Aldehyde and ketone small molecules based on carbon quantum dots, liquor identification method and three-channel fluorescence sensor

Abstract

The present invention discloses a method for identifying aldehyde and ketone small molecules and liquor based on carbon quantum dots and a three-channel fluorescence sensor, which belongs to the technical field of organic identification and bionic sensor. Aiming at the problems existing in the identification of aldehyde and ketone small molecules and liquor and other complex systems in the prior art, the present invention provides a series of methods for identifying aldehyde and ketone small molecules and liquor based on three types of carbon quantum dots, and designs a series of three-channel fluorescence array sensors using the method, which can be used for qualitative and quantitative analysis of 16 aldehyde and ketone small molecules and detection of complex matrices such as liquor rich in such compounds.

Description

Technical Field

[0001] The invention belongs to the technical field of organic identification and bionic sensors, and specifically relates to an aldehyde and ketone small molecule based on the reaction of three carbon quantum dots of m-phenylenediamine, m-aminophenol and o-phenylenediamine with hydroxylamine hydrochloride, a liquor identification method, and a three-channel fluorescence sensor designed using the method. Background Art

[0002] Aldehydes and ketones are important trace components of liquor, which give liquor a spicy taste. Aldehydes, ketones and acid esters work together to increase the aftertaste of liquor. Different liquors can be accurately distinguished and identified by detecting and identifying aldehyde and ketone compounds in liquor. Researchers have developed a variety of sensors for the identification of aldehydes and ketones. For example, a colorimetric sensor for the identification of gas-phase aldehydes and ketones was designed by using aniline and phenylhydrazine dyes, and combined with hierarchical clustering, principal component and support vector machine analysis methods to accurately identify a variety of aliphatic or aromatic aldehydes and ketones. The sensor was further applied to the identification of 10 liquor samples (whiskey, brandy, vodka) and ethanol.

[0003] CDs are ideal nanomaterials for building sensors due to their stable fluorescence signal output and accurate detection results. Single-channel fluorescence sensors are widely used in the field of analytical science due to their advantages such as fast response speed and high sensitivity. However, due to the complexity of the analytes, it is difficult to meet the analytical requirements by relying solely on simple fluorescence sensors. Compared with single-channel fluorescence sensors, multi-channel fluorescence sensors generate fingerprints based on the cross-reaction between multi-sensing elements and analytes, which can achieve rapid extraction and conversion of high-throughput information, and ultimately realize the analysis and identification of complex substances or substances with similar components. Summary of the invention

[0004] In view of the technical problems of high cost and complicated operation in the identification of aldehyde and ketone organic small molecules and complex systems such as liquor in the prior art, the present invention designs a method based on the reaction of aldehydes and ketones with hydroxylamine hydrochloride, the product of which generates amides under acidic conditions, which are easy to interact with CDs surface groups to produce differential fluorescence, thereby realizing the identification method of different aldehydes and ketones. The present invention provides a method for identifying aldehyde and ketone small molecules based on carbon quantum dots, and designs a three-channel fluorescence sensor using the method, which can be used for qualitative and quantitative analysis of aldehyde and ketone compounds and detection of complex matrices rich in such compounds (such as liquor).

[0005] The present invention first provides a method for identifying aldehyde and ketone small molecules based on carbon quantum dots, which comprises the following steps:

[0006] A. Mixing a solvent, m-aminophenol carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system A; mixing a solvent, m-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system B; mixing a solvent, o-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system C;

[0007] B. Add aldehyde and ketone small molecule solutions to identification systems A, B and C respectively to obtain sample groups A, B and C, and use the solvent used for the aldehyde and ketone small molecule solution with the same volume as the added aldehyde and ketone small molecule solution as a control;

[0008] C. Under the condition that the excitation wavelength is 365-380nm and the slits of the excitation wavelength and the emission wavelength are 10-15nm, the fluorescence intensity values ​​of sample groups A, B and C and the control group at the maximum emission wavelength are measured, and the fluorescence intensity value of the sample group is subtracted from the fluorescence intensity value of the corresponding control group to obtain the fluorescence change value of the aldehyde and ketone small molecules;

[0009] Qualitative analysis: linear discriminant analysis was used to distinguish according to the fluorescence change value;

[0010] Quantitative analysis: Based on the fluorescence change value, partial least squares regression was used for quantitative analysis;

[0011] In step A, the solvent is at least one of water or ethanol;

[0012] When it is a qualitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water, ethanol or liquor; the aldehyde and ketone small molecule is at least one of formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal;

[0013] When it is a quantitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water or ethanol; the aldehyde and ketone small molecules are formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal.

[0014] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, after adding the aldehyde and ketone small molecule solution to the identification system A, react for 10 to 20 minutes.

[0015] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, after adding the aldehyde and ketone small molecule solution to the identification system B, react for 10 to 20 minutes.

[0016] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, after adding the aldehyde and ketone small molecule solution to the identification system C, react for 10 to 20 minutes.

[0017] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of aminophenol carbon quantum dots in the sample group A is 0.5-1 mmol / L.

[0018] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of hydroxylamine hydrochloride in the sample group A is 0.1-1 mmol / L.

[0019] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of the interphenylenediamine carbon quantum dots in the sample group B is 0.5-1 mmol / L.

[0020] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of hydroxylamine hydrochloride in the sample group B is 0.1-1 mmol / L.

[0021] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of o-phenylenediamine carbon quantum dots in the sample group C is 0.5-1 mmol / L.

[0022] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of hydroxylamine hydrochloride in the sample group C is 0.1-1 mmol / L.

[0023] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, in step B, the concentration of aldehyde and ketone small molecules in the sample groups A, B and C is 0.02-10mmmol / L.

[0024] Among them, the above-mentioned aldehyde and ketone small molecule identification method based on carbon quantum dots, the synthesis method of the carbon quantum dots is: dissolving the material in ethanol, conducting a hydrothermal reaction, and after the reaction is completed, cooling, filtering, column chromatography separation and drying in sequence to obtain carbon quantum dot particles; the material is m-phenylenediamine, m-aminophenol or o-phenylenediamine.

[0025] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, when synthesizing carbon quantum dots, the mass ratio of the material to the volume of the ethanol is 1:100-150.

[0026] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, when synthesizing carbon quantum dots, the reaction temperature of the hydrothermal reaction is 180-200°C.

[0027] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, when synthesizing carbon quantum dots, the reaction time of the hydrothermal reaction is 4 to 6 hours.

[0028] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, when synthesizing carbon quantum dots, the filtration adopts a 0.2μm filter membrane.

[0029] Among them, in the above-mentioned carbon quantum dot-based aldehyde and ketone small molecule identification method, when synthesizing carbon quantum dots, the solvent used for column chromatography separation is CH3OH:CH2Cl2 in a volume ratio of 6 to 4:1.

[0030] The present invention also realizes the identification of complex systems such as liquor, and provides a liquor identification method based on carbon quantum dots. The qualitative identification of liquor is the same as the qualitative identification principle of aldehyde and ketone small molecules. On the basis of the above-mentioned qualitative analysis steps of aldehyde and ketone small molecules, the aldehyde and ketone small molecule solution is replaced with liquor (liquor does not need additional treatment such as dilution, and the original liquor sample is directly added), and an equal volume of Vol40-70% ethanol aqueous solution is used as a control.

[0031] Based on the above-mentioned qualitative identification method for aldehyde and ketone small molecules and liquor, the present invention also provides a three-channel fluorescence array sensor based on carbon quantum dots, which includes N first sensor units U1, N second sensor units U2 and N second sensor units U3, the substance in U1 is the above-mentioned identification system A, the substance in U2 is the above-mentioned identification system B, and the substance in U3 is the above-mentioned identification system C; N is an integer greater than 0.

[0032] In the above three-channel fluorescence array sensor based on carbon quantum dots, the present invention controls each sensing unit so that after adding the analyte, the total amount of the final system added is 1 to 1.5 mL.

[0033] The beneficial effects of the present invention are:

[0034] The present invention is based on the reaction of aldehyde and ketone small molecules with hydroxylamine hydrochloride, and the product generates amide under acidic conditions. The amide easily reacts with the surface group of carbon quantum dots to produce differential fluorescence changes, which will quench the fluorescence of o-phenylenediamine carbon quantum dots to varying degrees, and make m-phenylenediamine and m-aminophenol produce new fluorescence peaks. Through the overall fluorescence changes of the three quantum dots, qualitative and quantitative identification of different aldehydes, ketones and liquors can be achieved. According to experiments, the accuracy of linear discriminant analysis (LDA) can reach 100% in qualitative identification, and a good linear relationship can be obtained when partial least squares regression quantitative analysis is used for quantitative identification.

[0035] The three-channel fluorescence array sensor based on the above principle of the present invention has many advantages over traditional sensors, such as easy availability of raw materials and low cost. It does not require complex synthesis methods and can be applied to the qualitative and quantitative identification of various aldehyde and ketone organic small molecules and the identification of complex samples such as liquors (or mixed liquors) of different origins, flavors, brands, grades and years that are rich in such compounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a schematic diagram of a method for identifying pure aldehyde and ketone organic small molecule substances and distinguishing liquor by using a three-channel fluorescence array sensor constructed based on three carbon quantum dots of m-phenylenediamine, m-aminophenol, and o-phenylenediamine and hydroxylamine hydrochloride.

[0037] Figure 2 The three-channel fluorescence array sensor in Example 1 is 5.0×10 -2 Fluorescence response diagrams and LDA analysis result diagrams of different aldehydes and ketones at different mol / L; among them, a is m-aminophenol carbon quantum dots; b is m-phenylenediamine carbon quantum dots; c is o-phenylenediamine carbon quantum dots; d is the LDA standard score diagram.

[0038] Figure 3 This is the LDA standard score diagram of the three-channel fluorescence array sensor for different aldehydes and ketones in Example 1, where a is 0.02mmol / L; b is 0.10mmol / L; c is 0.20mmol / L; d is 0.60mmol / L; e is 1.0mmol / L; f is 2.0mmol / L; g is 6.0mmol / L; and h is 10mmol / L.

[0039] Figure 4 The fused spectrum diagram of the three-channel fluorescence sensor in Example 1 with different concentrations of fatty aldehydes added and the correlation diagram between the actual concentration and the predicted concentration of the PLSR model based on the fatty aldehyde fusion spectrum; wherein a and b are formaldehyde; c and d are acetaldehyde; e and f are isobutyraldehyde; g and h are valeraldehyde; i and j are heptanal.

[0040] Figure 5 The fusion spectrum of the three-channel fluorescence sensor in Example 1 with different concentrations of aromatic aldehydes added and the correlation diagram between the actual concentration and the predicted concentration of the PLSR model based on the aromatic aldehyde fusion spectrum; wherein a and b are furfural; c and d are benzaldehyde; e and f are phenylacetaldehyde; g and h are vanillin; i and j are cinnamaldehyde.

[0041] Figure 6The fused spectrum diagram of the three-channel fluorescence sensor in Example 1 with different concentrations of ketone and acetal added, and the correlation diagram between the actual concentration and the predicted concentration of the PLSR model based on the aldehyde-ketone fusion spectrum; wherein a and b are 2-pentanone; c and d are 2,3-butanedione; e and f are 2,3-pentanedione; g and h are 3-hydroxy-2-butanone; i and j are acetophenone; k and l are acetal.

[0042] Figure 7 It is the fusion spectrum diagram and LDA standard score diagram of the three-channel fluorescence array sensor for mixed aldehydes and ketones in Example 2; wherein a is the fusion fluorescence spectrum diagram and b is the LDA standard score diagram.

[0043] Figure 8 1 is the LDA standard score diagram of the three-channel fluorescence array sensor for different liquors in Examples 3 and 4; wherein a is the 12 different flavors of liquors in Example 3; b is the 40 different brands of strong-flavor liquors in Example 4. DETAILED DESCRIPTION

[0044] The detection mechanism of the three-channel fluorescence array sensor constructed based on three carbon quantum dots of m-phenylenediamine, m-aminophenol, and o-phenylenediamine and hydroxylamine hydrochloride is that aldehydes and ketones react with hydroxylamine hydrochloride, and their products generate amides under acidic conditions. Amides easily react with the surface groups of carbon quantum dots to produce differential fluorescence changes, which will quench the fluorescence of o-phenylenediamine carbon quantum dots to varying degrees, and make m-phenylenediamine and m-aminophenol produce new fluorescence peaks. Through the overall fluorescence changes of the three quantum dots, different aldehydes and ketones can be identified. In addition, there are certain differences in the composition and content of aldehyde and ketone compounds contained in liquors of different brands, grades and origins. These differences will lead to different fluorescence changes, and finally realize the identification of liquors from different flavors, brands, storage years and grades.

[0045] The present invention first provides a method for identifying aldehyde and ketone small molecules based on carbon quantum dots, which comprises the following steps:

[0046] A. Mixing a solvent, m-aminophenol carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system A; mixing a solvent, m-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system B; mixing a solvent, o-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system C;

[0047] B. Add aldehyde and ketone small molecule solutions to identification systems A, B and C respectively to obtain sample groups A, B and C, and use an equal volume of the solvent used for the aldehyde and ketone small molecule solutions as a control;

[0048] C. Under the condition that the excitation wavelength is 365-380nm and the slits of the excitation wavelength and the emission wavelength are 10-15nm, the fluorescence intensity values ​​of sample groups A, B and C and the control group at the maximum emission wavelength are measured, and the fluorescence intensity value of the sample group is subtracted from the fluorescence intensity value of the corresponding control group to obtain the fluorescence change value of the aldehyde and ketone small molecules;

[0049] Qualitative analysis: linear discriminant analysis was used to distinguish according to the fluorescence change value;

[0050] Quantitative analysis: Based on the fluorescence change value, partial least squares regression was used for quantitative analysis;

[0051] In step A, the solvent is at least one of water or ethanol;

[0052] When it is a qualitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water, ethanol or liquor; the aldehyde and ketone small molecule is at least one of formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal;

[0053] When it is a quantitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water or ethanol; the aldehyde and ketone small molecules are formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal.

[0054] During the qualitative and quantitative analysis of the present invention, although water or ethanol has little effect on U1 and U2, in order to make the test results more accurate, the control group generally adopts the solvent used for the organic small molecule solution to ensure that the solvents of the control group and the test group are the same in each test system.

[0055] In step B of the method of the present invention, after adding the aldehyde ketone small molecule solution to the identification system A, the reaction is carried out for 10 to 20 minutes; after adding the aldehyde ketone small molecule solution to the identification system B, the reaction is carried out for 10 to 20 minutes; after adding the aldehyde ketone small molecule solution to the identification system C, the reaction is carried out for 10 to 20 minutes.

[0056] In step B of the method of the present invention, the concentration of aminophenol carbon quantum dots in sample group A is 0.5-1 mmol / L; the concentration of hydroxylamine hydrochloride in sample group A is 0.1-1 mmol / L; the concentration of phenylenediamine carbon quantum dots in sample group B is 0.5-1 mmol / L; the concentration of hydroxylamine hydrochloride in sample group B is 0.1-1 mmol / L; the concentration of o-phenylenediamine carbon quantum dots in sample group C is 0.5-1 mmol / L; and the concentration of hydroxylamine hydrochloride in sample group C is 0.1-1 mmol / L.

[0057] The method of the present invention uses linear discriminant analysis for qualitative identification. Linear discriminant analysis is a supervised classification method. This method defines the sample category in advance and distinguishes samples of different categories. It generally analyzes the data through software such as SYSTAT13.2. In linear discriminant analysis, for different samples in the same series, the conditions of the reaction system of the two different samples need to be kept as consistent as possible. For a single sample in the same series, the conditions in the three channels are not required to be exactly the same. Since different series are not distinguished from each other as references, the conditions can be different.

[0058] When the method of the present invention is used for quantitative identification, partial least squares regression is used. For example, several points can be taken in the range of 0.02 to 10 mmol / L of the concentration of aldehyde and ketone small molecules in sample groups A, B and C, and the samples are prepared and tested according to the above method. The linear relationship of these points is analyzed by partial least squares regression, and then used to quantitatively analyze pure aldehyde and ketone small molecule solution samples of unknown concentration.

[0059] In the method of the present invention, the synthesis method of carbon quantum dots is: dissolving the material in ethanol, carrying out a hydrothermal reaction, and after the reaction is completed, cooling, filtering, column chromatography separation and drying are carried out in sequence to obtain carbon quantum dot particles; the material is m-phenylenediamine, m-aminophenol or o-phenylenediamine.

[0060] When synthesizing carbon quantum dots, the mass of the material is controlled to have a volume ratio of 1:100 to 150 to ethanol; the reaction temperature of the hydrothermal reaction is 180 to 200°C; the reaction time of the hydrothermal reaction is 4 to 6 hours; a 0.2 μm filter membrane is used for filtration; and the solvent used for column chromatography separation is CH3OH:CH2Cl2 in a volume ratio of 6 to 4:1.

[0061] The present invention also realizes the identification of complex systems such as liquor, and provides a liquor identification method based on carbon quantum dots. The qualitative identification of liquor is the same as the qualitative identification principle of aldehyde and ketone small molecules. On the basis of the above-mentioned qualitative analysis steps of aldehyde and ketone small molecules, the aldehyde and ketone small molecule solution is replaced with liquor (liquor does not need additional treatment such as dilution, and the original liquor sample is directly added), and because the ethanol solution has little effect on U1 and U2, an equal volume of Vol40-70% ethanol aqueous solution (this range includes the alcohol content range of most liquors) can be used as a control.

[0062] Based on the above-mentioned quantitative and qualitative identification method for aldehyde and ketone small molecules and liquor, the present invention also provides a three-channel fluorescence array sensor based on carbon quantum dots, which includes N first sensor units U1, N second sensor units U2 and N second sensor units U3, the substance in U1 is the above-mentioned identification system A, the substance in U2 is the above-mentioned identification system B, and the substance in U3 is the above-mentioned identification system C; N is an integer greater than 0. The principle of the three-channel fluorescence array sensor is the above-mentioned qualitative and quantitative detection principle, so according to the above-mentioned qualitative or quantitative analysis process, each material and its concentration are controlled, and when using the three-channel fluorescence array sensor, it can be operated according to the above-mentioned qualitative and quantitative methods.

[0063] In the above three-channel fluorescence array sensor based on carbon quantum dots, the present invention controls each sensing unit so that after adding the analyte, the total amount of the final system added is 1 to 1.5 mL.

[0064] The present invention is further described in detail below by way of examples, but the protection scope of the present invention is not limited to the scope of the examples.

[0065] In the embodiment, the synthesis method of carbon quantum dots is: mixing the material with anhydrous ethanol, transferring it to a reactor after dissolving, conducting a hydrothermal reaction at 180°C for 6 hours, filtering through a 0.2μm filter membrane after the reactor is naturally cooled to room temperature, and then purifying and separating by column chromatography (CH3OH / CH2Cl2 (6~4:1, v / v)) and then vacuum drying to obtain carbon quantum dot particles; the material is one of m-phenylenediamine, m-aminophenol, and o-phenylenediamine, the sample weight is 0.3000g, and the amount of ethanol used is 40mL.

[0066] Example 1

[0067] The three-channel fluorescence array sensor constructed in this embodiment can be used to identify and distinguish 16 kinds of aldehydes and ketones. It should be specifically explained that the first sensing unit U1 is: m-aminophenol carbon quantum dots + hydroxylamine hydrochloride; the second sensing unit U2 is: m-phenylenediamine carbon quantum dots + hydroxylamine hydrochloride; the third sensing unit U3 is: o-phenylenediamine carbon quantum dots + hydroxylamine hydrochloride.

[0068] In this embodiment, the aldehyde and ketone compounds to be identified include: formaldehyde (Q1), acetaldehyde (Q2), isobutyraldehyde (Q3), valeraldehyde (Q4), heptaldehyde (Q5), furfural (Q6), benzaldehyde (Q7), phenylacetaldehyde (Q8), vanillin (Q9), cinnamaldehyde (Q10), 2-pentanone (T1), 2,3-butanedione (T2), 2,3-pentanedione (T3), 3-hydroxy-2-butanone (T4), acetophenone (T5) and acetal (SQ). First, each aldehyde and ketone solution is prepared with anhydrous ethanol, and their original concentration range is 1.00-500mmol / L, so as to ensure that when 20μL of the above solution is added to the identification system, the final concentration of the aldehyde and ketone small molecules in the system is 0.02-10mmol / L, and this concentration range covers the actual concentration of 16 aldehyde and ketone small molecules in liquor. Within this range, 9 concentrations of each aldehyde and ketone small molecule were prepared, and their final concentrations in the system were: 0.02mmol / L, 0.05mmol / L, 0.10mmol / L, 0.20mmol / L, 0.60mmol / L, 1.0mmol / L, 2.0mmol / L, 6.0mmol / L, and 10mmol / L, respectively.

[0069] In this embodiment, 20 μL of anhydrous ethanol was added to each sensor unit in the control group, and 20 μL of aldehyde and ketone organic small molecule compound solutions of different concentrations were added to the reaction group. After adding the control group or the reaction group, the final concentration of carbon quantum dots in the system was 0.5 mmol / L, the final concentration of hydroxylamine hydrochloride was 0.50 mmol / L, and the total volume of the control group and the reaction group was 1000 μL.

[0070] After adding the control group or reaction group, start timing. After 15 minutes, under the condition of excitation wavelength of 365nm and slit of excitation wavelength and emission wavelength of 10nm, record the fluorescence intensity value of each reaction group and the corresponding control group. The fluorescence spectrum of each compound at each concentration is repeated 3 times. Subtract the fluorescence value of the control group from the fluorescence value of the reaction group to obtain the fluorescence change value of each aldehyde ketone small molecule at 9 concentrations, which can be used as the eigenvalue of the matrix. Therefore, each specific concentration of aldehyde ketone organic small molecule has 3 eigenvalues ​​based on the dual-channel array sensor, and is used for subsequent linear discriminant analysis (LDA) by SYSTAT13.2.

[0071] In this embodiment, in order to evaluate the quantitative analysis performance of the three-channel array sensor, the above-mentioned characteristic values ​​are also used for quantitative analysis by applying partial least squares regression.

[0072] The fluorescence spectra of 16 aldehyde and ketone small molecule compounds at a concentration of 0.05mmol / L are shown in the figure below. Figure 2a~2c are shown, and the fusion fluorescence spectra at the other 8 concentrations are shown in Figures 4 to 6 As shown, among them, 4a is formaldehyde; 4c is acetaldehyde; 4e is isobutyraldehyde; 4g is valeraldehyde; 4i is heptaldehyde; 5a is furfural; 5c is benzaldehyde; 5e is phenylacetaldehyde; 5g is vanillin; 5i is cinnamaldehyde; 6a is 2-pentanone; 6c is 2,3-butanedione; 6e is 2,3-pentanedione; 6g is 3-hydroxy-2-butanone; 6i is acetophenone; 6k is acetal.

[0073] The LDA discrimination results of 16 aldehyde and ketone small molecule compounds at a concentration of 0.05mmol / L are shown in the figure below: Figure 2 d, the LDA discrimination results at the other 8 concentrations are shown in Figure 3 As shown, a is 0.02mmol / L; b is 0.10mmol / L; c is 0.20mmol / L; d is 0.60mmol / L; e is 1.0mmol / L; f is 2.0mmol / L; g is 6.0mmol / L; and h is 10mmol / L.

[0074] It can be seen from the above that the accuracy rate of the jackknife cross discrimination at each concentration of the 16 aldehyde and ketone organic small molecule compounds in this embodiment is 100%.

[0075] The PLSR quantitative results of different aldehydes and ketones in this example are as follows Figures 4 to 6 As shown, among them, 4b is formaldehyde; 4d is acetaldehyde; 4f is isobutyraldehyde; 4h is valeraldehyde; 4j is heptaldehyde; 4b is furfural; 4d is benzaldehyde; 4f is phenylacetaldehyde; 4h is vanillin; 4j is cinnamaldehyde; 6b is 2-pentanone; 6d is 2,3-butanedione; 6f is 2,3-pentanedione; 6h is 3-hydroxy-2-butanone; 6j is acetophenone; 6l is acetal.

[0076] From the above, it can be seen that the PLSR quantitative results of 16 aldehyde and ketone organic small molecule compounds in this example are R 2 The values ​​are all greater than 0.9980, indicating a good linear relationship.

[0077] Example 2

[0078] The three-channel fluorescence array sensor constructed in this embodiment can not only identify the pure substances of the 16 aldehyde and ketone organic small molecule compounds in Example 1, but also distinguish and differentiate mixed aldehyde and ketone samples.

[0079] The different concentrations of aldehyde and ketone small molecule compounds in each channel in Example 1 were replaced with 4 mixed aldehyde and ketone ethanol solutions. Similarly, all data were repeated 3 times, and the fluorescence spectra were recorded. The three-channel fusion fluorescence spectra are shown in Figure 7 The obtained fluorescence spectrum will be used for further chemometric analysis.

[0080] The detailed information of the mixed aldehyde and ketone samples is shown in Table 1.

[0081] The fluorescence spectrum response diagram of the three-channel sensor to the mixed aldehyde and ketone fusion and the LDA discrimination results are shown in Figure 7 As shown in b, the LDA discrimination rate of different mixed aldehyde and ketone samples was 100%.

[0082] The above phenomenon shows that the three-channel fluorescence array sensor constructed by the present invention can have a good distinguishing effect on mixed aldehyde and ketone samples. Since the content of each aldehyde is within the actual content range of liquor, this method can be used to distinguish actual liquor samples.

[0083] Table 1 Detailed information of mixed aldehydes and ketones and the contents of some aldehydes and ketones in liquor (mmol / L)

[0084]

[0085]

[0086] Example 3

[0087] The array sensor constructed in this embodiment can not only identify aldehyde and ketone compounds, but also identify Chinese liquor samples of different flavors.

[0088] Representative liquors of 12 flavors from China (No. 5 and No. 41-51) were selected for analysis, and detailed liquor sample information is shown in Table 2. For liquor identification, it is only necessary to replace the aldehydes and ketones of different concentrations in Example 1 with liquor samples of the same volume (liquor does not need to be diluted, and the original liquor samples are directly added), and the other conditions are the same. The control under each channel is 20 μL, 52% ethanol aqueous solution, and the fluorescence spectrum of each sample is recorded after 15 minutes for further chemometric analysis.

[0089] In order to obtain more accurate analysis and discrimination results, 12 different types of liquor were discriminated by linear discriminant analysis (LDA). The discrimination results of LDA are shown in Figure 8a, and the discrimination accuracy is 100%.

[0090] Table 2 Information of different flavor liquor samples

[0091]

[0092]

[0093]

[0094] Example 4

[0095] The array sensor constructed in this embodiment can not only identify aldehyde and ketone compounds, but also identify samples of different brands of Luzhou-flavor Chinese liquor.

[0096] 40 different Luzhou-flavor brand liquors from China (numbered 1 to 40) were selected for analysis, and detailed liquor sample information is shown in Table 2. For liquor identification, it is only necessary to replace the aldehydes and ketones of different concentrations in Example 1 with liquor samples of the same volume (liquor does not need to be diluted, and the original liquor samples are directly added), and the other conditions are the same. The control under each channel is 20 μL, 52% ethanol solution, and the fluorescence spectrum of each sample is recorded after 15 minutes for further chemometric analysis.

[0097] In order to obtain more accurate analysis and discrimination results, 40 different brands of Luzhou-flavor liquor were discriminated by linear discriminant analysis (LDA). The discrimination results of LDA are shown in Figure 8b, and the discrimination accuracy is 100%.

Claims

1. A method for identifying aldehyde and ketone small molecules based on carbon quantum dots, characterized in that: The following steps are involved: A. Mixing a solvent, m-aminophenol carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system A; mixing a solvent, m-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system B; mixing a solvent, o-phenylenediamine carbon quantum dots and hydroxylamine hydrochloride to obtain an identification system C; B. Add aldehyde and ketone small molecule solutions to identification systems A, B and C respectively to obtain sample groups A, B and C, and use an equal volume of the solvent used for the aldehyde and ketone small molecule solutions as a control; C. Under the conditions of an excitation wavelength of 365-380 nm and a slit of 10-15 nm between the excitation wavelength and the emission wavelength, measure the fluorescence intensity values ​​of sample groups A, B and C and the control group at the maximum emission wavelength, and subtract the fluorescence intensity value of the corresponding control group from the fluorescence intensity value of the sample group to obtain the fluorescence change value of the aldehyde and ketone small molecules; Qualitative analysis: linear discriminant analysis was used to distinguish according to the fluorescence change value; Quantitative analysis: Based on the fluorescence change value, partial least squares regression was used for quantitative analysis; In step A, the solvent is at least one of water or ethanol; When it is a qualitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water, ethanol or liquor; the aldehyde and ketone small molecule is at least one of formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal; When it is a quantitative analysis, in step B, the solvent used for the aldehyde and ketone small molecule solution is at least one of water or ethanol; the aldehyde and ketone small molecules are formaldehyde, acetaldehyde, isobutyraldehyde, valeraldehyde, heptaldehyde, furfural, benzaldehyde, phenylacetaldehyde, vanillin, cinnamaldehyde, 2-pentanone, 2,3-butanedione, 2,3-pentanedione, 3-hydroxy-2-butanone, acetophenone or acetal.

2. The method for identifying aldehyde and ketone small molecules based on carbon quantum dots according to claim 1, characterized in that: At least one of the following is met: In step B, after adding the aldehyde and ketone small molecule solution to the identification system A, the reaction is carried out for 10 to 20 minutes; In step B, after adding the aldehyde and ketone small molecule solution to the identification system B, the reaction is carried out for 10 to 20 minutes; In step B, after adding the aldehyde and ketone small molecule solution to the identification system C, the reaction is carried out for 10 to 20 minutes.

3. The method for identifying aldehyde and ketone small molecules based on carbon quantum dots as claimed in claim 1, characterized in that: At least one of the following is met: In step B, the concentration of aminophenol carbon quantum dots in sample group A is 0.5-1 mmol / L; In step B, the concentration of hydroxylamine hydrochloride in the sample group A is 0.1-1 mmol / L; In step B, the concentration of the m-phenylenediamine carbon quantum dots in sample group B is 0.5-1 mmol / L; In step B, the concentration of hydroxylamine hydrochloride in the sample group B is 0.1-1 mmol / L; In step B, the concentration of o-phenylenediamine carbon quantum dots in the sample group C is 0.5-1 mmol / L; In step B, the concentration of hydroxylamine hydrochloride in the sample group C is 0.1-1 mmol / L.

4. The method for identifying aldehyde and ketone small molecules based on carbon quantum dots according to claim 1, characterized in that: In step B, the concentration of aldehyde and ketone small molecules in the sample groups A, B and C is 0.02~10mmmol / L.

5. The method for identifying aldehyde and ketone small molecules based on carbon quantum dots according to any one of claims 1 to 4, characterized in that: The synthesis method of the carbon quantum dots is as follows: dissolving the material in ethanol, carrying out a hydrothermal reaction, and after the reaction is completed, sequentially cooling, filtering, column chromatography separation and drying to obtain carbon quantum dot particles; the material is m-phenylenediamine, m-aminophenol or o-phenylenediamine.

6. The method for identifying aldehyde and ketone small molecules based on carbon quantum dots according to claim 5, characterized in that: When synthesizing carbon quantum dots, at least one of the following conditions must be met: The mass ratio of the material to the volume ratio of the ethanol is 1:100-150; The reaction temperature of the hydrothermal reaction is 180-200°C; The reaction time of the hydrothermal reaction is 4 to 6 hours; The filtration adopts a 0.2 μm filter membrane; The solvent used for column chromatography separation is CH3OH:CH2Cl2 in a volume ratio of 6-4:

1.

7. A method for identifying liquor based on carbon quantum dots, characterized in that: Based on the qualitative analysis steps described in any one of claims 1 to 6, the aldehyde and ketone small molecule solution is replaced with white wine, and an equal volume of Vol 40-70% ethanol aqueous solution is used as a control.

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