figure 5 The scanning electron microscope images of the perovskite paper-based reactor prepared in Example 1 and the reactor prepared in the control group;

[0034] Figure 6 This is a graph showing the detection results of the perovskite paper-based reactor prepared in Example 1 in different concentrations of mercury ions;

[0035] Figure 7 The fitting curves of the fluorescence intensity of the perovskite paper-based reactor prepared in Example 1 and different concentrations of mercury ions;

[0036] Figure 8 is the fluorescence intensity after different ions react with perovskite;

[0037] Fig. 9 The fluorescence and color changes of the perovskite paper-based reactor and commercial mercury ion detection test paper after reacting with mercury ion solutions of various concentrations. DETAILED DESCRIPTION

[0038] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but should be understood as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0039] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0040] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0041] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0042] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0043] The raw materials used in the present invention are all purchased from the market.

[0044] The technical solution of the present invention is further illustrated by the following embodiments.

[0045] Example 1

[0046] 1. Preparation of Water-soluble Perovskite Nanoparticle Solution

[0047] a. Cesium bromide (CsBr, 0.5 mmol), lead bromide (PbBr 2 , 0.5mmol), N,N-dimethylformamide (DMF, 10mL) were placed in a 80°C water bath and stirred at 200rpm for 1.5h to obtain the first product; oleic acid (0.5mL) and oleylamine (0.2mL) were added to the first product (0.1mL) to obtain the second product; the second product (0.1mL) was added to ethyl acetate (10mL), stirred at 700rpm for 0.5h, the precipitate was collected by centrifugation, and n-hexane (8mL) was added to resuspend to obtain a perovskite quantum dot solution;

[0048] b. Add perovskite quantum dot solution (1 mL), phospholipid (15 μM), and amino cholesterol (6 μM) into a 50 mL eggplant-shaped bottle, remove the organic solvent by vacuum rotary evaporation, add 3 mL of deionized water, and uniformly ultrasonicate at 320 W in an ultrasonic cleaning tank for 2 min to obtain a water-soluble perovskite nanoparticle solution (denoted as PPNCs).

[0049] Figure 1 This is a physical picture of the water-soluble perovskite nanoparticle solution prepared in Example 1. Figure 1 It can be seen that the solution appears bright green under ultraviolet light, indicating that the perovskite nanoparticles are stably and evenly dispersed in the aqueous solution.

[0050] Figure 2 This is a transmission electron microscope image of the water-soluble perovskite nanoparticle solution prepared in Example 1. The perovskite nanoparticles have regular square morphology, indicating that the perovskite still maintains its crystal structure in the aqueous solution.

[0051] Figure 3 This is the elemental analysis result of the water-soluble perovskite nanoparticle solution prepared in Example 1. The results show that water-soluble perovskite nanoparticles were successfully prepared in this example.

[0052] 2. Preparation of Perovskite Paper-based Reactor

[0053] A special absorbent paper with a diameter of 1.5 cm was cut using an embossing machine, and 200 uL of water-soluble perovskite nanoparticle solution was evenly coated on the special absorbent paper, placed in a -20°C refrigerator for 5 hours, and then placed in a freeze dryer for freeze drying overnight to obtain a perovskite paper-based reactor.

[0054] Special absorbent paper without adding water-soluble perovskite nanoparticle solution (PPNCs) was used as the control group.

[0055] Figure 4 This is a physical picture of the perovskite paper-based reactor prepared in Example 1.

[0056] Figure 5The scanning electron microscope images of the perovskite paper-based reactor prepared in Example 1 and the reactor prepared in the control group are shown in FIG. Figure 5 It shows that the perovskite nanoparticles prepared in Example 1 are successfully attached to the special absorbent paper, indicating that the perovskite paper-based reactor was successfully prepared.

[0057] 3. Perovskite paper-based reactor for detection of mercury ions in wastewater

[0058] Preparation of standard curve: The mercury ion solution standard was prepared into a series of concentrations (0nM, 1nM, 10nM, 100nM, 1μM, 10μM, 100μM), and the standard solutions of each concentration were detected using the perovskite paper-based reactor (Example 1) prepared in the same batch. The standard curve was drawn with the detected fluorescence intensity as the ordinate and the concentration of the mercury ion solution standard solution as the abscissa, and the standard curve equation y=-1141.8x+1465118 was obtained by fitting, R 2 =0.95. In addition, different ion solutions were added to observe the effect of other ions on the luminescence intensity of perovskite. The fitting curves of perovskite fluorescence intensity and different concentrations of mercury ions are shown in Figure 6 , 7, the effects of other ions on the fluorescence intensity of perovskite are shown in Figure 8 shown.

[0059] The fluorescence intensity of perovskite has good linearity with the mercury ion concentration (R 2 =0.95), the detection limit is 1 nM, and the sensitivity is high. Figure 6 , as shown in 7; from Figure 8 It can be seen that except for mercury ions that affect the fluorescence intensity of perovskite, other ions have no obvious effect on the fluorescence intensity of perovskite, with high specificity.

[0060] Comparative Example 1

[0061] The perovskite paper-based reactor of Example 1 and commercial mercury ion detection test paper (purchased from Luheng Biotechnology) were used to detect mercury ion solutions of various concentrations. Fig. 9 As shown, the embodiment is the first column (above), and the commercial test paper is the second column (below). The red box indicates the lowest mercury ion concentration limit that the embodiment and the commercial test paper can detect. It can be seen that the perovskite paper-based reactor has higher sensitivity than the commercial mercury ion detection test paper.

[0062] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for preparing a perovskite paper-based reactor, characterized in that: The following steps are involved: Dispersing CsBr and PbBr2 in N,N-dimethylformamide and heating to dissolve to obtain a first product; adding oleic acid and oleylamine to the first product to obtain a second product; The second product is added to ethyl acetate to obtain perovskite quantum dots using a saturated solution crystal method; The perovskite quantum dots are resuspended in n-hexane, and phospholipids and amino cholesterol are added to obtain a water-soluble perovskite nanoparticle solution by a thin film dispersion method; The water-soluble perovskite nanoparticle solution is evenly coated on absorbent paper, and a perovskite paper-based reactor is obtained by freeze-drying technology.

2. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The molar ratio of CsBr to PbBr2 is 1:1; The volume ratio of oleic acid, oleylamine and N,N-dimethylformamide is 2.5:1:50; The volume ratio of the first product to ethyl acetate is 1:100; The molar ratio of the phospholipid to the amino cholesterol is 5:

2.

3. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The reaction time required to obtain the first product was 1.5 h, the stirring speed was 200 rpm, and the temperature was 80°C.

4. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The reaction time required to obtain the second product is 0.5 h.

5. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The reaction conditions of the saturated solution crystallization method are: reaction time is 0.5h, and stirring speed is 700rpm.

6. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The reaction conditions of the thin film dispersion method are: ultrasonic time is 2 minutes, and ultrasonic power is 320W.

7. The method for preparing a perovskite paper-based reactor according to claim 1, characterized in that: The absorbent paper is pure white filter paper made from pure plant fiber through a special process.

8. A perovskite paper-based reactor prepared by the preparation method according to any one of claims 1 to 7.

9. The perovskite paper-based reactor according to claim 8, characterized in that: The diameter of the perovskite paper-based reactor is 1.5 cm.

10. Use of the perovskite paper-based reactor as claimed in claim 8 or 9 in detecting mercury ions in wastewater.

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