A perovskite paper-based reactor for detecting mercury ions in wastewater and its preparation method.

Abstract

This invention discloses a perovskite paper-based reactor and its preparation method for detecting mercury ions in wastewater, belonging to the field of detection technology. The method includes the following steps: dispersing CsBr and PbBr2 in N,N-dimethylformamide and heating to dissolve; adding oleic acid and oleylamine to the dissolved product; adding the resulting product to ethyl acetate; and obtaining perovskite quantum dots using a saturated solution crystallization method; resuspending the perovskite quantum dots in n-hexane; adding phospholipids and aminocholesterol; and obtaining a water-soluble perovskite nanoparticle solution using a thin-film dispersion method; uniformly coating the water-soluble perovskite nanoparticle solution onto absorbent paper; and obtaining the perovskite paper-based reactor through freeze-drying. This perovskite paper-based reactor can be used to detect the concentration of mercury ions in wastewater, exhibiting advantages such as high sensitivity, high selectivity, and simple operation.

Description

Technical Field

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

[0002] With rapid global industrialization and population growth, the demand for and consumption of energy are increasing daily. The need for nuclear energy and traditional fossil fuels is rising dramatically, but their operation inevitably generates radioactive wastewater and heavy metals. Mercury ions, a major heavy metal pollutant in wastewater, readily accumulate in aquatic organisms and enter the human body through the food chain. Mercury ions are highly toxic and can damage the human digestive and central nervous systems, posing a serious threat to human health. Therefore, rapid qualitative and quantitative detection of mercury ions is of great significance to multiple disciplines, including chemistry, environmental science, and biomedicine.

[0003] Traditional techniques for detecting mercury ions include atomic absorption spectrometry, high-performance liquid chromatography (HPLC), atomic fluorescence spectrometry (AFI), inductively coupled plasma mass spectrometry (ICP-MS), and enzyme-linked immunosorbent assay (ELISA). While these techniques can achieve sensitive and accurate detection of mercury ions, they are complex to operate, require expensive instruments, and lack portability, making them unsuitable for the precise detection of Hg. 2+ Real-time and rapid detection. Paper-based reactors, with their advantages of portability, ease of operation, rapid response, high sensitivity, ease of functionalization and integration, have shown great application potential in the field of biological detection and diagnostics. They are especially suitable for point-of-care testing and outdoor use, providing an effective solution for rapid, economical and environmentally friendly medical diagnostics.

[0004] Traditional organic fluorescent molecules suffer from poor photostability and low quantum efficiency, making it difficult to achieve sensitive and accurate mercury ion detection. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention proposes a perovskite paper-based reactor and its preparation method for detecting mercury ions in wastewater. Perovskite quantum dots, due to their advantages such as high quantum efficiency, tunable luminescence properties, high sensitivity, and low cost, have been widely used in in vitro diagnostic fields such as biosensing, bioimaging, and early tumor diagnosis. This invention cleverly combines perovskite quantum dots with a paper-based reactor and applies it to the detection of mercury ions in wastewater, significantly improving the sensitivity and portability of mercury ion detection.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

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

[0008] CsBr and PbBr2 were dispersed in N,N-dimethylformamide and dissolved by heating to obtain the first product;

[0009] Oleic acid and oleylamine were added to the first product to obtain the second product;

[0010] The second product was added to ethyl acetate, and perovskite quantum dots were obtained by saturated solution crystallization.

[0011] The perovskite quantum dots were resuspended in hexane, and phospholipids and amino cholesterol were added. A water-soluble perovskite nanoparticle solution was obtained by thin-film dispersion.

[0012] The water-soluble perovskite nanoparticle solution was uniformly coated onto absorbent paper, and a perovskite paper-based reactor was obtained by freeze-drying.

[0013] Furthermore, the molar ratio of CsBr to PbBr2 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 phospholipids to the aminolated 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 0.5 h;

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

[0020] The reaction conditions for the thin-film dispersion method are: ultrasonic time of 2 min and ultrasonic power of 320 W.

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

[0022] Technical objective 2: A perovskite paper-based reactor prepared using the above-described preparation method.

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

[0024] Technical Objective 3: Application of the described perovskite paper-based reactor in the detection of mercury ions in wastewater. The mercury ion specific recognition molecule is the surface ligand of water-soluble perovskite nanoparticles.

[0025] The reaction principle of this invention is as follows: Mercury ions form a high coordination effect with nitrogen atoms in the oleamine ligands on the perovskite surface, leading to changes in the electron transfer path and non-radiative recombination, which in turn alters the fluorescence signal. The high quantum efficiency of the perovskite and the specific binding of its abundant surface ligands to mercury ions enhance 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] This invention develops a method for preparing a perovskite paper-based reactor. This reactor possesses advantages such as high photoluminescence quantum yield, narrow emission spectrum, and photostability, and can detect mercury ion concentration in wastewater with high sensitivity and specificity. Furthermore, the perovskite paper-based reactor enables economical, portable, real-time detection of mercury ion concentration. Attached Figure Description

[0028] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0029] Figure 1 A photograph of the water-soluble perovskite nanoparticle solution prepared in Example 1;

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

[0031] Figure 3 The elemental analysis results are for the water-soluble perovskite nanoparticle solution prepared in Example 1.

[0032] Figure 4 This is a photograph of the perovskite paper-based reactor prepared in Example 1.

[0033] Figure 5 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 The graph shows the detection results of mercury ions at different concentrations in the perovskite paper-based reactor prepared in Example 1.

[0035] Figure 7 The fitted curves of fluorescence intensity and mercury ion concentrations for the perovskite paper-based reactor prepared in Example 1 are shown.

[0036] Figure 8 The fluorescence intensity represents the reaction of different ions with perovskite.

[0037] Figure 9 The fluorescence and color changes of perovskite paper-based reactors and commercial mercury ion detection test strips after interaction with mercury ion solutions of various concentrations were studied. Detailed Implementation

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

[0039] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0040] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0041] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be readily apparent to those skilled in the art. This specification and embodiments are merely exemplary.

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

[0043] All raw materials used in this invention were purchased from the market.

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

[0045] Example 1

[0046] 1. Preparation of water-soluble perovskite nanoparticle solutions

[0047] a. Cesium bromide (CsBr, 0.5 mmol), lead bromide (PbBr2, 0.5 mmol), and N,N-dimethylformamide (DMF, 10 mL) were placed in an 80°C water bath and stirred at 200 rpm for 1.5 h to obtain the first product. Oleic acid (0.5 mL) and oleylamine (0.2 mL) were added to the first product (0.1 mL) to obtain the second product. The second product (0.1 mL) was added to ethyl acetate (10 mL), stirred at 700 rpm for 0.5 h, centrifuged to collect the precipitate, and resuspended in n-hexane (8 mL) to obtain a perovskite quantum dot solution.

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

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

[0050] Figure 2 The image shows a transmission electron microscope (TEM) image of the water-soluble perovskite nanoparticle solution prepared in Example 1. The perovskite nanoparticles have a regular blocky morphology, indicating that the perovskite retains its crystal structure in aqueous solution.

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

[0052] 2. Preparation of perovskite paper-based reactors

[0053] Special absorbent paper with a diameter of 1.5 cm was obtained by cutting with an embossing tool. 200 μL of water-soluble perovskite nanoparticle solution was evenly coated on the special absorbent paper. After freezing in a -20°C freezer for 5 hours, it was freeze-dried overnight in a freeze dryer to obtain a perovskite paper-based reactor.

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

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

[0056] Figure 5The images show scanning electron microscope (SEM) images of the perovskite paper-based reactor prepared in Example 1 and the reactor prepared in the control group. Figure 5 The results show that the perovskite nanoparticles prepared in Example 1 were successfully attached to the special absorbent paper, indicating that the perovskite paper-based reactor was successfully prepared.

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

[0058] Preparation of standard curve: A series of concentrations (0 nM, 1 nM, 10 nM, 100 nM, 1 μM, 10 μM, 10 μM, 100 μM) of mercury ion solution standards were prepared, and the standard solutions of each concentration were detected using a perovskite paper-based reactor prepared in the same batch (Example 1). A standard curve was plotted with the detected fluorescence intensity as the ordinate and the concentration of the mercury ion solution standard as the abscissa. The standard curve equation obtained by fitting was y = -1141.8x + 1465118, R0. 2 =0.95. Solutions with different ions were added to observe the effect of other ions on the luminescence intensity of the perovskite. The fitting curves of perovskite fluorescence intensity and different concentrations of mercury ions are shown below. Figure 6 As shown in Figure 7, the effects of other ions on the fluorescence intensity of perovskite are as follows: Figure 8 As shown.

[0059] Perovskite fluorescence intensity and mercury ion concentration exhibit good linearity (R0). 2 =0.95), its detection limit is 1 nM, and it has high sensitivity, such as Figure 6 As shown in Figure 7; from Figure 8 It can be seen that, apart from mercury ions affecting the fluorescence intensity of perovskite, other ions did not significantly affect the fluorescence intensity of perovskite, demonstrating high specificity.

[0060] Comparative Example 1

[0061] Mercury ion solutions of various concentrations were tested using the perovskite paper-based reactor of Example 1 and commercial mercury ion detection test strips (purchased from Luheng Biotechnology). Figure 9 As shown, the examples are in the first column (top), and the commercial test strips are in the second column (bottom). The red boxes indicate the lower limit of detection for both the examples and the commercial test strips. It can be seen that the perovskite paper-based reactor exhibits higher sensitivity compared to commercial mercury ion detection test strips.

[0062] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for preparing a perovskite paper-based reactor for detecting mercury ions, characterized in that, Includes the following steps: CsBr and PbBr2 were dispersed in N,N-dimethylformamide and dissolved by heating to obtain the first product; Oleic acid and oleylamine were added to the first product to obtain the second product; The second product was added to ethyl acetate, and perovskite quantum dots were obtained by saturated solution crystallization. The perovskite quantum dots were resuspended in hexane, and phospholipids and amino cholesterol were added. A water-soluble perovskite nanoparticle solution was obtained by thin-film dispersion. The water-soluble perovskite nanoparticle solution was uniformly coated onto absorbent paper, and a perovskite paper-based reactor was obtained by freeze-drying. 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 phospholipids to the aminolated cholesterol is 5:2; 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. The reaction time required to obtain the second product is 0.5 h; The reaction conditions for the saturated solution crystallization method are: reaction time of 0.5 h and stirring speed of 700 rpm; The reaction conditions for the thin-film dispersion method are: ultrasonic time of 2 min and ultrasonic power of 320 W.

2. The method for preparing the perovskite paper-based reactor for detecting mercury ions according to claim 1, characterized in that, The absorbent paper is a pure white filter paper made of pure plant fibers.

3. A perovskite paper-based reactor for detecting mercury ions, prepared by the method according to any one of claims 1-2.

4. The perovskite paper-based reactor for detecting mercury ions according to claim 3, characterized in that, The perovskite paper-based reactor used for detecting mercury ions has a diameter of 1.5 cm.

5. The application of a perovskite paper-based reactor for detecting mercury ions as described in claim 3 or 4 in the detection of mercury ions in wastewater.

Images