Preparation method of hollow rod-like cobalt-based carbon material and application of hollow rod-like cobalt-based carbon material in electrochemical detection of bisphenol A

Abstract

The invention relates to the technical field of electrochemical detection materials, and particularly provides a preparation method of a hollow rod-like cobalt-based carbon material (H-R-Co / Cs) and application of the hollow rod-like cobalt-based carbon material in electrochemical detection of bisphenol A. The method comprises the following steps: by taking polyvinylpyrrolidone (PVP) as an auxiliary agent, firstly synthesizing a rod-like cobalt-based precursor (R-Co-ZIF) in a water phase; the preparation method comprises the following steps: firstly, preparing a precursor (H-R-Co-ZIF) by using a sol-gel method, then treating by using dopamine hydrochloride (DA) to obtain a hollow structure precursor (H-R-Co-ZIF), and carrying out argon high-temperature pyrolysis treatment to obtain the hollow rod-like cobalt-based carbon material (H-R-Co / Cs) which retains the hollow structure of the precursor, has the specific surface area of 263 m < 2 > g <-1 > and has good conductivity. The material prepared by the invention is used for electrochemical detection of BPA, and the prepared sensor has good reproducibility and stability and has potential application prospects in practical application.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical detection materials, and in particular to a preparation method of a hollow rod-shaped cobalt-based carbon material and its application in electrochemical detection of bisphenol A. Background Art

[0002] Bisphenol A (BPA) is an organic compound used as a monomer in the production of polycarbonate and a precursor for epoxy resins. BPA is commonly used in industrially produced food contact materials and can leach into food from packaging, posing a food safety concern. BPA is a common endocrine disruptor found in nature, and excessive consumption can lead to birth defects, infertility, obesity, prostate cancer, and other problems. To ensure human safety, the development of efficient analytical methods for the sensitive detection of BPA is essential.

[0003] Methods for monitoring BPA include high-performance liquid chromatography, liquid chromatography-mass spectrometry, gas chromatography, enzyme-linked immunosorbent assay (ELISA), and electrochemical sensing. Electrochemical sensing, due to its advantages such as simple instrumentation, rapid response, high sensitivity, and ease of operation, has become a research hotspot. However, the oxidation products of BPA molecules can cause fouling on the electrode surface and delay the electrode reaction process. Therefore, bare electrodes are often modified with modified materials to address this issue.

[0004] Electrode surface modification materials include carbon materials, metal oxides, precious metals, transition metals, etc. Among them, transition metal catalysts have attracted much attention due to their high activity, abundant resources and low price. Metal organic frameworks (MOFs) are a special structure with high thermal stability, mechanical strength, large pore volume, excellent specific surface area, and adjustable particle shape and size, and have broad application prospects. However, the conductivity and stability of original MOFs limit their application. At present, the optimal LOD of MOF-derived carbon materials for detecting BPA is 1.2μM, and there are generally problems such as slow response (>10s) and large fluctuations in actual sample recovery (±15%). In order to solve these shortcomings, the original MOFs are usually used as pyrolysis templates to obtain MOFs derivatives.

[0005] In recent years, MOF-derived hollow structures have attracted widespread attention due to their advantages such as clear internal pores, large specific surface area, and numerous active sites. Research results show that the material can be converted into a hollow structure in situ using dopamine hydrochloride (DA) as an etchant. Derivatives obtained through pyrolysis have unique advantages in electrochemical detection applications. Summary of the Invention

[0006] In view of this, the present invention proposes a preparation method of a hollow rod-shaped cobalt-based carbon material and its application in electrochemical detection of bisphenol A.

[0007] The technical solution of the present invention is achieved as follows: The present invention provides a method for preparing a hollow rod-shaped cobalt-based carbon material, which is specifically as follows:

[0008] Step 1, Preparation of Rod-Shaped Cobalt-Based Precursor (R-Co-ZIF): Dimethylimidazole (2-MeI) and polyvinylpyrrolidone (PVP) were dissolved in deionized water, designated Solution A. Co(NO₃)₂·6H₂O was dissolved in deionized water, designated Solution B. Solution B was then poured into Solution A, stirred in a water bath, allowed to stand, centrifuged, washed with water, and finally dried to obtain R-Co-ZIF.

[0009] Step 2, preparation of hollow rod-shaped cobalt-based precursor (HR-Co-ZIF): R-Co-ZIF was ultrasonically dissolved in Tris buffer, and then dopamine hydrochloride (DA) was added. The reaction was stirred at room temperature. After the reaction was completed, the mixture was centrifuged, washed with ethanol, and finally dried to obtain HR-Co-ZIF.

[0010] Step 3, preparation of hollow rod-shaped cobalt-based carbon material (HR-Co / Cs): the above sample is pyrolyzed at high temperature in argon to obtain the derivative HR-Co / Cs.

[0011] In some embodiments, in step 1, the mass ratio of 2-MeI, PVP and Co(NO3)2·6H2O is 1:0.44:0.65, and the volume of deionized water is 20 mL.

[0012] In some embodiments, in step 1, the water bath temperature is 30° C., the stirring time is 3 h, and the standing time is 12 h.

[0013] In some embodiments, in step 1, the centrifugation rate is 6500 r / min and the centrifugation time is 5 min.

[0014] In some embodiments, in step 1, the drying temperature is 60° C. and the drying time is 12 h.

[0015] In some embodiments, in step 2, the mass ratio of R-Co-ZIF to DA is 1:0.2, and the volume of Tris buffer is 40 mL.

[0016] In some embodiments, in step 2, the stirring time is 50 min; the centrifugal speed is 6500 r / min, and the centrifugation time is 5 min.

[0017] In some embodiments, in step 2, the drying temperature is 60° C. and the drying time is 12 hours.

[0018] In some embodiments, in step 2, the pH of the Tris buffer is 8.5.

[0019] In some embodiments, in step 3, the argon pyrolysis temperature is 800° C., the pyrolysis time is 2 h, and the heating rate is 2° C. / min.

[0020] The second aspect of the present invention also provides a hollow rod-shaped cobalt-based carbon material prepared by the above method.

[0021] Through the three-step synergy of PVP-guided growth → DA etching → confined pyrolysis, we unexpectedly discovered:

[0022] (1) The hollow structure improves mass transfer efficiency;

[0023] (2) When pyrolyzed at 800℃, the cobalt particles are just large enough to fit into the gaps between carbon layers, thus avoiding agglomeration. Figure 2 c TEM verification).

[0024] The third aspect of the present invention further provides a use of the above-mentioned hollow rod-shaped cobalt-based carbon material in electrochemical detection of bisphenol A.

[0025] In some embodiments, the specific method of the application includes: dispersing the hollow rod-shaped cobalt-based carbon material in a mixed solution containing ethanol, water and Nafion to obtain a loading liquid, wherein the volume ratio of ethanol, water and Nafion is 1:1.5:0.05, loading it onto the electrode surface to make a sensor, and detecting bisphenol A in PBS buffer solution with pH = 7.

[0026] In some embodiments, the method of loading onto the electrode surface comprises applying a loading liquid droplet onto the electrode surface using a pipette.

[0027] In some embodiments, the mass of HR-Co / Cs is 2 mg, the ratio of the mixed solution of ethanol, water and Nafion is 1:1.5:0.05, and the loading amount is 10 μL.

[0028] The present invention has the following beneficial effects compared to the prior art:

[0029] The prepared HR-Co / Cs has good conductivity and stability, which is conducive to its application as a modified material in electrochemical detection.

[0030] The prepared HR-Co / Cs has a large specific surface area, which is conducive to the exposure of active sites and improves the mass transfer efficiency.

[0031] The electrochemical performance of the constructed HR-Co / Cs / MGCE sensor is improved compared with other modified electrodes, and the resistance is significantly reduced, which is conducive to electron transfer.

[0032] The electrochemical performance of the constructed HR-Co / Cs / MGCE sensor is improved compared with other modified electrodes, and the resistance is significantly reduced, which is conducive to electron transfer.

[0033] The constructed HR-Co / Cs / MGCE sensor has a fast current response to BPA and can be stabilized within 3s. Its response current value is linearly correlated with the BPA concentration in the linear range of 0.5-30μM, with a detection limit (LOD) of 0.49μM (S / N=3) and a sensitivity of 0.77μA μM. -1 .

[0034] The constructed HR-Co / Cs / MGCE sensor has good selectivity, reproducibility and stability, and achieved good recovery rate in the simulation of actual sample detection, which has potential application prospects in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0036] Figure 1 Schematic diagram of the preparation process of hollow rod-shaped cobalt-based carbon materials and electrochemical sensors.

[0037] Figure 2 SEM images of (a) HR-Co-ZIF, (b) HR-Co / Cs, and TEM image of (c) HR-Co / Cs.

[0038] Figure 3 XRD images of (a) HR-Co-ZIF, (b) HR-Co / Cs, and (c) N2 adsorption / desorption isotherms of HR-Co / Cs (inset: pore size distribution diagram).

[0039] Figure 4 XPS image of HR-Co / Cs.

[0040] Figure 5 (a) CV curves of different working electrodes in 0.1M PBS containing 50μM BPA; (b) CV curves of different working electrodes in 0.1M PBS containing 5mM Fe(CN)6 3- / 4- Nyquist plot of 0.1 M KCl solution.

[0041] Figure 6 (a) HR-Co / Cs / MGCE in 0.1 M PBS solution containing 50 μM BPA at different scan rates (scan rate: 10-200 mV s -1 ) CV curve; (b) calibration curve between peak current and square root of scan rate.

[0042] Figure 7 (a) Current response of HR-Co / Cs / MGCE upon injection of 5 μM bisphenol A in PBS buffer at different pH values ​​(inset: sensitivity); (b) Current response of HR-Co / Cs / MGCE upon continuous injection of 5 μM bisphenol A at different potentials in 0.1 M PBS solution.

[0043] Figure 8 (a) Amperometric response of HR-Co / Cs / MGCE upon continuous addition of BPA in 0.1 M PBS (inset: response time of HR-Co / Cs / MGCE after addition of BPA); (b) relationship between the response current of HR-Co / Cs / MGCE and BPA concentration (inset: magnified part of the curve at low concentration).

[0044] Figure 9 (a) Response of HR-Co / Cs / MGCE to the continuous addition of BPA and other interferences; (b) Response of 5 HR-Co / Cs / MGCE under the same conditions; (c) Stability of HR-Co / Cs / MGCE at 4°C. DETAILED DESCRIPTION

[0045] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the present invention belong. If the definitions set forth in this section are contrary to or otherwise inconsistent with definitions set forth in the patents, patent applications, published patent applications, and other publications incorporated herein by reference, the definitions listed in this section take precedence over the definitions incorporated herein by reference.

[0047] Unless otherwise specified, the methods used in the following examples are conventional methods. The materials, reagents, and instruments used are conventional materials, reagents, and instruments in the art, unless otherwise specified, and can be obtained commercially by those skilled in the art.

[0048] When an amount, concentration or other value or parameter is expressed as a range, a preferred range or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any upper range limit or preferred value with any lower range limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range "1 to 5" is disclosed, the described range should be interpreted as including the ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within the range. In the present specification and claims, range definitions may be combined and / or interchanged, and if not otherwise stated, such ranges include all subranges contained therein.

[0049] Example 1

[0050] (1) Preparation of rod-shaped cobalt-based precursor (R-Co-ZIF): 0.765 g of dimethylimidazole (2-MeI) and 0.5 g of polyvinylpyrrolidone (PVP) were dissolved in 20 mL of deionized water, designated as solution A. 0.339 g of Co(NO3)2·6H2O was dissolved in 20 mL of deionized water, designated as solution B. Solution B was then poured into solution A, stirred in a water bath (30°C) for 3 h, allowed to stand for 12 h, centrifuged (6500 rpm, 5 min), washed with water, and finally dried at 60°C for 12 h to obtain R-Co-ZIF.

[0051] (2) Preparation of hollow rod-shaped cobalt-based precursor (HR-Co-ZIF): 0.1 g of R-Co-ZIF was ultrasonically dissolved in 40 mL of Tris buffer (pH = 8.5), and 20 mg of dopamine hydrochloride (DA) was added. The mixture was stirred at room temperature for 50 min. After the reaction, the mixture was centrifuged (6500 rpm, 5 min), washed with ethanol, and finally dried at 60°C for 12 h to obtain HR-Co-ZIF.

[0052] (3) Preparation of hollow rod-shaped cobalt-based carbon material (HR-Co / Cs): The above sample was pyrolyzed at 800°C (2°C / min) in argon for 2 h to obtain the derivative HR-Co / Cs.

[0053] (4) The application method of HR-Co / Cs is as follows: 2 g of HR-Co / Cs was ultrasonically dissolved in a mixed solution of 400 μL of ethanol, 600 μL of water, and 20 μL of Nafion. The material was loaded onto the surface of a polished magnetic glassy carbon electrode (MGCE) using a pipette and dried at room temperature to obtain HR-Co / Cs / MGCE. Electrochemical detection of BPA was performed in PBS buffer (pH = 7).

[0054] Figure 1 Schematic diagram of the preparation process of hollow rod-shaped cobalt-based carbon materials and electrochemical sensors.

[0055] (5) Material characterization

[0056] Figure 2 The SEM and TEM images of HR-Co-ZIF and HR-Co / Cs are shown in Figure 2. Figure 2 a, 2b) show that the precursor HR-Co-ZIF presents a rod-shaped hollow structure under the auxiliary effect of DA. After high-temperature pyrolysis, HR-Co / Cs still maintains the morphology of the precursor. TEM images ( Figure 2 c) The successful synthesis of the hollow structures of the two materials was verified. The hollow structures can provide abundant active sites, which is beneficial for their application in electrochemical detection.

[0057] Figure 3 ab are XRD images of the material, and the crystal structure of the material was studied using XRD. Figure 3 As shown in Figure a, the XRD pattern of HR-Co-ZIF shows diffraction peaks consistent with the characteristic peaks of simulated ZIF-L, confirming its high crystallinity and zeolite-like structure, indicating the successful synthesis of hollow rod-shaped HR-Co-ZIF, indicating that the introduction of DA did not change the crystal structure of the original MOFs. The XRD pattern of HR-Co / Cs after pyrolysis is shown in Figure 2. Figure 3 As shown in (b), there are three diffraction peaks at 44.22°, 51.51° and 75.85°, which are respectively pointed to the (111), (200) and (220) crystal planes of Co (PDF#15-0806), indicating that after high temperature calcination and under the catalysis of organic ligands, Co 2+ Reduced to Co 0 . Figure 3 c N2 adsorption / desorption isotherms of HR-Co / Cs. The N2 adsorption-desorption isotherms of HR-Co / Cs are all type IV. When the relative pressure exceeds 0.45, an obvious hysteresis loop appears on the curve, indicating that there is a mesoporous structure inside the material. In addition, Figure 3 The inset of c is its pore size distribution diagram, which confirms the existence of the mesoporous structure in the material, which can enhance the catalytic activity and promote ion transport. The calculated BET specific surface area of ​​HR-Co / Cs is 262.89 m 2 g -1 The higher surface area can increase the exposure of active sites, thereby improving the mass transfer efficiency. The above studies show that HR-Co / Cs has good mass transfer efficiency.

[0058] Taking HR-Co / Cs as sample, its elemental composition and valence state were analyzed by XPS technology. Figure 4a is the full XPS spectrum of HR-Co / Cs, which shows the presence of N, O, C and Co elements in the sample. Figure 4 b) Two characteristic peaks at 780.32 and 795.75 eV are found, which are attributed to Co 2p 3 / 2 and Co 2p 1 / 2 Detailed analysis of the Co 2p spectrum reveals that there is Co 2+ (780.82 / 796.04eV) and Co 3+ (777.94 / 792.81eV) three types, among which the ionic Co may come from the surface oxidation of metal Co. N 1s spectrum ( Figure 4 c) shows the presence of pyridinic-N (398.40 eV), Co-N (399.49 eV), pyridinic-N (400.11 eV) and graphitic-N (401.38 eV). O 1s spectrum as Figure 4 As shown in Figure d, the spectrum can be deconvoluted into two peaks at 529.06 eV and 531.32 eV, corresponding to lattice oxygen bound to Co (Co-O) and surface hydroxyl groups or adsorbed oxygen (-OH). Figure 4 e) indicates that there are four types of C, namely CC (283.96 eV), CN (285.00 eV), C=O (286.68 eV), and OC=O (289.67 eV).

[0059] (6) Electrochemical detection performance

[0060] The electrochemical behavior of different modified electrodes in 0.1M PBS solution containing 50μM BPA was evaluated by cyclic voltammetry. Figure 5 As shown in a, no oxidation peak was found on the bare electrode, but an oxidation peak was observed on HR-Co / Cs / MGCE, indicating that HR-Co / Cs / MGCE has electrochemical activity. Figure 5 As shown in b, compared with the bare MGCE, the resistance of HR-Co / Cs / MGCE showed a significant decrease, which is more conducive to the transfer of electrons. The CV response of HR-Co / Cs / MGCE to 50μM BPA at different scan rates was then studied. Figure 6 As shown in a, as the scan rate continues to increase, the oxidation peak current value also increases accordingly. -1 In the scan rate range, the oxidation peak current value is linearly related to the square root of the scan rate ( Figure 6 b), indicating that the electrocatalytic oxidation of BPA on the 50 μM BPA sensor surface is diffusion-controlled.

[0061] (7) Optimization of detection conditions

[0062] The effect of buffer pH on the current response of HR-Co / Cs / MGCE was studied, and the measurement results are shown in Figure 4. Figure 7 As shown in Figure a, HR-Co / Cs / MGCE exhibits the highest sensitivity and best detection performance when the buffer solution is at pH 4. Therefore, a PBS solution at pH 4 was selected as the buffer solution. In chronoamperometry, the detection potential is a key factor affecting the sensitivity and stability of electrochemical sensors. Figure 7 b is the current response diagram of HR-Co / Cs / MGCE when 5 μM BPA was continuously injected at different detection potentials. When the detection potential was 0.85 V, the current response of the electrochemical sensor was the best. Therefore, 0.85 V was selected as the optimal detection potential of HR-Co / Cs / MGCE for detecting BPA.

[0063] (8) Electrochemical detection of BPA

[0064] Based on the above optimized conditions, a detection platform was constructed. Figure 8 a) shows the chronoamperometric curve of HR-Co / Cs / MGCE when BPA at different concentrations was added to 0.1 M PBS under stirring. As shown in the figure, the chronoamperometric curve shows a clear current step with increasing BPA concentration. This reflects the sensor's rapid response to BPA and its catalytic ability. It is worth noting that after BPA injection, the chronoamperometric curve shows a rapid current response and reaches a steady state within 3 s ( Figure 8 a illustration), demonstrating that the HR-Co / Cs / MGCE sensor has a fast electrocatalytic response to BPA. The calibration curve between the sensor's response current value and BPA concentration ( Figure 8 b) shows that there is a good linear relationship between the response current value and the BPA concentration. In the concentration range of 0.5-30μM, the response current increases linearly, and the corresponding linear regression equations are I (μA) = 0.0539C (μM) + 1.4849 (R 2 =0.9947). According to calculation, when the signal-to-noise ratio (S / N=3), the detection limit (LOD) of the sensor is 0.49 μM and the sensitivity is 0.77 μAμM -1 .

[0065] (9) Determination of selectivity, reproducibility and stability

[0066] One of the key challenges facing BPA sensors in electrochemical detection is interference from other substances in real samples. To evaluate the sensor's selectivity for BPA, chronoamperometry was used to investigate the resistance of HR-Co / Cs / MGCE to potential interferences in real samples. Figure 9Figure a shows the amperometric response of the HR-Co / Cs / MGCE sensor to the continuous injection of BPA and an interfering substance at the same concentration at a constant potential of 0.85 V. As can be seen, the current increases significantly after the injection of BPA. The response does not change significantly after the injection of the interfering substance. Furthermore, even in the presence of other interfering substances in the system, the HR-Co / Cs / MGCE sensor maintains a good response to the newly added BPA. These results demonstrate that the prepared HR-Co / Cs / MGCE sensor has excellent selectivity for the detection of BPA.

[0067] The current responses of the five electrodes to BPA were then studied under the same conditions. The current responses of the five electrodes to BPA were very close, with a relative standard deviation (RSD) value of 4.07% ( Figure 9 b), indicating that HR-Co / Cs / MGCE has good reproducibility in detecting BPA.

[0068] The modified electrode was stored at 4°C for 20 days, and the response of the electrode to BPA was monitored every 5 days. Figure 9 As shown in Figure c, after 20 days of storage, the response of HR-Co / Cs / MGCE to BPA remained at 89.25% of the original response. The results show that the BPA electrochemical sensor based on HR-Co / Cs / MGCE has good stability.

[0069] (10) Simulate actual sample testing

[0070] To verify the feasibility of the sensor in practical applications, the HR-Co / Cs / MGCE was used to determine the BPA content in plastic bottled water samples. 1 mL of bottled water was diluted to 100 mL with 0.1 M PBS to obtain the test solution. BPA at varying concentrations was added to the test solution, using the test solution as the electrolyte. The BPA content in the spiked solution was detected using the HR-Co / Cs / MGCE, and the spiked recoveries and relative standard deviations (RSDs) were calculated. The results are shown in Table 1. The recoveries ranged from 98.87% to 100.10%, with RSDs between 0.36% and 2.41%. This demonstrates the suitability of the sensor for the determination of BPA in real-world samples.

[0071] Table 1 Simulated detection of BPA content in plastic bottled water samples

[0072] Addition amount (μM) Detection amount (μM) Recovery rate (%) RSD (%, n = 3) 50.00 49.75 99.50 2.41 75.00 74.15 98.87 1.56 100.00 100.10 100.10 0.36

[0073] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a hollow rod-shaped cobalt-based carbon material, characterized in that: The steps include: Step 1: Dissolve dimethylimidazole and polyvinylpyrrolidone in deionized water to form solution A, and dissolve Co(NO3)2·6H2O in deionized water to form solution B; pour solution B into solution A, stir under water bath conditions, let stand, centrifuge, wash with water, and dry to obtain a rod-shaped cobalt-based precursor; Step 2: Ultrasonic dispersion of the rod-shaped cobalt-based precursor in a Tris buffer solution at pH 8.5, addition of dopamine hydrochloride, stirring at room temperature for 50 min, centrifugation, ethanol washing, and drying to obtain a hollow rod-shaped cobalt-based precursor; Step 3: Pyrolyze the hollow rod-shaped cobalt-based precursor in an argon atmosphere to obtain a hollow rod-shaped cobalt-based carbon material.

2. The method for preparing the hollow rod-shaped cobalt-based carbon material according to claim 1, wherein: In step 1, the mass ratio of dimethylimidazole, polyvinylpyrrolidone and Co(NO3)2·6H2O is 1:0.44:0.

65.

3. The method for preparing the hollow rod-shaped cobalt-based carbon material according to claim 1, wherein: In step 1, the mixture was stirred in a water bath at 30° C. for 3 h, allowed to stand for 12 h, centrifuged, washed with water, and dried at 60° C. for 12 h to obtain a rod-shaped cobalt-based precursor.

4. The method for preparing the hollow rod-shaped cobalt-based carbon material according to claim 1, wherein: In step 2, the pH of the Tris buffer is 8.5, and the mass ratio of the rod-shaped cobalt-based precursor to dopamine hydrochloride is 1:0.

2.

5. The method for preparing the hollow rod-shaped cobalt-based carbon material according to claim 1, wherein: In step 2, the product was stirred at room temperature for 50 min, centrifuged, washed with ethanol, and dried at 60° C. for 12 h to obtain a hollow rod-shaped cobalt-based precursor.

6. The method for preparing the hollow rod-shaped cobalt-based carbon material according to claim 1, wherein: In step 3, the pyrolysis conditions are: argon atmosphere, 800°C, 2h, and a heating rate of 2°C / min.

7. A hollow rod-shaped cobalt-based carbon material, characterized in that: The method is prepared by any one of claims 1 to 6.

8. Use of the hollow rod-shaped cobalt-based carbon material according to claim 7 in electrochemical detection of bisphenol A.

9. The use according to claim 8, characterized in that Hollow rod-shaped cobalt-based carbon material was dispersed in a mixed solution containing ethanol, water and Nafion to obtain a loading liquid. The volume ratio of ethanol, water and Nafion was 1:1.5:0.

05. The loading liquid was loaded onto the electrode surface to make a sensor for detecting bisphenol A in PBS buffer at pH = 7.

10. The use according to claim 9, characterized in that The method of loading onto the electrode surface includes: applying the loading liquid droplets to the electrode surface through a pipette gun.

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