Preparation methods and applications of fluorescent sensing material arrays

Abstract

This invention discloses an organic fluorescent sensing material array and its application in monitoring meat quality. The fluorescent sensing array comprises material A, which is self-assembled from compounds shown in formula (I), and material B, which is self-assembled from compounds shown in formula (II). When this fluorescent sensing array comes into contact with volatile organic sulfur compounds released during meat spoilage, it exhibits a fluorescence quenching response. This fluorescent sensing array does not require long-term gas accumulation or sample pretreatment, and achieves high-sensitivity detection of meat quality by different recognition effects of volatile organic compounds released during meat spoilage, thus possessing high practical value.

Description

Technical Field

[0001] This invention belongs to the field of fluorescent sensing arrays composed of organic fluorescent nanomaterials, specifically involving fluorescent sensing arrays composed of two types of fluorescent sensing materials, the preparation method of the sensing array, and its application in meat monitoring. Background Technology

[0002] Compared to single sensing materials, sensor arrays offer higher resolution, stronger anti-interference capabilities, and are more suitable for applications in complex systems, making research on sensor arrays of significant importance. Meanwhile, food safety is a matter of great social concern; unsafe food can adversely affect human health and cause substantial economic losses. The main factors determining the freshness of meat during storage are the concentrations of sulfides, biogenic amines, and other volatile organic compounds produced by the degradation of amino acids due to external microbial activity during food spoilage or endogenous tissue metabolism. Simple, rapid, low-cost, and accurate food safety monitoring systems are of great importance. However, almost all existing detection technologies, including "electronic noses" and optical sensors, require the accumulation of absolute concentrations of sulfur-containing compounds and / or amines before collection to trigger a sensing reaction. This accumulation and collection process takes a long time (at least several hours), and it is difficult to achieve precise absolute concentrations, thus failing to determine the transition from fresh to spoilage and limiting the practical application of steam-based detection technologies in meat freshness monitoring. Therefore, there is a need to develop simple, rapid, and accurate new technologies for evaluating meat freshness. Compared to amines, which are present in fresh food, volatile organosulfur compounds, such as methyl sulfide, are only produced during spoilage. Using methyl sulfide as a marker for detecting food spoilage holds great potential. Therefore, developing highly sensitive fluorescence sensors, especially fluorescence sensor arrays that do not require long accumulation periods and have stronger anti-interference capabilities, is more suitable for detecting organosulfur compounds released during meat spoilage, particularly in scenarios where meat releases gases with multiple components. Summary of the Invention

[0003] To improve upon existing technologies, the present invention provides a fluorescence sensing array comprising material A obtained by self-assembly of a compound as shown in formula (I) and material B obtained by self-assembly of a compound as shown in formula (II):

[0004]

[0005] Among them, R1, R2, R5, and R6 may be the same or different, and are independently selected from hydrogen or C. 1-20 Alkyl group; R3, R4, R7, and R8 may be the same or different, and are independently selected from hydrogen and C. 1-20 Alkyl, 3-20 membered heterocyclic groups, C 1-20 Alkoxy, -N(C) 1-20Alkyl)2、-NHC 1-20 Alkyl, C 6-20 Aryl, 5-20 heteroaryl; n, m, r, q, s, t, u, v are the same or different, and are independent integers selected from 0-20, wherein at least one of m, q, s, and u is not 0, n and t are not 0; r and v are integers from 1-10.

[0006] According to an embodiment of the present invention, the self-assembly is carried out under various non-covalent interactions such as hydrogen bonding, π-π stacking, and donor-acceptor interactions, and the material A and material B form an array as two independent parts of the material.

[0007] According to an embodiment of the present invention, the organic fluorescence sensing array can perform fluorescence monitoring of the quality of various types of meat.

[0008] According to an embodiment of the present invention, n, m, q, r, s, t, u, and v can be the same or different, and are independent of each other, selected from integers from 1 to 10.

[0009] According to an embodiment of the present invention, R1, R2, R5, and R6 may be the same or different, and are independently selected from C. 1-14 Alkyl group; R3, R4, R7, and R8 may be the same or different, and are independently selected from C1. 1-14 Alkyl, C 1-14 Alkoxy, -N(C) 1-6 Alkyl)2、-NHC 1-6 Alkyl, 3-20 heteroaryl; n, m, q, r are the same or different, and are independent of each other, selected from 1-6 integers.

[0010] According to embodiments of the present invention, R1 and R2 may be the same or different, and are independently selected from the following groups:

[0011]

[0012] According to embodiments of the present invention, R3, R4, R7, and R8 may be the same or different, and are independently selected from the following groups:

[0013]

[0014] The end marked with * indicates the position where the functional groups are connected.

[0015] According to an embodiment of the present invention, materials A and B in the fluorescence sensing array are organic semiconductor nanomicelles obtained by self-assembly of the compounds of formulas (I) and (II), respectively.

[0016] According to an embodiment of the present invention, R1, R2, R5, and R6 are all hexyl groups, and R3, R4, R7, and R8 are all isobutoxy groups, with n = 3, m = 1, q = 1, r = 1, s = 1, t = 3, u = 1, and v = 1.

[0017] The present invention also provides a method for fabricating the fluorescent sensing array, comprising the following steps.

[0018] (1) The compound shown in formula (II) was synthesized and self-assembled using a rapid solution diffusion method to obtain material B;

[0019]

[0020] (2) The compound shown in formula (I) was synthesized and self-assembled using a rapid solution diffusion method to obtain material A;

[0021]

[0022] (3) Material A and Material B together form the fluorescence sensing array.

[0023] According to an embodiment of the present invention, in step (1), with Intermediates were prepared by reacting the raw materials with dipinalboronic acid ester. Wherein, X1, X2, X3, X4, and X5 are the same or different and are independently selected from chlorine, bromine, or iodine; the intermediate and the starting material are combined and further coupled to obtain the compound shown in formula (II);

[0024] According to an embodiment of the present invention, in step (2), when R3 and R4 are the same as R7 and R8 in step (1), the compound shown in formula (I) is reduced by sodium borohydride and reacted with selenium dioxide to obtain the compound shown in formula (I); when R3 and R4 are not the same as R7 and R8 in step (1), the step of synthesizing the compound shown in formula (II) in step (1) is repeated, and R7 and R8 are replaced by R3 and R4.

[0025] According to an exemplary embodiment of the present invention, when R3, R4 are the same as R7, R8, m = q = r = 1, and n = 3, the method for fabricating the fluorescence sensing array includes:

[0026] (I-1) Compound 1 (R3-Ph-Br) reacts with dipinazoboronic acid ester to give intermediate 2;

[0027]

[0028] (I-2) Intermediate 2 from step (I-1) is reacted with 4,7-dibromobenzothiadiazole to obtain intermediate 3;

[0029]

[0030] (I-3) React intermediate 3 from step (I-2) with dipinazoboronic acid ester to obtain intermediate 4;

[0031]

[0032] (I-4) React intermediate 4 from step (I-3) with 2,7-dibromo-R1,R2-alkylfluorene to obtain intermediate 5;

[0033]

[0034] Those skilled in the art will understand that when R3 and R4 are not the same, or when R7 and R8 are not the same, the method includes replacing R3 with R4 in the substrate of at least one of the above steps. When R1 and R2 are different from R5 and R6, the method includes replacing 2,7-dibromo-R1,R2-alkylfluorene with 2,7-dibromo-R5,R6-alkylfluorene.

[0035] (I-5) The compound 2,7-dibromo-R1,R2-alkylfluorene was reacted with dipinazoboronic acid ester to give intermediate 6;

[0036]

[0037] (I-6) The above intermediate 5 is reacted with intermediate 6 to obtain the compound shown in formula (II);

[0038]

[0039] (I-7) The compound of formula (II) was reduced with sodium borohydride to obtain intermediate 8;

[0040]

[0041] (I-8) Intermediate 8 was reacted with selenium dioxide to give the compound shown in formula (I);

[0042]

[0043] Those skilled in the art should understand that when m, n, q, s, t, u are not the same, or v and r are not the same, the coupling reaction in step (I-6) should be carried out in multiple steps, that is, the above-mentioned boron esterification reaction (i.e., the reaction in steps (I-1), (I-3) or (I-5)) and the coupling reaction (i.e., steps (I-2) and (I-4)) are carried out in an alternating manner, and the product compound (II) is obtained through multiple steps.

[0044] According to an embodiment of the present invention, the self-assembly in steps (1) and (2) is achieved by contacting the compound with a mixture of a good solvent and a poor solvent. This includes: dissolving the compounds represented by formulas (I) and (II) in good solvents respectively, then adding the poor solvents respectively, self-assembling by rapid solution diffusion, and then allowing them to stand to obtain suspensions of materials A and B respectively.

[0045] According to an embodiment of the present invention, step (2) further includes: allowing the suspension of the organic fluorescent sensing material to stand, and then using a pipette to remove the organic fluorescent sensing material located at the bottom of the container.

[0046] According to an embodiment of the present invention, the volume ratio (mL:mL) of the good solvent to the poor solvent is 1:3 to 20.

[0047] According to an embodiment of the present invention, in steps (1) and (2), the good solvent is selected from chloroalkanes and C... 2-5 Esters, such as dichloromethane, chloroform, 1,2-dichloroethane, ethyl acetate, or methyl acetate.

[0048] According to an embodiment of the present invention, in steps (1) and (2), the undesirable solvent is selected from one or more of methanol, ethanol, isopropanol, n-hexane, acetonitrile, and water.

[0049] According to an embodiment of the present invention, step (3) includes: sequentially injecting suspensions of material A and material B into a quartz tube, drying the solvent with a blower, and thus obtaining the organic fluorescent sensing array.

[0050] The fluorescence sensing array described in this invention is composed of fluorescent nanomicelle sensing materials assembled from two types of organic fluorescent molecules. Material A has a more sensitive fluorescence response to volatile organic sulfur compounds produced during meat spoilage due to sulfur bonds and sulfur-π interactions, while material B has a relatively sensitive fluorescence response to volatile organic sulfur compounds produced during meat spoilage due to sulfur-π interactions. When these two materials are combined to form a fluorescence sensing array, the fluorescence false alarm phenomenon caused by the selectivity of a single material can be avoided, which is beneficial for more accurate meat quality monitoring.

[0051] The present invention also provides the application of the fluorescence sensing array in monitoring meat quality, which can be used for real-time fluorescence detection of meat quality.

[0052] According to an embodiment of the present invention, the fluorescence sensing array can be used for rapid detection of meat quality. The rapid detection time is almost within 5 seconds, requiring almost no pretreatment. It only requires sealing a certain mass of meat for one minute to detect the gas.

[0053] A method for monitoring meat quality includes contacting the fluorescence sensing array with volatile organic compounds (VOCs) produced by the meat.

[0054] In this invention, when the fluorescent sensing array comes into contact with organic sulfur dioxide vapors emitted from a small amount of meat, the fluorescence changes to varying degrees due to the different physicochemical properties of each organic fluorescent sensing material and their different interactions with the volatile organic sulfur dioxide, thus causing changes in the fluorescence signal. Analysis of this information can be used for rapid fluorescence monitoring of actual meat.

[0055] Two different organic fluorescent sensing materials are coated inside a quartz tube and placed in a fluorescence sensing instrument. When the same concentration of volatile organic sulfur compounds produced by meat comes into contact with the two different organic fluorescent sensing materials, the signals from the different fluorescent sensing materials produce different fluorescence response intensities. Rapid and repeated fluorescence monitoring is achieved by analyzing the fluorescence change signals.

[0056] According to an embodiment of the present invention, the meat may be selected from at least one of chicken, pork, shrimp, beef, and fish.

[0057] According to an embodiment of the present invention, when meat is left at room temperature for about one day, it will produce more than 0.2 ppm of dimethyl sulfide. Slight spoilage of the meat can be detected by analyzing the response of the fluorescence sensor array. When meat is left at room temperature for more than two days, it will produce more than 0.8 ppm of dimethyl sulfide. Based on the response analysis of the fluorescence sensor array, the meat can be determined to be in a more severe state of spoilage.

[0058] The fluorescent sensing array of this invention is mainly composed of two different fluorescent sensing materials. When the organic fluorescent sensing material interacts with volatile organic sulfur compounds, such as dimethyl sulfide, released from spoiled meat, the organic fluorescent sensing material will produce different fluorescence changes due to sulfur bonds and sulfur-π interactions. By comprehensively analyzing the fluorescence response of material A and material B, according to the embodiment of this invention, the analysis can be as follows: if neither material A nor material B in the array quenches, the meat is fresh; if the fluorescence of material A is quenched and the compound in material B is not quenched, the meat is slightly spoiled; if both material A and material B in the array quench, the meat is severely spoiled.

[0059] A reagent kit comprising the aforementioned fluorescence sensing array.

[0060] Beneficial effects

[0061] 1. The organic fluorescence sensing array provided by this invention is composed of two compounds as shown in Formulas I and II, which are self-assembled. As a fluorescence sensing array, it exhibits higher anti-interference capabilities and is more suitable for applications in environments with various complex volatile organic compounds encountered in meat quality monitoring. The fluorescence sensing array composed of the above materials rapidly generates a fluorescence response upon contact with volatile organic compounds released from meat. This array detects the concentration of the volatile organic sulfur compounds released from meat at the ppb to ppm level, exhibiting a strong fluorescence quenching response. In contrast, this array shows no or a rapid increase in response to other interfering gases released from meat spoilage, such as water or amines, and other volatile organic compounds (hundreds or thousands of ppm) that may be released from meat spoilage. Since methyl sulfide is one of the important markers of meat spoilage, the detection method described in this invention has significant practical value for meat quality monitoring.

[0062] 2. The fluorescence sensor array in this invention has high sensitivity, good selectivity, fast response speed, and gas phase detection does not require pretreatment. It is easy to manufacture into a small and portable device, which can monitor the quality of several types of meat. Moreover, the structure and operation of the sensor array are simpler, which has strong practical value and is of great significance for ensuring food safety. It has broad application and development prospects.

[0063] 3. This invention provides a sensitive, simple, and rapid method for monitoring meat quality. Meat quality is monitored by utilizing the varying sensitivities of volatile organic sulfur compounds released during meat spoilage using a fluorescence sensor array.

[0064] Terminology Definitions and Explanations

[0065] Unless otherwise stated, the definitions of groups and terms recorded in this application specification and claims, including definitions as examples, exemplary definitions, definitions recorded in tables, and definitions of specific compounds in the examples, can be arbitrarily combined and combined with each other. Such combinations and combinations of group definitions and compound structures shall fall within the scope of this application's description and protection.

[0066] The numerical ranges described in this application specification and claims, when defined as "integers," should be understood to include both endpoints of the range and every integer within that range. For example, "integers from 0 to 10" should be understood to include every integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10. When the numerical range is defined as "numbers," it should be understood to include both endpoints of the range, every integer within that range, and every decimal within that range. For example, "numbers from 0 to 10" should be understood to include not only every integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10, but also decimals within that range.

[0067] Term "C"1-20 "Alkyl" should be understood to refer to straight-chain or branched saturated alkanes having 1 to 20 carbon atoms. For example, "C 1-14 "Alkyl" includes straight-chain and branched alkyl groups with 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, 1,1-dimethylpropyl, 2-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, etc., and their isomers.

[0068] The term "alkoxy group" refers to a group in which an oxygen atom is directly bonded to a carbon atom. -N(C 1-20 Alkyl)2、-NHC 1-20 Alkyl groups are groups in which a nitrogen atom is directly bonded to a carbon or hydrogen atom.

[0069] The term "3-20 membered heterocyclic group" refers to a saturated, unsaturated, or partially saturated monocyclic, bicyclic, or tricyclic ring containing 3 to 20 atoms, wherein 1, 2, 3, 4, or 5 ring atoms are selected from heteroatoms such as nitrogen, sulfur, or oxygen, and unless otherwise specified, they may be linked by carbon or nitrogen, wherein the -CH2- group is optionally replaced by -C(O)-; wherein the -NH in the ring is optionally replaced by an acetyl, formyl, methyl, or methanesulfonyl group; and wherein the ring is optionally replaced by one or more halogens. It should be understood that when the total number of S and O atoms in the heterocyclic group exceeds 1, these heteroatoms are not adjacent to each other. If the heterocyclic group is monocyclic, it is necessarily not aromatic. Examples of heterocyclic groups include, but are not limited to, piperidinyl, N-acetylpiperidinyl, N-methylpiperidinyl, N-formylpiperazinyl, N-methanesulfonylpiperazinyl, homopiperazinyl, piperazinyl, azacyclic butyl, oxacyclic butyl, morpholinyl, tetrahydroisoquinolinyl, tetrahydroquinolinyl, dihydroindolyl, tetrahydropyranyl, dihydro-2H-pyranyl, tetrahydrofuranyl, tetrahydrothiaranyl, tetrahydrothiaran-1-oxide, tetrahydrothiaran-1,1-dioxide, 1H-pyridin-2-one, and 2,5-dioxoimidazolyl.

[0070] C 6-20 The aryl group should be understood to preferably represent a monocyclic, bicyclic, or tricyclic hydrocarbon ring having aromatic or partially aromatic properties with 6-20 carbon atoms, preferably "C". 6-14 Aryl. The term "C" 6-14 "Aryl" should be understood to preferably represent a monovalent aromatic or partially aromatic monocyclic, bicyclic, or tricyclic hydrocarbon ring ("C") having 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms. 6-14"Aryl" refers to a ring with six carbon atoms ("C6 aryl"), such as phenyl. "Arylene" refers to a group on the benzene ring corresponding to the above term that has been substituted at a position by a substituent.

[0071] The 5-20 member heteroaryl compounds should be understood to include aromatic ring systems of monovalent monocyclic, bicyclic, or polycyclic forms. Preferably, they are monovalent monocyclic or bicyclic aromatic ring systems having ring atoms. The heteroatoms are each independently selected from N, O, and S heteroatoms and may be benzo-fused. In particular, the heteroaryl group is selected from thiophene, oxazolyl, thiazolyl, thiadiazolyl, imidazole, triazolyl, and their benzo[a] derivatives, such as benzothiophene, benzoxazolyl, benzothiazolyl, benzothiadiazolyl, benzoimidazolyl, benzotriazolyl, etc. Different atoms on the 5-20 member heteroaryl ring can be linked to other groups through connecting atoms to form the compounds of the present invention. When the 3-20 member heteroaryl group is monosubstituted or polysubstituted by other groups, the substitution sites are not limited. Attached Figure Description

[0072] Figure 1 This is the NMR spectrum of compound II-1 from Example 1 of the present invention.

[0073] Figure 2 This is the mass spectrometry data of compound II-1 in Example 1 of the present invention.

[0074] Figure 3 This is the NMR spectrum of compound I-1 from Example 2 of the present invention.

[0075] Figure 4 This is the mass spectrometry data of compound I-1 in Example 2 of the present invention.

[0076] Figure 5 This is a scanning electron microscope image of the aggregates formed by the self-assembly of compound II-1 under chloroform:methanol (1:10) conditions.

[0077] Figure 6 This is a scanning electron microscope image of the aggregates formed by the self-assembly of compound I-1 under chloroform:methanol (1:10) conditions.

[0078] Figure 7 The image shows the fluorescence change time series of different concentrations of dimethyl sulfide placed at room temperature using the fluorescence sensing array in Example 3.

[0079] Figure 8 This is a time-series diagram showing the fluorescence changes in chicken meat quality monitored by the fluorescence sensing array in Example 3, which was placed at room temperature for different times.

[0080] Figure 9 This is a time-series diagram showing the fluorescence changes of the fluorescence sensing array in Example 3, for different concentrations of ammonia that may be released from spoiled meat.

[0081] Figure 10 This is a time-series diagram showing the fluorescence changes of the fluorescence sensing array in Example 3 for different concentrations of water.

[0082] Figure 11 This is a time-series diagram showing the fluorescence changes of the fluorescence sensing array in Example 3 for styrene that may be released from different concentrations of decaying meat.

[0083] Figure 12 This is a time-series diagram showing the fluorescence changes of the fluorescence sensing array in Example 3, in response to different concentrations of chloroform that may be released from spoiled meat. Detailed Implementation

[0084] The technical solution of the present invention will be further described in detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanatory of the present invention, and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are covered within the scope of protection intended by the present invention.

[0085] Unless otherwise stated, the raw materials and reagents used in the following examples are commercially available products or can be prepared by known methods.

[0086] Example 1

[0087] Prepare compound II-1 with the following molecular formula.

[0088]

[0089] (1-1) 4.5 g of 4-bromophenol was added to a flask, and (S)-2-butanol and triphenylphosphine were added in a molar ratio of 1:0.8:1.2. The reaction was carried out in argon atmosphere at 0 °C using 80 mL of tetrahydrofuran as solvent. Then, diisopropyl azodicarbonate was slowly added in a molar ratio of 1:1.2. After the temperature was raised to room temperature, the mixture was stirred for 5 hours and separated by column chromatography to obtain the product.

[0090] (1-2) Take 3 g of the product from step (1-1) and add it to a flask. Add the corresponding amounts of pinacol diborate, potassium acetate, and 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride in a molar ratio of 1:1.2:3:0.05. Use 60 mL of 1,4-dioxane as solvent and react at 80 °C under Ar protection for 12 h. Separate by column chromatography to obtain the product.

[0091] (1-3) Take 1.5 g of the product obtained in step (1-2) and add it to a flask. Add the corresponding amounts of 4,7-dibromobenzothiadiazole and tetra(triphenylphosphine)palladium in a molar ratio of 1:1.1:0.05. Using 30 mL of 1,4-dioxane as solvent, add 5 mL of 2M potassium carbonate aqueous solution to the flask. React at 80 °C under Ar protection for 12 h. Separate by column chromatography to obtain the product.

[0092] (1-4) Take 1 gram of the product obtained in step (1-3) and add it to a flask. Add the corresponding amounts of pinacol diborate, potassium acetate, and 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride in a molar ratio of 1:1.2:3:0.05. Use 30 mL of 1,4-dioxane as solvent and react at 80 °C under Ar protection for 12 h. Separate by column chromatography to obtain the product.

[0093] (1-5) Take 0.5 g of the product obtained in step (1-4) and add it to a flask. Add the corresponding amount of 2,7-dibromo-9,9-bisdodecylfluorene, tetra(triphenylphosphine)palladium at a molar ratio of 1:1.1:0.05. Add 3.5 mL of 2M potassium carbonate aqueous solution to the flask using 20 mL of 1,4-dioxane as solvent. React at 80 °C under Ar protection for 12 h. Separate by column chromatography to obtain the product.

[0094] (1-6) Add 3 g of 2,7-dibromo-9,9-bisdodecylfluorene to a flask, and add the corresponding amounts of pinacol diborate, potassium acetate, and 1,1'-bis(diphenylphosphino)ferrocene palladium(II) dichloride in a molar ratio of 1:4:3:0.05. Using 100 mL of 1,4-dioxane as solvent, react at 80 °C under Ar protection for 12 h, followed by column chromatography to obtain the product.

[0095] (1-7) Take 0.2 g of the product obtained in step (1-5) and add it to a flask. Add the corresponding amount of the product obtained in step (1-6) and tetra(triphenylphosphine)palladium in a molar ratio of 1:0.45:0.05. Using 20 mL of 1,4-dioxane as solvent, add 3.5 mL of 2M potassium carbonate aqueous solution to the flask. React at 80 °C under Ar protection for 12 h. Separate by column chromatography to obtain product (Ⅱ-1); its NMR data is shown in the figure below. Figure 1 As shown; mass spectrometry data graph as shown Figure 2 As shown.

[0096] (1-8) Dissolve product II-1 obtained in step (1-7) in good solvent chloroform at a concentration of 6 mg / mL. Then, add methanol, a poor solvent, at a volume ratio of 1:10 between good solvent and poor solvent. Stir rapidly to carry out self-assembly and obtain a suspension of aggregates of molecule II-1, which is the sensing material B.

[0097] A small amount of II-1 aggregate was pipetted onto a silicon wafer and dried under vacuum. Then, gold was sputtered onto the surface of the aggregate material using a Leica ion sputtering system, specifically by loading 10-nanometer platinum particles onto the surface of the aggregate material. The morphology of the aggregate was then observed using a scanning electron microscope (SEM). The SEM images are shown below. Figure 5 As shown.

[0098] Example 2

[0099] Prepare compound I-1 with the following molecular formula.

[0100]

[0101]

[0102] (2-1) Take 100 mg of the product obtained in step (1-7) of Example 1 and add it to a flask. Add the corresponding amounts of sodium borohydride and cobalt chloride hexahydrate at a molar ratio of 1:20:0.1. Then add 10 mL of tetrahydrofuran and 11 mL of ethanol. The reaction is carried out at 0 °C under Ar protection and refluxed until the yellow fluorescence of the solution disappears. Extraction is performed, and column chromatography separation is not required for the next step.

[0103] (2-2) The product obtained in step (2-1) was added to a flask, along with a hot aqueous solution containing the corresponding amount of selenium dioxide at a molar ratio of 1:20. 10 mL of tetrahydrofuran and 11 mL of ethanol were added, and the reaction was carried out at room temperature with stirring under Ar protection. Column chromatography was used to separate the product (Ⅰ-1); the 1H NMR spectrum is shown below. Figure 3 As shown, the mass spectrometry is as follows Figure 4 As shown.

[0104] (2-3) Dissolve product I-1 obtained in step (2-2) in chloroform, a good solvent, at a concentration of 6 mg / mL. Then, add methanol, a poor solvent, at a volume ratio of 1:10 between the good solvent and the poor solvent. Stir rapidly to allow self-assembly and obtain a suspension of aggregates of molecule I-1, which is the sensing material A.

[0105] A small amount of aggregate I-1 was pipetteted and dropped onto a silicon wafer, which was then vacuum dried. Gold was then sputtered onto the surface of the aggregate material using a Leica ion sputtering system, specifically by loading 10-nanometer platinum particles onto the surface of the aggregate material. The morphology of the aggregate was then observed using a scanning electron microscope (SEM). The SEM images are shown below. Figure 6 As shown.

[0106] Example 3

[0107] Suspensions of aggregates of the two types of molecules prepared in Examples 1 and 2 (fluorescent sensing materials A and B) were taken out in appropriate amounts and coated into quartz tubes respectively. After removing the solvent, they were arranged into a fluorescent sensing array. The mass of methyl sulfide and meat was detected using a fluorescence method with a detection instrument. Different concentrations of methyl sulfide vapor were drawn into a 10 ml syringe for fluorescence detection. Then, 5 grams of chicken were stored at room temperature without sealing, and then sealed for one minute to accumulate the volatile organic compounds released by the meat. Similarly, a certain amount of vapor was drawn into a 10 ml syringe for detection. Blowing in different concentrations of methyl sulfide resulted in fluorescence quenching (e.g., ...). Figure 7 (As shown). Two fluorescent sensing arrays are composed of materials. Material A is more sensitive to methyl sulfide, and meat stored for different times will produce different fluorescent responses. Although the time point of fluorescence quenching may differ, chicken left at room temperature for about a day, after being sealed and accumulating steam for 1 minute, can cause fluorescence quenching in Material A. Material B, due to its lower sensitivity to sulfide, will show fluorescence quenching at a later time (e.g.,...). Figure 8 (As shown). Based on this, we use this array to achieve highly sensitive monitoring of chicken meat quality. The array can classify meat quality into three categories: fresh (neither type of material quenched), slightly spoiled (material A quenched but material B did not quench), and severely spoiled (both types of material quenched).

[0108] Example 4

[0109] Suspensions of the two types of molecular aggregates prepared in Examples 1 and 2 were taken out in appropriate amounts and coated into quartz tubes to form a fluorescence sensing array. The fluorescence sensing array material was exposed to several common volatile organic compounds that may be released from meat spoilage, and the changes in fluorescence intensity were observed using the same instrument and detection method as in Example 3. The aggregates showed negligible or elevated responses to several common volatile organic compounds that may be released from meat spoilage (ammonia, water, styrene, chloroform). Figure 9 (As shown in 10, 11, 12). This illustrates the selectivity of the sensor array for volatile organic sulfur compounds, and also shows that the material monitors meat quality through sulfides.

[0110] The embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for monitoring meat quality, comprising contacting a fluorescence sensing array with volatile organic compounds (VOCs) generated by the meat, characterized in that: If neither material A nor material B in the fluorescence sensing array quenches, the meat is fresh; if material A in the array quenches its fluorescence and material B does not quench, the meat is slightly spoiled; if both material A and material B in the array quench their fluorescence, the meat is severely spoiled. The array comprises material A, which is self-assembled from the compound shown in formula (I), and material B, which is self-assembled from the compound shown in formula (II): Among them, R1, R2, R5, and R6 are all R3, R4, R7, and R8 are the same, and are selected from one of the following groups: The end marked with * indicates the position where the functional groups are connected; n=3, m=1, q=1, r=1, s=1, t=3, u=1, v=1.

2. The method for monitoring meat quality according to claim 1, characterized in that, The fabrication method of the fluorescence sensing array includes the following steps: (1) The compound shown in formula (II) was synthesized and self-assembled using a rapid solution diffusion method to obtain material B; (2) The compound represented by formula (II) was synthesized and self-assembled using a rapid solution diffusion method to obtain material A; (3) Material A and Material B together form the fluorescence sensing array; In step (1), with Intermediates were prepared by reacting the raw materials with dipinalboronic acid ester. Wherein, X1, X2, X3, X4, and X5 are the same or different and are independently selected from chlorine, bromine, or iodine; the intermediate and the starting material are combined and further coupled to obtain the compound shown in formula (II); The compound shown in formula (II) was reduced by sodium borohydride and then reacted with selenium dioxide to obtain the compound shown in formula (I).

3. The method for monitoring meat quality according to claim 2, characterized in that, The self-assembly described in steps (1) and (2) is achieved by contacting the compound with a mixture of its good and bad solvents.

4. The method for monitoring meat quality according to claim 3, characterized in that, The self-assembly is performed by dissolving the compounds shown in formulas (I) and (II) in a good solvent, then adding a poor solvent, and performing rapid solution diffusion for self-assembly, followed by standing to obtain suspensions of materials A and B, respectively. The volume ratio of the good solvent to the bad solvent is 1:3 to 20; In steps (1) and (2), the good solvent is selected from chloroalkanes and C 2-5 At least one of the esters; In steps (1) and (2), the undesirable solvent is selected from at least one of methanol, ethanol, isopropanol, acetonitrile, and water.

5. The method for monitoring meat quality according to claim 4, characterized in that, The preferred solvent is selected from dichloromethane, chloroform, 1,2-dichloroethane, ethyl acetate, or methyl acetate.

Images