A flexible anti-pollution porous film and its preparation method and application
By using flexible anti-polluting porous films on wearable electrochemical sensors, the anti-polluting mass transmission channel is constructed, and the pollution problem of the sensor when detecting human body fluids is solved, high stability and reliability electrochemical detection is achieved, and the equipment is extended service life.
Patent Information
- Application Number
- CN202310435156.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-04-21
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2043-04-21
AI Technical Summary
When detecting human body fluids, existing wearable electrochemical sensors are susceptible to the influence of contaminants such as skin debris, protein and oil pollution in human body, resulting in a decrease in sensitivity and reliability, making it difficult to achieve real-time detection in situ.
A flexible anti-polluting porous film is adopted. By combining green tea with PVDF membrane, and modifying tea polyphenols and APTES on the surface, adding anti-polluting polypeptides to form micron-sized porous channels to build anti-polluting mass transmission channels to avoid large pollution pollution of matter.
The porous film can directly perform sweat detection without sample pretreatment, which improves the stability and reliability of electrochemical detection, extends the service life of the sensor, and ensures biocompatibility and no allergic reactions.
Smart Images
Figure CN116465940B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of sensor technology, and more particularly to a flexible anti-pollution porous film and a preparation method and application thereof. Background Art
[0002] In recent years, wearable electrochemical sensors have shown broad application prospects in human health monitoring due to their many advantages such as portability and ease of operation. Wireless wearable devices provide a non-invasive method to extract physiological parameters indicating health status in real time and transmit data continuously to the user's mobile device. Wearable devices that can detect various physical signals such as pulse, respiratory rate, and body temperature are being widely commercialized and integrated into daily life. However, such wearable devices cannot provide deeper molecular-level information in human body fluids (blood, interstitial fluid, tears, urine, and sweat). Human body fluids contain a large number of biomarkers, including electrolytes, metabolites, amino acids, hormones, and drugs that can be analyzed by wearable electrochemical sensors. Their composition changes dynamically with changes in health, stress, and diet. According to literature reports, the analysis of human body fluids can basically replace blood analysis. Therefore, continuous monitoring of biomarkers in human body fluids other than blood has the potential to complement laboratory-based blood analysis results, making real-time monitoring of daily health status and early disease detection and management possible.
[0003] Although great progress has been made in the research of flexible wearable sweat sensors at home and abroad in recent years, there is still a gap from practical application. At present, such wearable sensors have not been commercialized and marketed. The main reason is that the composition of body fluids is very complex. A large amount of skin debris, protein and a large amount of human oil will contaminate and passivate the electrodes, resulting in a decrease in the sensitivity and reliability of the sensor. Before the existing electrochemical sensor detection, the test sample needs to be pre-treated to remove most of the substances that will contaminate the electrode, and then the test is carried out. This pre-treatment method is suitable for laboratory detection range, which is not conducive to the in-situ real-time application of wearable sensors.
[0004] If wearable sensors are used to collect body fluids on the body, some large pollutants such as skin debris, proteins, and a large amount of human oil can be blocked in advance before electrochemical sensing during the in-situ mass transfer of body fluids, the stability and reliability of wearable electrochemical sensors can be greatly improved, which is of great significance for the practical application of experimental wearable sensors. However, there is currently little research on the anti-pollution of wearable electrochemical sensors in the mass transfer process, and there is an urgent need to develop anti-pollution wearable flexible materials. Summary of the invention
[0005] In view of this, the present invention provides a flexible anti-pollution porous film and a preparation method thereof and its application in a wearable sensor. The film of the present invention can construct an anti-pollution mass transfer channel before the body fluid is transferred to the working electrode surface, during the mass transfer process, which will greatly avoid the contamination of large pollutants, thereby improving the stability and reliability of electrochemical detection and extending the service life of the wearable sensor.
[0006] In order to achieve the above object, the present invention adopts the following technical solution:
[0007] A method for preparing a flexible anti-pollution porous film comprises the following steps:
[0008] (1) mixing green tea with water, adjusting the pH, stirring and shaking, filtering to obtain a green tea solution, and further adjusting the pH of the green tea solution for later use;
[0009] (2) The PVDF membrane was soaked in isopropanol for a period of time, and the surface of the PVDF membrane was repeatedly rinsed with water for 3 times to obtain a pre-treated membrane. The pre-wetted PVDF membrane was then soaked in a green tea aqueous solution and shaken for 6-24 hours. During the shaking process, an APTES ethanol solution and 10 mL, 5 mg mL -1 Sodium periodate aqueous solution, and finally, washed with deionized water to obtain tea polyphenol-APTES modified PVDF membrane;
[0010] (3) Mixing the tea polyphenol-APTES modified PVDF membrane with the anti-pollution polypeptide solution at room temperature, taking it out after completion, washing it, and drying it to obtain the flexible anti-pollution porous film.
[0011] Furthermore, the mass volume ratio of green tea to water in step (1) is 4g:120mL.
[0012] Furthermore, in step (1), the first step of adjusting the pH is to adjust the pH to 3 using HCl.
[0013] Furthermore, the stirring and shaking in step (1) is performed at a stirring speed of 130 r / min, and the stirring and shaking is performed at 60° C. for 50 minutes.
[0014] Furthermore, in step (1), the pH of the green tea solution is adjusted to 7.8 using alkaline Tris.
[0015] Furthermore, the PVDF membrane is immersed in step (2) for 30 minutes.
[0016] Furthermore, the concentration of the anti-pollution polypeptide solution in step (3) is 2 mg / mL, and the anti-pollution polypeptide is Cekekekek, wherein C represents cysteine, e represents glutamic acid, k represents lysine, lowercase represents D-type amino acid, and uppercase represents L-type amino acid.
[0017] Another object of the present invention is to provide a flexible anti-pollution porous film, which is prepared by the above-mentioned method for preparing the flexible anti-pollution porous film.
[0018] Another object of the present invention is to provide an application of the above-mentioned flexible anti-pollution porous film in a wearable sensor.
[0019] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:
[0020] 1) It can provide a porous channel with a micron size that can filter pollutants, so that biological fluids can be transferred from different directions, and can also ensure the mass transfer of sweat from bottom to top. In the process of mass transfer, the membrane also has an anti-pollution function, and sweat detection can be performed directly without sample pretreatment.
[0021] 2) The porous film has good flexibility, and the polypeptide-modified PVDF surface has very good biocompatibility, can better fit with human tissue, and will not cause allergies. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.
[0023] Figure 1 Schematic diagram of anti-pollution of wearable electrochemical sensors.
[0024] Figure 2 These are microscopic characterization images of the porous film of the present invention, wherein A is a surface scanning electron microscope image of the flexible mass transfer film; B. - a cross-sectional scanning electron microscope image of the flexible mass transfer film; C - an internal scanning electron microscope image of the flexible mass transfer film; D - an enlarged scanning electron microscope image of the interior of the flexible mass transfer film.
[0025] Figure 3 It is the mass transfer process and hydrophilic diffusion process of the porous film in different directions of the present invention.
[0026] Figure 4 The wearable sensor of the present invention monitors the E of different concentrations of uric acid (UA) OCV Signal response graph.
[0027] Figure 5 This is the DPV anti-pollution data of the wearable sensor of the present invention in different biological fluids. DETAILED DESCRIPTION
[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0029] Example 1
[0030] Materials and reagents
[0031] The anti-fouling peptides are Cekekekek (lowercase letters represent D amino acids, uppercase letters represent L amino acids), green tea, PVDF membrane, Tris, and bovine serum albumin (BSA).
[0032] Material preparation process
[0033] (1) Preparation of tea polyphenol modified flexible mass transfer PVDF membrane: First, 4 g of green tea was mixed with 120 mL of deionized water, and the pH of the solution was adjusted to 3 using HCl, and the mixture was shaken at 130 r / min and 60 °C for 50 minutes. Then, the tea leaves were filtered through a funnel to obtain a clear green tea solution, to which alkaline Tris was added to adjust the pH of the green tea solution to 7.8. Tea polyphenols have excellent acid resistance and are stable under acidic conditions. When the pH of the green tea solution is adjusted to alkaline, tea polyphenols become unstable and can be gradually precipitated from the solution through an oxidation reaction and deposited on the membrane by its own gravity, and firmly adhere to the membrane surface. Then, the flexible mass transfer PVDF membrane was soaked in isopropanol for 30 minutes, and the membrane surface was repeatedly rinsed with deionized water to obtain a pretreated membrane. The membrane was then soaked in green tea solution for 12 hours, and APTES ethanol solution and 10 mL, 5 mg mL -1 Sodium periodate aqueous solution. The control group used deionized water to pretreat the membrane for 12 hours by immersion method.
[0034] (2) Preparation of polypeptide anti-pollution modified flexible mass transfer membrane: Mix tea polyphenol-APTES modified flexible mass transfer PVDF membrane with 2 mg / mL anti-pollution polypeptide solution (Cekekek) at room temperature for 12 h. Finally, take out the anti-pollution flexible mass transfer membrane, clear ultrapure water, and dry it.
[0035] Figure 2 is a microscopic morphology diagram of the porous film in the present invention, from Figure 2 A shows that the surface of the flexible mass transfer film has densely packed pores ( Figure 2 A), and from the cross-sectional structure ( Figure 2 B and 2C) and the internal structure enlarged image ( Figure 2D) It can be seen that the flexible mass transfer membrane has a microporous structure with a pore size of approximately micrometer level and a large specific surface area, which can ensure the smooth passage of body fluids.
[0036] Example 2
[0037] The porous film obtained in Example 1 is used in a wearable sensor, such as Figure 1 As shown in the figure, a schematic diagram of the anti-pollution of a flexible wearable electrochemical sensor that can be monitored in situ (the left figure is the actual figure), which includes an anti-pollution electrochemical sensor and an anti-pollution flexible mass transfer film (right figure); the anti-pollution porous film can be used as a flexible film, covering the surface of the electrochemical sensor, and the back side can directly contact the human tissue, which can provide a porous channel for filtering micron-sized pollutants, so that biological fluids can be transferred from different directions, and can also ensure the mass transfer of human sweat from bottom to top. In this process, the anti-pollution porous film not only has the function of sweat mass transfer, but also can block large-sized pollutants through the pore size exclusion effect, so that the pollutants are isolated outside the wearable sensor, thereby avoiding contamination of the electrode. In addition, the anti-pollution hydrophilic polypeptide modified in the pore can ensure that hydrophobic pollutants will not be adsorbed on the surface of the flexible material to block the pore, and can also achieve the anti-adsorption effect of small-sized proteins in the mass transfer process. The flexible hydrogel material modified on the surface of the working electrode is a natural body fluid absorbent, which has the functions of storing body fluids, ion conduction and sensing, and can realize the function of detecting markers in body fluids in situ.
[0038] Data experiment:
[0039] Flexible mass transfer membrane hydrophilicity test and anti-fouling test process:
[0040] 1. Hydrophilicity test: above the mass transfer flexible membrane ( Figure 3 A, 3A1), below ( Figure 3 B), and lateral ( Figure 3 C) 50 μL water drops were added respectively to observe the mass transfer process and hydrophilic diffusion process of the flexible mass transfer film at different times.
[0041] 2. Evaluation of antifouling performance: Fluorescently labeled bovine serum albumin solution was dropped onto the surface of the flexible mass transfer film and allowed to stand for 2 hours. The amount of adsorbed protein on the surface was tested by a laser confocal tester to evaluate its antifouling performance. In addition, the flexible mass transfer film and the electrochemical sensor device were treated together in different complex environments (human sweat, urine, saliva, blood, etc.) for 0.5 hours, and then the antifouling performance test was carried out. The differential pulse voltammetry (DPV) signal change rate before and after different body fluid treatment was recorded to evaluate the antifouling performance ( Figure 5 ).
[0042] 3. Sensing test: The catalytic performance and specificity of the flexible electrochemical sensor for markers such as vitamin C and uric acid in PBS buffer solution were investigated by DPV, and the open circuit voltage (E OCV ); Finally, the electrochemical sensor detects vitamin C and uric acid in human sweat and transmits the monitoring signal to the mobile phone via Bluetooth device, realizing the home detection function of human metabolism ( Figure 4 ).
[0043] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.
[0044] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a flexible anti-pollution porous film, characterized in that: The following steps are involved: (1) Mix green tea and water, adjust the pH, stir and shake, filter to obtain a green tea solution, continue to adjust the pH of the green tea solution, and set aside; (2) Soaking the PVDF membrane in isopropanol for a period of time, washing the surface of the PVDF membrane with water to obtain a pretreated membrane, and then soaking the pre-wetted PVDF membrane in a green tea aqueous solution and shaking it for 6-24 hours. During the shaking process, APTES ethanol solution and sodium periodate aqueous solution were added. Finally, the tea polyphenol-APTES modified PVDF membrane was washed with deionized water. (3) Mixing the tea polyphenol-APTES modified PVDF membrane with the anti-pollution polypeptide solution at room temperature, taking it out after the mixture is finished, washing it, and air-drying it to obtain the flexible anti-pollution porous film; the concentration of the anti-pollution polypeptide solution is 2 mg / mL, and the anti-pollution polypeptide is Cekekekek; in the formula, C represents cysteine, e represents glutamic acid, and k represents lysine, lowercase represents D-type amino acids, and uppercase represents L-type amino acids.
2. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: The mass volume ratio of green tea to water in step (1) is 4 g:120 mL.
3. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: The first step of adjusting the pH in step (1) is to adjust the pH to 3 using HCl.
4. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: The stirring speed of the stirring and shaking in step (1) is 130 r / min, and the shaking is carried out at 60° C. for 50 minutes.
5. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: The step (1) of adjusting the pH of the green tea solution is to use alkaline Tris to adjust the pH of the green tea solution to 7.
8.
6. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: In step (2), the PVDF membrane is immersed in isopropanol for 30 min and rinsed 3 times.
7. The method for preparing a flexible anti-pollution porous film according to claim 1, characterized in that: The concentration of the sodium periodate aqueous solution in step (2) is 5 mg mL -1 .
8. A flexible anti-pollution porous film, characterized in that: The porous film is prepared by the method for preparing the flexible anti-pollution porous film according to any one of claims 1 to 7.
9. Use of a flexible anti-pollution porous film as claimed in claim 8 in a wearable sensor.