Conjugated polymer, hydrogel film fluorescence sensor, portable intelligent sensing platform and preparation method thereof

Abstract

The invention provides a conjugated polymer, a hydrogel film fluorescence sensor, a portable intelligent sensing platform and a preparation method thereof, and belongs to the technical field of intelligent sensing detection. According to the invention, a conjugated polymer poly (pyrene methylamine) is used as a sensing unit, cross-linked sodium alginate is used as a gel substrate, and flexible fluorescent films with different shapes are prepared through a 3D printing technology and are used as sensing platform sensors; a drawing is designed through a computer, and a portable detection device accessory is prepared by printing through a 3D printing technology; the portable intelligent detection platform is formed by assembling a hydrogel film, printed portable device accessories, a smart phone, a 365nm LED ultraviolet lamp, a mobile power supply and the like. The platform can visually detect Cr (VI) in agricultural samples outdoors on site, the problem that outdoor real-time detection is difficult to achieve by a traditional fluorescence sensor is solved, and timeliness and space flexibility of agricultural pollutant detection are achieved.

Description

Technical Field

[0001] The present invention relates to the field of intelligent sensing detection technology, and in particular to a conjugated polymer, a hydrogel film fluorescence sensor, a portable intelligent sensing platform and a preparation method thereof. Background Art

[0002] With the rapid advancement of industrialization and the widespread use of agricultural chemicals, heavy metal pollution has become increasingly serious. Among these heavy metal ions, the hazards caused by various chromium compounds (Cr) cannot be ignored. The biological toxicity, carcinogenicity and easy migration of Cr(VI) in water environments make the detection and treatment of chromium-containing wastewater an urgent environmental problem. With the advancement of technology and the emergence of new application scenarios, accurate and rapid on-site detection sensors have become a necessary condition for monitoring and controlling environmental pollution. Excellent photography and image processing capabilities have greatly promoted the miniaturization, integration and visual monitoring of sensors, making them an important tool for portable real-time measurement.

[0003] Compared with the traditional heavy metal ion detection method that relies on large precision instruments, although homogeneous fluorescence sensors have high sensitivity, no need for reference systems, and rich output signals, their disadvantages of being difficult to device and easy to pollute the system to be tested limit their use. With the development of smart sensors, thin-film fluorescence sensors have made great progress due to their advantages such as portability, easy deviceization, and no pollution to the system to be tested. As an innovative branch of fluorescence sensors, fluorescent gel film sensors cleverly combine the stability of solids with the dynamic exchange characteristics of solutions, and are particularly suitable for monitoring heavy metal ions in water environments. Fluorescent films based on various functional materials for detecting Cr(VI) have been reported one after another. However, the contact between thin-film fluorescence sensors and ions mainly depends on the pores of the film, and the insufficient contact between the ions to be tested and the sensing unit leads to low detection sensitivity and long response time. In addition, the current detection of heavy metal ions mainly relies on laboratories, but agricultural production sites are often far away from these facilities, which limits the timeliness and spatial flexibility of agricultural pollutant detection. Therefore, the development of portable intelligent sensing detection platforms for rapid, sensitive and real-time detection has potential value in environmental monitoring and public health protection. Summary of the invention

[0004] The purpose of the present invention is to provide a conjugated polymer, a hydrogel film fluorescence sensor, a portable intelligent sensing platform and a preparation method thereof, which are used to solve the technical problem that agricultural pollutants cannot be monitored in real time.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a conjugated polymer having the structure shown below:

[0007] Wherein, n=2-100 and n is a natural number.

[0008] The present invention provides a method for preparing a conjugated polymer, comprising the following steps:

[0009] In a three-electrode system, a conjugated polymer precursor, pyrenemethylamine, is subjected to constant potential polymerization in a boron trifluoride ether solution to obtain a conjugated polymer, poly(pyrenemethylamine);

[0010] The potential of the constant potential polymerization is 1.0-1.5V, the scanning speed is 90-110mV / s, and the polymerization time is 20-26h;

[0011] The concentration of the conjugated polymer precursor pyrenemethylamine in the boron trifluoride ether solution is 0.01-0.03 mol / L.

[0012] The present invention provides a method for preparing a hydrogel film fluorescence sensor, comprising the following steps:

[0013] (1) mixing sodium alginate and water to obtain a gel solution;

[0014] (2) mixing the conjugated polymer according to claim 1 and an organic solvent to obtain a fluorescent mother solution;

[0015] (3) mixing the fluorescent mother solution and the gel solution and heating them to obtain a hydrogel ink, and performing 3D printing on the hydrogel ink to obtain a fluorescent gel film;

[0016] (4) Immersing the fluorescent gel film in a calcium-containing crosslinking agent solution to perform a crosslinking reaction, and then drying to obtain a hydrogel fluorescent film sensor.

[0017] Furthermore, in the gel solution, the mass concentration of sodium alginate is 1 to 3%;

[0018] The volume ratio of the fluorescent mother solution to the gel solution is 1:1-1.5, the calcium-containing crosslinking agent solution comprises a CaCl2 solution, the concentration of the calcium-containing crosslinking agent solution is 0.1-0.3 mol / L, and the crosslinking reaction time is 50-100 min.

[0019] The invention also provides a hydrogel film fluorescence sensor.

[0020] The invention also provides an application of a hydrogel film fluorescence sensor in detecting chromate ions.

[0021] The present invention also provides a method for preparing a portable intelligent sensing platform, comprising the following steps:

[0022] Design drawings of portable equipment using Stratasys GrabCAD Print software on a computer;

[0023] Use Stratasys GrabCAD Print software to import 3D drawings into 3D printers;

[0024] The software automatically slices and layers the model according to the structural design, and prints the model material area and the support printing area separately; the material is bonded layer by layer according to the program, and the model is printed layer by layer;

[0025] Assemble accessories and other components into a smart sensing platform.

[0026] Furthermore, the printing steps are as follows: the software automatically slices and layers according to the structural design, and is divided into a model material printing area and a support printing area; the machine melts the ABS wire with a diameter of 2.0 mm and extrude it from a nozzle with a diameter head of 0.178 mm, and adheres the material layer by layer according to the program to print the model layer by layer; printing parameters: extrusion temperature is 220°C, extrusion speed is 10 mm / s, and ambient temperature is 90°C.

[0027] The invention provides a portable intelligent sensing platform.

[0028] The present invention also provides an application of a portable intelligent sensing platform in the field of photoelectric sensing devices.

[0029] Beneficial effects of the present invention:

[0030] The present invention provides an intelligent sensing detection platform assembled from a portable readout device based on a smart phone, including a sensor and a detection device. The sensor is composed of a sensing unit poly(pyrenemethylamine) and a sodium alginate gel substrate, and the detection device is a homemade portable device.

[0031] The sensing unit polypyrene has a unique "molecular line effect" that can amplify the fluorescent signal, thereby improving its detection sensitivity. The substrate is constructed into a hydrogel, which combines the stability of the solid with the dynamic exchange characteristics of the solution, increases the ion channel and specific surface area, promotes the contact between the ions to be measured and the sensing unit, solves the problem of low detection sensitivity and long response time of the thin film sensor caused by insufficient contact between the ions to be measured and the sensing unit, and expands its application in specific sensing scenarios. Flexible fluorescent films of different shapes are printed through 3D printing technology. Through computer design drawings, the detection device accessories are printed, and then the fluorescent film, smart phone, 365nmLED ultraviolet lamp and mobile power supply are assembled into a portable intelligent detection platform, which can realize on-site real-time detection of Cr(VI). It solves the problem that traditional heavy metal ion detection is difficult to detect in real time outdoors, and realizes the timeliness and spatial flexibility of agricultural pollutant detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a linear sweep voltammetry (LSV) spectrum of the conjugated polymer precursor prepared in Example 1 in boron trifluoride ether at a scan rate of 100 mV / s;

[0033] Figure 2 is a CV curve diagram of the conjugated polymer precursor prepared in Example 1;

[0034] Figure 3 This is a flow chart of the 3D printing preparation of the hydrogel film fluorescence sensor in Example 2;

[0035] Figure 4 This is a test diagram of the ion selectivity of the hydrogel film fluorescence sensor prepared in Example 2;

[0036] Figure 5 This is a sensitivity analysis diagram of the hydrogel film fluorescence sensor prepared in Example 2 to Cr(VI);

[0037] Figure 6 The linear equation obtained by the calibration curve of the hydrogel film fluorescence sensor prepared in Example 2 for Cr(VI);

[0038] Figure 7 This is a schematic diagram of the design and manufacture of the intelligent detection sensor platform of Example 3;

[0039] Figure 8 Schematic diagram of the intelligent detection sensor platform and its accessories of Example 3; wherein, 1-smartphone; 2-ultraviolet lamp chamber; 3-365nm ultraviolet lamp holder; 4-light door; 5-sample clamp; 6-sample chamber; 7-back cover; 8-light shielding strip; 9-mobile phone holder; 10-base;

[0040] Fig. 9 This is a schematic diagram of the optical path and shooting path during the test process of the intelligent detection sensor platform in Example 3;

[0041] Fig.10 This is the linear equation diagram obtained by applying the intelligent detection sensing platform in Example 3. DETAILED DESCRIPTION

[0042] The present invention provides a conjugated polymer having the structure shown below:

[0043] Wherein, n=2-100 and n is a natural number.

[0044] The present invention provides a method for preparing a conjugated polymer, comprising the following steps:

[0045] In a three-electrode system, a conjugated polymer precursor, pyrenemethylamine, is subjected to constant potential polymerization in a boron trifluoride ether solution to obtain a conjugated polymer, poly(pyrenemethylamine);

[0046] The potential of the constant potential polymerization is 1.0-1.5V, the scanning speed is 90-110mV / s, and the polymerization time is 20-26h;

[0047] The concentration of the conjugated polymer precursor pyrenemethylamine in the boron trifluoride ether solution is 0.01-0.03 mol / L.

[0048] In the present invention, the structural formula of the conjugated polymer precursor pyrenemethylamine is as follows:

[0049]

[0050] In the present invention, the three-electrode system is: ITO glass is used as the working electrode, platinum wire is used as the counter electrode, and homemade Ag / AgCl is used as the reference electrode.

[0051] In the present invention, the method of making Ag / AgCl by oneself is:

[0052] Using the constant voltage film forming method, at 6 mol·L -1 It was prepared by electrochemical deposition at a voltage of 1.5 V for 100 s in a hydrochloric acid solution; wherein the working electrode was silver wire, and the reference electrode and the counter electrode were platinum wires.

[0053] The data measured by using homemade Ag / AgCl in the present invention is more stable and reliable, thus avoiding the problem of unstable data deviation after repeated use of purchased Ag / AgCl.

[0054] In the present invention, the potential of the constant potential polymerization is preferably 1.2 V, the scanning speed is 100 mV / s, and the polymerization time is 24 h.

[0055] In the present invention, the concentration of the conjugated polymer precursor pyrenemethylamine in the boron trifluoride ether solution is preferably 0.02 mol / L.

[0056] The present invention provides a method for preparing a hydrogel film fluorescence sensor, comprising the following steps:

[0057] (1) mixing sodium alginate and water to obtain a gel solution;

[0058] (2) mixing the conjugated polymer according to claim 1 and an organic solvent to obtain a fluorescent mother solution;

[0059] (3) mixing the fluorescent mother solution and the gel solution and heating them to obtain a hydrogel ink, and performing 3D printing on the hydrogel ink to obtain a fluorescent gel film;

[0060] (4) Immersing the fluorescent gel film in a calcium-containing crosslinking agent solution to perform a crosslinking reaction, and then drying to obtain a hydrogel fluorescent film sensor.

[0061] In the present invention, the mass concentration of sodium alginate in the gel solution is 1-3%, preferably 2%.

[0062] In the present invention, the volume ratio of the fluorescent mother solution to the gel solution is 1:1 to 1.5, preferably 1:1; the calcium-containing crosslinking agent solution comprises a CaCl2 solution, and the concentration of the calcium-containing crosslinking agent solution is 0.1 to 0.3 mol / L, preferably 0.1 mol / L; the time of the crosslinking reaction is 50 to 100 min, preferably 60 min.

[0063] The invention also provides a hydrogel film fluorescence sensor.

[0064] The invention also provides an application of a hydrogel film fluorescence sensor in detecting chromate ions.

[0065] The present invention also provides a method for preparing a portable intelligent sensing platform, comprising the following steps:

[0066] Design drawings of portable equipment using Stratasys GrabCAD Print software on a computer;

[0067] Use Stratasys GrabCAD Print software to import 3D drawings into 3D printers;

[0068] The software automatically slices and layers the model according to the structural design, and prints the model material area and the support printing area separately; the material is bonded layer by layer according to the program, and the model is printed layer by layer;

[0069] The accessories and other components are assembled into an intelligent sensing platform, which includes a sensor and a detection device. The sensor is composed of a sensing unit poly(pyrenemethylamine) and a sodium alginate gel substrate. The detection device is a homemade portable detection device, which includes printed accessories, a smart phone, a 365nm LED ultraviolet lamp and a mobile power supply.

[0070] In the present invention, the printing steps are as follows: the software automatically slices and layers according to the structural design, and is divided into a model material printing area and a support printing area; the machine melts the ABS wire with a diameter of 2.0 mm and extrude it from a nozzle with a diameter head of 0.178 mm, and adheres the material layer by layer according to the program to print the model layer by layer; printing parameters: extrusion temperature is 220°C, extrusion speed is 10 mm / s, and ambient temperature is 90°C.

[0071] The invention provides a portable intelligent sensing platform.

[0072] The present invention also provides an application of a portable intelligent sensing platform in the field of photoelectric sensing devices.

[0073] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0074] Example 1

[0075] A method for preparing a conjugated polymer comprises the following steps:

[0076] A one-chamber three-electrode system was used. At a constant voltage of 1.2V, homemade Ag / AgCl was used as the reference electrode, and 1.5cm×1cm rectangular ITO conductive glass was used as the counter electrode and the working electrode. The conjugated polymer precursor pyrenemethylamine was mixed with boron trifluoride ether (electrolyte) and then subjected to constant potential polymerization. The concentration of the conjugated polymer precursor in the electrolyte was 0.02mol / L. The constant potential polymerization was carried out for 24h with a scanning rate of 100mV / s. The obtained polymer film was repeatedly washed with anhydrous ether to remove unpolymerized monomers, and then dried in a vacuum at 60°C to obtain a conjugated polymer.

[0077] The LSV of the conjugated polymer precursor prepared above in boron trifluoride ether is as follows: Figure 1 As shown, the concentration of the conjugated polymer precursor is 0.02 mol / L and the scanning rate is 100 mV / s. Figure 1 It can be seen that the initial oxidation potential of the precursor containing the conjugated polymer in boron trifluoride ether is 0.76V, and the polymerization potential is 1.2V.

[0078] Figure 2 is a CV curve diagram of the conjugated polymer precursor prepared in Example 1 in the voltage range of 0 to 1.6 V (scan rate is 100 mV / s); Figure 2 It can be seen that the current density of the conjugated polymer precursor increases with the increase of the scanning cycle number.

[0079] Example 2

[0080] A method for preparing a hydrogel film fluorescence sensor, such as Figure 3 As shown, the following steps are included:

[0081] like Figure 3As shown, the prepared conjugated polymer was dissolved in N,N-dimethylformamide, filtered through a filter membrane, and 10 mL of fluorescent mother solution of 0.05 g / L was prepared; sodium alginate was added to deionized water to prepare a 2% gel solution, and the solid particles were completely melted by constant temperature stirring at 70°C to obtain a gel solution; 10 mL of the gel solution and 10 mL of the fluorescent mother solution were heated and mixed at 70°C to obtain 3D printing ink; the ink was printed using a DB100 3D printer, the printing nozzle size was 90-250 μm, the 3D printing dispensing speed was 15 mm / s, the dispensing air pressure was 200 kPa, and the printing path was generated by Adobe Illustrator drawing and converted into a scalable vector graphic; after printing, the gel film was dried in an oven at 65°C for 10 min. Finally, the dried hydrogel film was soaked in a 0.1 M CaCl2 solution for 20 min to prepare the final 3D printed PAMP-SA hydrogel film.

[0082] The hydrogel film fluorescence sensor prepared in Example 2 was used for Cr(VI) detection. The specific method was to add aqueous solutions containing different anions and cations (ion types see Figure 4 The concentration of each ion is 10 -4 mol / L) was dropped onto the hydrogel film fluorescence sensor and its fluorescence intensity was immediately measured using a fluorescence spectrometer; Figure 4 Blank in the figure means blank, and the hydrogel film without adding anion and cation aqueous solution is tested.

[0083] Figure 4 This is a test diagram of the ion selectivity of the hydrogel film fluorescence sensor prepared in Example 2; Figure 4 It can be seen that the sensor has specific selectivity for Cr(VI).

[0084] The chromate concentration is 10 -8 ~10 -5 The gradient solutions in the mol / L range (concentrations were 1.1.20×10 - 8 mol / L; 2.2.52×10 -8 mol / L; 3.2.67×10 -8 mol / L; 4.3.19×10 -8 mol / L; 5.5.67×10 -8 mol / L; 6.1.22×10 -7 mol / L; 7.1.75×10 -7 mol / L; 8.3.10×10 -7 mol / L; 9.4.84×10 -7 mol / L; 10.8.45×10 -7mol / L; 11.1.76×10 -6 mol / L; 12.3.14×10 -6 mol / L; 13.1.11×10 -5 mol / L), and aqueous solutions containing different anions and cations (ion types see Figure 4 The concentration of each ion is 10 -4 mol / L) was dropped onto the hydrogel film fluorescence sensor and its fluorescence intensity was immediately measured using a fluorescence spectrometer. Figure 5 This is a sensitivity analysis diagram of the hydrogel film fluorescence sensor prepared in Example 2 to chromate ions (linear curve formed by chromate gradient solution and fluorescence intensity). The experimental results show that the intensity of the titration curve is linearly correlated with the ion concentration in the range of 12nM-11μM, as shown in FIG. Figure 6 As shown. By drawing lg[CrO4 2- ] and lg[I], the calibration curve was constructed to obtain the equation y=4.3780-0.2331x(R 2 =0.9665). The linear relationship shows that the PAMP-SA film prepared by inkjet 3D printing technology is suitable for CrO4 2 Quantitative detection of Figure 6 It can be seen that the hydrogel film can detect CrO4 at the micromole level in real time. 2- .

[0085] Example 3

[0086] The construction of a portable intelligent detection platform, such as Figure 7 As shown, the following steps are included:

[0087] Use the Stratasys GrabCAD Print software to design portable device drawings on a computer;

[0088] Use Stratasys GrabCAD Print software to import 3D drawings into 3D printers;

[0089] The printing steps are as follows: the software automatically slices and layers the model material printing area and the support printing area according to the structural design. The machine melts the 2.0mm diameter ABS wire and extrude it from the 0.178mm diameter nozzle. The material is bonded layer by layer according to the program, and the model is printed layer by layer. The printing parameters are based on the empirical values ​​of the experiment, that is, the extrusion temperature is 220℃, the extrusion speed is 10mm / s, and the ambient temperature is 90℃.

[0090] Assemble the printed accessories, smartphones, 365nm LED UV lamps and mobile power supplies, such as Figure 7 shown. Figure 8 This is a display diagram of the portable printing components. The accessories are: 1. Smart phone; 2. UV lamp chamber; 3. 365nm UV lamp holder; 4. Light door; 5. Sample clamp; 6. Sample chamber; 7. Back cover; 8. Shading strip; 9. Mobile phone holder; 10. Base. Fig. 9 Schematic diagram of the optical path and shooting path of the intelligent detection platform.

[0091] Fig.10 The calibration curve constructed by the chromate gradient solution and the blue channel value in the range of 0.5-150 μM for the intelligent detection platform constructed above is obtained by equation y=0.0046+0.0041x(R 2 =0.9832), the linear relationship shows that the intelligent platform can realize the CrO4 2- Quantitative portable detection of

[0092] As can be seen from the above embodiments, the present invention provides a conjugated polymer, a hydrogel film fluorescent sensor, a portable intelligent sensing platform and a preparation method thereof. The present invention uses a conjugated polymer poly(pyrenemethylamine) as a sensing unit and cross-linked sodium alginate as a gel substrate, and prepares flexible fluorescent films of different shapes as sensing platform sensors through 3D printing technology; through computer design drawings, portable detection device accessories are printed and prepared using 3D printing technology; a portable intelligent detection platform is assembled by assembling hydrogel film, printed portable device accessories, smart phones, 365nm LED ultraviolet lamps and mobile power supplies. The platform can visually detect Cr(VI) in agricultural samples in the outdoor field, solving the problem that traditional fluorescent sensors are difficult to achieve outdoor real-time detection, and realizing the timeliness and spatial flexibility of agricultural pollutant detection.

[0093] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A conjugated polymer, characterized in that The conjugated polymer has the structure shown below: Wherein, n=2-100 and n is a natural number.

2. The method for preparing the conjugated polymer according to claim 1, characterized in that: The following steps are involved: In a three-electrode system, a conjugated polymer precursor, pyrenemethylamine, is subjected to constant potential polymerization in a boron trifluoride ether solution to obtain a conjugated polymer, poly(pyrenemethylamine); The potential of the constant potential polymerization is 1.0-1.5V, the scanning speed is 90-110mV / s, and the polymerization time is 20-26h; The concentration of the conjugated polymer precursor pyrenemethylamine in the boron trifluoride ether solution is 0.01-0.03 mol / L.

3. A method for preparing a hydrogel film fluorescence sensor, characterized in that: The following steps are involved: (1) mixing sodium alginate and water to obtain a gel solution; (2) mixing the conjugated polymer according to claim 1 and an organic solvent to obtain a fluorescent mother solution; (3) mixing the fluorescent mother solution and the gel solution and heating them to obtain a hydrogel ink, and performing 3D printing on the hydrogel ink to obtain a fluorescent gel film; (4) Immersing the fluorescent gel film in a calcium-containing crosslinking agent solution to perform a crosslinking reaction, and then drying to obtain a hydrogel fluorescent film sensor.

4. The method for preparing the hydrogel film fluorescence sensor according to claim 3, characterized in that: In the gel solution, the mass concentration of sodium alginate is 1-3%; The volume ratio of the fluorescent mother solution to the gel solution is 1:1-1.5, the calcium-containing crosslinking agent solution comprises a CaCl2 solution, the concentration of the calcium-containing crosslinking agent solution is 0.1-0.3 mol / L, and the crosslinking reaction time is 50-100 min.

5. The hydrogel film fluorescence sensor prepared by the preparation method according to claim 3 or 4.

6. Use of the hydrogel film fluorescence sensor according to claim 5 in detecting chromate ions.

7. A method for preparing a portable intelligent sensing platform, characterized in that: The following steps are involved: Design drawings of portable equipment using Stratasys GrabCAD Print software on a computer; Use Stratasys GrabCAD Print software to import 3D drawings into 3D printers; The software automatically slices and layers the model according to the structural design, and prints the model material area and the support printing area separately; the material is bonded layer by layer according to the program, and the model is printed layer by layer; Assemble accessories and other components into a smart sensing platform.

8. The method for preparing the portable intelligent sensing platform according to claim 7, characterized in that: The steps of printing are as follows: the software automatically slices and layers according to the structural design, and is divided into a model material printing area and a support printing area; the machine melts the ABS wire with a diameter of 2.0 mm and extrude it from a nozzle with a diameter of 0.178 mm, and adheres the material layer by layer according to the program to print the model layer by layer; printing parameters: extrusion temperature is 220°C, extrusion speed is 10 mm / s, and ambient temperature is 90°C.

9. The portable intelligent sensing platform prepared by the preparation method according to claim 7 or 8.

10. Application of the portable intelligent sensing platform according to claim 9 in the field of photoelectric sensing devices.

Images