Transition metal functionalized covalent organic framework material as well as preparation method and application thereof

Abstract

The invention relates to a preparation method and application of a transition metal functionalized covalent organic framework material, and belongs to the technical field of nano materials, analytical chemistry and electrochemistry. The transition metal functionalized covalent organic framework material disclosed by the invention is a complex polymer formed by cobalt (II) functionalized (R)-PTCDA-RMP COF; the material is low in raw material cost, simple in preparation process and low in reaction energy consumption, and has industrial application prospects; an electrogenerated chemiluminescence sensor constructed by the material can realize recognition and analysis of (-)-menthol, (+)-menthol and many common bioactive small molecules; the invention provides a new technical path for solving the problems of distinguishing and analyzing (-)-menthol from (+)-menthol and other bioactive small molecules thereof in complex systems such as natural extracts and preparations.

Description

Technical Field

[0001] This invention relates to a transition metal functionalized covalent organic framework material, its preparation method and application, belonging to the fields of nanomaterials, analytical chemistry and electrochemistry. Background Technology

[0002] Among the enantiomers of menthol, (-)-menthol possesses clear cooling sensory activity and medicinal value, including analgesic and antibacterial effects. It is also a core functional component in food cooling agents, pharmaceutical excipients, and cosmetic active ingredients. (+)-menthol, however, has no effective function and is considered a trace harmful impurity. When the (+)-menthol content is below 0.1%, it can lead to unpleasant sensory experiences such as bitterness in the product, or compromise the efficacy and stability of pharmaceutical preparations. Especially in menthol-containing ointments and compound menthol nasal drops, the optical purity of (-)-menthol directly determines the efficacy: if the (+)-menthol content exceeds the standard (i.e., >0.5%), it will not only reduce the analgesic and other therapeutic effects but may also cause safety risks such as skin irritation. Therefore, achieving efficient identification and trace quantification of (-) / (+)-menthol is a core technical requirement for ensuring the quality and safety of menthol-based products.

[0003] Traditional chiral gas chromatography (GC) and high-performance liquid chromatography (HPLC) detection require two steps: first, enantiomeric separation is achieved through a chiral chromatographic column, and then quantification is completed through a detector. This process is fragmented. It requires complex chromatographic column systems and optical detection modules (such as ultraviolet lamps and ion sources), which are bulky and have poor portability. For the "on-site quality control" needs of scenarios such as peppermint oil production lines, food processing plants, and cosmetic workshops, it is impossible to achieve real-time detection of each batch of products, resulting in long detection cycles and severely restricting production efficiency.

[0004] In response to the shortcomings of the above-mentioned traditional technologies, electrochemiluminescence (ECL) technology exhibits unique adaptability. This technology is a novel analytical method that combines electrochemistry and chemiluminescence. Its core mechanism is "electrochemical excitation-luminescence signal amplification". By integrating functional elements on the surface of the working electrode, it can specifically solve the core pain points of menthol enantiomer detection. The specific advantages are as follows: (1) ECL instruments do not require the complex optical systems (such as ultraviolet lamps and ion sources) required by GC and HPLC. The working electrode and signal acquisition module can be integrated into a chip-level device, with a volume of only 1 / 100 of that of traditional GC instruments; (2) This miniaturized device can be applied to on-site scenarios such as peppermint oil production lines and food processing plants to realize real-time monitoring of the enantiomer composition of each batch of products. The detection cycle is shortened from the traditional "days" to "minutes", significantly improving production efficiency; (3) Its innovative design of "integration of chiral recognition element-ECL luminescence signal element" breaks the traditional technical paradigm of "separation-detection" separation of chiral detection, providing a new direction for the development of chiral compound analysis technology, and has significant academic innovation value and industrial application prospects.

[0005] The key technology for ECL chiral detection of (-)-menthol and (+)-menthol enantiomers is to design and select chiral materials that match the configuration of menthol, and then modify them on the electrode surface. The specific distinction between the enantiomers is achieved by utilizing the slight difference in their interaction with the menthol enantiomers.

[0006] Covalent organic frameworks (COFs) are one-dimensional, two-dimensional, or three-dimensional framework structures that rely entirely on strong covalent bonds (such as CC, CN, CO, etc.) to link organic monomers (such as aromatic polyamines, polyaldehydes, polyphenols, etc.) with specific geometries into a framework structure. Their chemical stability (resistance to acids and alkalis, and organic solvents) and thermal stability are far superior to traditional chiral materials (such as chiral polymers and metal-organic frameworks MOFs), which can avoid signal drift caused by material degradation during detection. COFs have designable topologies and abundant active sites, which can be used to construct "chiral recognition sites" by modifying chiral units, specifically binding to target enantiomers. At the same time, the large specific surface area of ​​COFs can enrich the analyte molecules, combined with the "high sensitivity and low background signal" characteristics of ECL. In addition, the structural tunability of COFs (such as pore size and functional groups) allows them to be adapted to different types of chiral molecules. Summary of the Invention

[0007] One of the technical objectives of this invention is to overcome the shortcomings of the prior art and provide a transition metal functionalized covalent organic framework material, namely Co. 2+ Functionalized chiral covalent organic framework material (R)-PTCDA-RMP COF, i.e. (R)-PTCDA-RMP COF supported on cobalt(II) complex polymer; The second technical objective of this invention is to provide the Co 2+ A method for preparing functionalized (R)-PTCDA-RMP COF is presented. This method uses low-cost raw materials, has a simple preparation process, and low reaction energy consumption, making it promising for industrial applications.

[0008] The third technical objective of this invention is to provide the Co 2+ The application of functionalized (R)-PTCDA-RMP COF is to construct an electrochemiluminescence sensor that enables the identification and analysis of (-)-menthol, (+)-menthol, and many common bioactive small molecules. This provides a solution to the problem of distinguishing (-)-menthol from (+)-menthol and other bioactive small molecules in complex systems such as natural extracts and formulations, and lays the foundation for subsequent activity evaluation or quality control.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: 1. A transition metal functionalized covalent organic framework material, wherein the transition metal functionalized covalent organic framework material is a cobalt(II) functionalized (R)-PTCDA-RMP COF material, which is essentially a covalent organic framework (R)-PTCDA-RMPCOF loaded with cobalt(II); The cobalt(II) functionalized (R)-PTCDA-RMP COF material has a carbon mass percentage of 90.88% and an atomic percentage as high as 97.35%; while the cobalt mass percentage is 9.12% and the atomic percentage is 2.65%; indicating that the material is mainly composed of a carbon framework. The cobalt(II)-functionalized (R)-PTCDA-RMP COF material has a (R)-PTCDA-RMP COF crystal structure, i.e., Co 2+ The coordination did not change the topological connection mode and repeating unit structure of (R)-PTCDA-RMP COF, but the crystal had defects and the crystallinity was reduced. The cobalt(II)-functionalized (R)-PTCDA-RMP COF material, used to construct a chiral electrochemiluminescence (ECL) sensor, exhibits a significantly higher ECL signal intensity for recognizing (-)-menthol than that for recognizing many common bioactive small molecules; it can be used to distinguish and analyze (-)-menthol from many common bioactive small molecules. The commonly used bioactive small molecules are as follows: (+)-Menthol (MENTH), D-cysteine ​​(Cys), L-cysteine ​​(Cys), D-cysteine ​​hydrochloride (Cysm), L-cysteine ​​hydrochloride (Cysm), D-alanine (Ala), L-alanine (Ala), D-methionine (Met), L-methionine (Met), D-glutamic acid (Glu), L-glutamic acid (Glu), D-arginine (Arg), L-arginine (Arg), D-tyrosine (Tyr), L-tyrosine (Tyr), D-penicillamine (Pen), L-penicillamine (Pen), L-carnitine, L-carnitine, D-lactic acid (HL), L-lactic acid (HL), D-serine (Ser), L-serine (Ser), D-aspartic acid (Asp), L - Aspartic acid (Asp), D-mandelic acid (Rmn), L-mandelic acid (Rmn), R-naproxen (Nap), S-naproxen (Nap), D-tryptophan (Trp), L-tryptophan (Trp); The (R)-PTCDA-RMP COF has the following structural formula: .

[0010] 2. The transition metal functionalized covalent organic framework material as described in 1 is prepared by the following method: 50 mL of N,N-dimethylformamide DMF was added to 0.0500 g of covalent organic framework (R)-PTCDA-RMP COF. After ultrasonic dispersion, 20 mL of an aqueous solution containing 0.0218 g of cobalt nitrate hexahydrate was added. The mixture was stirred at room temperature for 24 h, centrifuged, and the product was washed multiple times with deionized water until the washing water was clear. The product was then vacuum dried in an oven at 60 °C to obtain cobalt(II) functionalized (R)-PTCDA-RMP COF material, i.e., transition metal functionalized covalent organic framework material. The (R)-PTCDA-RMP COF is synthesized using a solvothermal method according to patent application number 2024118556754, with the following steps: 1.5 mM of 3,4,9,10-perylenetetracarboxylic acid dianhydride (PTCDA) was blended with 4.5 mM of (R)-(-)-2-methylpiperazine (RMP), and 60 mM of imidazole catalyst was added. The mixture was heated at 120 °C for 24 h with stirring. After the reaction was completed, the system was cooled to 85 °C, filtered, and the obtained solid was washed five times with deionized water to remove unreacted starting materials and catalyst. The solid was then dried under vacuum at 80 °C to remove the solvent and achieve high porosity, yielding a one-dimensional chiral covalent organic framework (R)-PTCDA-RMP COF.

[0011] 4. The application of the transition metal-functionalized covalent organic framework material described above for detecting (-)-menthol and many common bioactive small molecules, the steps of which are as follows: (1) Preparation of working electrode The platinum-carbon electrode GCE with a diameter of 4 mm was finely polished using 0.05 μm α-Al2O3 polishing powder; then the electrode was ultrasonically washed in ultrapure water and ethanol baths in sequence, and then dried at room temperature. Accurately weigh 3 mg of cobalt(II)-functionalized(R)-PTCDA-RMP COF material and the designed amount of (-)-menthol, add them to 1 mL of N,N-dimethylformamide, and sonicate to disperse them to obtain a homogeneous solution of [cobalt(II)-functionalized(R)-PTCDA-RMP COF+(-)-menthol] with a concentration of 3 mg / mL; take 8 μL of this solution and carefully coat it onto the surface of the glassy carbon electrode GCE, and air dry it at room temperature; finally, rinse the electrode with ultrapure water to remove any non-specifically adsorbed substances, and air dry it at room temperature to obtain the GCE / [cobalt(II)-functionalized(R)-PTCDA-RMP COF+(-)-menthol] working electrode; By replacing (-)-menthol with other common bioactive small molecules, a GCE / [cobalt(II)-functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule] working electrode was prepared; The commonly used bioactive small molecules are selected from one of the following: (+)-menthol (MENTH), D-cysteine ​​(Cys), L-cysteine ​​(Cys), D-cysteine ​​hydrochloride (Cysm), L-cysteine ​​hydrochloride (Cysm), D-alanine (Ala), L-alanine (Ala), D-methionine (Met), L-methionine (Met), D-glutamic acid (Glu), L-glutamic acid (Glu), D-arginine (Arg), L-arginine (Arg), D-tyrosine (Tyr), L-tyrosine (Tyr), D-penicillamine (Pen), L-penicillamine (Pen), L-carnitine, L-carnitine, D-lactic acid (HL), L-lactic acid (HL), D-serine (Ser), L-serine (Ser), D-aspartic acid (Asp), L - Aspartic acid (Asp), D-mandelic acid (Rmn), L-mandelic acid (Rmn), R-naproxen (Nap), S-naproxen (Nap), D-tryptophan (Trp), L-tryptophan (Trp); (2) Construction of electroluminescent chemiluminescence (ECL) sensor The GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(-)-menthol] working electrode or the GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule] working electrode prepared in step (1) is combined with an Ag / AgCl reference electrode and a platinum wire auxiliary electrode to form a three-electrode system. The three-electrode system is connected to an electrochemiluminescence analysis system. 0.10 M K2S2O8 and 0.1 M PBS are used as co-reactants. The pH value of the co-reactants is adjusted to 8.0 to form an ECL sensor for detecting (-)-menthol and other common bioactive small molecules. The ECL measured the photomultiplier tube voltage at 600 V, with a potential scan range from 0 to -1.6 V and a scan rate of 200 mV / s.

[0012] (3) Draw the standard curve Using different concentrations of (-)-menthol or (+)-menthol, a series of GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(-)-menthol] or GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(+)-menthol] working electrodes were constructed. The ECL signal was measured as described in step (2), and the ECL luminescence intensity versus concentration curve was plotted. (4) Replace (-)-menthol or (+)-menthol with the sample to be tested and detect its concentration with reference to the standard curve.

[0013] Studies have found that the ECL luminescence intensity of (-)-menthol or (+)-menthol is positively correlated with their concentration, as follows: I (-)-薄荷醇 = 4327.95 C +3712.08, R 2 = 0.9853 and I (+)-薄荷醇 = 1565.60 C +618.72, R 2 = 0.8716, and the limit of detection is 0.073 mmol / L.

[0014] Beneficial technical effects of the present invention 1. This invention utilizes the unique phenomenon of changes in electrochemiluminescence (ECL) characteristics caused by the complex polymer formed by cobalt(II) supported by (R)-PTCDA-RMP COF, opening up a new pathway for detecting (-)-menthol and (+)-menthol, as well as other common bioactive small molecules; this technology aims to overcome the limitations of existing detection technologies in the chiral analysis of menthol, providing a low-cost and highly sensitive detection method for chiral sensing.

[0015] 2. The preparation of the (R)-PTCDA-RMP COF-supported cobalt(II) complex polymer of the present invention involves only (R)-PTCDA-RMP COF and Co... 2+ The (R)-PTCDA-RMP COF was prepared by stirring at room temperature, while the (R)-PTCDA-RMP COF was prepared by a simple solvothermal synthesis method using achiral 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) and chiral (R)-2-methylpiperazine RMP. The entire preparation method is simple, easy to operate, and suitable for industrial promotion.

[0016] 3. The present invention constructs an electrochemiluminescence (ECL) chiral sensor using a cobalt(II)-cobalt (R)-PTCDA-RMP COF-loaded complex polymer. Due to (-)-menthol, its ECL signal intensity is significantly higher than that of (+)-menthol and a series of common bioactive small molecules. It can be successfully used to identify and detect (-)-menthol, (+)-menthol and other common bioactive small molecules. This provides a new path for the preparation of other novel COF-loaded transition metal complex polymers and their accurate identification and detection of other chiral analyses. Attached Figure Description

[0017] Figure 1 Field emission scanning electron microscope (FE-SEM) image (A) and energy dispersive X-ray spectroscopy (EDX) image (B) of cobalt(II) functionalized (R)-PTCDA-RMP COF material with Co element mapping. Figure 2 Comparison of X-ray powder diffraction (XRD) analysis of cobalt(II) functionalized (R)-PTCDA-RMP COF material with (R)-PTCDA-RMP COF and simulated (R)-PTCDA-RMP COF; Figure 3 UV-Vis absorption spectrum of cobalt(II) functionalized (R)-PTCDA-RMP COF material; Figure 4 The selectivity of ECL sensors constructed from cobalt(II)-functionalized (R)-PTCDA-RMP COF materials to different bioactive small molecules; Figure 5 Standard curves for detecting (-)-mintose and (+)-mintose using an ECL sensor constructed with cobalt(II) functionalized (R)-PTCDA-RMP COF material. Detailed Implementation

[0018] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention are now described. Example 1: A method for preparing (R)-PTCDA-RMP COF The synthesis of the (R)-PTCDA-RMP COF is carried out according to the method in application number 2024118556754, and the steps are as follows: 7.5 mM of 3,4,9,10-perylenetetracarboxylic acid dianhydride (PTCDA) was mixed with 22.5 mM of (R)-(-)-2-methylpiperazine (RMP), and 300 mM of imidazole catalyst was added. The mixture was heated at 120 °C for 24 h with stirring. After the reaction was completed, the system was cooled to 85 °C, filtered, and the obtained solid was washed five times with deionized water to remove unreacted starting material and catalyst. The solid was then dried under vacuum at 80 °C to remove the solvent, yielding a one-dimensional chiral covalent organic framework (R)-PTCDA-RMP COF. The (R)-PTCDA-RMP COF has the following construction formula:

[0019] Example 2: A method for preparing a transition metal functionalized covalent organic framework material 50 mL of N,N-dimethylformamide DMF was added to 0.0500 g of covalent organic framework (R)-PTCDA-RMP COF. After ultrasonic dispersion, 20 mL of an aqueous solution containing 0.0218 g of cobalt nitrate hexahydrate was added. The mixture was stirred at room temperature for 24 h, centrifuged, and the product was washed multiple times with deionized water until the washing water was clear. The product was then vacuum dried in a 60 °C oven to obtain cobalt(II) functionalized (R)-PTCDA-RMP COF material, i.e., transition metal functionalized covalent organic framework material.

[0020] Example 3 Performance testing of transition metal functionalized covalent organic framework materials (1) By Figure 1 Field emission scanning electron microscopy (FE-SEM) images of cobalt(II)-functionalized (R)-PTCDA-RMP COF materials and energy dispersive X-ray spectroscopy (EDX) images of Co element mapping (1B) show that cobalt has been uniformly introduced into the material; Based on EDS testing, the elemental composition of the sample material is shown in Table 1. As can be seen from Table 1, the material is mainly composed of carbon and cobalt. The mass fraction of carbon is 90.88%, and the atomic fraction of carbon is 97.35%, indicating that the material is dominated by a carbon framework. The mass fraction of cobalt is 9.12%, and the atomic fraction of cobalt is 2.65%, which also confirms that cobalt has been successfully introduced into the material. Table 1. EDS elemental content of cobalt(II) functionalized (R)-PTCDA-RMP COF materials

[0021] (2) By Figure 2 A comparison of X-ray powder diffraction (XRD) analyses of cobalt(II)-functionalized (R)-PTCDA-RMP COF material with (R)-PTCDA-RMP COF and simulated (R)-PTCDA-RMP COF shows that the cobalt(II)-functionalized (R)-PTCDA-RMP COF material retains the main peak of (R)-PTCDA-RMP COF, indicating that the synthesized complex did not change the topological connection mode and repeating unit structure of the (R)-PTCDA-RMP COF material, but its crystals have defects and reduced crystallinity.

[0022] (3) By Figure 3 The UV-Vis absorption spectrum of the cobalt(II) functionalized (R)-PTCDA-RMP COF material shows that the material exhibits two strong and broad absorption characteristics in the range of 475 ~ 600 nm. The presence of different absorption bands at 475 nm and 524 nm is characteristic of the perylene chromophore, indicating that the perylene group has been successfully incorporated into the material structure.

[0023] Example 4 Detection of (-)-menthol and many common bioactive small molecules (1) Preparation of working electrode: 0.05 μm α-Al2O3 polishing powder was used to finely polish a 4 mm diameter platinum carbon electrode GCE; the electrode was then ultrasonically washed in ultrapure water and ethanol baths, and then dried at room temperature; 3 mg of cobalt(II)-functionalized(R)-PTCDA-RMP COF material prepared in Example 2 and the designed amount of (-)-menthol were accurately weighed and added to 1 mL of N,N-dimethylformamide, and ultrasonically dispersed to obtain a uniform solution of [cobalt(II)-functionalized(R)-PTCDA-RMP COF + (-)-menthol] with a concentration of 3 mg / mL; 8 μL of this solution was carefully coated on the surface of the glassy carbon electrode GCE and air-dried at room temperature; finally, the electrode was rinsed with ultrapure water to remove any non-specifically adsorbed substances and air-dried at room temperature to obtain GCE / [cobalt(II)-functionalized(R)-PTCDA-RMP] COF+(-)-Menthol] Working electrode; A working electrode, GCE / [Cobalt(II)-functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule], was prepared by replacing (-)-menthol with other common bioactive small molecules. The common bioactive small molecules were selected from one of the following: (+)-menthol (MENTH), D-cysteine ​​(Cys), L-cysteine ​​(Cys), D-cysteine ​​hydrochloride (Cysm), L-cysteine ​​hydrochloride (Cysm), D-alanine (Ala), L-alanine (Ala), D-methionine (Met), L-methionine (Met), D-glutamic acid (Glu), L-glutamic acid (Glu), D-arginine (Arg), L-arginine (Arg), D-tyrosine (Tyr), L-tyrosine (Tyr), D-penicillamine (Pen), L-penicillamine (Pen), L-carnitine, L-carnitine, D... - Lactic acid (HL), L-lactic acid (HL), D-serine (Ser), L-serine (Ser), D-aspartic acid (Asp), L-aspartic acid (Asp), D-mandelic acid (Rmn), L-mandelic acid (Rmn), R-naproxen (Nap), S-naproxen (Nap), D-tryptophan (Trp), L-tryptophan (Trp); (2) Construct an electrochemiluminescence ECL sensor. The GCE / [cobalt(II)functionalized(R)-PTCDA-RMP COF+(-)-menthol] working electrode or GCE / [cobalt(II)functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule] working electrode prepared in step (1) is combined with an Ag / AgCl reference electrode and a platinum wire auxiliary electrode to form a three-electrode system. The three-electrode system is connected to the electrochemiluminescence analysis system at 0.10 M K2S2O8 and 0.1M PBS were used as co-reactants, and the pH of the co-reactants was adjusted to 8.0 to form an ECL sensor for detecting (-)-menthol and other common bioactive small molecules. The ECL detection of its photomultiplier tube high voltage is 600 V, the potential scanning range is from 0 to -1.6 V, and the scanning rate is 200 mV / s. (3) Plot the standard curve. Using different concentrations of (-)-menthol or (+)-menthol, construct a series of GCE / [cobalt(II)functionalized(R)-PTCDA-RMPCOF+(-)-menthol] or GCE / [cobalt(II)functionalized(R)-PTCDA-RMPCOF+(+)-menthol] working electrodes, and measure their ECL signals as described in step (2), and plot their ECL luminescence intensity versus concentration curve; (4) Replace (-)-menthol or (+)-menthol with the sample to be tested, and determine its concentration by referring to the standard curve; The study found that the ECL luminescence intensity of (-)-menthol and (+)-menthol was positively correlated with their concentration, specifically: I(-)-menthol = 4327.95 C + 3712.08, R² = 0.9853 and I(+)-menthol = 1565.60 C + 618.72, R² = 0.8716, with a detection limit of 0.073 mmol / L. Example 5: Identification and analysis of (-)-menthol and many common bioactive small molecules. (1) By Figure 4 As shown, the chiral electrochemiluminescence ECL sensor constructed from cobalt(II)-functionalized (R)-PTCDA-RMP COF material exhibits significantly different effects on different bioactive small molecules. The ECL signal intensity for (-)-menthol is significantly higher than that for (+)-menthol and many other common bioactive small molecules. Based on this property, the chiral electrochemiluminescence ECL sensor constructed from cobalt(II)-functionalized (R)-PTCDA-RMP COF material can be used to distinguish and analyze (-)-menthol from (+)-menthol and many other common bioactive small molecules. The common bioactive small molecules are as follows: (+)-menthol, D-cysteine, L-cysteine, D-cysteine ​​hydrochloride, L-cysteine ​​hydrochloride, D-alanine, L-alanine, D-methionine, L-methionine, D-glutamic acid, L-glutamic acid, D-aspartic acid, L-aspartic acid, D-tyrosine, L-tyrosine, D-penicillamine, L-penicillamine, D-carnitine, L-carnitine, D-lactic acid, L-lactic acid, D-serine, L-serine, D-mandelic acid, L-mandelic acid, D-tryptophan, L-tryptophan; This indicates that the material can be used to distinguish and analyze (-)-menthol from many common bioactive small molecules; (2) For example Figure 5 As shown, the electrochemiluminescence intensity of the ECL sensor constructed from cobalt(II)-functionalized (R)-PTCDA-RMP COF material is positively correlated with the concentrations of (-)-menthol and (+)-menthol, respectively. I (-)-薄荷醇 =4327.95 C +3712.08, R 2 = 0.9853 and I (+)-薄荷醇 = 1565.60 C +618.72, R 2 = 0.8716, and the limit of detection is 0.073 mmol / L.

Claims

1. A transition metal functionalized covalent organic framework material, characterized in that, The transition metal functionalized covalent organic framework material is a cobalt(II) functionalized (R)-PTCDA-RMP COF material, which is essentially a covalent organic framework (R)-PTCDA-RMP COF loaded with cobalt(II). The cobalt(II) functionalized (R)-PTCDA-RMP COF material has a carbon mass percentage of 90.88% and an atomic percentage as high as 97.35%; while the cobalt mass percentage is 9.12% and the atomic percentage is 2.65%; indicating that the material is mainly composed of a carbon framework. The cobalt(II)-functionalized (R)-PTCDA-RMP COF material has a (R)-PTCDA-RMP COF crystal structure, i.e., Co 2+ The coordination did not change the topological connection mode and repeating unit structure of (R)-PTCDA-RMP COF, but the crystal had defects and the crystallinity was reduced. The cobalt(II)-functionalized (R)-PTCDA-RMP COF material, used to construct a chiral electrochemiluminescence (ECL) sensor, exhibits a significantly higher ECL signal intensity for recognizing (-)-menthol than that for recognizing many common bioactive small molecules; it can be used to distinguish and analyze (-)-menthol from many common bioactive small molecules. The common bioactive small molecules are as follows: (+)-menthol, D-cysteine, L-cysteine, D-cysteine ​​hydrochloride, L-cysteine ​​hydrochloride, D-alanine, L-alanine, D-methionine, L-methionine, D-glutamic acid, L-glutamic acid, D-aspartic acid, L-aspartic acid, D-tyrosine, L-tyrosine, D-penicillamine, L-penicillamine, D-carnitine, L-carnitine, D-lactic acid, L-lactic acid, D-serine, L-serine, D-mandelic acid, L-mandelic acid, D-tryptophan, L-tryptophan; The (R)-PTCDA-RMP COF has the following structural formula: 。 2. The transition metal functionalized covalent organic framework material as described in claim 1, characterized in that, The preparation method is as follows: 50 mL of N,N-dimethylformamide DMF was added to 0.0500 g of covalent organic framework (R)-PTCDA-RMP COF. After ultrasonic dispersion, 20 mL of an aqueous solution containing 0.0218 g of cobalt nitrate hexahydrate was added. The mixture was stirred at room temperature for 24 h, centrifuged, and the product was washed multiple times with deionized water until the washing water was clear. The product was then vacuum dried in a 60 °C oven to obtain cobalt(II) functionalized (R)-PTCDA-RMP COF material, i.e., transition metal functionalized covalent organic framework material.

3. The use of the transition metal functionalized covalent organic framework material as described in claim 1 for detecting (-)-menthol and many common bioactive small molecules.

4. The use as described in claim 3 for detecting (-)-menthol and many common bioactive small molecules, characterized in that, The steps are as follows: (1) Preparation of working electrode The platinum-carbon electrode GCE with a diameter of 4 mm was finely polished using 0.05 μm α-Al2O3 polishing powder; then the electrode was ultrasonically washed in ultrapure water and ethanol baths in sequence, and then dried at room temperature. Accurately weigh 3 mg of cobalt(II)-functionalized(R)-PTCDA-RMP COF material and the designed amount of (-)-menthol, add them to 1 mL of N,N-dimethylformamide, and sonicate to disperse them to obtain a homogeneous solution of [cobalt(II)-functionalized(R)-PTCDA-RMP COF+(-)-menthol] with a concentration of 3 mg / mL; take 8 μL of this solution and carefully coat it onto the surface of the glassy carbon electrode GCE, and air dry it at room temperature; finally, rinse the electrode with ultrapure water to remove any non-specifically adsorbed substances, and air dry it at room temperature to obtain the GCE / [cobalt(II)-functionalized(R)-PTCDA-RMP COF+(-)-menthol] working electrode; By replacing (-)-menthol with other common bioactive small molecules, a GCE / [cobalt(II)-functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule] working electrode was prepared; The common bioactive small molecules mentioned are selected from one of the following: (+)-menthol, D-cysteine, L-cysteine, D-cysteine ​​hydrochloride, L-cysteine ​​hydrochloride, D-alanine, L-alanine, D-methionine, L-methionine, D-glutamic acid, L-glutamic acid, D-arginine, L-arginine, D-tyrosine, L-tyrosine, D-penicillamine, L-penicillamine, L-carnitine, L-carnitine, D-lactic acid, L-lactic acid, D-serine, L-serine, D-aspartic acid, L-aspartic acid, D-mandelic acid, L-mandelic acid, R-naproxen, S-naproxen, D-tryptophan, L-tryptophan; (2) Construction of electroluminescent chemiluminescence (ECL) sensor The GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(-)-menthol] working electrode or the GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+analyte bioactive small molecule] working electrode prepared in step (1) is combined with an Ag / AgCl reference electrode and a platinum wire auxiliary electrode to form a three-electrode system. The three-electrode system is connected to an electrochemiluminescence analysis system. 0.10 M K2S2O8 and 0.1 M PBS are used as co-reactants. The pH value of the co-reactants is adjusted to 8.0 to form an ECL sensor for detecting (-)-menthol and other common bioactive small molecules. The ECL test showed that the high voltage of the photomultiplier tube was 600 V, the potential scan range was from 0 to -1.6 V, and the scan rate was 200 mV / s. (3) Draw the standard curve Using different concentrations of (-)-menthol or (+)-menthol, a series of GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(-)-menthol] or GCE / [Cobalt(II)functionalized(R)-PTCDA-RMP COF+(+)-menthol] working electrodes were constructed. The ECL signal was measured as described in step (2), and the ECL luminescence intensity versus concentration curve was plotted. (4) Replace (-)-menthol or (+)-menthol with the sample to be tested and detect its concentration with reference to the standard curve.

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