Preparation method and detection application of cobalt cyanide composite structure modified carbon cloth self-supporting electrode

Abstract

The invention discloses a cobalt cyanide and basic cobalt carbonate composite structure modified carbon cloth self-supporting electrode as well as a preparation method and detection application thereof. The cobalt cyanide and basic cobalt carbonate composite structure is obtained by carrying out chemical etching on cobalt carbonate nanorods growing on carbon cloth in situ in an alkaline formamide medium; in the alkaline etching process, formamide is decomposed into cyanide ligands, the cyanide ligands and part of Co < 2 + > in a precursor form a brown Co (CN) 3 cubic structure, the cobalt carbonate nanorods maintain the morphology, but the surfaces of the cobalt carbonate nanorods are converted into cobalt cyanide nanocubes, the composite structure presents an urchin-shaped morphology, the structure provides a large specific surface area and rich catalytic active sites, and the catalytic activity of the cobalt carbonate nanorods is improved. Adsorption and electrochemical catalysis of an analyte on the surface of the electrode are facilitated. An electrochemical sensing platform based on the self-supporting electrode shows good electro-catalytic performance on rutin, the detection linear range is 0.05-70 [mu] mol.L <-1 >, the detection limit is 8.47 nmol.L <-1 >, the sensitivity is 317.9 A.M <-1 >. Cm <-2 >, and the self-supporting electrode has good selectivity, stability and reproducibility.

Description

TECHNICAL FIELD

[0001] The present application relates to a preparation method of a cobalt cyanide composite structure modified carbon cloth self-supporting electrode, and application in electrochemical sensing detection. BACKGROUND

[0002] Rutin is a bioactive flavonoid glycoside widely present in some plants, including buckwheat, aloe vera, fruits and herbal products. It has a wide range of physiological activities, such as antiviral, anti-inflammatory, anticancer and antioxidant, etc. Therefore, rutin is commonly used in the food or pharmaceutical industry to prevent or treat related diseases, such as diabetes, hypertension, neuroinflammation, and even coronavirus (COVID-19). However, excessive intake of rutin can cause symptoms such as eczema, allergy, tension, and dermatitis. Therefore, it is of great significance to establish a simple and efficient new method for rutin detection for food and drug analysis. Existing detection technologies such as high performance liquid chromatography, chemiluminescence, and capillary electrophoresis have their own characteristics, but they are generally limited by complex operation, expensive equipment, etc. In contrast, electrochemical detection technology stands out due to its advantages such as portability, rapid response, high sensitivity, simple operation, and low cost. In particular, it is worth noting that the rutin molecule structure contains two electroactive hydroxyl groups, which makes it very suitable for direct electrochemical detection, not only with excellent sensitivity, but also with a simple and efficient detection process.

[0003] Prussian blue analogues, as a typical class of metal-organic framework materials, exhibit unique structural advantages and application potential. This class of materials not only has an open porous structure and a large specific surface area, but also has outstanding characteristics such as simple preparation, low cost, and adjustable metal active sites. However, poor conductivity and stability limit their practical application in the field of electrochemistry. Sun's research team innovatively developed Co(CN)3 microcrystalline materials, which maintain the structural characteristics of PBA-like materials while effectively solving the problem of uneven coordination structure of traditional single-atom catalysts through the special coordination mode of cyanide ligand and cobalt center. It is worth noting that due to the small volume of cyanide ions, this material achieves a higher active site density than conventional M-N-C materials, and exhibits excellent catalytic performance in the oxygen reduction reaction (ORR). Unfortunately, the application potential of this innovative material in the field of electrochemical sensing has not been developed.

[0004] The present application intends to grow cobalt hydroxide carbonate nanorods in situ on the surface of carbon cloth; to perform chemical etching on the cobalt hydroxide carbonate nanorods grown in situ on the carbon cloth in a basic formamide medium, and to obtain a self-supporting electrode of cobalt cyanide@cobalt hydroxide carbonate composite structure modified carbon cloth. In the composite structure prepared by the template method, Co(CN)3 cubic units can be uniformly dispersed on the surface of the nanorods, and the existence of such a heterostructure can provide a large specific surface area, rich catalytic active sites, fast charge transfer and low mass transfer resistance. Therefore, based on the Co(CN)3@Co(CH) / CC electrochemical sensing platform, the adsorption capture and electrochemical catalysis of the substrate rutin can be accelerated, and a high-sensitivity, high-selectivity and high-stability rutin electrochemical detection method can be established. SUMMARY

[0005] In view of the deficiencies of the prior art and the research and application needs in the field, one of the purposes of the present application is to provide a cobalt cyanide@cobalt hydroxide carbonate composite structure modified carbon cloth self-supporting electrode; characterized in that the self-supporting electrode is composed of carbon cloth and cobalt cyanide@cobalt hydroxide carbonate composite structure grown in situ on the surface of the carbon cloth; the cobalt cyanide@cobalt hydroxide carbonate composite structure is prepared by hydrothermal reaction on the cobalt hydroxide carbonate nanorods grown in situ on the carbon cloth in a basic formamide medium; the carbon cloth is denoted as CC; the cobalt hydroxide carbonate nanorods grown in situ on the carbon cloth are denoted as Co(CH) / CC; and the cobalt cyanide@cobalt hydroxide carbonate composite structure modified carbon cloth self-supporting electrode is denoted as Co(CN)3@Co(CH) / CC.

[0006] The second purpose of the present application is to provide a preparation method of a cobalt cyanide@cobalt hydroxide carbonate composite structure modified carbon cloth self-supporting electrode, comprising the following steps:

[0007] (a) Preparation of Co(CH) / CC

[0008] CC with a size of 2 cm*3 cm is sequentially ultrasonically washed in anhydrous ethanol and deionized water for 15 min, and then is placed in a reaction kettle containing 30 mL of a 15 mmol·L -1 dilute nitric acid, heated at 120 DEG C for 3 h, and then transferred into a 50 mL reaction kettle after cooling and washing; 1 mmol of Co(NO3)2·6H2O, 1.5 mmol of NH4F and 5 mmol of urea are dissolved in 50 mL of deionized water, and after stirring and dissolving, 30 mL of the reaction solution is transferred into the reaction kettle containing the CC, sealed and subjected to hydrothermal reaction at 120 DEG C for 10 h, and then cooled, washed and dried to obtain Co(CH) / CC.

[0009] (b) Co(CN)3@Co(CH) / CC

[0010] Co(CH) / CC prepared in step (a), 20 mL of formamide and 0.5 mL of potassium hydroxide solution with a concentration of 1 mol / L -1 were added into a 50 mL autoclave, which was sealed and hydrothermally reacted at 170-180 ℃ for 12 h, and then washed and dried after cooling to obtain Co(CN)3@Co(CH) / CC.

[0011] The Co(CN)3@Co(CH) / CC self-supporting electrode structure presents a sea urchin-like morphology, in which the nanorod morphology of the basic cobalt carbonate is still maintained, but the surface is in-situ converted into cyanide cobalt nanocubes of a Prussian blue-like structure, which can provide a large specific surface area and more catalytic active sites, and is conducive to the adsorption and catalysis of analytes on the electrode surface.

[0012] The third object of the present application is to provide a content of a cyanide cobalt@basic cobalt carbonate composite structure modified carbon cloth self-supporting electrode for detecting rutin, characterized in that 0.1 mol / L pH 6.0 phosphate buffer is used as a supporting electrolyte, different amounts of rutin are added to the electrolyte solution, Co(CN)3@Co(CH) / CC is used as a working electrode, differential pulse voltammetry is used for detection, a linear regression equation of the oxidation peak current of rutin and its concentration is obtained, the oxidation peak current of rutin in the tablet extract is determined by differential pulse voltammetry, and the actual concentration of rutin in the tablet is obtained by substituting the linear regression equation, and then the content of rutin in the tablet is obtained.

[0013] Compared with the prior art, the present application has the following beneficial effects:

[0014] (a) In the cyanide cobalt@basic cobalt carbonate composite structure modified carbon cloth self-supporting electrode, the Co(CN)3 cube units can be uniformly dispersed on the surface of the nanorod, and such a heterostructure can provide a large specific surface area, rich catalytic active sites, fast charge transfer and low mass transfer resistance.

[0015] (b) Based on the Co(CN)3@Co(CH) / CC, an electrochemical sensing platform can be constructed, which can accelerate the adsorption capture and electrochemical catalysis of the substrate rutin, and based on this, a high-sensitivity, high-selectivity and high-stability rutin electrochemical detection method can be established. The sensor has good sensing performance for rutin, has a wide detection range of 0-70 μmol·L -1 , a low detection limit of 8.47 μmol·L -1 , a high sensitivity of 317.9 μA·μM -1 ·cm -2 , and good selectivity and stability. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1a, b and c, d are SEM images of Co(CH) / CC and Co(CN)3@CoCH / CC corresponding to Comparative Example 1 and Example 1, respectively, e is the energy dispersive X-ray spectrum of Co(CN)3@CoCH / CC corresponding to Example 1.

[0017] Figure 2 are DPV plots of Co(CN)3@Co(CH) / CC, Co(CN)3@Co(CH) / CC-2, Co(CN)3@Co(CH) / CC-3 corresponding to Example 1, Example 2 and Example 3, respectively, in phosphate buffer (0.1 mol L −1 KCl containing 5.0 mmol L −1 [Fe(CN)6] 3− / 4− solution (left) and electrochemical impedance plots (right).

[0018] Figure 3 are CV plots (left) and electrochemical impedance plots (right) of CC (a), Co(CH) / CC (b), Co(CN)3 / CC (c) and Co(CN)3@Co(CH) / CC (d) corresponding to Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1, respectively, in phosphate buffer (0.1 mol L −1 KCl containing 5.0 mmol L −1 [Fe(CN)6] 3− / 4− solution (left) and electrochemical impedance plots (right).

[0019] Figure 4 are DPV plots of CC (curve a), Co(CH) / CC (curve b), Co(CN)3 / CC (curve c) and Co(CN)3@Co(CH) / CC (curve d) corresponding to Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1, respectively, in phosphate buffer (0.1 mol L −1 containing 50 µmmol L −1 rutin (pH 6.0).

[0020] Figure 5 are DPV responses of Co(CN)3@CoCH / CC electrode corresponding to Example 1 in phosphate buffer containing different concentrations of rutin (a) and the linear fitting curve of the oxidation peak current density versus the rutin concentration (b).

[0021] Figure 6 a is the normalized response signal (%) of Example 1 in the presence of each interfering compound. 6b is the stability of Co(CN)3@Co(CH) / CC corresponding to Example 1 towards rutin during continuous operation; (inset: retained current (%) versus cycle number).

[0022] Figure 7The DPV curve of the Co(CN)3@Co(CH) / CC electrode corresponding to Example 1 in the extract solution of different contents of rutin tablets. DETAILED DESCRIPTION

[0023] For a further understanding of the present application, the application will be described in further detail in connection with the accompanying drawings and examples, but the application should not be limited in any way by the details of the application.

[0024] Example 1:

[0025] (a) Preparation of Co(CH) / CC

[0026] The CC with a size of 2 cm x 3 cm was sequentially ultrasonically washed in anhydrous ethanol and deionized water for 15 min, and then was placed in a 30 mL reaction kettle containing 30 mL of deionized water with a concentration of 15 mmol L -1 of Co(NO3)2 6H2O, 1.5 mmol of NH4F and 5 mmol of urea were dissolved in 50 mL of deionized water, and after stirring and dissolving, 30 mL of the reaction solution was transferred into the reaction kettle containing the CC, and after sealing, the hydrothermal reaction was carried out at 120 ℃ for 10 h, and after cooling, the product was washed and dried to obtain Co(CH) / CC;

[0027] (b) Co(CN)3@Co(CH) / CC

[0028] The Co(CH) / CC prepared in step (a), 20 mL of formamide and 0.5 mL of a potassium hydroxide solution with a concentration of 1 mol L -1 of Co(NO3)2 6H2O, 1.5 mmol of NH4F and 5 mmol of urea were dissolved in 50 mL of deionized water, and after stirring and dissolving, 30 mL of the reaction solution was transferred into the reaction kettle containing the CC, and after sealing, the hydrothermal reaction was carried out at 120 ℃ for 10 h, and after cooling, the product was washed and dried to obtain Co(CH) / CC;

[0029] Example 2:

[0030] (a) Preparation of Co(CH) / CC

[0031] The Co(CH) / CC was prepared according to the method and conditions of step (a) in Example 1

[0032] (b) Co(CN)3@Co(CH) / CC

[0033] The Co(CH) / CC prepared in step (a), 20 mL of formamide and 0.5 mL of a potassium hydroxide solution with a concentration of 1 mol L -1 of Co(NO3)2 6H2O, 1.5 mmol of NH4F and 5 mmol of urea were dissolved in 50 mL of deionized water, and after stirring and dissolving, 30 mL of the reaction solution was transferred into the reaction kettle containing the CC, and after sealing, the hydrothermal reaction was carried out at 120 ℃ for 10 h, and after cooling, the product was washed and dried to obtain Co(CH) / CC;

[0034] Example 3

[0035] (a) Preparation of Co(CH) / CC

[0036] Prepared according to the method and conditions of step (a) in Example 1

[0037] (b) Preparation of Co(CN)3@Co(CH) / CC

[0038] Co(CH) / CC prepared in step (a), 20 mL formamide and 0.5 mL potassium hydroxide solution with a concentration of 1 mol L -1 -1 were added into a 50 mL reactor, which was sealed and hydrothermally reacted at 180 ℃ for 12 h. After cooling, Co(CN)3@Co(CH) / CC-3 was obtained after washing and drying.

[0039] Comparative Example 1

[0040] (a) Acidification of CC

[0041] CC with a size of 2 cm x 3 cm was sequentially washed in anhydrous ethanol and deionized water by ultrasonic for 15 min, and then placed in a reactor containing 30 mL dilute nitric acid with a concentration of 15 mmol L -1 -1. After heating at 120 ℃ for 3 h, the acidified CC was obtained after cooling, washing and drying.

[0042] Comparative Example 2

[0043] (a) Preparation of Co(CH) / CC

[0044] Prepared according to the method and conditions of step (a) in Example 1

[0045] Comparative Example 3

[0046] (a) Acidification of CC

[0047] Prepared according to the method and conditions of step (a) in Example 1

[0048] (b) Preparation of Co(CN)3 / CC

[0049] CC, 1 mmol Co(NO3)2·6H2O, 20 mL formamide and 0.5 mL potassium hydroxide solution with a concentration of 1 mol L -1 -1 were added into a 50 mL reactor, which was sealed and hydrothermally reacted at 170 ℃ for 12 h. After cooling, Co(CN)3 / CC was obtained after washing and drying.

[0050] Figure 1Figures a, b, c, and d show the SEM images of Co(CH) / CC and Co(CN)3@CoCH / CC for Comparative Example 1 and Example 1, respectively. Figure e shows the energy-dispersive X-ray spectrum of Co(CN)3@CoCH / CC for Example 1. The CoCH precursor exhibits a regularly shaped nanorod structure, resembling a spherical sea urchin (Figures a and b). The diameter of the spherical "sea urchin" is approximately 5 μm. This is likely due to the hydrothermal reaction occurring under high temperature and pressure, resulting in a rapid formation of numerous nanorods, which further aggregate to form the spherical "sea urchin." When further treated with formamide and KOH solution, under alkaline heating conditions, the formamide decomposes into cyanide ligands, which then react with the Co on the precursor. 2+ As shown in Figures c and d, a brown cyanide complex is formed, and the morphology of some nanorods transforms into nanocubic Co(CN)3. After the formation of Co(CN)3, the morphology of the cobalt hydroxide carbonate nanorods is almost invisible, indicating that the formed PBA-like Co(CN)3 completely covers the nanorod template. The edge morphology of the nanocubes is clearly visible, but the surface is rough, and the size is approximately 3.5 μm. The rough surface can endow the catalyst with more defects and active sites, providing more active area for charge transfer and helping to increase catalytic activity. Figure e shows that C, Co, N, and O elements are uniformly distributed in the nanocubic structure.

[0051] Figure 2 The examples 1, 2, and 3 correspond to Co(CN)3@Co(CH) / CC, Co(CN)3@Co(CH) / CC-2, and Co(CN)3@Co(CH) / CC-3, respectively, in a solution containing 0.1 mol L... −1 5.0 mmol L of KCl −1 [Fe(CN)6] 3− / 4− The CV plot (left) and electrochemical impedance spectroscopy (right) in solution show significant differences in the electrochemical performance of Co(CN)3@Co(CH) / CC at different temperatures. Co(CN)3@Co(CH) / CC prepared at 170 °C exhibits the largest oxidation peak current and the smallest electrochemical impedance, indicating that Co(CN)3@Co(CH) / CC prepared at this temperature has the best electrochemical performance.

[0052] Figure 3 The values ​​of CC (a), CoCH / CC (b), Co(CN)3 / CC (c), and Co(CN)3@CoCH / CC (d) corresponding to Comparative Examples 1, 2, 3, and 1 are respectively, in a solution containing 0.1 mol L. −1 5.0 mmol L of KCl −1 [Fe(CN)6] 3− / 4−CV plot (left) and electrochemical impedance plot (right) in solution. Bare CC shows smaller redox signal and larger peak-to-peak potential (DE p ) than Co(CN)3@Co(CH) / CC, Co(CN)3 / CC, CoCH / CC, Co(CN)3@Co(CH) / CC due to the hydrophobicity and low surface area of bare CC itself, which leads to limited catalytic sites and catalytic activity. Compared with Co(CN)3 / CC, Co(CN)3@Co(CH) / CC has larger peak current (DI p = 6.63 mA) and smaller DE p (~ 280 mV), which indicates that the heterostructure forms a rough surface during the preparation process, exposing more catalytically active sites, providing a larger specific surface area, which is conducive to the adsorption and catalysis of the redox probe on the surface, thus showing good electrocatalytic performance.

[0053] Figure 4 DPV plots of CC (curve a), Co(CH) / CC (curve b), Co(CN)3 / CC (curve c) and Co(CN)3@Co(CH) / CC (curve d) corresponding to Comparative Example 1, Comparative Example 2, Comparative Example 3 and Example 1 in phosphate buffer solution (0.1 mol L −1 , pH 6.0) containing 50 μm mol L −1 Rutin. Bare CC shows weak oxidation peak for rutin, with an oxidation peak current (I pa ) of ~ 166 μA. After modification with CoCH / CC, I pa slightly increases to ~ 278 μA, which is due to the CoCH nanorods modified on the surface of CC, which contains polar groups such as CO3 2- and OH - , which improves the hydrophobicity and catalytic active sites of CC, so it shows an increased I pa . It is worth noting that the direct modification of Co(CN)3 on the surface of bare CC does not significantly enhance I pa ~ 416 μA, while Co(CN)3@Co(CH) / CC has the largest peak current signal ~ 724 μA, indicating that the heterostructure of Co(CN)3@Co(CH) / CC can provide a large surface area, more catalytically active sites, more material transfer channels and faster electron transfer rate, which greatly enhances the electrocatalytic ability of Co(CN)3@Co(CH) / CC for rutin.

[0054] Figure 5The figures show the DPV response (a) and linear fitting curves of the oxidation peak current density of the Co(CN)3@Co(CH) / CC electrode corresponding to Example 1 under different rutin concentrations. The results show that no oxidation peak was observed in the absence of rutin. The oxidation peak increased with rutin concentration from 0.5 to 70 μmol·L⁻¹. -1 I pa The value gradually increases. The rutin concentration and peak response current range from 0.5 to 70 μmol·L⁻¹. -1 A certain linear relationship is observed within the range. pa The linear relationship with rutin concentration was observed in the range of 0.5–5 μmol·L⁻¹. -1 and 5 ~ 70 μmol·L -1 Two linear segments, such as Figure 5 As shown in b. 0.5 ~5 μmol·L -1 and 5 ~ 70 μmol·L -1 I respectively pa1 = − 4.149C (μmol·L) -1 -3.5503 (R) 2 = 0.8787) and I pa2 = − 0.0350C (μmol·L) -1 -6.844 (R) 2 = 0.9810) is represented by two equations. It has a low detection limit (LOD) of 8.47 nmol·L⁻¹. -1 (S / N = 3), high sensitivity (317.9 μA·μM) -1 ·cm -2 ).

[0055] Figure 6 a represents the normalized response signal (%) of Example 1 in the presence of each interfering compound. 5b represents the stability of rutin during continuous operation of the Co(CN)3@Co(CH) / CC electrode corresponding to Example 1; (Inset: Retention current (%) vs. cycle number). The results show that the electrochemical sensing platform based on the Co(CN)3@Co(CH) / CC electrode exhibits good anti-interference capability and excellent stability when detecting rutin.

[0056] Figure 7For the DPV curve of Co(CN)3@Co(CH) / CC electrode in different content of rutin tablet extract, first grind the rutin tablet into powder, take 67 mg (20 mg / tablet) rutin powder and dissolve in 10 mL ethanol by ultrasonic. After centrifugation to remove insoluble matter, dilute the supernatant to 100 mL with ultrapure water, take 30, 90, 300 μL of the above dilution respectively, add 10 mL PB (pH = 6.0) to prepare three rutin extract samples, carry out three parallel experiments for each sample to detect rutin, calculate the concentration using the standard curve, and calculate the actual content in the rutin tablet.

[0057] Table 1: Performance comparison of Co(CN)3@Co(CH) / CC electrode for detecting rutin and other electroanalytical methods

[0058] Modified electrode Detection technique Linear range (pM) Detection limit (nM) MIP / MWCNTs / GCE DPV 0.4 ~ 10 110 GO-Cs / GCE DPV 0.9 ~ 90 560 Ce-PEDOT / GCE DPV 0.02 ~ 9 500 GI-HA / GCE DPV 0.01 ~ 800 18 Mg-Al-Si@PC / GCE DPV 1.0 ~ 10 10 Co(CN)3@Co(CH) / CC DPV 0.05 ~ 70 8.47

[0059] As can be seen from Table 1, when the Co(CN)3@Co(CH) / CC electrode is used to detect rutin, the linear range is close to or better than some of the reported modified electrodes, but the detection limit is significantly lower than the values in the listed literature, indicating that the Co(CN)3@Co(CH) / CC electrode has sensitive electrocatalytic performance and good selectivity for rutin, thus showing better stability and sensitivity.

[0060] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the above examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent conversion methods, all of which are included in the protection scope of the present application.

Claims

1. A self-supported electrode of carbon cloth modified by cobalt cyanide@basic cobalt carbonate composite structure, characterized in that The self-supporting electrode is composed of carbon cloth and in-situ grown cobalt cyanide@basic cobalt carbonate composite structure on the surface thereof; the cobalt cyanide@basic cobalt carbonate composite structure is prepared by hydrothermal reaction on the basic cobalt carbonate nanorods in-situ grown on the carbon cloth in a basic formamide medium; the carbon cloth is denoted as CC; the basic cobalt carbonate nanorods in-situ grown on the carbon cloth are denoted as Co(CH) / CC; and the self-supporting electrode of the carbon cloth modified by the cobalt cyanide@basic cobalt carbonate composite structure is denoted as Co(CN)3@Co(CH) / CC.

2. The method for preparing the self-supporting electrode of cobalt cyanide and basic cobalt carbonate composite structure modified carbon cloth according to claim 1, characterized in that The method comprises the following steps: (a) preparation of Co(CH) / CC The CC with size of 2 cm × 3 cm was sequentially ultrasonically washed in anhydrous ethanol and deionized water for 15 min, and then was placed in a 30 mL reaction kettle containing 15 mmol·L -1 After being heated in a reaction kettle containing dilute nitric acid at 120 ℃ for 3 h and being washed after cooling, 1 mmol of Co(NO3)2·6H2O, 1.5 mmol of NH4F and 5 mmol of urea were dissolved in 50 mL of deionized water, 30 mL of the reaction solution was taken out and transferred into the reaction kettle containing the CC, and after being sealed, the hydrothermal reaction was carried out at 120 ℃ for 10 h. After being cooled, washed and dried, Co(CH) / CC was obtained. (b) Co(CN)3@Co(CH) / CC Co(CH) / CC prepared in step (a), 20 mL of formamide and 0.5 mL of a potassium hydroxide solution with a concentration of 1 mol L -1 were added to a 50 mL autoclave, which was sealed and then subjected to hydrothermal reaction at 170-180 ℃ for 12 h. After cooling, washing and drying, Co(CN)3@Co(CH) / CC was obtained. The Co(CN)3@Co(CH) / CC self-supporting electrode structure presents urchin-like morphology, wherein the nanorod morphology of the basic cobalt carbonate is still maintained, but the surface thereof is in-situ converted into cobalt cyanide nanocubes of a Prussian blue-like structure, the composite structure can provide large specific surface area and more catalytic active sites, and is favorable for adsorption and catalysis of analytes on the electrode surface.

3. The cobalt cyanide and basic cobalt carbonate composite structure modified carbon cloth self-supporting electrode for detecting the content of rutin according to claim 1, characterized in that, With 0.1 mol / L phosphate buffer solution with pH 6.0 as a supporting electrolyte, different amounts of rutin are added into the electrolyte solution, a differential pulse voltammetry is adopted to detect the working electrode of Co(CN)3@Co(CH) / CC, a linear regression equation of the oxidation peak current of rutin and the concentration thereof is obtained; the oxidation peak current of rutin in the tablet extract is measured by the differential pulse voltammetry, the linear regression equation is substituted, the actual concentration of rutin in the tablet is obtained, and then the content of rutin in the tablet is calculated.

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