CN115353659A - Preparation and application of gel film for in-situ and high-resolution detection of pH in sediment - Google Patents
Preparation and application of gel film for in-situ and high-resolution detection of pH in sediment Download PDFInfo
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- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 25
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- ROOXNKNUYICQNP-UHFFFAOYSA-N ammonium persulfate Chemical compound [NH4+].[NH4+].[O-]S(=O)(=O)OOS([O-])(=O)=O ROOXNKNUYICQNP-UHFFFAOYSA-N 0.000 claims abstract description 8
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- KWYHDKDOAIKMQN-UHFFFAOYSA-N N,N,N',N'-tetramethylethylenediamine Chemical compound CN(C)CCN(C)C KWYHDKDOAIKMQN-UHFFFAOYSA-N 0.000 claims abstract description 4
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- PJNZPQUBCPKICU-UHFFFAOYSA-N phosphoric acid;potassium Chemical compound [K].OP(O)(O)=O PJNZPQUBCPKICU-UHFFFAOYSA-N 0.000 description 1
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Abstract
The invention relates to a preparation method and application of a gel film for detecting pH in sediments in an in-situ and high-resolution manner. Adding ammonium persulfate solution and tetramethyl ethylene diamine solution, and mixing. And clamping the U-shaped plate between the two pieces of glass, injecting mixed liquid into a rectangular gap between the two pieces of glass, cooling to form a film, taking out the film, soaking the film in deionized water, and replacing the film for multiple times to obtain the polyacrylamide gel. Dissolving fluorescein isothiocyanate in carbonate buffer solution to obtain FITC stock solution. The polyacrylamide gel was mixed into the reaction. And taking out the reacted polyacrylamide gel, adding the polyacrylamide gel into deionized water, and replacing the polyacrylamide gel for many times. Soaking in phosphate buffer solution with different pH values. And measuring the pH response curve of the pH sensing film. The preparation method is simple, convenient and efficient, does not need complex experimental steps and has lower preparation cost.
Description
Technical Field
The invention relates to preparation and application of a gel film for detecting pH in sediments in situ and at a high resolution, and belongs to the technical field of detection of pH in sediments.
Background
The surface layer of the sediment undergoes strong mineral dissolution-precipitation reactions and various biogeochemical processes, resulting in a strong pH gradient near the sediment-water interface. Changes in the pH of the sediment-water interface directly affect the migration and release of contaminants from the sediment and are critical to monitoring the pH in the sediment. The pH microelectrode technology and the pH optical fiber sensor are two common important means for detecting pH at present, and the one-dimensional vertical distribution of the pH of a sediment interface can be obtained by a single-point step-by-step measurement mode. However, deposits have a high degree of heterogeneity, and a one-dimensional vertical distribution of pH does not identify the heterogeneity of deposits. The development of planar optical sensors provides a new approach to detect the two-dimensional spatial distribution of pH in sediments. The planar optical sensor is placed between the sediment and the container wall, the fluorescence image of the planar optical sensor is captured by combining the excitation light source and the camera, and the two-dimensional spatial distribution characteristic of the pH in the sediment is obtained according to the fluorescence intensity change of the optical sensor. However, planar optical sensors also have limitations in detecting the spatial distribution of pH in deposits in situ, and in use must require that the planar optical sensor be placed between the deposit and the container wall in order to acquire a fluorescence image of the sensor. Therefore, when the planar optical sensor is used for in-situ detection of the pH value in the sediment, a large sediment section imaging device or a special sediment collecting container needs to be combined, so that the cost and the difficulty of in-situ detection are increased. Therefore, a method for simply and conveniently detecting the pH two-dimensional spatial distribution in the in-situ high-resolution sediment is very important.
The membrane Diffusion Equilibration (DET) technique is a simple passive sampling technique that obtains information about dissolved species in sediment by placing a polyacrylamide hydrogel in the sediment to equilibrate with dissolved species in the pore water and then removing the hydrogel for analysis. The measurement of various solutes, such as dissolved phosphorus, iron, sulfur, has been accomplished by simple colorimetric reactions and computer density imaging metrology techniques. The DET technique enables two-dimensional measurement of dissolved substances by using inexpensive equipment and materials. Therefore, determination of the two-dimensional spatial distribution of pH in sediments based on DET techniques is a viable approach.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the existing problems and defects, the invention aims to provide the preparation and the application of the gel membrane for detecting the pH in the sediment in situ and at high resolution, the preparation method is simple, convenient and efficient, complex experimental steps are not needed, and the preparation cost is lower. The pH-sensitive gel film is prepared by soaking the prepared polyacrylamide gel in an alkaline solution containing FITC, wherein amino groups on the polyacrylamide are combined with carbon-sulfur amine bonds of the FITC, and the FITC is modified in the polyacrylamide gel. The gel film shows bright yellow-green fluorescence under 480nm exciting light, the fluorescence intensity is increased along with the increase of the pH value, and the gel film has good response in the range of pH 4.0-8.0. The gel film is vertically inserted into the sediment to enable the gel film to be balanced with dissolved substances in pore water of the surrounding sediment, and the two-dimensional space distribution of the pH value in the sediment can be obtained by combining a simple excitation light source and a color camera after the gel film is taken out.
The technical scheme is as follows: in order to realize the purpose, the invention adopts the following technical scheme:
a method for preparing a gel film for detecting pH in sediments in situ and at high resolution comprises the following steps:
step 1: uniformly mixing N, N' -methylene bisacrylamide and acrylamide according to the mass ratio of 1;
and 2, step: and (2) mixing the gel stock solution obtained in the step (1), a 10% ammonium persulfate solution and a 99% tetramethyl ethylene diamine solution according to the following ratio of 1:0.02: uniformly mixing the components in a volume ratio of 0.004 to obtain a mixed solution;
and step 3: taking two pieces of rectangular glass with the same length and width and a U-shaped plate with the same length and width, clamping the U-shaped plate between the two pieces of glass, and forming a rectangular gap between the glass and the U-shaped plate;
and 4, step 4: quickly injecting the mixed solution obtained in the step (2) into the rectangular gap obtained in the step (3), taking out the film after cooling to form a film, soaking the film in deionized water, replacing the deionized water for many times until gel which is completely expanded is formed, and cleaning redundant ions to obtain polyacrylamide gel;
and 5: dissolving fluorescein isothiocyanate in 0.10mol/L carbonate buffer solution with pH =9.2 to obtain FITC stock solution;
step 6: mixing the polyacrylamide gel obtained in the step (3) into the FITC stock solution obtained in the step (4) for reaction;
and 7: step 6, after the reaction is finished, taking out the polyacrylamide gel after the reaction, adding the polyacrylamide gel into deionized water, replacing the deionized water for multiple times, removing the FITC residual in the previous reaction until the fluorescence cannot be detected in the deionized water, and obtaining a pH sensitive gel film;
and step 8: respectively preparing at least six phosphate buffer solutions with different pH values of 2-10, soaking the FITC-modified polyacrylamide gel obtained in the step (7) in the phosphate buffer solutions with different pH values, and balancing for at least 1h to respectively obtain a plurality of gel membranes after balancing;
and step 9: 8, obtaining fluorescent images with different pH values by using the balanced gel film obtained in the step 8 through a gel imaging system;
step 10: extracting the intensity of the green channel of the fluorescence image obtained in the step 9 by using Matlab or ImageJ software, carrying out curve fitting on the intensity and the corresponding pH value to obtain a pH response curve of the pH sensing membrane, and fitting by using the following Boltzmann equation:
ythe intensity of the green channel of the fluorescence image at different pH values;a，banddxrespectively the empirical parameters and the width of the curve,pKato measure the center coefficient of the range, the calibration curve of the pH sensitive gel film is obtained.
Further, the thickness of the U-shaped plate in the step 3 is 0.4 to 0.8mm.
Further, the thickness of the U-shaped plate is 0.8mm.
Further, the concentration of the FITC stock solution in the step 5 is 0.05 to 0.1mg/ml.
Further, the reaction time in the step 6 is 6-24h.
The application of the gel film for detecting the pH in the sediment in situ and high resolution is characterized in that the pH sensitive gel film is prepared into a pH sensitive gel probe, the pH sensitive gel probe is inserted into a sample to be detected, gel imaging is used for imaging to obtain a fluorescence image, and calculation and drawing are performed according to the fluorescence image to obtain the two-dimensional spatial distribution of the pH in the sediment.
Has the advantages that: compared with the prior art, the preparation method is a novel gel film preparation for detecting the pH value in the sediment in situ and at high resolution and the application thereof, and the invention has the following advantages: the preparation method is simple, convenient and efficient, does not need complex experimental steps and has lower preparation cost. The pH-sensitive gel film is prepared by immersing a preformed polyacrylamide gel in an alkaline solution containing FITC, wherein amino groups on the polyacrylamide are bonded with carbon-sulfur amine bonds of the FITC, and the FITC is modified in the polyacrylamide gel.
Drawings
FIG. 1 is a reaction structure of FITC and polyacrylamide gel in an example of the present invention;
FIG. 2 is a flow chart of an embodiment of the present invention;
FIG. 3 is a schematic of fluorescence images of gel films at different pH for embodiments of the present invention;
FIG. 4 is a calibration curve of a pH sensitive gel film of an embodiment of the present invention;
FIG. 5 is a two-dimensional spatial distribution of pH in example sediments of the invention
In the figure, 1 is a gel membrane, 2 is a PVDF filter membrane, 3 is a gel support plate, 4 is a light filter, 5 is a gel membrane, 6 is a transparent support plate, and 7 is an excitation light source.
Detailed Description
The present invention is further illustrated by the following figures and specific examples, which are to be understood as illustrative only and not as limiting the scope of the invention, which is to be given the full breadth of the appended claims and any and all equivalent modifications thereof which may occur to those skilled in the art upon reading the present specification.
Examples
Preparation of sensitive gel film
(1) According to the following steps of 1:19 dissolving N, N' -methylene-bisacrylamide and acrylamide in 500ml of deionized water to prepare a gel stock solution;
(2) The gel stock solution, 10% ammonium persulfate solution and tetramethylethylenediamine solution were mixed according to a 1:0.02: mixing at a volume ratio of 0.004;
(3) Quickly injecting the mixed solution in the step (2) into two pieces of glass containing a U-shaped interlayer with the thickness of 0.8mm, taking out the film after the solution is cooled to form a film, soaking the film in deionized water, and replacing the deionized water for multiple times to obtain polyacrylamide gel;
(4) Fluorescein Isothiocyanate (FITC) was dissolved in 0.10M carbonate buffer solution at pH =9.2 to prepare a FITC stock solution, and the concentration of Fluorescein Isothiocyanate (FITC) was 0.05 to 0.1mg/ml at this time.
(5) Soaking the polyacrylamide gel prepared in the step (3) in the FITC stock solution in the step (4) for reaction for 12 hours, wherein the reaction process equation is shown in figure 1;
(6) And after the soaking is finished, taking out the polyacrylamide gel, soaking the polyacrylamide gel in deionized water, and replacing the deionized water for many times to remove FITC used as reaction so as to obtain the FITC-modified polyacrylamide gel.
Drawing of standard curve
(1) Preparing a buffer solution without pH value by using 0.10M potassium dihydrogen phosphate and 0.05M sodium tetraborate;
(2) Cutting the prepared pH sensitive gel film into gel wafers with the diameter of 1 cm;
(3) Soaking the gel wafer in buffer solutions with different pH values for balancing for 6 hours;
(4) Irradiating the gel membrane by using an excitation light source of 480nm, and acquiring a fluorescence image of the gel by using a camera, wherein the reaction process is shown in FIG. 2;
(5) Analyzing the fluorescence image obtained in the step (4), extracting the intensity of a green channel of the image by using Matlab software as shown in figure 3, fitting the intensity with a corresponding pH value to obtain a pH response curve of the pH sensitive gel membrane, and fitting by using a Boltzmann equation:
in the formulayThe intensity of the green channel of the fluorescence image at different pH values;a，banddxrespectively the empirical parameters and the width of the curve,pKais the measurement range center coefficient.
The response curve of the pH fluorescence sensing film to pH is shown in FIG. 4, and a calibration curve is finally obtained:
the pH sensitive gel film has a monitoring range of 4.0-8.0.
Application of sensitive gel in sediment
The prepared pH sensitive gel membrane is placed on a PET support plate with the thickness of 0.8mm, then a PVDF filter membrane is covered on the gel membrane, and the gel membrane and the PVDF filter membrane are fixed on the PET support plate by a waterproof adhesive tape to prepare the pH sensitive gel probe. Collecting a sediment column sample from a Meilianwan lake region of a collected Taihu lake, and vertically inserting a pH sensitive gel probe into the sediment column sample; after balancing for 12h, taking out the gel probe and taking out the gel film, placing the gel film on a transparent film supporting plate, and slightly wiping off water on the surface of the film by using a thin PET plate; then covering a layer of transparent PET thin plate to prevent the evaporation of the solution in the gel; and finally, imaging the gel interlayer by using a gel imaging system to obtain a fluorescence image of the gel.
According to the method, the two-dimensional spatial distribution of pH in the sediment can be obtained after calculation and mapping. The results show that the gel film can obtain a gradient distribution image of pH at a sediment-water interface, as shown in FIG. 5, the pH shows a gradient distribution at the sediment-water interface, and the pH has a gradually-decreasing trend from overlying water to sediment; the result shows that the pH sensitive gel film detects the two-dimensional spatial distribution of the sediment micro-interface pH in situ and in high resolution.
Claims (6)
1. A method for preparing a gel film for detecting pH in sediments in situ and at high resolution is characterized by comprising the following steps: the method comprises the following steps:
step 1: uniformly mixing N, N' -methylene bisacrylamide and acrylamide according to the mass ratio of 1;
step 2: mixing the gel stock solution obtained in the step 1, a 10% ammonium persulfate solution and a 99% tetramethyl ethylene diamine solution according to the weight ratio of 1:0.02: uniformly mixing the components in a volume ratio of 0.004 to obtain a mixed solution;
and 3, step 3: taking two pieces of rectangular glass with the same length and width and a U-shaped plate with the same length and width, clamping the U-shaped plate between the two pieces of glass, and forming a rectangular gap between the glass and the U-shaped plate;
and 4, step 4: quickly injecting the mixed solution obtained in the step (2) into the rectangular gap obtained in the step (3), taking out the film after cooling to form a film, soaking the film in deionized water, replacing the deionized water for many times until gel which is completely expanded is formed, and cleaning redundant ions to obtain polyacrylamide gel;
and 5: dissolving fluorescein isothiocyanate in a carbonate buffer solution with 0.10mol/L pH =9.2 to obtain a FITC stock solution;
step 6: mixing the polyacrylamide gel obtained in the step (3) into the FITC stock solution obtained in the step (4) for reaction;
and 7: step 6, after the reaction is finished, taking out the polyacrylamide gel after the reaction, adding the polyacrylamide gel into deionized water, replacing the deionized water for multiple times, removing the FITC residual in the previous reaction until the fluorescence cannot be detected in the deionized water, and obtaining a pH sensitive gel film;
and 8: respectively preparing at least six phosphate buffer solutions with different pH values of 2-10, soaking the FITC-modified polyacrylamide gel obtained in the step (7) in the phosphate buffer solutions with different pH values, and balancing for at least 1h to respectively obtain a plurality of gel membranes after balancing;
and step 9: 8, obtaining fluorescent images with different pH values by using the balanced gel film obtained in the step 8 through a gel imaging system;
step 10: extracting the intensity of the green channel of the fluorescence image obtained in the step 9 by using Matlab or ImageJ software, performing curve fitting on the intensity and the corresponding pH value to obtain a pH response curve of the pH sensing membrane, and performing fitting by using the following Boltzmann equation:
ythe intensity of the green channel of the fluorescence image at different pH values;a，banddxrespectively representing the empirical parameters and the width of the curve,pKato measure the center coefficient of the range, the calibration curve of the pH sensitive gel film is obtained.
2. The method of claim 1 for the in situ, high resolution detection of pH in deposits of gel films, wherein: the thickness of the U-shaped plate in the step 3 is 0.4 to 0.8mm.
3. The method for preparing a gel film for in-situ, high-resolution detection of pH in deposits according to claim 2, wherein: the thickness of the U-shaped plate is 0.8mm.
4. The method for preparing a gel film for in-situ, high-resolution detection of pH in deposits according to claim 1, wherein: the concentration of the FITC stock solution in the step 5 is 0.05 to 0.1mg/ml.
5. The method of claim 1 for the in situ, high resolution detection of pH in deposits of gel films, wherein: the reaction time in the step 6 is 6-24h.
6. The application of the gel film for detecting the pH value in the sediment in situ and with high resolution is characterized in that: and preparing the pH sensitive gel film into a pH sensitive gel probe, inserting the pH sensitive gel probe into a sample to be detected, imaging by using gel imaging to obtain a fluorescence image, and calculating and drawing according to the fluorescence image to obtain the two-dimensional spatial distribution of the pH in the sediment.
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Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999030611A1 (en) * | 1997-12-16 | 1999-06-24 | Optical Sensors Incorporated | Membranes and optical sensors made therewith having improved barrier properties |
| WO2008113460A1 (en) * | 2007-03-16 | 2008-09-25 | Construction Research & Technology Gmbh | Production of copolymers comprising sulfo groups |
| WO2009002459A2 (en) * | 2007-06-22 | 2008-12-31 | Massachusetts Institute Of Technology | Free flow isoelectric focusing devices and methods |
| CN103242494A (en) * | 2013-05-27 | 2013-08-14 | 上海交通大学 | Preparation method of composite microgel with temperature, pH and magnetic field sensitivities |
| KR20160040883A (en) * | 2014-10-06 | 2016-04-15 | 충남대학교산학협력단 | Fluorescent Polyacrylamide Hydrogel attached Glucose Oxidase, method for preparing of the same and sensor including the same |
| CN108572165A (en) * | 2018-06-19 | 2018-09-25 | 南京大学 | A kind of pH tablets optrode fluorescence sense film, preparation method and application |
| CN111484632A (en) * | 2020-04-24 | 2020-08-04 | 广东工业大学 | Fluorescent color-changeable intelligent hydrogel and preparation method thereof and pH value sensor |
| CN111501122A (en) * | 2020-05-08 | 2020-08-07 | 广东工业大学 | Luminescent hydrogel fiber and preparation method and application thereof |
| CN112730358A (en) * | 2020-12-17 | 2021-04-30 | 中国科学院南京地理与湖泊研究所 | Optical sensing film for monitoring pH two-dimensional dynamic distribution in sediment |
| CN113820451A (en) * | 2021-07-15 | 2021-12-21 | 南开大学 | Detection method of DNA double-layer hydrogel film sensor based on intelligent deformation response |
-
2022
- 2022-08-08 CN CN202210942792.9A patent/CN115353659A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1999030611A1 (en) * | 1997-12-16 | 1999-06-24 | Optical Sensors Incorporated | Membranes and optical sensors made therewith having improved barrier properties |
| WO2008113460A1 (en) * | 2007-03-16 | 2008-09-25 | Construction Research & Technology Gmbh | Production of copolymers comprising sulfo groups |
| DE102007012786A1 (en) * | 2007-03-16 | 2009-01-08 | Construction Research & Technology Gmbh | Preparation of sulfo-containing copolymers |
| WO2009002459A2 (en) * | 2007-06-22 | 2008-12-31 | Massachusetts Institute Of Technology | Free flow isoelectric focusing devices and methods |
| CN103242494A (en) * | 2013-05-27 | 2013-08-14 | 上海交通大学 | Preparation method of composite microgel with temperature, pH and magnetic field sensitivities |
| KR20160040883A (en) * | 2014-10-06 | 2016-04-15 | 충남대학교산학협력단 | Fluorescent Polyacrylamide Hydrogel attached Glucose Oxidase, method for preparing of the same and sensor including the same |
| CN108572165A (en) * | 2018-06-19 | 2018-09-25 | 南京大学 | A kind of pH tablets optrode fluorescence sense film, preparation method and application |
| CN111484632A (en) * | 2020-04-24 | 2020-08-04 | 广东工业大学 | Fluorescent color-changeable intelligent hydrogel and preparation method thereof and pH value sensor |
| CN111501122A (en) * | 2020-05-08 | 2020-08-07 | 广东工业大学 | Luminescent hydrogel fiber and preparation method and application thereof |
| CN112730358A (en) * | 2020-12-17 | 2021-04-30 | 中国科学院南京地理与湖泊研究所 | Optical sensing film for monitoring pH two-dimensional dynamic distribution in sediment |
| CN113820451A (en) * | 2021-07-15 | 2021-12-21 | 南开大学 | Detection method of DNA double-layer hydrogel film sensor based on intelligent deformation response |
Non-Patent Citations (3)
| Title |
|---|
| 周庆翰: "聚丙烯酰胺水凝胶的制备及pH 敏感性的研究", 西南民族大学学报·自然科学版, vol. 39, no. 5, pages 695 - 698 * |
| 胡炜;张颖;: "温度和pH双重敏感荧光复合微凝胶制备和表征", 化学学报, no. 18, pages 1855 * |
| 角裕子: "反応性高分子ラングミュア・プロジェット膜を用いたナノ界面の修飾", 高分子論文集(KOBUNSHI RONBUNSHU), vol. 59, no. 10, pages 590 - 595 * |
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