Pt-WO3 electrode material for high-performance detection of luteolin, preparation method of Pt-WO3 electrode material and sensor

Abstract

The invention provides a Pt-WO3 electrode material for high-performance detection of luteolin, a preparation method of the Pt-WO3 electrode material and a sensor, and belongs to the technical field of electrochemical detection. The preparation method of the electrode material comprises the following steps: S1, mixing K2WO4 and deionized water, then adjusting the pH value to 2, and then adding H2O2 to obtain a mixed solution A; s2, mixing and stirring the mixed solution A and an H2PtCl6 solution, then adding NaBH4, and continuously stirring to obtain a mixed solution B; S3, reacting the mixed solution B in a reaction kettle, and after the reaction is finished, washing, drying and grinding to obtain the Pt-WO3 electrode material. According to the invention, the electrochemical sensor material is prepared from Pt and WO3 systems for detection of luteolin for the first time, and the prepared sensing electrode is good in sensing performance, wide in linear range, low in detection limit and relatively high in sensitivity.

Description

Technical Field

[0001] The invention belongs to the technical field of electrochemical detection, and particularly relates to a Pt-WO3 electrode material for high-performance detection of luteolin and a preparation method and a sensor thereof. Background Art

[0002] Luteolin is a natural flavonoid compound, which is widely found in various plants such as herbs, fruits and vegetables. It has potential pharmacological effects, such as anti-inflammatory, anti-allergic, uric acid-lowering, anti-tumor, antibacterial and antiviral, and has significant medical effects on human health. Based on the recognized pharmacological activity of luteolin, there is an urgent need for accurate analysis and precise determination of luteolin. There are many analytical tools for the detection of luteolin, such as chromatography, capillary electrophoresis, and spectral analysis, but they have limitations, such as complex and time-consuming sample preparation, sensitivity issues, and lack of real-time or on-site analysis.

[0003] Therefore, more advanced and reliable technologies are needed to improve the detection effect of luteolin, and electrochemical detection has brought huge application potential in various fields due to its low cost, fast response, simple operation, high sensitivity, good selectivity, etc. Therefore, it is urgent to develop an electrochemical sensor with better performance to detect luteolin. Summary of the invention

[0004] In view of this, the purpose of the present invention is to provide a Pt-WO3 electrode material and a preparation method and a sensor for high-performance detection of luteolin. The present invention is the first to prepare an electrochemical sensor material through a Pt and WO3 system to detect luteolin. The prepared sensing electrode has good sensing performance, a wide linear range, a low detection limit and high sensitivity.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a Pt-WO3 electrode material for high-performance detection of luteolin, comprising the following steps:

[0007] S1. K2WO4 and deionized water were mixed and the pH value was adjusted to 2, and H2O2 was added to obtain a mixed solution A;

[0008] S2. The mixed solution A and H2PtCl6 solution were mixed and stirred, and then NaBH4 was added and continued to stir to obtain a mixed solution B:

[0009] S3. The mixed solution B is reacted in a reactor, and after the reaction is completed, it is washed, dried and ground to obtain a Pt-WO3 electrode material.

[0010] Preferably, the mass volume ratio of K2WO4, deionized water and H2O2 in S1 is 0.3-0.5 g: 20-40 mL: 3-4 mL.

[0011] Preferably, the pH value in S1 is adjusted using 6 mol / L HCl.

[0012] Preferably, the mass volume ratio of the mixed solution A, H2PtCl6 solution and NaBH4 in S2 is 20-30mL:2-3mL:0.01-0.015g.

[0013] Preferably, the stirring time in S2 is 0.5 to 2 h.

[0014] Preferably, the temperature in S3 is 160-180° C. and the reaction time is 6-10 h.

[0015] Preferably, the washing in S3 is performed with ethanol for 4 times.

[0016] Preferably, the drying temperature in S3 is 45°C.

[0017] In a second aspect, the present invention provides a Pt-WO3 electrode material for high-performance detection of luteolin, which is prepared by the above-mentioned preparation method.

[0018] In a third aspect, the present invention provides a method for preparing a sensor for high-performance detection of luteolin, comprising the following preparation steps:

[0019] The GCE electrode was polished; and the polished GCE was tested by cyclic voltammetry in a solution of 5 mM K3[Fe(CN)6], 5 mM K4[Fe(CN)6] and 0.1 M KCl, where the scan rate was 100 mV, the potential region was -0.2-0.6 V, and the electrode polishing was completed when the potential difference between the oxidation peak and the reduction peak was less than 100 mV.

[0020] The Pt-WO3 electrode material, ethanol, ultrapure water and 0.5% naphthol are mixed and then ultrasonically dispersed to obtain a dispersion;

[0021] The dispersion was dripped onto the polished surface of the GCE electrode and naturally air-dried to obtain a sensor for high-performance detection of luteolin.

[0022] Preferably, the mass volume ratio of the Pt-WO3 electrode material, ethanol, ultrapure water and 0.5% naphthol is 1 mg: 300 uL: 700 uL: 10 uL.

[0023] Preferably, the amount of the dispersion is 6uL / cm 2 .

[0024] Beneficial technical effects:

[0025] The present invention is the first to detect luteolin by preparing electrochemical sensor materials through Pt and WO3 system. Pt has good catalytic performance and conductive properties, and produces crystal defects in the composite material. Such defects can provide more active sites, further increasing the electron transfer efficiency. Therefore, the prepared sensing electrode has good sensing performance, wide linear range, low detection limit and high sensitivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The XRD patterns of the sensing materials obtained in Example 1 and Comparative Example 1 are shown below;

[0027] Figure 2 The SEM images of the sensing materials obtained in Example 1 and Comparative Example 1;

[0028] Figure 3 The CV curve of the sensor prepared by the sensing material of Example 1 detecting luteolin;

[0029] Figure 4 This is a performance test diagram of the sensor prepared with the sensing material of Example 1 for detecting luteolin. DETAILED DESCRIPTION

[0030] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0031] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to those skilled in the art. The present invention description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] The "room temperature" and "normal temperature" mentioned in the present invention are all calculated as 25±2°C unless otherwise specified.

[0036] The raw materials and instruments used in the following examples of the present invention are commercially available unless otherwise specified.

[0037] Example 1

[0038] This embodiment provides a Pt-WO3 electrode material for high-performance detection of luteolin, and the preparation method is as follows:

[0039] S1. Add 0.3 g K2WO4 to 20 mL deionized water, then add 6 mol / L HCl solution until the pH is 2, and then add 3 mL H2O2 to obtain a mixed solution A;

[0040] S2. The mixed solution was added with 0.01 g / mL H2PtCl6 solution 2 mL, stirred for 30 minutes, then 0.01 g NaBH4 was added, and stirred for 2 hours to obtain a mixed solution B;

[0041] S3. The mixed solution B was transferred into a reactor, reacted at 160°C for 6 hours, taken out and cooled, washed with ethanol 4 times, dried, and ground to obtain a nano-WO3 composite material, namely, Pt-WO3 material.

[0042] Example 2

[0043] This embodiment provides a Pt-WO3 electrode material for high-performance detection of luteolin, and the preparation method is as follows:

[0044] S1. Add 0.4 g K2WO4 to 30 mL deionized water, then add 6 mol / L HCl solution until the pH is 2, and then add 4 mL H2O2 to obtain a mixed solution A;

[0045] S2. The mixed solution was added with 0.01 g / mL H2PtCl6 solution 3 mL, stirred for 30 minutes, then 0.015 g NaBH4 was added, and stirred for 2 hours to obtain a mixed solution B;

[0046] S3. The mixed solution B was transferred into a reactor, reacted at 170°C for 8 hours, taken out and cooled, washed with ethanol 4 times, dried, and ground to obtain a nano-WO3 composite material, namely, Pt-WO3 material.

[0047] Comparative Example 1

[0048] 0.3 g K2WO4 was added to 20 mL deionized water, and then 6 mol / L HCl was added until the pH was 2, and then 3 mL H2O2 was added to obtain a mixed solution. The mixed solution was charged into a reactor, reacted at 160 ° C for 6 hours, taken out and cooled, washed with ethanol 4 times, and then dried at 45 ° C. Grind to obtain nano WO3 material.

[0049] Experimental Example 1

[0050] XRD spectrum analysis:

[0051] like Figure 1 As shown, the synthesized WO3 has (002), (200), (112), (202), (222), (400), (402), (224) crystal plane peaks near 22.9o, 27.6o, 33.5o, 36.3o, 49.2o, 55.3o, 57.4o, 63o, 71.1o, which is consistent with the crystal structure of octahedral WO3. The (111) crystal plane peak appears near 39.3o, which is attributed to Pt. The (002) peak of Pt at 22.9o in the Pt-WO3 composite indicates the successful modification of Pt on WO3 nanomaterials.

[0052] Experimental Example 2

[0053] Structural characterization:

[0054] like Figure 2 As shown, the WO3 material is a nano-aggregate composed of nanoparticles (a); after being compounded with Pt, WO3 can be well modified and tends to aggregate into nanorods (b). The compound of Pt and WO3 produces crystal defects (c), which indicates that there is an interaction between the two.

[0055] Experimental Example 3

[0056] Sensing material detection of luteolin performance test

[0057] 1. Preparation of sensing materials for high-performance detection of luteolin

[0058] Electrode polishing:

[0059] The GCE electrode was polished with 0.3 μm and 0.05 μm Al2O3 powders to remove the oxide layer on the electrode surface, and the polished GCE was tested by cyclic voltammetry in a solution of 5 mM K3[Fe(CN)6], 5 mM K4[Fe(CN)6] and 0.1 M KCl, with a scan rate of 100 mV and a potential region of -0.2-0.6 V. The electrode polishing was completed when the potential difference between the oxidation peak and the reduction peak was less than 100 mV.

[0060] Sensing material and polished electrode composite:

[0061] Take 1 mg of the sensing material obtained in Example 1, then add 300 uL of ethanol, 700 uL of ultrapure water, and 10 uL of 0.5% naphthol for ultrasonic dispersion to obtain a uniform dispersion, take 5 uL of the above dispersion and titrate it onto the polished electrode surface, and naturally air-dry to obtain a sensing material for high-performance detection of luteolin.

[0062] 2. Linear relationship detection

[0063] like Figure 3 As shown in a, when the Pt-WO3 / GCE electrode prepared in this patent detects 100nM luteolin (dissolved in BR buffer, pH: 3.0), the cyclic voltammetry (CV) curve shows regular changes in the redox signal as the scan rate increases, the redox peak intensity gradually increases, the oxidation peak potential moves to the right, and the reduction peak potential moves to the left. The peak voltage and the logarithm of the scan rate show a linear relationship ( Figure 3 b), the charge transfer coefficient is calculated to be 0.515 and the charge transfer number is 2.48, indicating that the reaction is a diproton-electron reaction process.

[0064] 3. Sensitivity and detection limit detection

[0065] like Figure 4 As shown in a, the differential pulse voltammetry (DPV) response diagram of the Pt-WO3 / GCE electrode prepared in this patent to different concentrations of luteolin (dissolved in BR buffer, pH: 3.0). The relationship between the corresponding DPV peak current and concentration is shown in Figure 4 As shown in b, the DPV peak current showed a linear correlation with luteolin in the concentration range of 10-1000nM and 1000-8000nM, respectively. The overall linear range was: 10-8000nM, the highest sensitivity of detection was 1.85uA / uM, and the detection limit was 0.35nM.

[0066] 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 preparing a Pt-WO3 electrode material for high-performance detection of luteolin, characterized in that: The following steps are involved: S1. K2WO4 and deionized water were mixed and the pH value was adjusted to 2, and H2O2 was added to obtain a mixed solution A; S2. The mixed solution A and H2PtCl6 solution were mixed and stirred, and then NaBH4 was added and continued to stir to obtain a mixed solution B: S3. The mixed solution B is reacted in a reactor, and after the reaction is completed, it is washed, dried and ground to obtain a Pt-WO3 electrode material.

2. The preparation method according to claim 1, characterized in that: The mass volume ratio of K2WO4, deionized water and H2O2 in S1 is 0.3-0.5g:20-40mL:3-4mL.

3. The preparation method according to claim 1, characterized in that: The pH value in S1 is adjusted using 6 mol / L HCl.

4. The preparation method according to claim 1, characterized in that: The mass volume ratio of the mixed solution A, H2PtCl6 solution and NaBH4 in S2 is 20-30mL:2-3mL:0.01-0.015g.

5. The preparation method according to claim 1, characterized in that: The reaction temperature in S3 is 160-180° C. and the reaction time is 6-10 h.

6. A Pt-WO3 electrode material for high-performance detection of luteolin, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 5.

7. A method for preparing a sensor for high-performance detection of luteolin, characterized in that: The method comprises the following preparation steps: Polish the GCE electrode; The Pt-WO3 electrode material according to claim 1, ethanol, ultrapure water and 0.5% naphthol are mixed and ultrasonically dispersed to obtain a dispersion; The dispersion was dripped onto the polished surface of the GCE electrode and naturally air-dried to obtain a sensor for high-performance detection of luteolin.

8. The preparation method according to claim 8, characterized in that: The mass volume ratio of the Pt-WO3 electrode material, ethanol, ultrapure water and 0.5% naphthol is 1 mg: 300 uL: 700 uL: 10 uL.

9. The preparation method according to claim 8, characterized in that: The amount of the dispersion is 6uL / cm 2 .

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