Preparation method and application of mercury ion sensor

Abstract

The invention discloses a preparation method and application of a mercury ion sensor, and the preparation method comprises the following steps: sensor preparation: sequentially taking two polythiophene derivatives p-BTH and p-BN, respectively dissolving the polythiophene derivatives in N, N-dimethylformamide, adding acetylacetone and absolute ethyl alcohol, and carrying out ultrasonic treatment; transferring the materials into a reaction kettle, heating for reaction, slowly cooling to room temperature, centrifuging, taking supernate, filtering and purifying the solution by using a microporous membrane, and taking out for later use; the two kinds of prepared polythiophene modified carbon quantum dots are sequentially named as CD-BTH and CD-BN; fitting a standard curve to obtain an Hg < 2 + > detection standard curve of the CD-BTH and an Hg < 2 + > detection standard curve of the CD-BN. The sensor prepared by the synthesis method disclosed by the invention has the advantages of high sensitivity, high selectivity, capability of implementing dynamic monitoring, relatively simple equipment maintenance and low cost, is suitable for large-scale use in detection of forbidden substances in the automobile industry, and can implement large-scale and rapid detection on mercury ions. Compared with a traditional detection method, the detection cost is reduced for enterprises.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of automobile banned substance detection, in particular to a preparation method and application of a mercury ion sensor. BACKGROUND

[0002] Mercury element is one of the banned substances controlled by the automobile industry. Traditional mercury element detection methods include spectroscopy, chromatography and electrochemical analysis. In common spectroscopic analysis methods, such as atomic absorption spectrometry, only one element can be determined at a time, and the linear range is limited, and the sensitivity is insufficient for some elements. For inductively coupled plasma atomic emission spectrometry with higher sensitivity, the equipment is expensive, the operation cost is high, and the spectral interference is complex. In common chromatographic analysis methods, such as ion chromatography, the direct detection ability of metal ions is limited, and the body interference is large. In high-performance liquid chromatography with higher sensitivity, derivatization is required, and the method development is complex, and the instrument operation cost is high, which limits the further application in automobile banned substance detection. For electrochemical analysis method, the equipment maintenance is difficult and the operation cost is high, which is not conducive to large-scale production and detection, and cannot be practically applied to automobile banned substance detection. SUMMARY

[0003] One of the purposes of the application is to provide a preparation method of a mercury ion sensor. The sensor prepared by the synthesis method has high sensitivity, high selectivity, can be dynamically monitored, and the equipment maintenance is relatively simple, the cost is low, is suitable for large-scale use in automobile industry banned substance detection, can implement large-scale and rapid detection of mercury ions, and reduces the detection cost for enterprises compared with the traditional detection method.

[0004] The second purpose of the application is to provide an application of the mercury ion sensor in automobile banned substance detection.

[0005] The application provides the following scheme:

[0006] According to one aspect of the application, the application provides a preparation method of a mercury ion sensor, comprising the following steps:

[0007] S1, sensor preparation:

[0008] S1-1, dissolve a polythiophene derivative p-BTH in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, ultrasonic dispersion, and obtain solution A;

[0009] S1-2, dissolve a polythiophene derivative p-BN in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, ultrasonic dispersion, and obtain solution B;

[0010] S1-3, add solution A into a reaction kettle, heat to perform hydrothermal reaction; cool the reaction liquid to room temperature, centrifugal to take supernatant, the supernatant is purified by microporous membrane filtration to obtain polythiophene modified carbon quantum dots CD-BTH ethanol solution;

[0011] S1-4, add solution B into a reaction kettle, heat to perform hydrothermal reaction; cool the reaction liquid to room temperature, centrifugal to take supernatant, the supernatant is purified by microporous membrane filtration to obtain polythiophene modified carbon quantum dots CD-BN ethanol solution;

[0012] S2, standard curve fitting:

[0013] S2-1, take polythiophene modified carbon quantum dots CD-BTH ethanol solution in a quartz cuvette, use a fluorescence spectrometer to measure at 617 nm, use a syringe to add Hg 2+ ion solution to the CD-BTH ethanol solution; when the concentration of Hg 2+ increases to 30 μM, the fluorescence intensity of CD-BTH decreases to 1%, in the range of 3-21 μM, the fluorescence intensity of CD-BTH is linearly related to the concentration of Hg 2+ , the detection limit LOD is calculated as 23 nM; the Hg 2+ detection standard curve of CD-BTH is obtained.

[0014] S2-2, take polythiophene modified carbon quantum dots CD-BN ethanol solution in a quartz cuvette, use a fluorescence spectrometer to measure at 580 nm, use a syringe to add Hg 2+ ion solution to the CD-BN ethanol solution; when the concentration of Hg 2+ increases to 30 μM, the fluorescence intensity of CD-BN decreases to 3%, in the range of 0-24 μM, the fluorescence intensity of CD-BN is linearly related to the concentration of Hg 2+ , the detection limit LOD is calculated as 90 nM; the Hg 2+ detection standard curve of CD-BN is obtained.

[0015] Further, in step S1-1, the ratio of the polythiophene derivative p-BTH, N,N-dimethylformamide, acetylacetone and anhydrous ethanol is 0.08-0.12 g:8-12 mL:8-12 mL:18-22 mL.

[0016] Further, in step S1-2, the ratio of the polythiophene derivative p-BN, N,N-dimethylformamide, acetylacetone and anhydrous ethanol is 0.08-0.12 g:8-12 mL:8-12 mL:18-22 mL.

[0017] Furthermore, in steps S1-3, the temperature of the hydrothermal reaction is 150-170℃, and the reaction time is 5-7h.

[0018] Furthermore, in steps S1-4, the temperature of the hydrothermal reaction is 150-170℃, and the reaction time is 5-7h.

[0019] Furthermore, in steps S1-3, the pore size of the microporous membrane is 0.20-0.24 μm; the filtration and purification time is 10-14 h.

[0020] Furthermore, in steps S1-4, the pore size of the microporous membrane is 0.20-0.24 μm; and the filtration and purification time is 10-14 h.

[0021] Furthermore, in step 2-1, the CD-BTH ethanol solution is 2-4 mL.

[0022] According to two aspects of the present invention, an application of a mercury ion sensor in the detection of prohibited substances in automobiles is provided: the detection of prohibited substances in automobiles includes the detection of mercury ion content in automobile door panel samples, comprising the following steps: taking 0.2g of automobile door panel sample, processing the door panel sample by microwave digestion, making up to 200mL, transferring the sample solution to a quartz cuvette containing carbon quantum dots, and determining the mercury ion content in the automobile door panel sample by comparing it with the ICP measurement value. 2+ concentration.

[0023] According to three aspects of the present invention, a mercury ion sensor is provided for detecting Hg in natural lake water samples. 2+ The application in concentration detection includes the following steps: Take 3 mL of natural lake water sample and filter out insoluble impurities. Since the mercury content in natural lake water is below the detection limit, the spiking method is used for analysis. After spiking, the mercury ion concentrations are 6 μM, 12 μM, and 18 μM, respectively. The recovery rate of the spiking method for natural samples is 95%-105%.

[0024] The above solution achieves the following beneficial technical effects:

[0025] The sensor prepared by the method of this invention has high sensitivity and selectivity, can perform dynamic monitoring, and is relatively simple to maintain. It is also low in cost, making it suitable for large-scale use in the automotive industry for detecting prohibited substances. It can perform large-scale, rapid detection of mercury ions. Compared to traditional detection methods, it reduces detection costs for enterprises. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the fabrication process of the mercury ion sensor of this invention.

[0027] Figure 2This is a fluorescence effect view of CD-BTH ethanol solution and CD-BN ethanol solution provided in a specific embodiment of the present invention.

[0028] Figure 3 This is a CD-BTH standard curve diagram provided in a specific embodiment of the present invention.

[0029] Figure 4 This is a CD-BN standard curve diagram provided in a specific embodiment of the present invention. Detailed Implementation

[0030] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] As one aspect of the present invention, a method for preparing a mercury ion sensor includes the following steps:

[0032] S1. Sensor fabrication:

[0033] S1-1. Dissolve the polythiophene derivative p-BTH in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, and disperse by ultrasonication to obtain solution A;

[0034] S1-2. Dissolve the polythiophene derivative p-BN in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, and disperse by ultrasonication to obtain solution B.

[0035] S1-3. Add solution A to the reaction vessel and heat to carry out hydrothermal reaction; cool the reaction solution to room temperature, centrifuge to collect the supernatant, and purify the supernatant by microporous membrane filtration to obtain polythiophene-modified carbon quantum dot CD-BTH ethanol solution.

[0036] S1-4. Add solution B to the reaction vessel and heat to carry out hydrothermal reaction; cool the reaction solution to room temperature, centrifuge to collect the supernatant, and purify the supernatant by microporous membrane filtration to obtain polythiophene-modified carbon quantum dot CD-BN ethanol solution.

[0037] S2, Standard Curve Fitting:

[0038] S2-1. Take a solution of polythiophene-modified carbon quantum dots (CD-BTH) in an ethanol cuvette and measure it at 617 nm using a fluorescence spectrometer. Add Hg dropwise to the CD-BTH ethanol solution using a pipette. 2+ Ionic solutions; when Hg 2+When the concentration of CD-BTH was gradually increased to 30 μM, the fluorescence intensity decreased to 1%. Within the range of 3-21 μM, the fluorescence intensity of CD-BTH was related to that of Hg. 2+ The concentration showed a linear relationship, and the calculated limit of detection (LOD) was 23 nM; the Hg of CD-BTH was obtained. 2+ Detection standard curve;

[0039] S2-2. Take a solution of polythiophene-modified carbon quantum dots (CD-BN) in ethanol and place it in a quartz cuvette. Measure the concentration at 580 nm using a fluorescence spectrometer. Add Hg dropwise to the CD-BN ethanol solution using a pipette. 2+ Ionic solutions; when Hg 2+ When the concentration of CD-BN was gradually increased to 30 μM, the fluorescence intensity decreased to 3%. Within the range of 0-24 μM, the fluorescence intensity of CD-BN was related to that of Hg. 2+ The concentration showed a linear relationship, and the calculated limit of detection (LOD) was 90 nM; the Hg of CD-BN was obtained. 2+ Standard curve for detection.

[0040] According to certain embodiments of the present invention, in step S1-1, the ratio of the polythiophene derivative p-BTH, N,N-dimethylformamide, acetylacetone and anhydrous ethanol is 0.08-0.12g: 8-12mL: 8-12mL: 18-22mL.

[0041] According to certain embodiments of the present invention, in steps S1-2, the ratio of the polythiophene derivative p-BN, N,N-dimethylformamide, acetylacetone and anhydrous ethanol is 0.08-0.12g: 8-12mL: 8-12mL: 18-22mL.

[0042] According to certain embodiments of the present invention, in steps S1-3, the temperature of the hydrothermal reaction is 150-170°C, and the reaction time is 5-7 hours.

[0043] According to certain embodiments of the present invention, in steps S1-4, the temperature of the hydrothermal reaction is 150-170°C, and the reaction time is 5-7 hours;

[0044] According to certain embodiments of the present invention, in steps S1-3, the pore size of the microporous membrane is 0.20-0.24 μm; and the filtration and purification time is 10-14 h.

[0045] According to certain embodiments of the present invention, in steps S1-4, the pore size of the microporous membrane is 0.20-0.24 μm; and the filtration and purification time is 10-14 h.

[0046] According to certain embodiments of the present invention, in step 2-1, the CD-BTH ethanol solution is 2-4 mL.

[0047] As a second aspect of the present invention, the present invention provides an application of a mercury ion sensor in the detection of prohibited substances in automobiles: the detection of prohibited substances in automobiles includes the detection of mercury ion content in automobile door panel samples, comprising the following steps: taking 0.2g of automobile door panel sample, processing the door panel sample by microwave digestion, making up to 200mL, transferring the sample solution to a quartz cuvette containing carbon quantum dots, and determining the mercury ion content in the automobile door panel sample by comparing with the ICP measurement value. 2+ concentration.

[0048] According to three aspects of the present invention, a mercury ion sensor is provided for detecting Hg in natural lake water samples. 2+ The application in concentration detection includes the following steps: Take 3 mL of natural lake water sample and filter out insoluble impurities. Since the mercury content in natural lake water is below the detection limit, the spiking method is used for analysis. After spiking, the mercury ion concentrations are 6 μM, 12 μM, and 18 μM, respectively. The recovery rate of the spiking method for natural samples is 95%-105%.

[0049] Example 1

[0050] A method for preparing a mercury ion sensor includes the following steps:

[0051] 1) Sensor preparation: 0.1 g each of two polythiophene derivatives, p-BTH and p-BN, were dissolved in 10 mL of N,N-dimethylformamide, along with 10 mL of acetylacetone and 20 mL of anhydrous ethanol. The solutions were sonicated for 10 min. The solutions were then transferred to a stainless steel reactor lined with polytetrafluoroethylene (PTFE), heated to 160°C using a laboratory furnace, and reacted for 6 h. After slow cooling to room temperature, the solutions were centrifuged, and the supernatant was purified by filtration through a 0.22 μm microporous membrane. The purified solution was dialyzed for 12 h and then stored for later use. The two polythiophene-modified carbon quantum dots were named CD-BTH and CD-BN, respectively.

[0052] 2) Standard curve fitting: 3 mL of ethanol solutions of multicolor controllable polythiophene-modified carbon quantum dots (CD-BTH and CD-BN) were sequentially placed in quartz cuvettes. Fluorescence spectroscopy measurements were performed at 617 nm and 580 nm, respectively. Hg was then added dropwise to the ethanol solutions of CD-BTH and CD-BN sequentially using a pipette. 2+ Ionic solutions when Hg 2+ When the concentration of CD-BTH was gradually increased to 30 μM, the fluorescence intensity of CD-BTH decreased to 1%. Within the range of 3-21 μM, the fluorescence intensity of CD-BTH was related to that of Hg. 2+ The concentration showed a linear relationship, and the calculated limit of detection (LOD) was 23 nM; when Hg 2+When the concentration of CD-BTH was gradually increased to 30 μM, the fluorescence intensity of CD-BTH decreased to 3%. Within the range of 0-24 μM, the fluorescence intensity of CD-BN was similar to that of Hg. 2+ The concentration showed a linear relationship, and the calculated detection limit (LOD) was 90 nM.

[0053] Example 2

[0054] A mercury ion sensor in natural lake water samples (Hg) 2+ Applications in concentration detection include the following steps:

[0055] A certain amount of natural lake water sample was taken, and insoluble impurities were filtered out. Since the mercury content in the natural lake water was below the detection limit, a spiking method was used for analysis. The mercury ion concentrations after spiking were 6 μM, 12 μM, and 18 μM, respectively. The recovery rate of the spiking method for natural samples was 95%-105%. The results are shown in the table below:

[0056]

[0057] Example 3

[0058] Application of a mercury ion sensor in the detection of prohibited substances in automobiles: The detection of prohibited substances in automobiles includes the detection of mercury ion content in automobile door panel samples, comprising the following steps:

[0059] Take 0.2g of door panel sample, process it using microwave digestion, and bring the volume to 200mL. Transfer the sample solution to a quartz cuvette containing carbon quantum dots. Analyze the door panel sample and compare the results with ICP measurements; the error is within 3%. The results are shown in the table below:

[0060]

[0061] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined.

[0062] For the sake of simplicity, the method embodiments are described as a series of actions. However, those skilled in the art should understand that the embodiments of the present invention are not limited to the described order of actions, because according to the embodiments of the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions involved are not necessarily essential to the embodiments of the present invention.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a mercury ion sensor, characterized in that, Includes the following steps: S1. Sensor fabrication: S1-1. Dissolve the polythiophene derivative p-BTH in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, and disperse by ultrasonication to obtain solution A; S1-2. Dissolve the polythiophene derivative p-BN in N,N-dimethylformamide, add acetylacetone and anhydrous ethanol, and disperse by ultrasonication to obtain solution B. S1-3. Add solution A to the reaction vessel and heat to carry out hydrothermal reaction; cool the reaction solution to room temperature, centrifuge to collect the supernatant, and purify the supernatant by microporous membrane filtration to obtain polythiophene-modified carbon quantum dot CD-BTH ethanol solution. S1-4. Add solution B to the reaction vessel and heat to carry out hydrothermal reaction; cool the reaction solution to room temperature, centrifuge to collect the supernatant, and purify the supernatant by microporous membrane filtration to obtain polythiophene-modified carbon quantum dot CD-BN ethanol solution. S2, Standard Curve Fitting: S2-1. Take a solution of polythiophene-modified carbon quantum dots (CD-BTH) in an ethanol cuvette and measure it at 617 nm using a fluorescence spectrometer. Add Hg dropwise to the CD-BTH ethanol solution using a pipette. 2+ Ionic solutions; when Hg 2+ When the concentration of CD-BTH was gradually increased to 30 μM, the fluorescence intensity decreased to 1%. Within the range of 3-21 μM, the fluorescence intensity of CD-BTH was related to that of Hg. 2+ The concentration showed a linear relationship, and the calculated limit of detection (LOD) was 23 nM; the Hg of CD-BTH was obtained. 2+ Detection standard curve; S2-2. Take a solution of polythiophene-modified carbon quantum dots (CD-BN) in ethanol and place it in a quartz cuvette. Measure the concentration at 580 nm using a fluorescence spectrometer. Add Hg dropwise to the CD-BN ethanol solution using a pipette. 2+ Ionic solutions; when Hg 2+ When the concentration of CD-BN was gradually increased to 30 μM, the fluorescence intensity decreased to 3%. Within the range of 0-24 μM, the fluorescence intensity of CD-BN was related to that of Hg. 2+ The concentration showed a linear relationship, and the calculated limit of detection (LOD) was 90 nM; the Hg of CD-BN was obtained. 2+ Standard curve for detection.

2. The preparation method according to claim 1, characterized in that: In step S1-1, the ratio of the polythiophene derivative p-BTH, N,N-dimethylformamide, acetylacetone and anhydrous ethanol is 0.08-0.12g: 8-12mL: 8-12mL: 18-22mL.

3. The preparation method according to claim 1, characterized in that: In steps S1-2, the ratio of the polythiophene derivative p-BN, N,N-dimethylformamide, acetylacetone, and anhydrous ethanol is 0.08-0.12g: 8-12mL: 8-12mL: 18-22mL.

4. The preparation method according to claim 1, characterized in that: In steps S1-3, the temperature of the hydrothermal reaction is 150-170℃, and the reaction time is 5-7h.

5. The preparation method according to claim 1, characterized in that: In steps S1-4, the temperature of the hydrothermal reaction is 150-170℃, and the reaction time is 5-7h.

6. The preparation method according to claim 1, characterized in that: In steps S1-3, the pore size of the microporous membrane is 0.20-0.24 μm; the filtration and purification time is 10-14 h.

7. The preparation method according to claim 1, characterized in that: In steps S1-4, the pore size of the microporous membrane is 0.20-0.24 μm; the filtration and purification time is 10-14 h.

8. The preparation method according to claim 1, characterized in that: In step 2-1, the CD-BTH ethanol solution is 2-4 mL.

9. Application of a mercury ion sensor in the detection of prohibited substances in automobiles: the detection of prohibited substances in automobiles includes the detection of mercury ion content in automobile door panel samples, characterized in that, The steps include: taking 0.2g of a car door panel sample, processing the sample using microwave digestion, making up to 200mL, transferring the sample solution to a quartz cuvette containing carbon quantum dots, and determining the Hg content in the car door panel sample by comparing it with ICP measurements. 2+ concentration.

10. A mercury ion sensor for Hg in natural lake water samples 2+ Its application in concentration detection is characterized by, The procedure includes the following steps: Take 3 mL of natural lake water sample and filter out insoluble impurities. Since the mercury content in the natural lake water is below the detection limit, the spiking method is used for analysis. After spiking, the mercury ion concentrations are 6 μM, 12 μM, and 18 μM, respectively. The recovery rate of the spiking method for natural samples is 95%-105%.

Images