Electrochemical voltammetry spectrum acquisition method for flower and fruit traditional Chinese medicinal materials

Abstract

The invention provides an electrochemical voltammetry spectrum acquisition method for flower and fruit traditional Chinese medicinal materials, and belongs to the technical field of chemical detection. The method comprises the following steps: firstly, extracting flower and fruit traditional Chinese medicinal materials, then mixing an extracting solution with an acidic buffer solution, adjusting the pH value of a detection solution, and then collecting an electrochemical cyclic voltammetry map by adopting a carbon nanotube modified screen-printed electrode. After the carbon nanotube modified screen-printed electrode is combined with an acidic buffer solution, phenol and acid electroactive substances in the flower and fruit traditional Chinese medicinal materials can stably exist in the acidic environment, and after the phenol and acid electroactive substances are rapidly transferred by the carbon nanotube and grabbed by surface oxygen-containing groups, the phenol and acid electroactive substances in the flower and fruit traditional Chinese medicinal materials can be rapidly absorbed by the carbon nanotube. The electrochemical redox behavior from no to existence or from weak to strong is shown in a cyclic voltammetry curve, and the establishment of the electrochemical voltammetry fingerprint spectrum of the flower and fruit traditional Chinese medicinal materials is facilitated. The acquisition method provided by the invention is a universal acquisition method suitable for electrochemical voltammetry maps of flower and fruit traditional Chinese medicinal materials.

Description

Technical Field

[0001] The invention belongs to the technical field of chemical detection, and in particular relates to a method for collecting electrochemical voltammetric spectra of flower and fruit Chinese medicinal materials. Background Art

[0002] As a component of traditional Chinese medicine, flower and fruit Chinese medicinal materials are suitable for the treatment and prevention of a variety of diseases. Compared with root, tuber and stem medicinal materials, flower and fruit medicinal materials have a wider audience, and the quality control of Chinese medicinal materials is a key link to ensure the efficacy and safety of traditional Chinese medicine.

[0003] Fingerprint technology is an effective method for evaluating the quality of traditional Chinese medicine, identifying authenticity, distinguishing species, quality control and spectrum-effect relationship research. At present, the fingerprint technologies used for authenticity identification and quality evaluation of traditional Chinese medicines mainly include chromatography, mass spectrometry, spectroscopy and electrochemical methods. Among them, the slow detection speed, high instrument cost, complex sample processing and high operation requirements of chromatography, mass spectrometry and spectroscopy limit their application. The electrochemical method has low cost, no need for separation and purification, and is easy to operate. It is especially suitable for on-site detection and has received widespread attention in the fields of traditional Chinese medicine evaluation and identification. Among them, the electrochemical fingerprint based on voltammetric characteristics can intuitively display the information of all electrochemically active substances inside the medicinal materials in the scanning curve, and can simply and efficiently present the common signals of multiple chemical components without having to analyze the information of individual compounds one by one. Unfortunately, most electroactive substances in Chinese medicinal materials, such as phenols and acids, have low electrochemical redox signal intensities on the surface of conventional electrodes. Although some researchers have modified sensitive materials on electrodes to improve detection sensitivity and selectivity, the specificity of the materials limits their application breadth, resulting in electrochemical spectra based on voltammetric characteristics being mostly used in the study of specific single Chinese medicinal materials, but not suitable for the characteristic fingerprint collection and authenticity identification of a certain type of Chinese medicinal materials.

[0004] Therefore, there is an urgent need for an electrochemical voltammetry spectrum acquisition method that can be applied to a certain type of Chinese medicinal materials. Summary of the invention

[0005] The purpose of the present invention is to provide a method for collecting electrochemical voltammetric spectra of flower and fruit Chinese medicinal materials. The collection method provided by the present invention is applicable to a variety of flower and fruit Chinese medicinal materials.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] The present invention provides a method for collecting electrochemical voltammetric spectra of flower and fruit Chinese medicinal materials, comprising the following steps:

[0008] (1) mixing flower and fruit Chinese medicinal materials with ethanol aqueous solution to obtain an extract;

[0009] (2) mixing the extract obtained in step (1) with a buffer solution to obtain a detection solution; the pH value of the buffer solution is 2.0 to 6.0;

[0010] (3) Dropping the detection liquid obtained in step (2) onto the surface of the carbon nanotube-modified screen-printed electrode, performing cyclic voltammetry scanning, and obtaining an electrochemical voltammetry spectrum.

[0011] Preferably, in step (1), the particle size of the flower and fruit Chinese medicinal materials is ≤0.42 mm.

[0012] Preferably, the volume percentage of ethanol in the ethanol aqueous solution in step (1) is 40-80%.

[0013] Preferably, in step (1), the volume ratio of the mass of the flower and fruit Chinese medicinal materials to the ethanol aqueous solution is (0.2-1.0) g: (10-30) mL.

[0014] Preferably, the mixing in step (1) is performed by ultrasound; the temperature of the ultrasound is 25 to 60° C., and the time of the ultrasound is 0.5 to 2 h.

[0015] Preferably, the volume ratio of the extract to the buffer in step (2) is 1:(0.5-2).

[0016] Preferably, the buffer in step (2) is at least one of disodium hydrogen phosphate-sodium dihydrogen phosphate buffer and acetic acid-sodium acetate buffer.

[0017] Preferably, in step (3), the ratio of the volume of the detection solution to the working area of ​​the carbon nanotube-modified screen-printed electrode is (40-80) μL: (0.07-0.13) cm 2 .

[0018] Preferably, the scanning rate of the cyclic voltammetry scan in step (3) is 10 to 100 mV / s.

[0019] Preferably, the range of the cyclic voltammetry scan in step (3) is -0.9 to 1.0 V.

[0020] The present invention provides a method for collecting electrochemical voltammetry spectra of flower and fruit Chinese medicinal materials, comprising the following steps: (1) mixing flower and fruit Chinese medicinal materials with ethanol aqueous solution to obtain an extract; (2) mixing the extract obtained in step (1) with a buffer solution to obtain a detection solution; the pH value of the buffer solution is 2.0 to 6.0; (3) dropping the detection solution obtained in step (2) onto the surface of a carbon nanotube modified screen-printed electrode, performing cyclic voltammetry scanning, and obtaining an electrochemical voltammetry spectrum. The present invention first extracts flower and fruit Chinese medicinal materials, then mixes the extract solution with an acidic buffer solution, adjusts the pH value of the detection solution, and then uses a carbon nanotube modified screen-printed electrode to collect an electrochemical cyclic voltammetry spectrum. After the carbon nanotube-modified screen-printed electrode and the acidic buffer solution are used together, the phenolic and acidic electroactive substances in the flower and fruit Chinese medicinal materials can stably exist in the acidic environment. After the rapid electron transfer of the carbon nanotubes themselves and the capture of the surface oxygen-containing groups, the electrochemical redox behavior from nothing to something or from weak to strong is shown in the cyclic voltammetry curve, which is helpful for the establishment of the electrochemical voltammetric fingerprint of flower and fruit Chinese medicinal materials. The collection method provided by the present invention is a universal collection method suitable for the electrochemical voltammetric spectrum of flower and fruit Chinese medicinal materials. The results of the embodiment show that the collection method provided by the present invention is suitable for a variety of flower and fruit Chinese medicinal materials, but not for non-flower and fruit Chinese medicinal materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The electrochemical voltammetry spectrum of the second cycle in Example 1 and Comparative Examples 1-2;

[0022] Figure 2 The electrochemical voltammetry spectra of the second cycle in Example 2 and Comparative Examples 3-4 are shown;

[0023] Figure 3 The electrochemical voltammetry spectra of the second cycle in Example 3 and Comparative Examples 5-6 are shown;

[0024] Figure 4 The electrochemical voltammetry spectra of the second cycle in Example 4 and Comparative Examples 7-8 are shown;

[0025] Figure 5 The electrochemical voltammetry spectra of the second cycle in Example 5 and Comparative Examples 9-10 are shown;

[0026] Figure 6 The electrochemical voltammetry spectra of the second cycle in Example 6 and Comparative Examples 11-12;

[0027] Figure 7 The electrochemical voltammetry spectra of the second cycle in Example 7 and Comparative Examples 13-14 are shown;

[0028] Figure 8 The electrochemical voltammetry spectra of the second cycle in Example 8 and Comparative Examples 15-16;

[0029] Fig. 9 The electrochemical voltammetry spectra of the second cycle in Example 1 and Comparative Example 17;

[0030] Fig.10 The electrochemical voltammetry spectra of the second cycle in Example 3 and Comparative Examples 18-20 are shown. DETAILED DESCRIPTION

[0031] The present invention provides a method for collecting electrochemical voltammetric spectra of flower and fruit Chinese medicinal materials, comprising the following steps:

[0032] (1) mixing flower and fruit Chinese medicinal materials with ethanol aqueous solution to obtain an extract;

[0033] (2) mixing the extract obtained in step (1) with a buffer solution to obtain a detection solution; the pH value of the buffer solution is 2.0 to 6.0;

[0034] (3) Dropping the detection liquid obtained in step (2) onto the surface of the carbon nanotube-modified screen-printed electrode, performing cyclic voltammetry scanning, and obtaining an electrochemical voltammetry spectrum.

[0035] Unless otherwise specified, the present invention has no particular limitation on the sources of the raw materials, and commercially available products known to those skilled in the art may be used.

[0036] The invention mixes flower and fruit Chinese medicinal materials with ethanol aqueous solution to obtain an extract.

[0037] In the present invention, the particle size of the flower and fruit Chinese medicinal materials is preferably ≤0.42 mm. The present invention controls the particle size of the flower and fruit Chinese medicinal materials within the above range, which can make the active substances in the Chinese medicinal materials dissolve more fully.

[0038] When the particle size of the flower and fruit Chinese medicinal materials is not within the above range, the present invention preferably crushes the flower and fruit Chinese medicinal materials. The present invention has no special limitation on the crushing operation, and adopts the crushing technical scheme well known to those skilled in the art to ensure that the particle size of the flower and fruit Chinese medicinal materials after crushing is within the above range. In an embodiment of the present invention, the present invention crushes the flower and fruit Chinese medicinal materials by a high-speed crusher and then passes through a 60-mesh sieve.

[0039] In the present invention, the volume percentage of ethanol in the ethanol aqueous solution is preferably 40-80%. In an embodiment of the present invention, the volume percentage of ethanol in the ethanol aqueous solution can specifically be 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or 80%.

[0040] In the present invention, the volume ratio of the mass of the flower and fruit Chinese medicinal materials to the ethanol aqueous solution is preferably (0.2-1.0) g:(10-30) mL, more preferably (0.3-0.8) g:(10-30) mL, and further preferably (0.5-0.8) g:(10-30) mL.

[0041] In the present invention, the mixing is preferably ultrasonic.

[0042] In the present invention, the temperature of the ultrasound is preferably 25 to 60°C; the time of the ultrasound is preferably 0.5 to 2 hours. In an embodiment of the present invention, the temperature of the ultrasound can be specifically 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C; the time of the ultrasound can be specifically 0.5h, 1h, 1.5h or 2h. The present invention controls the volume content, dosage, mixing method, temperature and time of ethanol in the ethanol aqueous solution within the above range, which can make the active substances in the Chinese medicinal materials dissolve more fully.

[0043] After the ultrasonic treatment is completed, the present invention preferably centrifuges the ultrasonic solution or allows it to stand to take out the supernatant to obtain an extract.

[0044] In the present invention, the centrifugal speed is preferably 2500-5000 rpm, more preferably 4000 rpm.

[0045] In the present invention, the standing time is preferably 0.5 to 2 hours, more preferably 1 to 2 hours.

[0046] After obtaining the extract, the present invention mixes the extract with a buffer solution to obtain a detection solution.

[0047] In the present invention, the pH value of the buffer solution is 2.0 to 6.0. In an embodiment of the present invention, the pH value of the buffer solution may be specifically 2.0, 3.0, 4.0, 5.0 or 6.0.

[0048] In the present invention, the buffer is preferably at least one of disodium hydrogen phosphate-sodium dihydrogen phosphate buffer and acetic acid-sodium acetate buffer, more preferably disodium hydrogen phosphate-sodium dihydrogen phosphate buffer. The present invention uses disodium hydrogen phosphate-sodium dihydrogen phosphate buffer, which has excellent effects on the electrochemical voltammetry spectrum collection of various flower and fruit Chinese medicinal materials, and is more versatile.

[0049] In the present invention, the volume ratio of the extract and the buffer is preferably 1:(0.5-2). In an embodiment of the present invention, the volume ratio of the extract and the buffer may specifically be 1:0.5, 1:1, 1:1.5 or 1:2. The present invention controls the pH value of the buffer and the volume ratio of the extract and the buffer within the above range, and the phenolic and acidic electroactive substances of flower and fruit Chinese medicinal materials can stably exist in the acidic environment. After the rapid electron transfer of the carbon nanotubes themselves and the capture of the surface oxygen-containing groups, the electrochemical redox behavior of the phenolic and acidic substances from nothing to something or from weak to strong is displayed in the cyclic voltammetry curve, which is helpful for the establishment of the electrochemical voltammetric fingerprint of flower and fruit Chinese medicinal materials.

[0050] The present invention has no special limitation on the operation of mixing the extract and the buffer solution, and the two can be mixed evenly using a material mixing technical solution well known to those skilled in the art.

[0051] After the mixing is completed, the present invention preferably filters the mixed solution to obtain a test solution.

[0052] In the present invention, the filtration is preferably carried out using a 0.22-0.45 μm filter membrane.

[0053] After obtaining the detection liquid, the present invention drops the detection liquid onto the surface of the carbon nanotube-modified screen-printed electrode, performs cyclic voltammetry scanning, and obtains an electrochemical voltammetry spectrum.

[0054] In the present invention, the carbon nanotubes in the carbon nanotube-modified screen-printed electrode are preferably single-walled carbon nanotubes, double-walled carbon nanotubes or multi-walled carbon nanotubes; the outer diameter of the single-walled carbon nanotube is preferably 1-2 nm; the length of the single-walled carbon nanotube is preferably 5-30 μm; the outer diameter of the double-walled carbon nanotube is preferably 2-4 nm; the length of the double-walled carbon nanotube is preferably 48-52 μm, more preferably 50 μm; the outer diameter of the multi-walled carbon nanotube is preferably 4-6 nm; the length of the multi-walled carbon nanotube is preferably 0.5-2 μm. The present invention uses carbon nanotubes to modify the screen-printed electrode, and the electroactive substances of phenols and acids in flower and fruit Chinese medicinal materials are rapidly transferred by carbon nanotubes themselves and captured by surface oxygen-containing groups. The electrochemical redox behavior of phenols and acids from nothing to something or from weak to strong is shown in the cyclic voltammetry curve, which is helpful for the establishment of electrochemical voltammetric fingerprints of flower and fruit Chinese medicinal materials. The present invention does not specifically limit the source of the carbon nanotubes, and commercial products well known to those skilled in the art can be used. In an embodiment of the present invention, the carbon nanotubes are purchased from China Science Times Nano Center.

[0055] The present invention has no special limitation on the preparation method of the carbon nanotube modified screen-printed electrode, and any preparation method well known to those skilled in the art may be used.

[0056] In the present invention, the preferred method for preparing the carbon nanotube modified screen-printed electrode is: 125 μL N,N-dimethylformamide and 100 μL deionized water are mixed to obtain a dispersant; 1.0 mg carbon nanotubes and 10 μL nafion solution with a mass concentration of 5% are added, ultrasonically dispersed for 1 hour to obtain a carbon nanotube drop coating liquid, 3 to 7 μL of the carbon nanotube drop coating liquid is dripped onto the working electrode of a blank screen-printed electrode, and dried at room temperature to obtain a carbon nanotube modified screen-printed electrode.

[0057] The present invention has no special limitation on the source of the blank screen-printed electrode, and commercial products known to those skilled in the art can be used. In an embodiment of the present invention, the blank screen-printed electrode is purchased from Changsha Sanjun Electronic Technology Co., Ltd., model 220.

[0058] In the present invention, the ratio of the volume of the detection liquid to the working area of ​​the carbon nanotube-modified screen-printed electrode is preferably (40-80) μL: (0.07-0.13) cm 2 .

[0059] In the present invention, the scanning rate of the cyclic voltammetry scan is preferably 10-100 mV / s. In an embodiment of the present invention, the scanning rate of the cyclic voltammetry scan can be specifically 10 mV / s, 25 mV / s, 50 mV / s, 75 mV / s or 100 mV / s.

[0060] In the present invention, the range of the cyclic voltammetry scan is preferably -0.9 to 1.0V.

[0061] In the present invention, the number of cycles of the cyclic voltammetry scan is preferably 1 to 2 cycles.

[0062] The present invention has no special limitation on the equipment for the cyclic voltammetry scanning, and any equipment known to those skilled in the art can be used. In an embodiment of the present invention, the cyclic voltammetry scanning equipment is an EmStat4R portable electrochemical analyzer.

[0063] The collection method provided by the present invention is a universal collection method applicable to the electrochemical voltammetric spectrum of flower and fruit Chinese medicinal materials. The method is simple, easy to operate, low-cost, and can be carried out on site. The combination of carbon nanotube-modified screen-printed electrodes and acidic buffers is conducive to the enrichment of electroactive phenols and acids in flower and fruit Chinese medicinal materials, significantly changing the electrochemical voltammetric characteristics of flower and fruit Chinese medicinal materials from "no" response to "yes" response; it can enhance the electrochemical signal intensity of some flower and fruit Chinese medicinal materials from "weak" response to "strong" response, which is conducive to the establishment of electrochemical voltammetric fingerprints of flower and fruit Chinese medicinal materials.

[0064] The technical solutions in the present invention will be described clearly and completely below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0065] In each embodiment, the preparation method of the carbon nanotube modified screen-printed electrode (CNTs / SPCE) is as follows: 125 μL of N,N-dimethylformamide and 100 μL of deionized water are mixed to obtain a dispersant; 1.0 mg of carbon nanotubes (CNTs) and 10 μL of a 5% mass concentration of nafion solution are added, ultrasonically dispersed for 1 hour to obtain a carbon nanotube drop coating liquid, and 7 μL of the carbon nanotube drop coating liquid is drop-coated on a working electrode of a blank screen-printed electrode (Changsha Sanjun Electronic Technology Co., Ltd., model 220), and dried at room temperature to obtain a carbon nanotube modified screen-printed electrode, wherein the carbon nanotube is a multi-walled carbon nanotube, the outer diameter of the multi-walled carbon nanotube is 4 to 6 nm, and the length of the multi-walled carbon nanotube is 0.5 to 2 μm.

[0066] Example 1

[0067] (1) The wolfberries produced in Zhongning, Ningxia were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed wolfberries were weighed, 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the wolfberry mass to the ethanol aqueous solution was 0.5 g: 20 mL), ultrasonicated at 40° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0068] (2) Take 1 mL of the extract, add 1 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 2.0 (the volume ratio of the extract to the buffer is 1:1), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0069] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0070] Comparative Example 1

[0071] (1) The wolfberries produced in Zhongning, Ningxia were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed wolfberries were weighed, 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the wolfberry mass to the ethanol aqueous solution was 0.5 g: 20 mL), ultrasonicated at 40° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0072] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.6 to 0.8 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0073] Comparative Example 2

[0074] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 1 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 1.

[0075] The electrochemical voltammetry spectra of the second cycle in Example 1 and Comparative Examples 1-2 are as follows: Figure 1 As shown. Figure 1 It can be seen that the wolfberry test solution presents an electrochemical voltammogram including three pairs of redox response peaks on CNTs@SPCE. Compared with the case where there is no peak response on SPCE, it can be proved that the CNTs modified electrode is important for enriching electroactive substances; compared with the wolfberry extract showing a pair of weak redox peaks on CNTs@SPCE, it can be proved that the acidic buffer environment is important for the stable existence of electroactive substances.

[0076] Example 2

[0077] (1) Flos honeysuckle produced in Shandong was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed flos honeysuckle was weighed, 10 mL of 60% ethanol aqueous solution was added (the volume ratio of the mass of the flos honeysuckle to the ethanol aqueous solution was 0.5 g:10 mL), ultrasonicated at 25° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0078] (2) Take 1 mL of the extract, add 1 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 4.0 (the volume ratio of the extract to the buffer is 1:1), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0079] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.9 to 1.0 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0080] Comparative Example 3

[0081] (1) Flos honeysuckle produced in Shandong was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed flos honeysuckle was weighed, 10 mL of 60% ethanol aqueous solution was added (the volume ratio of the mass of the flos honeysuckle to the ethanol aqueous solution was 0.5 g:10 mL), ultrasonicated at 25° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0082] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.9 to 1.0 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0083] Comparative Example 4

[0084] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 2 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 2.

[0085] The electrochemical voltammetry spectra of the second cycle in Example 2 and Comparative Examples 3-4 are as follows: Figure 2 shown.

[0086] Example 3

[0087] (1) The chrysanthemums from Jiaozuo, Henan Province were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed chrysanthemums were weighed, and 30 mL of 60% ethanol aqueous solution (the volume ratio of the mass of the chrysanthemums to the ethanol aqueous solution was 0.8 g:30 mL) was added. The mixture was ultrasonicated at 50° C. for 1 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0088] (2) Take 1 mL of the extract, add 1.5 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 2.0 (the volume ratio of the extract to the buffer is 1:1.5), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0089] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 50 mV / s and the scanning range is -0.9 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0090] Comparative Example 5

[0091] (1) The chrysanthemums from Jiaozuo, Henan Province were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed chrysanthemums were weighed, and 30 mL of 60% ethanol aqueous solution (the volume ratio of the mass of the chrysanthemums to the ethanol aqueous solution was 0.8 g:30 mL) was added. The mixture was ultrasonicated at 50° C. for 1 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0092] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 50 mV / s and the scanning range is -0.9 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0093] Comparative Example 6

[0094] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 3 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 3.

[0095] The electrochemical voltammetry spectra of the second cycle in Example 3 and Comparative Examples 5 to 6 are as follows: Figure 3 shown.

[0096] Example 4

[0097] (1) Forsythia suspensa produced in Shangluo, Shaanxi Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed Forsythia suspensa was weighed, 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of Forsythia suspensa to the ethanol aqueous solution was 0.5 g: 20 mL), ultrasonicated at 50° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0098] (2) Take 1 mL of the extract, add 1 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 2.0 (the volume ratio of the extract to the buffer is 1:1), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0099] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 50 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0100] Comparative Example 7

[0101] (1) Forsythia suspensa produced in Shangluo, Shaanxi Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed Forsythia suspensa was weighed, 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of Forsythia suspensa to the ethanol aqueous solution was 0.5 g: 20 mL), ultrasonicated at 50° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0102] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 50 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0103] Comparative Example 8

[0104] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 4 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 4.

[0105] The electrochemical voltammetry spectra of the second cycle in Example 4 and Comparative Examples 7 to 8 are as follows: Figure 4 shown.

[0106] Example 5

[0107] (1) Rose flowers produced in Lanzhou, Gansu Province were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed rose flowers were weighed, and 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of the rose flowers to the ethanol aqueous solution was 0.8 g:20 mL). The mixture was ultrasonicated at 40° C. for 2 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0108] (2) Take 1 mL of the extract, add 2 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 4.0 (the volume ratio of the extract to the buffer is 1:2), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0109] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0110] Comparative Example 9

[0111] (1) Rose flowers produced in Lanzhou, Gansu Province were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed rose flowers were weighed, and 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of the rose flowers to the ethanol aqueous solution was 0.8 g:20 mL). The mixture was ultrasonicated at 40° C. for 2 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0112] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.6 to 0.8 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0113] Comparative Example 10

[0114] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 5 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 5.

[0115] The electrochemical voltammetry spectra of the second cycle in Example 5 and Comparative Examples 9 to 10 are as follows: Figure 5 shown.

[0116] Example 6

[0117] (1) The hawthorn produced in Qingzhou, Shandong Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.5 g of the crushed hawthorn was weighed, and 20 mL of a 60% ethanol aqueous solution was added (the volume ratio of the mass of hawthorn to the ethanol aqueous solution was 0.5 g: 20 mL). The mixture was ultrasonicated at 25° C. for 1 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0118] (2) Take 1 mL of the extract, add 1 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 4.0 (the volume ratio of the extract to the buffer is 1:1), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0119] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0120] Comparative Example 11

[0121] (1) The hawthorn produced in Qingzhou, Shandong Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.5 g of the crushed hawthorn was weighed, and 20 mL of a 60% ethanol aqueous solution was added (the volume ratio of the mass of hawthorn to the ethanol aqueous solution was 0.5 g: 20 mL). The mixture was ultrasonicated at 25° C. for 1 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0122] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.6 to 0.8 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0123] Comparative Example 12

[0124] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 6 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 6.

[0125] The electrochemical voltammetry spectra of the second cycle in Example 6 and Comparative Examples 11-12 are as follows: Figure 6 shown.

[0126] Example 7

[0127] (1) The Schisandra chinensis produced in Benxi, Liaoning Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 1.0 g of the crushed Schisandra chinensis was weighed, and 30 mL of a 50% ethanol aqueous solution was added (the volume ratio of the mass of Schisandra chinensis to the ethanol aqueous solution was 1.0 g:30 mL). The mixture was ultrasonicated at 50° C. for 2 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0128] (2) Take 1 mL of the extract, add 1.5 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 2.0 (the volume ratio of the extract to the buffer is 1:1.5), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0129] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0130] Comparative Example 13

[0131] (1) The Schisandra chinensis produced in Benxi, Liaoning Province was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 1.0 g of the crushed Schisandra chinensis was weighed, and 30 mL of a 50% ethanol aqueous solution was added (the volume ratio of the mass of Schisandra chinensis to the ethanol aqueous solution was 1.0 g:30 mL). The mixture was ultrasonicated at 50° C. for 2 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0132] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.6 to 0.8 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0133] Comparative Example 14

[0134] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 7 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 7.

[0135] The electrochemical voltammetry spectra of the second cycle in Example 7 and Comparative Examples 13-14 are as follows: Figure 7 shown.

[0136] Example 8

[0137] (1) The Yunnan safflower was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed safflower was weighed, and 30 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of the safflower to the ethanol aqueous solution was 0.8 g:30 mL). The mixture was ultrasonicated at 40° C. for 0.5 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0138] (2) Take 1 mL of the extract, add 1.5 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 4.0 (the volume ratio of the extract to the buffer is 1:1.5), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0139] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0140] Comparative Example 15

[0141] (1) The Yunnan safflower was crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm). 0.8 g of the crushed safflower was weighed, and 30 mL of a 40% ethanol aqueous solution was added (the volume ratio of the mass of the safflower to the ethanol aqueous solution was 0.8 g:30 mL). The mixture was ultrasonicated at 40° C. for 0.5 h, and the supernatant was collected after centrifugation at 4000 rpm to obtain an extract;

[0142] (2) Take 60 μL of the extract and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the range of -0.6 to 0.8 V is cyclically scanned for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0143] Comparative Example 16

[0144] The carbon nanotube modified screen-printed electrode (CNTs@SPCE) in step (3) of Example 8 was replaced by a blank screen-printed electrode (SPCE), and the other parameters were the same as those in Example 8.

[0145] The electrochemical voltammetry spectra of the second cycle in Example 8 and Comparative Examples 15-16 are as follows: Figure 8 shown.

[0146] Comparative Example 17

[0147] (1) The wolfberries produced in Zhongning, Ningxia were crushed by a high-speed crusher and passed through a 60-mesh sieve (particle size ≤ 0.42 mm), 0.5 g of the crushed wolfberries were weighed, 20 mL of a 40% ethanol aqueous solution was added (the volume ratio of the wolfberry mass to the ethanol aqueous solution was 0.5 g: 20 mL), ultrasonicated at 40° C. for 1 h, centrifuged at 4000 rpm, and the supernatant was collected to obtain an extract;

[0148] (2) Take 1 mL of the extract, add 1 mL of disodium hydrogen phosphate-sodium dihydrogen phosphate (0.2 mol / L) buffer with a pH value of 7.5 (the volume ratio of the extract to the buffer is 1:1), mix well, and filter through a 0.22 μm filter membrane to obtain a test solution;

[0149] (3) Take 60 μL of the test solution and drop it onto the surface of the carbon nanotube modified screen-printed electrode (CNTs@SPCE) and perform cyclic voltammetry scanning. The scanning rate is 25 mV / s and the scanning range is -0.6 to 0.8 V for 2 cycles to obtain the electrochemical voltammetry spectrum.

[0150] The electrochemical voltammetry spectra of the second cycle in Example 1 and Comparative Example 17 are as follows: Fig. 9 As shown. Fig. 9 It can be seen that the wolfberry extract can present a characteristic electrochemical voltammetry spectrum on the CNTs@SPCE electrode after being buffered by an acidic solution, but this cannot be obtained after being buffered by an alkaline solution.

[0151] Comparative Example 18

[0152] The chrysanthemum in step (1) of Example 3 was replaced with Rhizoma Cyathulae, and other parameters were the same as those in Example 3.

[0153] Comparative Example 19

[0154] The chrysanthemum in step (1) of Example 3 was replaced by Rehmannia glutinosa, and the other parameters were the same as those in Example 3.

[0155] Comparative Example 20

[0156] The chrysanthemum in step (1) of Example 3 was replaced with Dioscorea opposita, and other parameters were the same as those in Example 3.

[0157] The electrochemical voltammetry spectra of the second cycle in Example 3 and Comparative Examples 18 to 20 are as follows: Fig.10 As shown. Fig.10 It can be seen that the collection method provided by the present invention is suitable for collecting the voltammogram of the flower-based medicinal material Chrysanthemum, and is not suitable for non-flower and fruit-based medicinal materials such as the root-based Chinese Achyranthes bidentata, the tuberous root-based Chinese Rehmannia glutinosa, and the rhizome-based Chinese yam. The collection method provided by the present invention has specific applicability.

[0158] In summary, the collection method of the present invention is a universal collection method suitable for the electrochemical voltammetry spectra of flower and fruit Chinese medicinal materials. It can change the electrochemical voltammetry characteristics of some flower and fruit Chinese medicinal materials, changing them from "no" response to "yes" response; it can enhance the electrochemical signal intensity of some flower and fruit Chinese medicinal materials, changing them from "weak" response to "strong" response.

[0159] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for collecting electrochemical voltammetric spectra of flower and fruit Chinese medicinal materials, comprising the following steps: (1) mixing flower and fruit Chinese medicinal materials with ethanol aqueous solution to obtain an extract; (2) mixing the extract obtained in step (1) with a buffer solution to obtain a detection solution; the pH value of the buffer solution is 2.0 to 6.0; (3) Dropping the detection liquid obtained in step (2) onto the surface of the carbon nanotube-modified screen-printed electrode, performing cyclic voltammetry scanning, and obtaining an electrochemical voltammetry spectrum.

2. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: In the step (1), the particle size of the flower and fruit Chinese medicinal materials is ≤0.42 mm.

3. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: In the step (1), the volume percentage of ethanol in the ethanol aqueous solution is 40-80%.

4. The electrochemical voltammetry spectrum collection method according to claim 3, characterized in that: In the step (1), the volume ratio of the mass of the flower and fruit Chinese medicinal materials to the ethanol aqueous solution is (0.2-1.0) g: (10-30) mL.

5. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The mixing in step (1) is performed by ultrasound; the temperature of the ultrasound is 25 to 60° C., and the time of the ultrasound is 0.5 to 2 h.

6. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The volume ratio of the extract to the buffer in step (2) is 1:(0.5-2).

7. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The buffer in step (2) is at least one of disodium hydrogen phosphate-sodium dihydrogen phosphate buffer and acetic acid-sodium acetate buffer.

8. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The ratio of the volume of the detection solution in step (3) to the working area of ​​the carbon nanotube-modified screen-printed electrode is (40-80) μL: (0.07-0.13) cm 2 .

9. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The scanning rate of the cyclic voltammetry scan in step (3) is 10 to 100 mV / s.

10. The electrochemical voltammetry spectrum collection method according to claim 1, characterized in that: The range of the cyclic voltammetry scan in step (3) is -0.9 to 1.0 V.

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