A wearable multi-color change chiral lactic acid detection film and a preparation method and application thereof

Abstract

The application provides a wearable multi-color change chiral lactic acid detection film and a preparation method and application thereof. The preparation scheme uses gamma-cyclodextrin MOFs as a chiral source, uses tetracyanoethenyl indene and rhodamine hydrazine as color change response molecules, and uses a layered diffusion method to construct a novel chiral lactic acid sensing material RT@CDMOF. Further, the RT@CDMOF is prepared into a flexible wearable mixed matrix film by using polyether sulfone as a matrix, the RT@CDMOF is uniformly loaded and coated into the film, is attached to a body surface, absorbs lactic acid in sweat to produce color change, and realizes exercise degree health monitoring. The wearable multi-color change chiral lactic acid detection film can realize multi-color change visual detection of the minimum chiral physiological active molecule lactic acid, effectively overcomes defects of an enzyme detection method in stability and the like, realizes rapid and convenient on-site detection and identification, and has important significance for developing a novel and efficient chiral small molecule recognition and detection technology.

Description

Technical Field

[0001] This invention relates to the field of health monitoring technology, specifically to a wearable multicolor chiral lactic acid detection film, its preparation method, and its application. Background Technology

[0002] Chiral molecules often possess completely different physiological activities, making the development of efficient and accurate chiral molecule recognition technologies an urgent need in fields such as drug development and medical diagnostics. The effectiveness of chiral enantiomer recognition is closely related to the structural characteristics of the chiral molecule itself. Macromolecular chiral enantiomers often have significant steric hindrance differences and complex functional groups, making chiral recognition relatively simple. Conversely, small molecule chiral enantiomers exhibit minimal structural differences; their simple molecular structures cannot provide readily available active functional sites for detection and recognition, posing a significant challenge to efficient recognition. Although chiral small molecules have relatively simple structures, they often possess important physiological activities; therefore, developing novel and efficient chiral small molecule recognition and detection technologies is of great significance.

[0003] Lactic acid is the smallest chiral physiologically active molecule and a metabolic product of anaerobic respiration. It is not only an important physiological metabolite but also widely used as a food additive in the food industry. L-lactic acid is a normal metabolic product in the human body, while D-lactic acid is a potential carcinogen. Detecting and differentiating the configuration and content of lactic acid in the human body and food is of great significance. Currently, various recognition technologies based on lactate dehydrogenase are the main methods for detecting and differentiating chiral lactic acid. However, the fragile stability of enzymes and their stringent requirements for application environments such as temperature and pH limit their large-scale and rapid application. Developing novel non-enzymatic sensing technologies based on chemical materials can effectively overcome the shortcomings of enzymes in terms of stability, enabling rapid and convenient on-site detection and identification. However, the extremely small steric hindrance difference between lactate enantiomers poses a significant challenge to the development of non-enzymatic chiral lactic acid recognition technologies. Existing non-enzymatic chiral lactic acid recognition technologies rely on large and complex equipment such as circular dichroism spectroscopy and nuclear magnetic resonance, which are cumbersome and time-consuming to operate. Research on simple and convenient chiral lactic acid detection and identification technologies remains lacking.

[0004] Metal-organic frameworks (MOFs) are a classic class of organic-inorganic hybrid functional materials. Their periodic porous structure and customizable functions make them ideal for developing various novel sensing materials. Currently, various chiral sensing materials developed based on MOFs have shown great development potential. However, due to the extremely small steric hindrance difference between lactic acid enantiomers and the chemical stability of the lactic acid molecule itself, the chiral recognition process of lactic acid is not only difficult but also struggles to generate resolvable signal changes. Developing novel chiral recognition signal analysis techniques based on the functional characteristics of MOFs is crucial for achieving efficient detection and recognition of chiral lactic acid. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a wearable multicolor chiral lactic acid detection film, its preparation method, and its applications. Two probe molecules, tetracyanenyl indene (TCN) and rhodamine hydrazide (RGH), are in situ grown and encapsulated within the pores of γ-cyclodextrin MOFs (CDMOFs), constructing a novel chiral lactic acid sensing material, RT@CDMOF. This material preferentially recognizes L-lactic acid, producing a visible color change from blue to red. This process is accompanied by an enhanced fluorescence emission transition from dark red to bright yellow, making it a chiral lactic acid detection material with multicolor properties. Furthermore, this material is prepared into a flexible, wearable hybrid matrix film using polyethersulfone (PES) as a matrix. RT@CDMOF is uniformly loaded and encapsulated in the film and applied to the body surface. It absorbs lactic acid from sweat, producing color changes, thus enabling health monitoring of exercise levels.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: using chiral cyclodextrin MOFs as chiral sources and TCN and RGH as color-changing response molecules, a novel chiral lactic acid sensing material RT@CDMOF is constructed by using a layered diffusion method.

[0007] The specific steps for preparing the novel chiral lactic acid sensing material RT@CDMOF are as follows: ① Weigh out 2-5 mg of TCN and 12-20 mg of RGH, and dissolve them in 8-15 mL of chloroform to prepare solution A. ② Separately weigh out 0.52-1.20 g of γ-cyclodextrin and 0.18-0.36 g of potassium hydroxide, and dissolve them in 8-20 mL of deionized water to prepare solution B. ③ Carefully add solution B on top of solution A to form a layered mixture. ④ Expose the mixture to saturated methanol vapor and let it stand at room temperature for 3-5 days to obtain dark blue cubic RT@CDMOF crystals.

[0008] The specific steps of the preparation method of the above-mentioned RT@CDMOF flexible wearable hybrid matrix membrane are as follows: ① Weigh 0.15-0.30 g of PES powder and dissolve it in N,N'-dimethylacetamide (DMA, 1-3 mL) by heating to prepare a mother liquor with a concentration of 15-30% (mass / volume). ② Weigh 50-100 mg of freshly prepared RT@CDMOF, grind it, and add it to the PES mother liquor. Stir vigorously to disperse it evenly. ③ Drop the final mixture onto a clean glass surface, carefully smooth it with a spatula, and then dry it at 65-80 ℃ for 1-2 hours to obtain a light blue translucent thin film material.

[0009] The above-mentioned application of a wearable multicolor chiral lactic acid detection membrane is characterized by applying the RT@CDMOF mixed matrix membrane to the body surface and performing aerobic exercise for 30-60 minutes at room temperature. By recording multiple changes in the color and fluorescence of the membrane before and after exercise, the concentration of lactic acid in sweat is indicated, thereby achieving visual monitoring of the exercise level and avoiding bodily damage caused by excessive exercise. Beneficial effects

[0010] Compared with existing technologies, the wearable multicolor chiral lactic acid detection film, its preparation method, and its application, as described in this invention, have the following advantages: This invention utilizes γ-cyclodextrin MOFs as the chiral source and TCN and RGH as the color-changing response molecules to construct a novel chiral lactic acid sensing material, RT@CDMOF, using a layered diffusion method. Furthermore, using PES as a matrix, RT@CDMOF is prepared into a flexible, wearable hybrid matrix membrane. RT@CDMOF is uniformly loaded and coated onto the membrane, and when applied to the body surface, it absorbs lactic acid from sweat, producing a color change to monitor exercise levels and health. This wearable, multi-color-changing chiral lactic acid detection membrane enables the visual detection of lactic acid, the smallest chiral physiologically active molecule, through multiple color changes. It effectively overcomes the shortcomings of enzyme detection methods in terms of stability, achieving rapid and convenient on-site detection and identification. This is of great significance for the development of novel and efficient chiral small molecule recognition and detection technologies. Attached Figure Description

[0011] Figure 1 A schematic diagram of the tetracyanenyl indene (TCN) structure provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of rhodamine hydrazide (RGH) provided in an embodiment of the present invention; Figure 3 Photograph of the RT@CDMOF flexible wearable hybrid matrix membrane provided in Embodiment 1 of the present invention; Figure 4 The PXRD comparison spectra of RT@CDMOF and its flexible wearable hybrid matrix membrane provided in Embodiment 1 of the present invention; Figure 5 These are scanning electron microscope images at different magnifications of the RT@CDMOF flexible wearable hybrid matrix membrane provided in Embodiment 1 of the present invention; Figure 6 This is a cross-sectional scanning electron microscope image of the RT@CDMOF flexible wearable hybrid matrix membrane provided in Embodiment 1 of the present invention; Figure 7 Photographs of the pre-motion thin film provided in Embodiment 1 of the present invention under natural light (left) and ultraviolet light (right); Figure 8The images show the film after motion provided in Embodiment 1 of the present invention under natural light (left) and ultraviolet light (right). Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Unless otherwise specified, specific conditions in the embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used without a specified manufacturer are all commercially available conventional products. The color-changing responsive molecules TCN and RGH were synthesized according to the literature steps; their molecular structures can be found in [reference needed]. Figure 1 and Figure 2 As shown.

[0013] The following is a detailed description of a wearable multicolor chiral lactic acid detection film, its preparation method, and its application according to an embodiment of the present invention.

[0014] This invention provides a wearable multicolor chiral lactic acid detection film, its preparation method, and its application, comprising the following steps: Preparation of chiral lactic acid sensing material RT@CDMOF: TCN (2-5 mg) and RGH (12-20 mg) were weighed and dissolved in 8-15 mL of chloroform to prepare solution A. Separately, 0.52-1.20 g of γ-cyclodextrin and 0.18-0.36 g of potassium hydroxide were weighed and dissolved in 8-20 mL of deionized water to prepare solution B. Solution B was carefully added on top of solution A to form a layered mixture. The mixture was exposed to saturated methanol vapor and allowed to stand at room temperature for 3-5 days to obtain dark blue cubic RT@CDMOF crystals.

[0015] Preparation of RT@CDMOF flexible wearable hybrid matrix membrane: Weigh 0.15-0.30 g of PES powder and dissolve it in N,N'-dimethylacetamide (DMA, 1-3 mL) by heating to prepare a stock solution with a concentration of 15-30% (mass / volume). Weigh 50-100 mg of freshly prepared RT@CDMOF, grind it, and add it to the PES stock solution. Stir vigorously to disperse it evenly. Drop the final mixture onto a clean glass surface, carefully smooth it with a spatula, and then dry it at 65-80 ℃ for 1-2 hours to obtain a light blue translucent thin film material.

[0016] Application of wearable multicolor chiral lactic acid detection membrane: The RT@CDMOF mixed matrix membrane is applied to the body surface and aerobic exercise is performed at room temperature for 30-60 minutes. By recording the multiple changes in the color and fluorescence of the membrane before and after exercise, the concentration of lactic acid in sweat can be indicated, thereby realizing the visual monitoring of exercise intensity and avoiding physical damage caused by excessive exercise.

[0017] The basic working principle of this invention is as follows: The probe molecules TCN and RGH exhibit pH-responsive activity. TCN is deep blue and emits dark red fluorescence in alkaline environments. As the pH gradually decreases, its color gradually turns grayish-white, and the fluorescence intensity decreases accordingly, with a pH abrupt change range of 3-5. RGH is nearly colorless and has almost no fluorescence emission activity in alkaline environments. As the pH gradually decreases, its color gradually turns pink, accompanied by a gradual increase in bright yellow fluorescence, with a pH abrupt change range of 3-5. TCN and RGH have completely opposite pH-responsive activities, and their response abrupt changes occur within roughly the same pH range. After encapsulating RGH and TCN into the CDMOF pore structure, the two probe molecules are surrounded by a chiral environment. Their pH-responsive activity indicates the selectively adsorbed lactic acid molecules, while the CDMOF provides chiral recognition and differentiation, selectively recognizing L-lactic acid molecules through chiral hydrogen bonding and adsorbing and capturing them within the pores. L-lactic acid molecules that are selectively captured enter the CDMOF and, by utilizing the acidity of their carboxyl groups, cause pH response changes in two probe molecules, RGH and TCN, thus exhibiting multiple color-changing behavior. By utilizing changes in color, fluorescence, and other signals, the chiral lactic acid molecules can be detected and identified.

[0018] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0019] Example 1 Example 1 provides a wearable multicolor chiral lactic acid detection film, its preparation method, and its application, which includes the following steps: Preparation of chiral lactic acid sensing material RT@CDMOF: TCN (2 mg) and RGH (12 mg) were weighed and dissolved in 8 mL of chloroform to prepare solution A. Separately, 0.52 g of γ-cyclodextrin and 0.18 g of potassium hydroxide were weighed and dissolved in 8 mL of deionized water to prepare solution B. Solution B was carefully added on top of solution A to form a layered mixture. The mixture was exposed to saturated methanol vapor and allowed to stand at room temperature for 3 days to obtain dark blue cubic RT@CDMOF crystals.

[0020] Preparation of RT@CDMOF flexible wearable hybrid matrix membrane: 0.15 g of PES powder was weighed and dissolved in N,N'-dimethylacetamide (DMA, 1 mL) by heating to prepare a 15% (mass / volume) stock solution. 50 mg of freshly prepared RT@CDMOF was weighed, ground, and added to the PES stock solution, and stirred vigorously to disperse it evenly. The final mixture was dropped onto a clean glass surface, carefully smoothed with a spatula, and then dried at 65 °C for 1 hour to obtain a light blue translucent thin film material. Figure 3 ), and passed the PXRD test ( Figure 4 ), Scanning electron microscopy test ( Figure 5 and Figure 6 The structure and morphology of the RT@CDMOF flexible wearable hybrid matrix membrane were characterized and analyzed.

[0021] Application of wearable multicolor chiral lactate detection membrane: The RT@CDMOF hybrid matrix membrane was applied to the body surface, and the patient underwent 30 minutes of aerobic exercise at room temperature. The multiple changes in the color and fluorescence of the membrane before and after exercise were recorded. Figure 7 and Figure 8 The feedback indicates that the concentration of lactic acid in sweat is 10 ppm, thereby enabling visual monitoring of exercise intensity.

[0022] Example 2 Example 2 provides a wearable multicolor chiral lactic acid detection film, its preparation method, and its application, which includes the following steps: Preparation of chiral lactic acid sensing material RT@CDMOF: TCN (3 mg) and RGH (15 mg) were weighed and dissolved in 12 mL of chloroform to prepare solution A. Separately, 0.80 g of γ-cyclodextrin and 0.24 g of potassium hydroxide were weighed and dissolved in 15 mL of deionized water to prepare solution B. Solution B was carefully added on top of solution A to form a layered mixture. The mixture was exposed to saturated methanol vapor and allowed to stand at room temperature for 4 days to obtain dark blue cubic RT@CDMOF crystals.

[0023] Preparation of RT@CDMOF flexible wearable hybrid matrix film: 0.20 g of PES powder was weighed and dissolved in N,N'-dimethylacetamide (DMA, 2 mL) by heating to prepare a 20% (mass / volume) stock solution. 75 mg of freshly prepared RT@CDMOF was weighed, ground, and added to the PES stock solution, and stirred vigorously to disperse it evenly. The final mixture was dropped onto a clean glass surface, carefully smoothed with a spatula, and then dried at 70 ℃ for 1.5 hours to obtain a light blue translucent thin film material. The structure and morphology of the RT@CDMOF flexible wearable hybrid matrix film were characterized and analyzed by PXRD and scanning electron microscopy.

[0024] Application of wearable multicolor chiral lactic acid detection membrane: The RT@CDMOF mixed matrix membrane is applied to the body surface and aerobic exercise is performed at room temperature for 45 minutes. By recording the multiple changes in the color and fluorescence of the membrane before and after exercise, feedback indicates that the concentration of lactic acid in sweat is 20 ppm, thereby realizing the visual monitoring of exercise intensity and avoiding physical damage caused by excessive exercise.

[0025] Example 3 Example 3 provides a wearable multicolor chiral lactic acid detection film, its preparation method, and its application, which includes the following steps: Preparation of chiral lactic acid sensing material RT@CDMOF: TCN (5 mg) and RGH (20 mg) were weighed and dissolved in 15 mL of chloroform to prepare solution A. Separately, 1.20 g of γ-cyclodextrin and 0.36 g of potassium hydroxide were weighed and dissolved in 20 mL of deionized water to prepare solution B. Solution B was carefully added on top of solution A to form a layered mixture. The mixture was exposed to saturated methanol vapor and allowed to stand at room temperature for 5 days to obtain dark blue cubic RT@CDMOF crystals.

[0026] Preparation of RT@CDMOF flexible wearable hybrid matrix film: 0.30 g of PES powder was weighed and dissolved in N,N'-dimethylacetamide (DMA, 3 mL) by heating to prepare a 30% (mass / volume) stock solution. 100 mg of freshly prepared RT@CDMOF was weighed, ground, and added to the PES stock solution, and stirred vigorously to disperse it evenly. The final mixture was dropped onto a clean glass surface, carefully smoothed with a spatula, and then dried at 80 °C for 2 hours to obtain a light blue translucent thin film material. The structure and morphology of the RT@CDMOF flexible wearable hybrid matrix film were characterized and analyzed by PXRD and scanning electron microscopy.

[0027] Application of wearable multicolor chiral lactic acid detection membrane: The RT@CDMOF mixed matrix membrane is applied to the body surface and aerobic exercise is performed for 60 minutes at room temperature. By recording the multiple changes in the color and fluorescence of the membrane before and after exercise, the concentration of lactic acid in sweat is indicated to be 30 ppm, thereby realizing the visual monitoring of exercise intensity and avoiding physical damage caused by excessive exercise.

[0028] In summary, the preparation method of the RT@CDMOF wearable multicolor chiral lactic acid detection film of this invention is simple; when applied to the body surface, it absorbs lactic acid in sweat and produces a color change, realizing real-time health monitoring of exercise levels. It effectively overcomes the defects of enzyme detection methods in terms of stability, etc., and can quickly and conveniently perform on-site detection and identification, which is of great significance for the development of new and efficient chiral small molecule recognition and detection technologies.

[0029] The embodiments described above are some, but not all, embodiments of the present invention. The detailed description of the embodiments of the present invention is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for preparing a chiral lactic acid sensing material RT@CDMOF, characterized in that, Includes the following steps: (1) Dissolve 2-5 mg of tetracyanenylindene (TCN) and 12-20 mg of rhodamine hydrazide (RGH) in 8-15 mL of chloroform to obtain solution A; (2) Dissolve 0.52-1.20 g of γ-cyclodextrin and 0.18-0.36 g of potassium hydroxide in 8-20 mL of deionized water to obtain solution B; (3) Carefully add solution B on top of solution A to form a layered mixed solution; (4) Expose the layered mixed solution to saturated methanol vapor and let it stand at room temperature for 3-5 days to obtain dark blue blocky RT@CDMOF crystal material.

2. The chiral lactic acid sensing material RT@CDMOF prepared by the method according to claim 1.

3. A method for preparing a wearable multicolor chiral lactic acid detection membrane, characterized in that, Includes the following steps: (1) Weigh 0.15-0.30 g of polyethersulfone (PES) powder, heat and dissolve it in 1-3 mL of N,N-dimethylacetamide (DMA) to prepare a polyethersulfone mother liquor with a concentration of 15-30% (mass / volume). (2) Weigh 50-100 mg of the freshly prepared chiral lactic acid sensing material RT@CDMOF as described in claim 2, grind it, add it to the polyethersulfone mother liquor, and stir vigorously to disperse it evenly to obtain a mixture; (3) The mixture is dropped onto a clean glass surface, carefully smoothed with a scraper, and then dried at 65-80°C for 1-2 hours to obtain a light blue semi-transparent film material, which is the wearable multicolor chiral lactic acid detection film.

4. The wearable multicolor chiral lactic acid detection membrane prepared by the method according to claim 3.

5. The application of the wearable multicolor chiral lactic acid detection film according to claim 4 in health monitoring of exercise intensity, characterized in that, The film is applied to the body surface, absorbs lactic acid in sweat and produces a color change, thus enabling health monitoring of exercise levels.

6. The application according to claim 5, characterized in that, The film is applied to the body surface, and aerobic exercise is performed for 30-60 minutes at room temperature. By recording multiple changes in the color and fluorescence of the film before and after exercise, feedback can be provided to indicate the concentration of lactic acid in sweat, thus achieving visual monitoring of the exercise level and avoiding bodily damage caused by excessive exercise.

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