Test paper for identifying authenticity of citrus chachiensis hortorum and preparation method of test paper

Abstract

The invention discloses a test paper for identifying authenticity of citrus chachiensis hortorum. The test paper comprises a substrate and thioglycollic acid modified silver-indium-sulfur quantum dots loaded on the surface of the substrate. According to the method, the fluorescence quenching phenomenon caused by electron transfer of PMF and sulfydryl in TGA-AgInS2 quantum dots in pericarpium citri reticulatae extracting solutions of different producing areas and aging years is directly utilized for the first time, and the TGA-AgInS2 quantum dots react with the pericarpium citri reticulatae extracting solutions to generate rich color change information, so that the authenticity of the citrus chachiensis hortorum is rapidly and visually detected; the related detection method is higher in stability, quicker in response, simpler and more convenient to operate, more portable in device, free of special requirements on detection instruments and personnel and wide in applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical analysis and detection, and particularly relates to a test paper for identifying authenticity of dried tangerine peel and a preparation method thereof. Background Art

[0002] Dried tangerine peel (CRP) is the dried mature peel of Citrus reticulata Blanco and its cultivars of the Rutaceae family. CRP has a unique aroma and taste and is used as a common functional food and dietary seasoning. Moreover, because it is rich in alkaloids, flavonoids, volatile oils and other bioactive substances, CRP has the effects of regulating qi and strengthening the spleen, drying dampness and resolving phlegm, and is widely used in clinical practice to relieve cough, expectorant, respiratory inflammation and indigestion. The edible value and medicinal value of CRP are highly related to its origin and aging years. The varieties of dried tangerine peel are mainly divided into Guangdong dried tangerine peel (Citrus reticulata'Chachi', CRC) produced in Xinhui County, Guangdong Province and dried tangerine peel (Citrus reticulata Blanco, CRB) produced in other production areas. Among them, Guangdong dried tangerine peel has better pharmacological effects. At the same time, there is a certain relationship between the aging year of dried tangerine peel and its quality, which is very important for the identification of the origin and aging year of CRP.

[0003] At present, the method for identifying the origin and aging years of CRP is usually sensory evaluation, which mainly evaluates the appearance and aroma of volatile substances of CRP through vision and taste, but the subjective cognitive differences and complex professional knowledge requirements cannot meet the quality control needs of commercially available tangerine peel. In order to further achieve objective and accurate CRP quality analysis, instrumental analysis methods such as high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), near-mid-infrared spectroscopy (NIR / MIR), terahertz time-domain spectroscopy (Thz-TDS), and electronic nose (E-nose) have been applied to a certain extent; these methods have high identification accuracy, high sensitivity, and stable results, but there are problems such as high cost and complex process. Therefore, it is urgent to develop a simpler, faster, more accurate and stable CRP quality identification method. Summary of the invention

[0004] The main purpose of the invention is to provide a test paper for authenticity identification of Guang Chenpi in view of the deficiencies in the prior art, which can realize rapid and efficient detection of Guang Chenpi and provide a new strategy for quality identification of Guang Chenpi.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A test paper for identifying the authenticity of dried tangerine peel comprises a substrate and thioglycolic acid-modified silver indium sulfide quantum dots loaded on the surface of the substrate.

[0007] In the above scheme, the thioglycolic acid-modified silver indium sulfur quantum dots are prepared by hot injection with silver salt, indium salt, sulfur source and thioglycolic acid as main raw materials; the specific preparation steps include: dissolving silver salt and indium salt in water, and stirring (vigorously stirring for 3 to 5 minutes) to form a uniform milky white Ag-In precursor solution; adding sodium citrate and thioglycolic acid to the obtained Ag-In precursor solution in sequence and mixing evenly, injecting the sulfur source solution into the obtained mixed solution, heating reaction, and obtaining a thioglycolic acid-modified silver indium sulfur quantum dot dispersion.

[0008] Furthermore, the thioglycolic acid-modified silver indium sulfide quantum dots exhibit a brown-yellow color and emit a strong orange-red fluorescence under ultraviolet light (365 nm).

[0009] Furthermore, the thioglycolic acid-modified silver indium sulfide quantum dots are spherical in shape, with an average particle size of 2.5 to 3.0 nm; and the strongest emission wavelength is 600 nm.

[0010] In the above scheme, the silver salt can be selected from silver nitrate, silver fluoride, silver chlorate, etc., and the indium salt can be selected from indium chloride, indium sulfide, indium sulfate, etc.

[0011] In the above scheme, the molar ratio of the silver salt to the indium salt is 1:4 to 4.8.

[0012] In the above scheme, the molar ratio of thioglycolic acid to sodium citrate is 1:3 to 3.5.

[0013] In the above scheme, the molar ratio of the introduced silver salt to thioglycolic acid is 1:4 to 4.8.

[0014] In the above scheme, the temperature used for the heating reaction is 90-100° C. and the time is 1-1.5 h.

[0015] In the above scheme, the substrate can be a paper-based carrier that can grow quantum dots in situ and is resistant to high temperatures and has no fluorescence.

[0016] In the above scheme, the paper-based substrate can be selected from cellulose-based filter paper, wood pulp filter paper and other high-temperature resistant non-fluorescent filter paper.

[0017] The above-mentioned method for preparing the authenticity identification test paper of Guang Chenpi introduces a paper-based substrate during the preparation process of the silver indium sulfide quantum dots modified with thioglycolic acid, so that the synthesized silver indium sulfide quantum dots modified with thioglycolic acid continuously grow on the surface of the paper-based substrate, and then takes out and dries it.

[0018] In the above scheme, the drying time is 3 to 4 hours.

[0019] The present invention also provides a method for identifying the authenticity of Guang Chenpi using the Guang Chenpi authenticity identification test paper, comprising the following steps:

[0020] 1) Preparation of tangerine peel extracts from different origins:

[0021] The dried tangerine peel samples from different origins or different years are crushed and sieved, and the tangerine peel powders from different origins are respectively mixed with a water-based solution, subjected to ultrasonic extraction, centrifugal separation, and microfiltration (through a 0.22 μm microporous filter membrane) to obtain CRP water extracts from different origins or CRC extracts from different years;

[0022] 2) How to identify the authenticity of Guang Chenpi

[0023] Add CRP extract or CRC extract to the Xiangguang tangerine peel authenticity identification test paper to soak the test paper. After sufficient reaction, obtain the color information corresponding to the tangerine peel samples from different origins or years under ultraviolet light conditions, establish the relationship between the tangerine peel samples from different origins or years and the color information, and realize the visual detection of the origin or year of the tangerine peel.

[0024] In the above scheme, the origin of the tangerine peel is selected from 6 origins including Guangdong, Sichuan, Zhejiang, Fujian, Guangxi and Hubei.

[0025] In the above scheme, the age of the Guang Chenpi of different years is 1 to 15 years.

[0026] Furthermore, the age of the Guang Chenpi is 1, 3, 5, 10, or 15 years.

[0027] In the above scheme, for tangerine peel samples from different origins, the ultrasonic extraction steps used include: mixing tangerine peel powder from different origins with boiling water (temperature is 90-100° C.) at a solid-liquid ratio of 3-4 g:200-220 mL, and then placing it in an ultrasonic cleaning machine at 45-50° C. for ultrasonic extraction for 50-55 minutes.

[0028] In the above scheme, for the Guang Chenpi samples of different years, the ultrasonic extraction steps adopted include: mixing the Guang Chenpi powder of different years with the alcohol aqueous solution according to the solid-liquid ratio of 3-4g:100-110mL, and then placing it in an ultrasonic cleaning machine at 25-30℃ for ultrasonic extraction for 40-45min.

[0029] Furthermore, in the alcohol aqueous solution, the concentration of alcohol is 70-75 vol%.

[0030] In the above scheme, the paper-based sensor loaded with quantum dots in step (4) is further immersed in the quantum dot solution for 1 to 2 days.

[0031] In the above scheme, the volume of the CRP water extracts from different origins or the CRC extracts from different years added to the test paper surface is 10-15 μL / cm 2 .

[0032] In the above scheme, the sufficient reaction time is 3 to 5 minutes.

[0033] In the above solution, the color information is RGB numerical information.

[0034] In the above scheme, the method for establishing the relationship between tangerine peel samples from different origins or different years and color information includes:

[0035] 1) establishing color matching cards corresponding to tangerine peels from different origins or different years according to the established tangerine peel samples and color information from different origins or different years according to the color or RGB values;

[0036] 2) The color information is analyzed by combining the random forest analysis (RF) model, and a chemometric algorithm model is established through RGB.

[0037] The principle of the present invention is:

[0038] The present invention directly utilizes the fluorescence quenching phenomenon caused by the electron transfer between polymethoxyflavonoid compounds (PMF) and the thiol groups in the obtained TGA-AgInS2 quantum dots, based on the rich color change information generated by the reaction of PMF (nobiletin, citrus flavonoids, 3,5,6,7,8,3',4'-heptamethoxyflavonoids, etc.) in the tangerine peel extracts from different origins and aging years with TGA-AgInS2 quantum dots, and further processes the color information in combination with the random forest analysis (RF) model, to construct a sensor for visually distinguishing the authenticity of tangerine peel.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1) The present invention proposes for the first time to directly utilize the fluorescence quenching phenomenon caused by the electron transfer of PMF in tangerine peel extracts from different origins and aging years and thiol groups in TGA-AgInS2 quantum dots, and utilize the rich color change information generated after the reaction of TGA-AgInS2 quantum dots with tangerine peel extracts to achieve rapid visual detection of the authenticity of Guang tangerine peel;

[0041] 2) The present invention loads TGA-AgInS2 quantum dots on a substrate such as a paper base to construct a paper-based sensor, and directly drops the TGA-AgInS2 quantum dots to be detected onto the surface of the paper-based sensor for a few minutes of full reaction, and then obtains the color information corresponding to the tangerine peel samples from different origins or different years under ultraviolet irradiation conditions, which can provide a new idea for the rapid detection of the authenticity of Guang tangerine peel;

[0042] 3) The detection method of the present invention has higher stability, faster response, simpler operation, and more portable device. It has no special requirements for detection instruments and personnel and has wide applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The present invention is a schematic diagram of a method for using a TGA-AgInS2 quantum dot paper-based visualization sensor to identify the authenticity of Guang Chenpi.

[0044] Figure 2 (A) is the transmission electron microscopy image of TGA-AgInS2 QDs obtained in Example 1; (B) is the fluorescence and ultraviolet spectra of TGA-AgInS2 QDs; (C) is the XPS spectra of TGA-AgInS2 QDs; (D) is the Fourier transform infrared spectra of TGA-AgInS2 QDs.

[0045] Figure 3 (A) is the fluorescence image of the reaction of TGA-AgInS2 QDs with various flavonoids and phenolic acids under 365nm ultraviolet light obtained in Example 1; (B) is the fluorescence lifetime and fitting curve before and after the reaction of TGA-AgInS2 QDs with Nob (nobiletin); (C) is the Fourier transform infrared spectrum of TGA-AgInS2 QDs, Nob, and the reaction of TGA-AgInS2 QDs with Nob; TEM images of TGA-AgInS2 QDs before (D) and after (E) the reaction with Nob; (F) is the Zeta potential diagram of TGA-AgInS2QDs before and after the reaction with Nob.

[0046] Figure 4 (A) is the fluorescence image of the paper-based sensor reacting CRP from different sources with AgInS2 QDs obtained in Example 1; (B) is the fluorescence image of the paper-based sensor reacting CRC with different storage years with AgInS2 QDs. DETAILED DESCRIPTION

[0047] The applicant will further explain the present invention in detail below in conjunction with specific embodiments so that those skilled in the art can more clearly understand the present invention. However, the following content should not be construed as limiting the scope of protection of the claims of the present invention.

[0048] The chemical reagents and solvents used in the examples are all analytically pure. The stirring is carried out using a magnetic stirrer.

[0049] In the following embodiment, the preparation method of thioglycolic acid modified silver indium sulfur quantum dots (TGA-AgInS2 QDs) includes the following steps: weighing 0.0625mmol silver nitrate (AgNO3) and 0.25mmol indium chloride (InCl3) and dissolving them in 90mL ultrapure water, and stirring vigorously to form a uniform milky white Ag-In precursor solution; adding 1mmol sodium citrate (SC) and 0.3mmol thioglycolic acid to the obtained precursor solution in sequence and stirring until evenly mixed, the obtained mixed solution emits a special irritating smell of sulfide; weighing 0.39mmol sodium sulfide (Na2S) and dissolving it in 10mL ultrapure water to obtain a sodium sulfide solution, and quickly injecting the sodium sulfide solution into the stirring mixed solution with a syringe, and continuously reacting in the open air at 100°C for 1h to obtain a thioglycolic acid modified silver indium sulfur quantum dot solution, which is brown-yellow and emits strong orange-red fluorescence under a 365nm ultraviolet lamp.

[0050] Example 1

[0051] A test paper for authenticity identification of dried tangerine peel, the preparation method of which comprises the following steps:

[0052] 1) Use a hole punch to cut the cellulose-based filter paper into round pieces (1 cm in diameter);

[0053] 2) Weigh 0.0625mmol silver nitrate (AgNO3) and 0.25mmol indium chloride (InCl3) and dissolve them in 90mL ultrapure water, and stir vigorously to form a uniform milky white Ag-In precursor solution; add 1mmol sodium citrate (SC) and 0.3mmol thioglycolic acid to the obtained precursor solution in sequence and stir until uniformly mixed, and the obtained mixed solution emits a special pungent smell of sulfide; weigh 0.39mmol sodium sulfide (Na2S) and dissolve it in 10mL ultrapure water to obtain a sodium sulfide solution, and use a syringe to quickly inject the sodium sulfide solution into the stirring mixed solution, and react continuously in the open air at 100°C for 1h; take out the paper-based sensor loaded with quantum dots;

[0054] 3) Place the paper-based sensor loaded with quantum dots on a clean glass plate and quickly dry it in a 60° C. oven (3 to 4 h), and place it at room temperature for later use.

[0055] Example 2

[0056] A test paper for authenticity identification of dried tangerine peel, the preparation method of which comprises the following steps:

[0057] 1) Use a hole punch to cut the cellulose-based filter paper into round pieces with a diameter of 0.5 cm.

[0058] 2) Weigh 0.0625mmol silver nitrate (AgNO3) and 0.25mmol indium chloride (InCl3) and dissolve them in 90mL ultrapure water, and stir vigorously to form a uniform milky white Ag-In precursor solution; add 1mmol sodium citrate (SC) and 0.3mmol thioglycolic acid to the obtained precursor solution in sequence and stir until uniformly mixed, and the obtained mixed solution emits a special pungent smell of sulfide; weigh 0.39mmol sodium sulfide (Na2S) and dissolve it in 10mL ultrapure water to obtain a sodium sulfide solution, and use a syringe to quickly inject the sodium sulfide solution into the stirring mixed solution, and react continuously in the open air at 100°C for 1h; take out the paper-based sensor loaded with quantum dots;

[0059] 3) Place the paper-based sensor loaded with quantum dots on a clean glass plate and quickly dry it in a 45°C oven (5-6h), and place it at room temperature for later use.

[0060] Example 3

[0061] A test paper for authenticity identification of dried tangerine peel, the preparation method of which comprises the following steps:

[0062] 1) Use a hole punch to cut the cellulose-based filter paper into round pieces with a diameter of 0.8 cm;

[0063] 2) Weigh 0.0625mmol silver nitrate (AgNO3) and 0.30mmol indium chloride (InCl3) and dissolve them in 90mL ultrapure water, and stir vigorously to form a uniform milky white Ag-In precursor solution; add 1mmol sodium citrate (SC) and 0.32mmol thioglycolic acid to the obtained precursor solution in sequence and stir until uniformly mixed, and the obtained mixed solution emits a special pungent smell of sulfide; weigh 0.39mmol sodium sulfide (Na2S) and dissolve it in 10mL ultrapure water to obtain a sodium sulfide solution, and use a syringe to quickly inject the sodium sulfide solution into the stirring mixed solution, and react continuously in the open air at 95°C for 1h; take out the paper-based sensor loaded with quantum dots;

[0064] 3) Place the paper-based sensor loaded with quantum dots on a clean glass plate and quickly dry it in a 50°C oven (4-5h), and place it at room temperature for later use.

[0065] Application Example 1

[0066] The authentic identification test paper for dried tangerine peel obtained in Example 1 is applied to identify dried tangerine peel products, and the specific steps include:

[0067] 1) Preparation of tangerine peel extracts from different origins:

[0068] The dried samples of dried tangerine peel from different origins (Xinhui tangerine peel from Guangdong, Sichuan tangerine peel, and tangerine peel from other origins) were crushed and passed through a 50-mesh sieve; the tangerine peel powder from different origins was mixed with a boiling water solution at a solid-liquid ratio of 4 g:800 mL, and then placed in an ultrasonic cleaning machine for ultrasonic extraction at 50°C for 50 min; centrifuged at 4000 r / min for 10 min, and the supernatant was filtered through a 0.22 μm microporous filter membrane to obtain CRP water extracts from different origins;

[0069] 2) respectively dripping CRP water extracts from different origins onto the authenticity identification test paper of Guang Chenpi obtained in Example 1 until the circular paper piece is just soaked; waiting for natural evaporation, and using a Canon EOS Kiss X6i camera with fixed parameters to capture a paper base image with color differences under ultraviolet light excited at 365nm;

[0070] 3) Use Photoshop 2021 to obtain 10×10 pixel points for each sampling point in the visualized color image; use Matlab9.5.0R2018b (Mathworks, Natick, MA.USA) to convert the image information into RGB numerical information; apply supervised pattern recognition based on random forest (RF) to the model for pattern discriminant analysis, and establish the relationship between RGB numerical information and the different origins of tangerine peel samples.

[0071] Application Example 2

[0072] The authentic identification test paper for dried tangerine peel obtained in Example 1 is applied to identify dried tangerine peel products, and the specific steps include:

[0073] 1) Preparation of extracts of dried orange peel from different years:

[0074] The dried Xinhui dried tangerine peel stored in different years (respectively 1, 3, 5, 10, and 15 years) was crushed and passed through a 50-mesh sieve; the Guang tangerine peel powder of different years was mixed with a methanol aqueous solution with a volume fraction of 70% according to a solid-liquid ratio of 4g:400mL, and then placed in an ultrasonic cleaning machine for ultrasonic extraction at 30°C for 40min, centrifuged at 4000r / min for 10min, and the supernatant was filtered through a 0.22μm microporous membrane to obtain a CRC alcohol extract;

[0075] 2) respectively dripping CRC alcohol extracts of different years onto the authenticity identification test paper of Guang Chenpi obtained in Example 1 until the circular paper piece is just soaked; waiting for natural evaporation, and using a Canon EOS Kiss X6i camera with fixed parameters to capture a paper-based image with color differences under ultraviolet light excited at 365 nm;

[0076] 3) Use Photoshop 2021 to obtain 10×10 pixel points for each sampling point in the visualized color image; use Matlab9.5.0R2018b (Mathworks, Natick, MA.USA) to convert the image information into RGB numerical information; apply supervised pattern recognition based on random forest (RF) to the model for pattern discriminant analysis, and establish the relationship between RGB numerical information and tangerine peel samples of different years.

[0077] Figure 2 This is the characterization result of TGA-AgInS2 QDs obtained in Example 1.

[0078] Figure 3 This is a fluorescence image of the reaction of TGA-AgInS2 QDs obtained in Example 1 with various flavonoids and phenolic acids under 365nm ultraviolet light. It can be clearly observed that obvious color change occurs only when the quantum dots react with polymethoxyflavonoids.

[0079] Figure 4 This embodiment uses TGA-AgInS2 quantum dot test paper to detect the visualized color reaction test results of CRP / CRC from different origins / different years. There are obvious differences in the RGB color changes of CRP / CRC from different origins. In the discrimination of tangerine peel from different origins, Guangdong tangerine peel appears dark blue, Sichuan tangerine peel appears bluish purple, and tangerine peel from other production areas appears orange; in the discrimination of Guangdong tangerine peel from different years, there are obvious differences in the color changes of Guangdong tangerine peel from different years. Based on the above visualization results, the authenticity of Guangdong tangerine peel can be directly identified by naked eyes.

[0080] The specific discrimination results according to the above scheme are shown in Table 1 and Table 2. The number of training set samples is greater than the number of prediction set samples. The TGA-AgInS2 paper-based sensor showed excellent discrimination ability, making the discrimination accuracy between CRP from different origins or CRC from different years reach 100%, indicating that the above method of the present invention can quickly realize the accurate identification of the authenticity of Guang Chenpi.

[0081] Table 1 Confusion matrix of random forest model of AgInS2 QDs paper-based sensor for CRP from different sources

[0082]

[0083] Table 2 Confusion matrix of AgInS2 QDs paper sensor for CRC random forest model of different Chenhua years

[0084]

[0085]

[0086] Comparative Example 1

[0087] A TGA-modified CdTe quantum dot, the preparation method of which comprises the following steps:

[0088] 0.046 g of cadmium dichloride and 18 μL TGA were dissolved in ultrapure water with stirring, the pH value of the solution was adjusted to 10 with sodium hydroxide, and stirred in an ice bath under a nitrogen flow for 20 min; 0.0089 g of Na2TeO3 was added to the solution, reacted for 5 min, and then 0.08 g of NaBH4 was dissolved in 1 mL of pure water and added to the above reaction solution. The resulting solution was transferred to an oil bath (100°C) and refluxed for 1.5 h; finally, orange TGA-capped CdTe QDs were obtained and used as a fluorescent probe with an emission wavelength of 556 nm.

[0089] After testing, it was found that the comparative example could not achieve fluorescent visual identification of CRP from different origins or CRC from different aging years based on the fluorescent information under 365nm ultraviolet light.

[0090] Comparative Example 2

[0091] A TGA-modified AgInS2 quantum dot, the preparation method of which comprises the following steps:

[0092] 0.03mmol AgNO3 and 0.10mmol In(NO3)3 were dissolved in 60mL ultrapure water and stirred to form a uniform mixture. After stirring for 5 minutes, about 300μL TGA was added to the mixture, and the pH value of the mixed solution was adjusted to 4.00 with 0.05M NaOH solution; the resulting mixed solution was heated at 90°C for 45 minutes under a continuous supply of nitrogen to obtain TGA-modified AgInS2 quantum dots.

[0093] After testing, the fluorescence performance of the TGA-modified AgInS2 quantum dots obtained in this comparative example is poor, and it is impossible to achieve fluorescent visual identification of CRP from different origins or CRC from different aging years based on the fluorescence information under 365nm ultraviolet light.

[0094] The above embodiments are only examples for clear explanation, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here, so the obvious changes or modifications derived are still within the protection scope of the invention.

Claims

1. A test paper for authenticity identification of dried tangerine peel, characterized in that: The invention comprises a substrate and thioglycolic acid-modified silver indium sulfur quantum dots loaded on the surface of the substrate.

2. according to claim 1, the authenticity identification test paper of Guang Chenpi is characterized in that, The thioglycolic acid-modified silver indium sulfide quantum dots are spherical in shape, and have an average particle size of 2.5 to 3.0 nm.

3. according to claim 1 the authenticity identification test paper of Guang Chenpi, it is characterized in that, The thioglycolic acid-modified silver indium sulfur quantum dots are prepared by a hot injection method using silver salt, indium salt, sulfur source and thioglycolic acid as main raw materials.

4. according to claim 3 the authenticity identification test paper of Guang Chenpi, it is characterized in that, The specific preparation steps of the thioglycolic acid modified silver indium sulfur quantum dots include: dissolving silver salt and indium salt in water, and stirring to form a uniform milky white Ag-In precursor solution; sequentially adding sodium citrate and thioglycolic acid to the obtained Ag-In precursor solution and mixing them evenly, injecting a sulfur source solution into the obtained mixed solution, and heating to react to obtain a thioglycolic acid modified silver indium sulfur quantum dot dispersion.

5. according to claim 4, the authenticity identification test paper of Guang Chenpi is characterized in that, The heating reaction is carried out at a temperature of 90 to 100° C. and for a time of 1 to 1.5 hours.

6. according to claim 1 the authenticity identification test paper of Guang Chenpi is characterized in that, The substrate is a paper-based substrate.

7. The preparation method of the authenticity identification test paper of Guang Chenpi according to claim 1, characterized in that, The substrate is introduced during the preparation process of the thioglycolic acid-modified silver indium sulfur quantum dots. After the reaction is completed, the substrate is taken out and dried to obtain the Guang Chenpi authenticity identification test paper.

8. A method for identifying the authenticity of Guang Chenpi using the Guang Chenpi authenticity identification test paper according to any one of claims 1 to 6 or the Guang Chenpi authenticity identification test paper obtained by the preparation method according to claim 7, characterized in that: The steps include: 1) Preparation of tangerine peel extracts from different origins: The stored dried tangerine peel samples from different origins or different years are crushed and sieved, and the tangerine peel powders from different origins are respectively mixed with a water-based solution, subjected to ultrasonic extraction, centrifugal separation, and microfiltration to obtain CRP water extracts from different origins or CRC extracts from different years; 2) How to identify the authenticity of Guang Chenpi Add CRP extract or CRC extract to the Xiangguang tangerine peel authenticity identification test paper to soak the test paper, evaporate and dry naturally, obtain the color information corresponding to the tangerine peel samples from different origins or years under ultraviolet light conditions, establish the relationship between the tangerine peel samples from different origins or years and the color information, and realize the visual detection of the origin or year of the tangerine peel.

9. The method according to claim 8, characterized in that The origins of dried tangerine peel are selected from Guangdong, Sichuan, Zhejiang, Fujian, Guangxi and Hubei; the age of Guangdong dried tangerine peel ranges from 1 to 15 years.

10. The method according to claim 8, characterized in that The sufficient reaction time is 3 to 5 minutes.

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