Baijiu detection method based on colorimetric and fluorescent double-signal sensing array

Abstract

The invention discloses a baijiu detection method based on a colorimetric and fluorescent dual-signal sensing array, and relates to the technical field of substance detection and analysis. According to the detection method, the principle that rhodamine B and rhodamine 6G have remarkable ultraviolet-visible spectrums and fluorescence characteristic peaks, and rhodamine B and rhodamine 6G can be accelerated to be catalytically degraded by MnONSs under the acidic condition is utilized, so that optical signals (colorimetric-fluorescence double signals) of rhodamine B and rhodamine 6G can be adjusted by adjusting the catalytic action of MnONSs; according to the method, a colorimetric and fluorescent dual-signal sensing array is constructed, then the dual-signal sensing array is utilized to form characteristic fingerprints of various Baijiu samples, rapid and accurate detection of Baijiu is achieved, and the method is few in types of detection materials, simple and convenient to operate and more suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of material detection and analysis technology, mainly to the field of liquor detection technology, and specifically to a liquor detection method based on a colorimetric and fluorescence dual-signal sensor array. Background Technology

[0002] Baijiu is one of the world's six major distilled spirits. Influenced by geographical location, temperature, climate, raw materials, and brewing techniques, baijiu has gradually evolved into 12 different flavor types over thousands of years, including strong aroma, light aroma, sauce aroma, and rice aroma. Baijiu with different flavor types and brands exhibits unique flavors and tastes, satisfying consumers' personalized needs. However, problems have also emerged. Driven by the pursuit of high profits, a large number of counterfeit and substandard baijiu products have flooded the market, severely damaging the image of baijiu. Therefore, there is an urgent need to develop modern testing technologies for baijiu quality control and market supervision.

[0003] Currently, sensory evaluation and instrumental analysis are frequently used in the analysis and testing of baijiu (Chinese liquor), playing a crucial role in its production, sales, and market supervision, and helping to ensure product quality. However, sensory evaluation relies on professional tasters, and its application is mainly limited to large enterprises, making widespread adoption quite difficult. Instrumental analysis, on the other hand, faces challenges due to complex preprocessing and time-consuming processes, hindering real-time and large-scale testing. Therefore, there is an urgent need to develop simple, rapid, and efficient testing methods.

[0004] In recent years, sensor array technology has rapidly developed as a powerful method for detecting complex analytes and has been widely applied in fields such as liquor, food, and health. A sensor array consists of multiple sensitive materials designed for the target analyte. Through the cross-reaction between the sensitive materials and the analyte, a unique fingerprint spectrum can be formed for each analyte. The analyte can be identified using pattern recognition methods such as hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA). Compared to sensors designed specifically for a single analyte, although the accuracy of the detection results is affected by the sensitivity and selectivity of each sensitive material in the sensor array, this effect can be overcome by the unique fingerprint spectrum obtained through the cross-reaction of each analyte, thus enabling the simultaneous detection of different analytes.

[0005] In existing technologies, dyes are used as sensitive materials to construct colorimetric or fluorescence sensor arrays, thereby achieving accurate identification of baijiu (Chinese liquor), as illustrated by patent CN112730399A. However, these single optical signal sensor arrays consist of more than ten dyes and other optical materials, which imposes a huge workload on operators and lacks selectivity and accuracy, hindering their large-scale application in baijiu production and testing. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing liquor detection methods based on fluorescence sensor arrays, such as poor accuracy and cumbersome operation, and to propose a liquor detection method based on a colorimetric and fluorescence dual-signal sensor array.

[0007] To achieve the above-mentioned objectives, this invention proposes a method for detecting baijiu (Chinese liquor) based on a colorimetric-fluorescence dual-signal sensor array, comprising the following steps: (1) A colorimetric and fluorescence dual-signal sensing array is constructed using detection materials; the detection materials include Rhodamine B, Rhodamine 6G and MnO2NSs; (2) The constructed colorimetric and fluorescence dual-signal sensor array was used to detect different types of liquor samples and obtain the colorimetric and fluorescence signals of each liquor sample. (3) Using the colorimetric and fluorescence signals of each liquor sample, a characteristic fingerprint spectrum of each liquor sample is formed; (4) Based on the feature fingerprint spectrum, the pattern recognition method is used to distinguish and identify the liquor to be tested.

[0008] This invention discloses a method for detecting baijiu (Chinese liquor) based on a colorimetric-fluorescence dual-signal sensor array. It utilizes the significant UV-Vis spectral and fluorescence characteristic peaks of Rhodamine B and Rhodamine 6G, and the accelerated catalytic degradation of Rhodamine B and Rhodamine 6G by MnO2 NSs under acidic conditions. By adjusting the catalytic effect of MnO2 NSs, the optical signals (colorimetric-fluorescence dual signals) of Rhodamine B and Rhodamine 6G can be modulated. A dual-signal sensor array for colorimetry and fluorescence is constructed, and this array is used to generate characteristic fingerprint spectra of various baijiu samples. This enables rapid and accurate detection of baijiu. Furthermore, this method uses fewer types of detection materials, is simple and convenient to operate, and is more suitable for large-scale application.

[0009] In step (1), preferably, the preparation method of the MnO2NSs includes: a. Add sodium dodecyl sulfate solution and sulfuric acid to water, mix and dissolve to obtain a mixed solution, and then heat the mixed solution; wherein the concentration of the sodium dodecyl sulfate solution is 0.08-0.12 mol / L, the concentration of the sulfuric acid is 18-19 mol / L, and the volume ratio of the added sodium dodecyl sulfate solution to sulfuric acid is 18-22:1; b. Add potassium permanganate to the heated mixed solution and heat to react, to obtain a suspension; wherein the amount of potassium permanganate added is 0.04-0.06 mol / L; c. The suspension is centrifuged, filtered and washed sequentially to obtain MnO2NSs.

[0010] The manganese dioxide nanosheets prepared by the above method exhibit a wrinkled two-dimensional layered structure, which provides a huge surface area for the reaction of Rhodamine B and Rhodamine 6G, thereby making the reaction speed faster and more thorough in the detection process, and the changes in the colorimetric and fluorescence signals of Rhodamine B and Rhodamine 6G more obvious, which can greatly improve the accuracy of detection.

[0011] Preferably, in step a, the heating temperature is 93-98℃ and the time is 10-20 min.

[0012] Preferably, in step b, the heating reaction temperature is 93-98℃ and the time is 50-70 min.

[0013] Preferably, in step c, the centrifugation speed is 7000-9000 r / s and the time is 8-12 min.

[0014] Preferably, the colorimetric and fluorescence dual-signal sensor array is obtained by adding Rhodamine B and Rhodamine 6G to a 96-well plate, then adding an aqueous solution of MnO2 NSs, and extracting the colorimetric and fluorescence signals of the mixed solution.

[0015] In step (2), preferably, during the detection of the liquor sample, the volume ratio of the detection material (total amount of MnO2NSs aqueous solution and Rhodamine B or Rhodamine 6G) to the liquor sample is 5-7:2.

[0016] Preferably, in the process of testing the liquor sample, the amount of Rhodamine B and Rhodamine 6G added to the test material is 8-12 μg / mL; the volume ratio of MnO2NSs aqueous solution to Rhodamine B is 2-3:1; the volume ratio of MnO2NSs aqueous solution to Rhodamine 6G is 1-2:1; and the concentration of MnO2NSs in the MnO2NSs aqueous solution is 0.8-1.2 mg / mL.

[0017] Preferably, the reaction time during the testing of liquor samples is 2-2.5 min.

[0018] In step (3), preferably, the characteristic fingerprint spectrum includes a colorimetric characteristic signal and a fluorescence characteristic signal; the colorimetric characteristic signal refers to the ultraviolet-visible absorption intensity (ultraviolet-visible absorption spectrum) of Rhodamine B at 550 nm or Rhodamine 6G at 575 nm; the fluorescence characteristic signal refers to the fluorescence intensity (fluorescence spectrum) of Rhodamine B at 525 nm or Rhodamine 6G at 550 nm.

[0019] In step (4), preferably, the pattern recognition method includes: principal component analysis, hierarchical clustering analysis, linear discriminant analysis, and radial basis function neural network analysis.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention relates to a method for detecting baijiu (Chinese liquor) based on a colorimetric-fluorescence dual-signal sensor array. It utilizes the significant UV-Vis spectral and fluorescence characteristic peaks of Rhodamine B and Rhodamine 6G, and the accelerated catalytic degradation of Rhodamine B and Rhodamine 6G by MnO2NSs under acidic conditions. By adjusting the catalytic effect of MnO2NSs, the optical signals (colorimetric-fluorescence dual signals) of Rhodamine B and Rhodamine 6G can be modulated. This method constructs a dual-signal sensor array for both colorimetric and fluorescence detection, and then uses this dual-signal sensor array to generate characteristic fingerprint spectra of various baijiu samples, achieving rapid and accurate detection of baijiu.

[0021] 2. The method for detecting baijiu based on a colorimetric-fluorescence dual-signal sensor array of the present invention uses fewer types of detection materials, is simple and convenient to operate, and is more suitable for large-scale promotion and application. Attached Figure Description

[0022] Figure 1 Transmission electron microscope image of MnO2 NSs prepared in Example 1 of this invention; Figure 2 The UV-Vis absorption spectrum of MnO2 NSs prepared in Comparative Example 1 of this invention; Figure 3 Fourier transform infrared spectrum of MnO2NSs prepared in Example 1 of this invention; Figure 4 The detection results of 12 kinds of liquor samples in Example 1 of this invention are shown in the figure (A is fingerprint spectrum; B is heat map; C is principal component analysis; D is cluster analysis). Detailed Implementation

[0023] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention. Example 1

[0024] A method for detecting baijiu (Chinese liquor) based on a colorimetric-fluorescence dual-signal sensor array includes the following steps: (1) A colorimetric and fluorescence dual-signal sensing array was constructed using detection materials; the detection materials were Rhodamine B, Rhodamine 6G and MnO2NSs, respectively; The preparation method of MnO2NSs is as follows: a. Add 5 mL of sodium dodecyl sulfate solution (0.1 mol / L) and 250 μL of sulfuric acid (concentration of 18.4 mol / L) to 44.25 mL of distilled water, mix and dissolve to obtain a mixed solution, and then heat the mixed solution (heat at 95℃ for 15 min). b. Add potassium permanganate to the heated mixed solution and heat the solution (heat at 95°C for 60 min) to obtain a suspension; wherein the amount of potassium permanganate added is 0.05 mol / L; c. The suspension was centrifuged (at a speed of 8000 r / s for 10 min), filtered, and washed sequentially to obtain MnO2 NSs.

[0025] The morphology and structure of the prepared manganese dioxide nanosheets were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and ultraviolet-visible absorption spectroscopy. As shown in Figure 1, the prepared manganese dioxide nanosheets exhibit a wrinkled two-dimensional layered structure, providing a large surface area for the reaction of rhodamine B and rhodamine 6G. In ultraviolet-visible absorption spectroscopy... Figure 2 In [the study], manganese dioxide nanosheets exhibited different absorptions in the 300–700 nm range. Fourier transform infrared spectroscopy further confirmed the functional groups of the manganese dioxide nanosheets, such as […]. Figure 3 As shown, a characteristic peak appears at 508 cm⁻¹. -1 This confirms the existence of Mn-O stretching vibrations; (2) The constructed colorimetric and fluorescence dual-signal sensor array was used to detect different types of liquor samples and obtain the colorimetric and fluorescence signals of each liquor sample. 1 ml of MnO2 NSs aqueous solution (1 mg / ml) and 1 ml of a baijiu sample were added to a 1 mL centrifuge tube, and the mixture was incubated at room temperature for 2 min. Then, Rhodamine B (0.5 ml, 10 μg / mL) or Rhodamine 6G (0.5 ml, 10 μg / mL) were added, respectively. Finally, the UV-Vis absorption and fluorescence spectra of the mixed solutions were measured. A total of 12 different brands and aroma types of baijiu were tested, and a data matrix of 12 baijiu × 4 arrays × 5 replicates was generated. The change in optical signal is calculated using the following formula: A = (A0 - A1) / A0 F = (F0 - F1) / F0 A0 and A1 represent the UV-Vis absorption intensities of Rhodamine B at 550 nm (or Rhodamine 6G at 575 nm) in the absence of baijiu and in the presence of baijiu, respectively. F0 and F1 represent the fluorescence intensities of Rhodamine B at 525 nm (or Rhodamine 6G at 550 nm) in the absence of baijiu and in the presence of baijiu, respectively. like Figure 4 The fingerprint spectra and thermal maps of 12 types of baijiu (Chinese liquor) shown in A and 4B reveal different responses from the 12 baijiu to the sensor array. Baijiu can suppress the fluorescence of Rhodamine B and Rhodamine 6G. The intensity of UV-Vis absorption is also suppressed by baijiu. This may be due to differences in the types and contents of organic acids in baijiu. The sensing characteristics of the sensor array are achieved through pattern recognition methods. In LDA (… Figure 4 In C), the 60 data points were divided into 12 groups, each corresponding to a different type of baijiu. HCA results ( Figure 4 As shown in D), all baijiu samples (12 types of baijiu × 5 duplicate samples) can be accurately distinguished, and no misclassification occurs; (3) Using the colorimetric and fluorescence signals of each liquor sample, a characteristic fingerprint spectrum of each liquor sample is formed; The characteristic fingerprint spectrum includes colorimetric characteristic signals and fluorescence characteristic signals; the colorimetric characteristic signal refers to the UV-Vis absorption intensity of Rhodamine B at 550 nm or Rhodamine 6G at 575 nm (UV-Vis absorption spectrum); the fluorescence characteristic signal refers to the fluorescence intensity of Rhodamine B at 525 nm or Rhodamine 6G at 550 nm (fluorescence spectrum). (4) Based on the feature fingerprint spectrum, the pattern recognition method is used to distinguish and identify the liquor to be tested.

[0026] This invention utilizes the significant UV-Vis spectral and fluorescence characteristic peaks of Rhodamine B and Rhodamine 6G, and the fact that Rhodamine B and Rhodamine 6G can be accelerated and catalytically degraded by MnO2 NSs under acidic conditions. Based on the principle that the optical signals (colorimetric-fluorescence dual signals) of Rhodamine B and Rhodamine 6G can be modulated by adjusting the catalytic effect of MnO2 NSs, a dual-signal sensing array of colorimetric and fluorescence signals is constructed. This dual-signal sensing array is then used to generate characteristic fingerprint spectra of various baijiu samples, achieving rapid and accurate detection of baijiu. Furthermore, this method uses fewer types of detection materials, is simple and convenient to operate, and is more suitable for large-scale application.

[0027] Comparative Example 1: The method of the embodiment in patent CN112730399A was used to detect baijiu (Chinese liquor).

[0028] The optical signal sensor array in this method consists of more than ten kinds of dyes and other optical materials, which brings a huge workload to the operators. In addition, it lacks selectivity and has poor accuracy, which is not conducive to its large-scale promotion and use in the production and testing of liquor.

[0029] Comparative Example 2 The detection method in Example 1 was used to detect the liquor, except that the manganese dioxide catalyst prepared in Example 1 of patent CN113117668A was used instead of the MnO2 NSs of the present invention.

[0030] After replacing the MnO2 catalyst with the one prepared in Example 1 of patent CN113117668A, the MnO2 catalyst, being rod-shaped (unlike the plate-shaped catalyst of this invention, which has a larger specific surface area, more contact sites, and a faster and more thorough reaction), exhibits slower reaction speed and lower sensitivity when detecting baijiu (Chinese liquor). Furthermore, the preparation process of this MnO2 catalyst requires complex and cumbersome techniques such as high temperature and reflux condensation, with strict conditions that are difficult to control, thus hindering large-scale production.

Claims

1. A method for detecting baijiu (Chinese liquor) based on a colorimetric and fluorescence dual-signal sensor array, characterized in that, Includes the following steps: (1) A colorimetric and fluorescence dual-signal sensing array is constructed using detection materials; the detection materials include Rhodamine B, Rhodamine 6G and MnO2NSs; (2) The constructed colorimetric and fluorescence dual-signal sensor array was used to detect different types of liquor samples and obtain the colorimetric and fluorescence signals of each liquor sample. (3) Using the colorimetric and fluorescence signals of each liquor sample, a characteristic fingerprint spectrum of each liquor sample is formed; (4) Based on the feature fingerprint spectrum, the pattern recognition method is used to distinguish and identify the liquor to be tested.

2. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (1), the preparation method of the MnO2NSs includes: a. Add sodium dodecyl sulfate solution and sulfuric acid to water, mix and dissolve to obtain a mixed solution, and then heat the mixed solution; wherein the concentration of the sodium dodecyl sulfate solution is 0.08-0.12 mol / L, the concentration of the sulfuric acid is 18-19 mol / L, and the volume ratio of the added sodium dodecyl sulfate solution to sulfuric acid is 18-22:1; b. Add potassium permanganate to the heated mixed solution and heat to react, to obtain a suspension; wherein the amount of potassium permanganate added is 0.04-0.06 mol / L; c. The suspension is centrifuged, filtered and washed sequentially to obtain MnO2NSs.

3. The method for detecting baijiu (Chinese liquor) according to claim 2, characterized in that, In step a, the heat treatment temperature is 93-98℃ and the time is 10-20 minutes.

4. The method for detecting baijiu (Chinese liquor) according to claim 2, characterized in that, In step b, the heating reaction is carried out at a temperature of 93-98℃ for 50-70 minutes.

5. The method for detecting baijiu (Chinese liquor) according to claim 2, characterized in that, In step c, the centrifugation speed is 7000-9000 r / s, and the time is 8-12 min.

6. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (2), during the testing of the liquor sample, the volume ratio of the testing material to the liquor sample is 5-7:

2.

7. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (2), the amount of Rhodamine B and Rhodamine 6G added to the detection material is 8-12 μg / mL; the volume ratio of MnO2NSs aqueous solution to Rhodamine B is 2-3:1; the volume ratio of MnO2NSs aqueous solution to Rhodamine 6G is 1-2:1; and the concentration of MnO2NSs in the MnO2NSs aqueous solution is 0.8-1.2 mg / mL.

8. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (2), the reaction time during the detection of the liquor sample is 2-2.5 min.

9. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (3), the characteristic fingerprint spectrum includes colorimetric characteristic signal and fluorescence characteristic signal; the colorimetric characteristic signal refers to the ultraviolet-visible absorption intensity of Rhodamine B at 550 nm or Rhodamine 6G at 575 nm; the fluorescence characteristic signal refers to the fluorescence intensity of Rhodamine B at 525 nm or Rhodamine 6G at 550 nm.

10. The method for detecting baijiu (Chinese liquor) according to claim 1, characterized in that, In step (4), the pattern recognition method includes: principal component analysis, hierarchical clustering analysis, linear discriminant analysis, and radial basis function neural network analysis.

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