A visual detection method, detection device and water jet printing method for metal ions

Abstract

The present invention belongs to the field of chemical sensing technology, and specifically relates to a visual detection method, a detection device and a water jet printing method for metal ions (especially multiple metal ions). The present invention provides a visual detection method for metal ions, including graphically displaying the color response of fluorescent materials to metal ions, and identifying and distinguishing metal ions based on the graphical display. This method extracts the response results and draws radar charts of different metal ions based on the different color responses of fluorescent materials after interacting with different metal ions. Different metal ions can be more intuitively identified and distinguished through the visual radar chart. This method provides color blind patients with the opportunity to detect color changes and obtain chemical sensing technology, which is more superior and humane than traditional colorimetric detection methods. The present invention also provides a visual detection device for metal ions, which uses the above-mentioned visual detection method to detect metal ions.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical sensing, and specifically relates to a visual detection method of metal ions (especially multiple metal ions), a detection device and a water jet printing method. Background Art

[0002] Metal ions are not only an important component of chemical raw materials, but also participate in many biochemical processes and even determine the structure and function of many biological macromolecules. Therefore, abnormal metabolism of metal ions or excessive exposure to heavy metal ions can cause many diseases. Therefore, the qualitative and quantitative detection and monitoring of metal ions is crucial for environmental protection, food safety and even the timely prevention and treatment of related diseases.

[0003] Although traditional detection methods such as inductively coupled plasma mass spectrometry and atomic absorption spectroscopy can detect metal ions with high specificity and high sensitivity, they are greatly limited due to high detection costs, cumbersome operations, complex equipment, time-consuming detection, and the need for professional technicians to operate.

[0004] In contrast, the colorimetric or fluorescent probes based on chemical sensing developed in recent years have the advantages of being simple, fast, portable, and independent of instruments and equipment. They have made great progress in metal ion detection, but they are not very suitable for people with color blindness or color weakness, and there are still relatively few colorimetric or fluorescent probes with the ability to identify and detect multiple metal ions. Summary of the invention

[0005] To solve the deficiencies of the prior art, the present invention provides a detection method and device, which can realize visual detection of metal ions, especially can realize visual detection of multiple metal ions, and is a simple and fast metal ion detection method. The present invention also provides a printing method.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] A method for visual detection of metal ions. Specifically, the method is particularly suitable for visual detection of multiple metal ions. The method includes: graphically displaying the color response of fluorescent materials to metal ions, and identifying and distinguishing metal ions based on the graphical display.

[0008] Wherein, the graphical display includes processing the color response through a color system.

[0009] The color response includes the color change and / or fluorescence change produced by the fluorescent material to the metal ions.

[0010] The fluorescent material includes a base material and a fluorescent group bonded to the base material, and the fluorescent group has coordination ability to the metal ions.

[0011] The method comprises: obtaining a color graph after the fluorescent material responds to the color of the metal ions, extracting the color characteristic value of the color graph through a color system, and identifying and distinguishing the metal ions based on the color characteristic value.

[0012] The color characteristic values ​​of the color graph are plotted into a radar chart, and the metal ions are distinguished according to the shape of the radar chart.

[0013] Wherein, the color system is selected from the RGB-CMYK color system.

[0014] The color characteristic values ​​include R, G, B, C, M, Y, and K values.

[0015] The method comprises: obtaining a color graph of a fluorescent material solution after the color response to metal ions, processing the color graph through a color system, and identifying and distinguishing metal ions.

[0016] The fluorescent material solution refers to a solution in which the fluorescent material is dissolved in an organic solvent.

[0017] The concentration of the fluorescent material solution is 0.1 mg / mL. -1 -10g.mL -1 .

[0018] The method comprises: obtaining a color pattern of the fluorescent paper after the color response to the metal ions, processing the color pattern through the RGB-CMYK color system, and identifying and distinguishing the metal ions.

[0019] Wherein, the fluorescent paper contains the fluorescent material.

[0020] A visual detection device for metal ions, the device adopts the above-mentioned visual detection method for metal ions to detect metal ions; the device includes a graphical display component and an identification component; the graphical display component is used to graphically display the color response of the fluorescent material to the metal ions; the identification component is used to identify and distinguish the metal ions based on the graphical display.

[0021] Wherein, the graphical display component includes a graphics acquisition unit and a color system unit.

[0022] Wherein, the graphic acquisition unit includes a color graphic shooting module.

[0023] The color system unit includes a color system, and the color graphics after the color response are processed by the color system to extract the color characteristic value of the color graphics.

[0024] Wherein, the identification component includes a data processing system; the data processing system plots the color characteristic values ​​of the color graphics into a radar chart, and identifies and distinguishes metal ions according to the shape of the radar chart.

[0025] Wherein, the graphical display component also includes a color response unit of the fluorescent material to metal ions.

[0026] Wherein, the color response unit contains fluorescent material.

[0027] The fluorescent material is disposed in the color response unit in at least one form of a film, a coating, a fiber, a gel, a solution or a fluorescent paper.

[0028] The above method or device can be used in the fields of computer science, bio-imaging or chemical sensing.

[0029] Wherein said computer science includes portable devices.

[0030] Wherein, the chemical sensor includes a fluorescent probe, which is used for food safety supervision, water quality monitoring, pesticide residue detection, toxic substance detection or wastewater detection.

[0031] A water jet printing method, the method comprising:

[0032] preparing a fluorescent substrate containing a fluorescent material;

[0033] preparing an aqueous solution containing metal ions;

[0034] The aqueous solution containing the metal ions is printed on the fluorescent substrate to obtain printed text or patterns.

[0035] The text or pattern on the fluorescent substrate can be erased, and after erasing, the fluorescent substrate can be used for printing again.

[0036] The beneficial effects of the present invention are:

[0037] 1. The present invention provides a method for visual detection of metal ions, which is achieved based on the differences in color and fluorescence changes of the fluorescent material after interacting with different metal ions. The present invention provides a new method for visual detection of metal ions based on the RGB-CMYK color system. Since the RGB-CMYK color system is an objective and unified indicator that has been widely used in portable devices, portable devices (e.g., smart phones) can replace human eyes as digital eyes to observe and record color changes in chemical sensors, and further translate and present analysis results in a visual form that is easy for untrained users to understand. By extracting the deep information of the response results and drawing the RGB-CMYK graph of the corresponding metal ions, various metal ions can be distinguished more intuitively. During the detection process, a dual-channel signal output with color and fluorescence changes is simultaneously provided. By comparing the visualized radar patterns of the color responses to different metal ions, Ag can be distinguished. + , Fe 2+ 、Co 2+ , Fe 3+ 、Zn 2+ 、Cd 2+ 、Al 3+ By graphically displaying the color response (color change or fluorescence change) between the fluorescent material provided by the present invention and the metal ions, different metal ions (such as Ag + , Fe 2+ 、Co 2+ , Fe 3+ 、Zn 2+ 、Cd 2+ and Al 3+ ), without relying on the color sensitivity of the naked eye. This method provides color blind people with the opportunity to detect color changes and obtain chemical sensing technology. It is more superior and humane than traditional colorimetric vision methods.

[0038] 2. The present invention also provides a visual detection method for multi-metal ions, which is implemented based on the differences in color and fluorescence changes of the fluorescent material after interacting with different metal ions. By comparing the color responses of different metal ions, multiple metal ions can be distinguished. By observing the color or fluorescence changes of the fluorescent material after interacting with different metal ions, visual detection of multiple metal ions can be achieved.

[0039] 3. The present invention provides a fluorescent material suitable for the above method, and a preparation method and application thereof, wherein the fluorescent material has good fluorescent properties and dissolution processing properties. The fluorescent material can be used to prepare a variety of directly usable material forms, such as fluorescent detection solutions, fluorescent films, nanofibers, electrospun membranes, fluorescent gels, fluorescent paper, etc.; and is particularly suitable for the above detection methods and devices.

[0040] 4. The fluorescent material can be selected from natural polysaccharide polymers such as cellulose, starch, chitosan and their derivatives as the matrix material. The natural polysaccharide polymers and their derivatives are abundant in nature, have the advantages of biodegradability and good biocompatibility, and are easy to chemically modify. In addition, the regularly distributed hydroxyl groups on them can effectively increase the number or density of detection and recognition sites, and are therefore particularly suitable for the visual detection of the metal particles of the present invention.

[0041] Specifically, the fluorescent material of the present invention can realize the identification of various metal ions, and has a dual-channel signal output of color and fluorescence changes. Various material forms prepared using the fluorescent material have the advantages of portability, biocompatibility, rapid responsiveness, etc. In addition to being suitable for the detection method of the present invention, it can also be widely used in water quality monitoring, wastewater detection and other fields.

[0042] 5. The present invention also provides a water jet printing method, which uses water as a solvent to achieve printing, thus meeting environmental protection requirements; in addition, the printing method uses a fluorescent material to react with metal ions to achieve printing, and has a rewritable function, that is, it can be printed again after being erased, and has the advantages of environmental protection, biocompatibility, rapid responsiveness, etc., providing a new direction for the printing field. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 To prepare the cellulose acetate bonded with the terpyridine fluorescent group in Example 1 1 H-NMR spectrum.

[0044] Figure 2 This is a photo of the cellulose acetate bonded with the terpyridine fluorescent group in Preparation Example 2 under visible light and 365nm ultraviolet light.

[0045] Figure 3 These are the actual photos and corresponding spectra after adding various metal ions to the two organic solutions of CA-TPY in Example 1.

[0046] Figure 4 The following are photos of the fluorescent test paper of Example 2 under visible light and 365 nm ultraviolet light after various metal ions were added.

[0047] Figure 5The RGB spatial distribution diagram of the response results of HPC-TPY to different metal ions extracted in Example 3 and the RGB-CMYK radar diagram of typical metal ions.

[0048] Figure 6 These are actual photos of the text written on fluorescent paper and the pattern printed by water jet in Example 4 under visible light and 365nm ultraviolet light. DETAILED DESCRIPTION

[0049] [Fluorescent materials]

[0050] The detection method and detection device of the present invention need to use a fluorescent material that has a color response to metal ions. The fluorescent material includes a base material and a fluorescent group bonded to the base material, and the fluorescent group has a coordination ability to the metal ions.

[0051] In the present invention, the color response of the fluorescent material to the metal ions is achieved by the coordination of the fluorescent groups to the metal ions.

[0052] In the present invention, the fluorescent group is bonded to the base material via a covalent bond.

[0053] In the present invention, the matrix material is selected from at least one of polysaccharides and polysaccharide derivatives.

[0054] Exemplarily, the matrix material is selected from at least one of starch, dextran, chitosan, chitin, alginic acid, cellulose and cellulose derivatives.

[0055] In the present invention, the starch is not specifically limited, and those skilled in the art can know that it is suitable for the system of the present invention, for example, at least one selected from amylopectin, amylose, high amylose, and modified starch; or, selected from soluble starch; or, selected from at least one selected from potato starch, corn starch, cassava starch, wheat starch, sweet potato starch, pea starch, water chestnut starch, and soybean starch.

[0056] In the present invention, the cellulose is, for example, at least one selected from microcrystalline cellulose, cotton pulp, wood pulp, bamboo pulp, straw pulp, absorbent cotton, bagasse, wood and cellulose obtained from plant straw.

[0057] In the present invention, the cellulose derivative is, for example, at least one selected from cellulose ethers and cellulose esters having a substituent.

[0058] In the present invention, the cellulose ester is at least one selected from cellulose acetate, cellulose acetate butyrate, cellulose propionate, cellulose butyrate, cellulose nitrate, cellulose benzoate, and cellulose cinnamate.

[0059] In the present invention, the cellulose ether is at least one selected from methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose.

[0060] Exemplarily, the fluorescent material has a structure as shown in formula (I),

[0061]

[0062] wherein n is the degree of polymerization; R is the same or different and is independently selected from R' or R";

[0063] Wherein, R' is selected from a responsive fluorescent group, and R" is selected from -H, -CH 2 CH 3 、-CH 3 、-COCH 3 、-NO 2 、-SO 3 H, -COPh, -COCH=CHPh, -CONHPh, -COCH 2 CH 3 、-COCH 2 CH 2 CH 3 、-CH 2 COOH or -CH 2 CH 2 OH;

[0064] The substitution degree of the responsive fluorescent group on the matrix material is 0.0001-2.5, preferably 0.01-2, 0.5-1.5, 1.5-2.5; more preferably 0.0001-0.5, 0.01-1, for example 0.04, 0.05, 0.14, 0.24.

[0065] Exemplarily, n = 1-2000; preferably, n = 200-800. In the present invention, the fluorescent group is provided by a fluorescent molecule.

[0066] In the present invention, the fluorescent molecule is, for example, at least one selected from porphyrin fluorescent molecules, spiro fluorescent molecules, rhodamine fluorescent molecules, aggregation-induced emission fluorescent molecules, and pyridine fluorescent molecules.

[0067] In the present invention, the porphyrin fluorescent molecule is, for example, at least one selected from protoporphyrin, tetraphenylporphyrin, tetramethoxyporphyrin, and tetrapyridylporphyrin.

[0068] In the present invention, the spirocyclic fluorescent molecule is, for example, at least one selected from spiropyran and spirooxazine.

[0069] In the present invention, the rhodamine fluorescent molecule is, for example, at least one selected from the group consisting of rhodamine B, rhodamine 110, rhodamine 123, rhodamine 6G, carboxytetramethylrhodamine, and tetramethylrhodamine ethyl ester.

[0070] In the present invention, the aggregation-induced emission fluorescent molecules are, for example, at least one selected from tetraphenylethylene and its derivatives, tetraphenylsilole and its derivatives.

[0071] In the present invention, the pyridine fluorescent molecule is, for example, at least one selected from pyridine and its derivatives, bipyridine and its derivatives, terpyridine and its derivatives, phenanthroline and its derivatives, acridine and its derivatives.

[0072] According to an exemplary embodiment of the present invention, the fluorescent material is cellulose acetate modified with terpyridine.

[0073] [Visual detection method of metal ions]

[0074] A method for visually detecting metal ions includes: graphically displaying the color response of a fluorescent material to metal ions, and identifying and distinguishing the metal ions based on the graphical display.

[0075] In the present invention, the graphical display includes processing the color response through a color system. Further, the graphical display includes a color graphic after the color response, such as a photo. Exemplarily, the color system is selected from the RGB-CMYK color system.

[0076] In the present invention, the color response includes the color change and / or fluorescence change produced by the fluorescent material to the metal ions. Exemplarily, the color change refers to the color change observed under visible light irradiation. Exemplarily, the fluorescence change refers to the fluorescence change produced after ultraviolet light irradiation, preferably 365nm ultraviolet light.

[0077] In the present invention, the metal ion is selected from Ag + , Fe 2+ 、Co 2+ , Fe 3+ 、Zn 2+ 、Cd 2+ and Al 3+ At least one of .

[0078] In the present invention, the fluorescent material has coordination ability to the metal ions. Exemplarily, the fluorescent material contains a fluorescent group, and the fluorescent group has coordination ability to the metal ions.

[0079] The fluorescent material exhibits different color responses to different metal ions.

[0080] In the present invention, the fluorescent material is specifically the fluorescent material mentioned above.

[0081] The fluorescent material can be prepared into various forms such as film, coating, fiber, gel, solution or fluorescent paper.

[0082] According to a preferred embodiment of the present invention, the solution refers to a solution in which the fluorescent material is dissolved in an organic solvent.

[0083] For example, the concentration of the fluorescent material solution is 0.1 mg.mL -1 -10g.mL -1 . Preferably 2mg.mL -1 .

[0084] Exemplarily, the fluorescent material exhibits different color responses after adding different metal ions in different organic solvent systems.

[0085] As an example, the NN dimethylformamide (DMF) solution of cellulose acetate modified with terpyridine (CA-TPY) exhibits blue-green fluorescence; the addition of Zn 2+ After adding Fe 2+ , its blue-green fluorescence is quenched and changes from colorless to purple; adding Co 2+ , its blue-green fluorescence is quenched and changes from colorless to orange.

[0086] As an example, the acetonitrile solution of cellulose acetate modified with terpyridine (CA-TPY) has no fluorescence; adding Zn 2+ , the solution changes from non-fluorescent to blue fluorescent; adding Fe 2+ , the solution changes from colorless to purple; adding Fe 3+ , the solution changes from colorless to yellow.

[0087] According to a preferred embodiment of the present invention, the fluorescent material is prepared into fluorescent paper, and after different metal ions are added, the fluorescent paper exhibits different color responses.

[0088] As an example, the fluorescent paper is made of wood pulp cellulose and terpyridine modified ester. The fluorescent paper itself is white and exhibits blue-green fluorescence; Fe 2+ After that, the fluorescent paper changes from white to dark purple and the blue-green fluorescence is quenched; 2+ After that, the blue-green fluorescence of the fluorescent paper was quenched and dark blue fluorescence was presented; 2+ Afterwards, the fluorescent paper changes from white to orange.

[0089] In one embodiment of the present invention, the above-mentioned visualization detection method of metal ions specifically includes: taking a photo of the color response of the fluorescent material to the metal ions, processing the photo through the RGB-CMYK color system, and identifying and distinguishing the metal ions.

[0090] It also specifically includes: taking a photo of the color response of the fluorescent material to the metal ions, extracting the color characteristic values ​​of the photo, such as R, G, B, C, M, Y, and K values, and identifying and distinguishing the metal ions by comparing the R, G, B, C, M, Y, and K values ​​of the photo.

[0091] The R, G, B, C, M, Y, and K values ​​of the photo are plotted into a radar chart, and the metal ions are distinguished according to the shape of the radar chart.

[0092] The R, G, B, C, M, Y, and K values ​​of the photo are obtained using analysis software, such as commercial software Photoshop.

[0093] [Visual detection device for metal ions]

[0094] A visual detection device for metal ions, the device adopts the above-mentioned visual detection method for metal ions to detect metal ions, the device includes a graphical display component and an identification component, the graphical display component is used to graphically display the color response of the fluorescent material to the metal ions, and the identification component is used to identify and distinguish the metal ions based on the graphical display.

[0095] In the present invention, the graphical display component includes a graphic acquisition unit and a color system unit. The graphical display component acquires the color response of the fluorescent material to the metal ions (such as a color graphic) through the graphic acquisition unit, and processes the color response (such as processing to obtain the color characteristic value of the color graphic) through the color system unit.

[0096] Exemplarily, the graphic acquisition unit includes a color graphic shooting module, for example, a camera module, such as a video camera, a digital camera, etc., preferably a digital camera.

[0097] Exemplarily, the graphical display component obtains a color graphic, such as a photo, after the fluorescent material responds to the color of the metal ions through a color graphic shooting module.

[0098] Exemplarily, the color system unit includes a color system, and the graphical display component processes the color graphics after the color response through the color system to extract the color characteristic value of the color graphics. Preferably, the color characteristic value is obtained using analysis software, such as commercial software Photoshop.

[0099] Exemplarily, the color system is selected from the RGB-CMYK color system, and the color characteristic values ​​of the color graphics include R, G, B, C, M, Y, and K values.

[0100] In the present invention, the color response includes the color change and / or fluorescence change produced by the fluorescent material to the metal ion. Exemplarily, the color change refers to the color change observed under visible light. Exemplarily, the fluorescence change is the fluorescence change produced by ultraviolet light, preferably 365nm ultraviolet light.

[0101] In the present invention, the metal ion is selected from Ag + , Fe 2+ 、Co 2+ , Fe 3+ 、Zn 2+ 、Cd 2+ and Al 3+ At least one of .

[0102] In the present invention, the graphical display component further comprises a color response unit of a fluorescent material to metal ions. Preferably, the color response unit contains a fluorescent material.

[0103] Preferably, the fluorescent material is the aforementioned fluorescent material. Preferably, the fluorescent material can be arranged in the color response unit in various forms such as a film, a coating, a fiber, a gel, a solution or a fluorescent paper, for example, a fluorescent material solution or a fluorescent paper containing the fluorescent material. Preferably, the fluorescent material has a coordination ability to the metal ion. Exemplarily, the fluorescent material contains a fluorescent group, and the fluorescent group has a coordination ability to the metal ion.

[0104] The fluorescent material exhibits different color responses to different metal ions.

[0105] According to a preferred embodiment of the present invention, the color response unit contains a solution of the fluorescent material dissolved in an organic solvent.

[0106] For example, the concentration of the fluorescent material solution is 0.1 mg.mL -1 -10g.mL -1 . Preferably 2mg.mL -1 .

[0107] Exemplarily, the fluorescent material exhibits different color responses after adding different metal ions in different organic solvent systems.

[0108] As an example, the NN dimethylformamide (DMF) solution of cellulose acetate modified with terpyridine (CA-TPY) exhibits blue-green fluorescence; the addition of Zn 2+After adding Fe 2+ , its blue-green fluorescence is quenched and changes from colorless to purple; adding Co 2+ , its blue-green fluorescence is quenched and changes from colorless to orange.

[0109] As an example, the acetonitrile solution of cellulose acetate modified with terpyridine (CA-TPY) has no fluorescence; adding Zn 2+ , the solution changes from non-fluorescent to blue fluorescent; adding Fe 2+ , the solution changes from colorless to purple; adding Fe 3+ , the solution changes from colorless to yellow.

[0110] According to a preferred embodiment of the present invention, the color response unit contains fluorescent paper made of the fluorescent material, and after different metal ions are added, the fluorescent paper exhibits different color responses.

[0111] As an example, the fluorescent paper is made of wood pulp cellulose and terpyridine modified ester. The fluorescent paper itself is white and exhibits blue-green fluorescence; Fe 2+ After that, the fluorescent paper changes from white to dark purple and the blue-green fluorescence is quenched; 2+ After that, the blue-green fluorescence of the fluorescent paper was quenched and dark blue fluorescence was presented; 2+ Afterwards, the fluorescent paper changes from white to orange.

[0112] In the present invention, the identification component also includes a data processing system; the data processing system plots the R, G, B, C, M, Y, and K values ​​of the photo into a radar chart, and identifies and distinguishes metal ions according to the shape of the radar chart.

[0113] Different metal ions correspond to radar graphs of different shapes, so that various metal ions can be identified and distinguished according to the shapes of the radar graphs.

[0114] In one embodiment of the present invention, after different metal ions have color responses in the fluorescent detection reagent, a digital camera is used to take photos of the color response of the fluorescent material to the metal ions, and the commercial software Photoshop is used to extract a series of R, G, B, C, M, Y, and K values ​​of the taken photos, and the R, G, B, C, M, Y, and K values ​​are plotted into an RGB-CMYK radar chart. The various metal ions are identified and distinguished by the different shapes of the RGB-CMYK radar chart.

[0115] The fluorescent material is HPC-TPY organic solution with a concentration of 2 mg.mL -1The HPC-TPY organic solution exhibits different color responses after adding different metal ions. The RGB-CMYK radar chart obtained after adding different metal ions to the HPC-TPY organic solution is as follows: Figure 5 shown.

[0116] [Application of Visual Detection Methods and Devices for Metal Ions]

[0117] The present invention also provides the application of the above-mentioned visualization detection method and device for metal ions, preferably in the fields of computer science (big data, artificial intelligence), biological imaging, chemical sensing, etc.

[0118] Among them, the computer science (big data, artificial intelligence) includes portable devices, such as digital cameras and smartphones.

[0119] Among them, the chemical sensor includes a fluorescent probe, which can be used for food safety supervision, water quality monitoring, pesticide residue detection, toxic substance detection, wastewater detection, etc.

[0120] [Preparation of fluorescent materials]

[0121] The present invention also provides a method for preparing the fluorescent material, comprising the following steps: reacting the base material with the fluorescent molecules to obtain the fluorescent material. The base material and the fluorescent molecules have the above-mentioned definitions.

[0122] The method for preparing the fluorescent material specifically comprises the following steps:

[0123] 1) dissolving and dispersing the matrix material in an organic solvent to react with the fluorescent molecules;

[0124] 2) Purifying the product obtained in step 1) to obtain a fluorescent material.

[0125] Wherein, in step 1), the reaction is an esterification reaction or an etherification reaction.

[0126] Preferably, the reaction temperature is 40-100°C, preferably 80°C.

[0127] Preferably, the reaction time is 4-72 h, preferably 12 h.

[0128] The fluorescent molecules are activated in advance, preferably by 1,1′-carbonyldiimidazole (CDI).

[0129] The yield of the fluorescent material prepared by the preparation method is 65-90%.

[0130] Wherein, in step 1), the organic solvent is selected from at least one of dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), tetrahydrofuran (THF), ethanol, propylene glycol, n-butanol, ethyl acetate, acetone, butanone, chloroform, dichloromethane, pyridine and N-methylpyrrolidone. Preferably, the organic solvent is selected from N,N-dimethylformamide (DMF).

[0131] Wherein, in step 2), the purification includes washing with an organic solvent or dialysis.

[0132] Exemplarily, the matrix material is selected from any one of cellulose acetate and wood pulp cellulose.

[0133] Exemplarily, the fluorescent molecule is selected from any one of 2,2':6',2"-terpyridine-4-carboxylic acid (TPY-COOH) and 4'-bromo-2,2':6',2"-terpyridine (TPY-Br).

[0134] For example, the 2,2':6',2"-terpyridine-4-carboxylic acid (TPY-COOH) is activated by 1,1'-carbonyldiimidazole (CDI).

[0135] [Water jet printing method]

[0136] The present invention also provides a water jet printing method, the method comprising:

[0137] preparing a fluorescent substrate containing a fluorescent material;

[0138] preparing an aqueous solution containing metal ions;

[0139] The aqueous solution containing the metal ions is printed on the fluorescent substrate to obtain printed text or patterns.

[0140] Wherein, the fluorescent substrate containing fluorescent material is a fluorescent film containing fluorescent material or a fluorescent paper containing fluorescent material.

[0141] The fluorescent film is prepared by a preparation method comprising the following steps: dissolving the fluorescent material in a solvent and coating the solvent on a film.

[0142] Wherein, the fluorescent material has the definition mentioned above.

[0143] Wherein, the solvent is selected from at least one of N,N-dimethylformamide, ethyl acetate, chloroform, dichloromethane, N,N-dimethylacetamide, acetone and the like.

[0144] The film is preferably a plastic film, and preferably, the plastic film is selected from any one of PET film, polystyrene film, polymethacrylic acid film, polypropylene film, or polyvinyl chloride film.

[0145] Among them, in the solution containing fluorescent material, the mass percentage of the fluorescent material is 0.5-60wt%, preferably 0.5wt%, 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, 60wt% or a range between any two of the above values.

[0146] The fluorescent paper is prepared by a preparation method comprising the following steps: preparing the fluorescent material into an emulsion dispersion, and obtaining the fluorescent paper through a papermaking process.

[0147] Wherein, the fluorescent material has the definition mentioned above.

[0148] Wherein, the emulsion dispersion is prepared by a homogenizer.

[0149] The papermaking process is not specifically limited, and for example, a conventional papermaking process in the art can be used.

[0150] Wherein, the aqueous solution containing the metal ions is printed on the fluorescent substrate, and the metal ions in the aqueous solution react with the fluorescent substrate to produce printed text or patterns.

[0151] The printing may be performed by writing or by printing with a printer, such as an inkjet printer, such as an Epson-L130 inkjet printer.

[0152] Wherein, the metal ions have the definition as described above.

[0153] The aqueous solution contains one or more metal ions. During printing, a fluorescent substrate with colored text or pattern is obtained through a color development reaction between the metal ions and the fluorescent substrate.

[0154] The text or pattern on the fluorescent substrate can be erased, and after erasing, the fluorescent substrate can be used for printing again.

[0155] The text or pattern on the fluorescent substrate can be erased by chemical and / or physical methods. For example, the text or pattern on the fluorescent substrate can be erased by tetrabutylammonium fluoride (TBAF) aqueous solution and then written or printed again.

[0156] The technical scheme of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only exemplary descriptions and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are included in the scope that the present invention is intended to protect.

[0157] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0158] Preparation Example 1

[0159] Preparation of fluorescent material CA-TPY by esterification method

[0160] In a 100 mL two-necked flask, 2.67 g of 2,2':6',2"-terpyridine-4-carboxylic acid (TPY-COOH) was dissolved in 30 mL of DMF at 80°C, followed by the addition of 1.56 g of 1,1'-carbonyldiimidazole (CDI) and stirring until no more bubbles were emitted to obtain activated TPY-COOH. In another 250 mL two-necked flask, 6.36 g of cellulose acetate (C) was dissolved in 90 ml of DMF. 2.45 ), the activated TPY-COOH solution was added to the DMF solution of cellulose acetate and reacted at 80°C for 12 hours. After cooling to room temperature, the unreacted small molecules were removed by dialyzing in a dialysis bag (molecular weight cutoff 14000) with DMF as the external liquid, and then precipitated in deionized water, filtered, washed, and freeze-dried to obtain 6.21 g of white powder, namely CA-TPY, with a yield of 68%.

[0161] The CA-TPY is cellulose acetate modified with terpyridine, and the degree of substitution of terpyridine is 0.14.

[0162] Preparation Example 2

[0163] Preparation of fluorescent material CA-TPY' by esterification method

[0164] In a 100 mL two-necked flask, 1.34 g of 2,2':6',2"-terpyridine-4-carboxylic acid (TPY-COOH) was dissolved in 15 mL of DMF at 80°C, followed by the addition of 0.78 g of 1,1'-carbonyldiimidazole (CDI) and stirring until no more bubbles were emitted to obtain activated TPY-COOH. In another 250 mL two-necked flask, 6.36 g of cellulose acetate (C) was dissolved in 90 mL of DMF. 2.45), the activated TPY-COOH solution was added to the DMF solution of cellulose acetate and reacted at 80°C for 12 hours. After cooling to room temperature, the unreacted small molecules were removed by dialyzing in a dialysis bag (molecular weight cutoff 14000) with DMF as the external liquid, and then precipitated in deionized water, filtered, washed, and freeze-dried to obtain 5.47 g of white powder, namely CA-TPY', with a yield of 71%.

[0165] The CA-TPY' is cellulose acetate modified with terpyridine, and the degree of substitution of terpyridine is 0.05.

[0166] Preparation Example 3

[0167] Preparation of fluorescent material Cell-TPY by esterification method

[0168] The crushed bacca wood pulp (11.35 g, 70 mmol) was added to 250 mL of DMF and stirred into a uniform suspension. In a 100 mL two-necked flask, 3.88 g (14 mmol) of 2,2':6',2"-terpyridine-4-carboxylic acid (TPY-COOH) was dissolved in 50 mL of DMF at 80°C, followed by the addition of 2.27 g (14 mmol) of 1,1'-carbonyldiimidazole (CDI), and stirred until no more bubbles emerged to obtain activated TPY-COOH. The activated TPY-COOH solution was then added to the wood pulp suspension. The suspension was heated to 80°C and stirred for 12 h, cooled to room temperature and filtered, and the filter cake was washed three times with fresh DMF to remove unreacted reagents. After drying, 10.28 g of modified wood pulp, i.e. Cell-TPY, was obtained with a yield of 67%.

[0169] The Cell-TPY is wood pulp cellulose connected to a terpyridine-modified ester, and the degree of substitution of terpyridine is 0.04.

[0170] Preparation Example 4

[0171] Preparation of fluorescent material HPC-TPY by etherification method

[0172] 3 g of hydroxypropyl cellulose (HPC) was weighed and dissolved in 30 mL of DMF, followed by the addition of 0.94 g (3 mmol) of 4'-bromo-2,2':6',2"-terpyridine (TPY-Br). Under the catalytic condition of 0.83 g (6 mmol) of potassium carbonate, an etherification reaction was carried out (the etherification reaction temperature was 80 ° C; the etherification reaction time was 24 h). The obtained product was precipitated, washed, dried, and then dissolved to obtain 3.24 g of the product, namely HPC-TPY, with a yield of 82%.

[0173] The HPC-TPY is hydroxypropyl cellulose modified with terpyridine, and the degree of substitution of terpyridine is 0.24.

[0174] Figure 1 To prepare the cellulose acetate bonded with the terpyridine fluorescent group in Example 1 1 H-NMR graph. It can be seen from the figure that the terpyridine fluorescent group has been successfully bonded to the cellulose acetate molecular chain.

[0175] Figure 2 The photographs are of the cellulose acetate bonded with the terpyridine fluorescent group under visible light and 365nm ultraviolet light in Preparation Example 2. As can be seen from the figure, the cellulose acetate bonded with the terpyridine fluorescent group has good fluorescence properties.

[0176] Example 1

[0177] Solution Method for Detection of Multi-metal Ions

[0178] Weigh 0.2 g CA-TPY (cellulose acetate modified with terpyridine, terpyridine substitution degree is 0.14) and dissolve it in acetonitrile to a concentration of 2 mg.mL -1 .

[0179] Weigh 0.2 g CA-TPY (cellulose acetate modified with terpyridine, terpyridine substitution degree is 0.14) and dissolve it in N-N dimethylformamide (DMF) to a concentration of 2 mg.mL -1 .

[0180] Figure 3 The following are the actual photos and corresponding spectra of the various metal ions added to the two organic solutions of CA-TPY in Example 1. Figure 3 It can be seen that the two different organic solutions of CA-TPY exhibit different fluorescence properties: the DMF solution of CA-TPY exhibits blue-green fluorescence, while the acetonitrile solution of CA-TPY has no fluorescence. By adding different metal ions to the above two different solutions, different colors and fluorescence responses can be obtained: for example, in the DMF system, adding Zn 2+ After that, its blue-green fluorescence was significantly enhanced. 2+ , its blue-green fluorescence is quenched and changes from colorless to purple. When Co is added 2+ , the solution color changes from colorless to orange; different from the DMF system, in the acetonitrile system, adding Zn 2+ The solution changes from non-fluorescent to blue fluorescence; when Fe 2+ , the solution changes from colorless to purple; when Fe is added 3+ The solution changes from colorless to yellow, and thus the divalent iron and trivalent iron ions can be distinguished. By comparing the differences in color and fluorescence changes after adding different metal ions to the above two solutions, Ag can be significantly distinguished and identified. + , Fe 2+ ,Co 2+, Fe 3+ , Zn 2+ , Cd 2+ , Al 3+ And other seven metal ions.

[0181] Example 2

[0182] Detection of multi-metal ions by test paper method

[0183] 10 g of the wood pulp cellulose-terpyridine modified ester Cell-TPY obtained in Preparation Example 3 was weighed and dispersed in deionized water, and then a homogenizer was used to make a uniform emulsion dispersion, and then a fluorescent test paper was obtained by a traditional papermaking process. Different colors and fluorescent responses can be obtained by dropping different metal ions on the fluorescent test paper.

[0184] Figure 4 The following are photos of the prepared fluorescent test paper under visible light and 365nm ultraviolet light after adding various metal ions. Figure 4 It can be seen that the prepared test paper itself is white and exhibits blue-green fluorescence. After adding different metal ions, it exhibits different colors and fluorescence responses: 2+ After that, the test paper changes from white to dark purple and the blue-green fluorescence is quenched; 2+ After that, the blue-green fluorescence of the test paper was quenched and dark blue fluorescence appeared; 2+ After that, the test paper changes from white to orange. From the above phenomenon, it can be seen that the obtained fluorescent test paper has the ability to detect a variety of metal ions.

[0185] Example 3

[0186] Detection of multi-metal ions by data visualization

[0187] The sample HPC-TPY obtained in Preparation Example 4 was dissolved in an organic solvent, and a digital camera was used to take real photos of the color and fluorescence response of the fluorescence detection reagent to different metal ions. Subsequently, a series of R, G, B, C, M, Y, and K values ​​of the real photos were extracted using commercial software Photoshop. The extracted R, G, B, C, M, Y, and K values ​​were plotted, and various metal ions were distinguished by the different shapes of the radar charts.

[0188] Figure 5 The RGB spatial distribution diagram of the extracted HPC-TPY response to different metal ions and the typical RGB-CMYK radar diagram are shown in the figure. It can be seen from the figure that by extracting the deep information of the response results and drawing them into a diagram, various metal ions can be distinguished more intuitively.

[0189] Example 4

[0190] Rewritable ink writing and water jet printing

[0191] The fluorescent test paper prepared in Example 2 is used as a substrate for water writing paper or water jet printing, with Fe 2+ 、Co 2+ 、Zn 2+ The aqueous solution of metal ions is used as ink for writing or they are loaded into the ink cartridge of the inkjet printer Epson-L130, and then water-jet printing is performed, and text or patterns of various colors are obtained through the color reaction between the metal ions and the fluorescent test paper.

[0192] Figure 6 These are photos of text written on fluorescent paper and patterns printed by waterjet under visible light and 365nm ultraviolet light. Figure 6 It can be seen that Fe 2+ The aqueous solution is used as ink, and the purple word "Fu" can be written on fluorescent paper. After soaking it in TBAF aqueous solution, the "Fu" is wiped off and can be replaced with Fe 2+ The aqueous solution is used as ink to write again. In the water jet printing experiment, it can be seen from the figure that using different metal ion aqueous solutions as ink, different colors and fluorescence of the same pattern can be printed on fluorescent paper, thus realizing multi-color water jet printing.

[0193] The above is an explanation of the embodiments of the present invention. However, the present invention is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A visual detection method for metal ions, It is characterized in that The visual detection method comprises: Graphically displaying the color response of the fluorescent material to the metal ions, and identifying and distinguishing the metal ions based on the graphical display; The graphical display includes obtaining a color graph after the fluorescent material responds to the color of the metal ions, extracting the color characteristic value of the color graph through a color system, and identifying and distinguishing the metal ions based on the color characteristic value; The color response includes the color change and fluorescence change produced by the fluorescent material to the metal ions; the color change refers to the color change observed under visible light irradiation; the fluorescence change refers to the fluorescence change produced after ultraviolet light irradiation; The fluorescent material comprises a base material and a fluorescent group bonded to the base material, wherein the fluorescent group has coordination ability to the metal ion; the fluorescent group is bonded to the base material through a covalent bond, and the fluorescent group is provided by at least one of the following fluorescent molecules: porphyrin fluorescent molecules, spirocyclic fluorescent molecules, rhodamine fluorescent molecules, aggregation-induced emission fluorescent molecules, and pyridine fluorescent molecules; the base material is selected from at least one of polysaccharides and polysaccharide derivatives; The visual detection method is used for visual detection of multiple metal ions, wherein the metal ions are selected from Ag + , Fe 2+ 、Co 2 + , Fe 3+ 、Zn 2+ 、Cd 2+ and Al 3+ At least one of .

2. The visual detection method according to claim 1, It is characterized in that The method comprises: drawing the color characteristic values ​​of the color graph into a radar chart, and distinguishing metal ions according to the shape of the radar chart.

3. The visual detection method according to claim 1, It is characterized in that The matrix material is selected from at least one of starch, dextran, chitosan, chitin, alginic acid, cellulose and cellulose derivatives; The porphyrin fluorescent molecule is selected from at least one of protoporphyrin, tetraphenylporphyrin, tetramethoxyporphyrin, and tetrapyridylporphyrin; The spirocyclic fluorescent molecule is selected from at least one of spiropyran and spirooxazine; The rhodamine fluorescent molecule is selected from at least one of rhodamine B, rhodamine 110, rhodamine 123, rhodamine 6G, carboxytetramethylrhodamine, and tetramethylrhodamine ethyl ester; The aggregation-induced emission fluorescent molecule is selected from at least one of tetraphenylethylene and its derivatives, tetraphenylsilole and its derivatives; The pyridine fluorescent molecule is selected from at least one of pyridine and its derivatives, bipyridine and its derivatives, terpyridine and its derivatives, phenanthroline and its derivatives, and acridine and its derivatives.

4. The visual detection method according to claim 1, It is characterized in that The color system is selected from the RGB-CMYK color system; The color characteristic values ​​include R, G, B, C, M, Y, and K values.

5. The visual detection method according to claim 1, It is characterized in that The method comprises: obtaining a color graph of a fluorescent material solution after the color response to metal ions, processing the color graph through a color system, and identifying and distinguishing metal ions.

6. The visual detection method according to claim 5, Its characteristics are, The fluorescent material solution refers to a solution in which the fluorescent material is dissolved in an organic solvent; The concentration of the fluorescent material solution is 0.1 mg.mL -1 -10g.mL -1 .

7. The visual detection method according to claim 1, It is characterized in that The method comprises: obtaining a color pattern of fluorescent paper after color response to metal ions, processing the color pattern through an RGB-CMYK color system, and identifying and distinguishing metal ions; The fluorescent paper contains the fluorescent material.

8. A visual detection device for metal ions, It is characterized in that The device detects metal ions using the visualization detection method for metal ions described in claims 1-7; the device includes a graphical display component and an identification component; the graphical display component is used to graphically display the color response of the fluorescent material to the metal ions; the identification component is used to identify and distinguish metal ions based on the graphical display.

9. The device according to claim 8, It is characterized in that The graphic display component includes a graphic acquisition unit and a color system unit.

10. The device according to claim 9, It is characterized in that The graphics acquisition unit includes a color graphics shooting module; The color system unit includes a color system, and the color graphics after the color response are processed by the color system to extract the color characteristic value of the color graphics.

11. The device according to any one of claims 8 to 10, It is characterized in that The identification component includes a data processing system; the data processing system plots the color characteristic values ​​of the color graphics into a radar chart, and identifies and distinguishes metal ions according to the shape of the radar chart.

12. The device according to any one of claims 8 to 10, It is characterized in that The graphical display component also includes a color response unit of the fluorescent material to the metal ions; The color response unit contains fluorescent material; The fluorescent material is disposed in the color response unit in at least one form of a film, a coating, a fiber, a gel, a solution or a fluorescent paper.

13. Application of the visualization detection method according to any one of claims 1 to 7 or the device according to any one of claims 8 to 12 in the fields of computer science, bioimaging or chemical sensing.

14. The use according to claim 13, It is characterized in that Devices used in computer science include portable equipment; Devices used for chemical sensing include fluorescent probes for food safety supervision, water quality monitoring, pesticide residue detection, toxic substance detection, or wastewater testing.

15. A water jet printing method, It is characterized in that The water jet printing method comprises: Prepare a fluorescent substrate containing a fluorescent material; the fluorescent substrate containing a fluorescent material comprises a substrate material and a fluorescent group bonded to the substrate material, the fluorescent group having coordination ability to metal ions; the fluorescent group is bonded to the substrate material through a covalent bond, and the fluorescent group is provided by at least one of the following fluorescent molecules: porphyrin fluorescent molecules, spirocyclic fluorescent molecules, rhodamine fluorescent molecules, aggregation-induced emission fluorescent molecules, pyridine fluorescent molecules; the substrate material is selected from at least one of polysaccharides and polysaccharide derivatives; Prepare an aqueous solution containing metal ions; the metal ions are selected from Ag + , Fe 2+ 、Co 2+ , Fe 3+ 、Zn 2+ 、Cd 2+ and Al 3+ At least one of; Printing the aqueous solution containing the metal ions on the fluorescent substrate to obtain printed text or patterns; The text or pattern on the fluorescent substrate can be erased, and after erasing, the fluorescent substrate can be used for printing again.

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