A novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, preparation method and application

Abstract

The present invention discloses a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, a preparation method and an application, which relate to the technical field of electrochemical analysis. The key points of the technical solution are as follows: The electrochemical sensor includes a glassy carbon electrode and a noble metal PdRu / NC composite attached to the glassy carbon electrode. The preparation process includes four steps: the synthesis of MET, the synthesis of NC, the synthesis of PdRu / NC, and the synthesis of PdRu / NC / GCE. It can be used to detect CA in daily foods. The electrochemical sensor has the characteristics of low cost, convenient detection process, time-saving, and high sensitivity; its preparation method is simple and the raw materials are easily available; the application range is wide, and it can be used to detect the caffeic acid content in fruits, vegetables, coffee and other daily foods.

Description

Technical Field

[0001] The present invention relates to the technical field of electrochemical analysis, and more specifically, it relates to a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, a preparation method and an application thereof. Background Art

[0002] Caffeic acid is a naturally occurring phenolic compound that is widely present in fruits, vegetables, coffee and other daily foods. Appropriate amounts of caffeic acid (CA) have anti-cancer and anti-tumor effects, while excessive caffeic acid (CA) treatment shows significant cytotoxicity, which may lead to the development of cancer. Therefore, a reliable caffeic acid analysis method is crucial for food safety.

[0003] Existing methods for detecting caffeic acid in foods often use high-performance liquid chromatography technology, capillary electrophoresis, fluorescence spectroscopy, etc. These methods have been established in the quantitative determination of caffeic acid, but these methods have disadvantages such as high cost, cumbersome detection process, and long time consumption. Therefore, we have developed a caffeic acid electrochemical sensor with advantages such as low cost, time-saving, high sensitivity and wide application range. Summary of the Invention

[0004] The purpose of the present invention is to provide a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, a preparation method and an application thereof. The electrochemical sensor has the characteristics of low cost, convenient detection process, time-saving and high sensitivity; the preparation method of the electrochemical sensor is simple and the raw materials are easily available; the electrochemical sensor has a wide application range and can be used to detect the caffeic acid content in fruits, vegetables, coffee and other daily foods.

[0005] The above technical purpose of the present invention is achieved through the following technical solutions: a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, wherein the electrochemical sensor includes a glassy carbon electrode and a noble metal PdRu / NC composite attached to the glassy carbon electrode.

[0006] A preparation method of a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor: includes the following 4 steps:

[0007] S1. Synthesis of MET;

[0008] S2. Synthesis of NC;

[0009] S3. Synthesis of PdRu / NC;

[0010] S4. Synthesis of PdRu / NC / GCE.

[0011] The present invention is further provided as:

[0012] The specific operation of synthesizing MET in S1 is as follows: Dissolve 5.0 g of ZnCl2 in a mixed solvent of 50 mL of ethanol, 75 mL of pure water, 20 mL of 25%-28% ammonia water, and 50 mL of N,N-dimethylformamide. Add 6.26 mL of 1H-1,2,3-triazole to the mixture, stir vigorously at 25 °C for 24 hours, then centrifuge at 9800 rpm to collect the white precipitate, wash it with 9 mL of ethanol, wash it 3 times, and dry it under vacuum at 80 °C to obtain MET.

[0013] The present invention is further configured as:

[0014] The specific operation of synthesizing NC in S2 is as follows: Heat the MET synthesized in S1 from 25 °C to 900 °C at a heating rate of 5 °C / min under a N2 atmosphere, hold it at 900 °C for 2 h, cool it to 25 °C, and after pyrolysis, obtain NC.

[0015] The present invention is further configured as:

[0016] The specific operation of synthesizing PdRu / NC in S3 is as follows: Take 20 mg of the NC prepared in S2 and dissolve it in 20 mL of water, then add PdCl2 with a concentration of 1 mg / mL and RuCl3·H2O to the mixture; stir the mixture for 12 hours and add 60 mg of NaBH4, then keep stirring for 12 hours, and then centrifuge at 9800 rpm to collect PdRu / NC, wash it with 9 mL of water, wash it 3 times, and dry it under vacuum at 70 °C.

[0017] The present invention is further configured as:

[0018] The specific operation of synthesizing PdRu / NC / GCE in S4 is as follows: After polishing the GCE on a polishing cloth containing 0.05 μm Al2O3 powder and washing it, dissolve the PdRu / NC material prepared in S3 in ultrapure water, dilute it to a concentration of 2 mg / mL, take 6 μL of the PdRu / NC dispersion and drop it on the GCE, and dry it under infrared light to obtain PdRu / NC / GCE.

[0019] Application of a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor: The electrochemical sensor can be used to detect CA in daily foods.

[0020] In summary, the present invention has the following beneficial effects: The electrochemical sensor is characterized by low cost, convenient, time-saving detection process, and high sensitivity. The chemical sensor has a wide linear range of 1 nM - 100 nM and 100 nM - 15 nM, and the detection limit is as low as 0.19 nM (S / N = 3). It also has high selectivity (55 μA / μM) and reproducibility; the preparation method of the electrochemical sensor is simple, and the raw materials are easily available; the electrochemical sensor has a wide application range, and the sensor has also been successfully used to detect CA in actual samples of red wine, strawberries, and blueberries, providing a new method for CA detection in food analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 (A) is the SEM image of MET prepared by the present invention, Figure 1 (B) is the SEM image of PdRu / NC prepared by the present invention;

[0022] Figure 2 (A) is the DPV spectrum of PdRu / NC / GCE of the present invention for caffeic acid at different concentrations, Figure 2 (B) is the working curve of PdRu / NC / GCE of the present invention for the detection of caffeic acid;

[0023] Figure 3 To test the effect of interferon on 5 μM caffeic acid;

[0024] Figure 4 is the current response between different sensors prepared in Examples 1 - 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following is a further detailed description of the present invention in conjunction with the attached Figures 1-4 drawings.

[0026] Example 1: A novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, preparation method and application, as Figures 1-4 shown, a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, the electrochemical sensor includes a glassy carbon electrode and a noble metal PdRu / NC composite attached to the glassy carbon electrode.

[0027] A preparation method of a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor: includes the following 4 steps:

[0028] S1. Synthesis of MET;

[0029] S2. Synthesis of NC;

[0030] S3. Synthesis of PdRu / NC;

[0031] Synthesis of S4. PdRu / NC / GCE

[0032] The specific operation of the synthesis of MET in S1 is as follows: Dissolve 5.0 g of ZnCl2 in a mixed solvent of 50 mL of ethanol, 75 mL of pure water, 20 mL of 25%-28% ammonia water, and 50 mL of N,N-dimethylformamide. Add 6.26 mL of 1H-1,2,3-triazole to the mixture, stir vigorously at 25 °C for 24 hours, then centrifuge at 9800 rpm to collect the white precipitate, wash it with 9 mL of ethanol, wash it 3 times, and dry it under vacuum at 80 °C to obtain MET.

[0033] The specific operation of the synthesis of NC in S2 is as follows: Heat the MET synthesized in S1 from 25 °C to 900 °C at a heating rate of 5 °C / min under a N2 atmosphere, hold it at 900 °C for 2 h, cool it to 25 °C, and after pyrolysis, obtain NC.

[0034] The specific operation of the synthesis of PdRu / NC in S3 is as follows: Take 20 mg of the NC prepared in S2 and dissolve it in 20 mL of water, then add PdCl2 and RuCl3·H2O with a concentration of 1 mg / mL to the mixed solution; stir the mixture for 12 hours and add 60 mg of NaBH4, then keep stirring for 12 hours, and then centrifuge at 9800 rpm to collect PdRu / NC, wash it with 9 mL of water, wash it 3 times, and dry it under vacuum at 70 °C.

[0035] The specific operation of the synthesis of PdRu / NC / GCE in S4 is as follows: After polishing the GCE on a polishing cloth containing 0.05 μm Al2O3 powder and washing it, dissolve the PdRu / NC material prepared in S3 in ultrapure water, dilute it to a concentration of 2 mg / mL, take 6 μL of the PdRu / NC dispersion and drop it on the GCE, and dry it under infrared light to obtain PdRu / NC / GCE.

[0036] Application of a novel noble metal PdRu / NC / GCE caffeic acid electrochemical sensor: The electrochemical sensor can be used to detect CA in daily foods.

[0037] From Figure 2 (A) and Figure 2 (B), it can be seen that the PdRu / NC / GCE electrochemical sensor prepared in Example 1 has a wide linear range of 1 nM - 100 nM and 100 nM - 15 nM, and the detection limit is as low as 0.19 nM (S / N = 3).

[0038] From Figure 3 It can be seen that the PdRu / NC / GCE electrochemical sensor prepared in Example 1 has strong anti-interference ability, high selectivity (55 μA / μM), and high repeatability.

[0039] Example 2: The difference between this example and Example 1 is that PdCl2 is not added in S3, and the finally prepared electrochemical sensor is Ru / NC / GCE.

[0040] Example 3: The difference between this example and Example 1 is that RuCl3·H2O is not added in S3, and the finally prepared electrochemical sensor is Pd / NC / GCE.

[0041] It can be clearly seen through Figure 4 that the current response effect of the PdRu / NC / GCE electrochemical sensor is better than that of the Ru / NC / GCE prepared in Example 2 and the Pd / NC / GCE prepared in Example 3.

[0042] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A noble metal PdRu / NC / GCE caffeic acid electrochemical sensor, characterized in that: The electrochemical sensor includes a glassy carbon electrode and a noble metal PdRu / NC composite attached to the glassy carbon electrode. The preparation method of the noble metal PdRu / NC / GCE caffeic acid electrochemical sensor includes the following four steps: S1. Synthesis of MET: Dissolve ZnCl2 in a mixed solvent of ethanol, pure water, ammonia water and N,N-dimethylformamide. Add 1H-1,2,3-triazole to the mixture. Under vigorous stirring, stir for 24 hours. Collect the white precipitate by centrifugation, wash with ethanol, and dry in vacuum to obtain MET; S2. Synthesis of NC: Heat the MET synthesized in S1 from 25 °C to 900 °C at a heating rate of 5 °C / min under a N2 atmosphere, keep it at 900 °C for 2 h, cool to 25 °C, and obtain NC after pyrolysis; S3. Synthesis of PdRu / NC; S4. Synthesis of PdRu / NC / GCE.

2. The noble metal PdRu / NC / GCE caffeic acid electrochemical sensor according to claim 1, characterized in that: The specific operation of the synthesis of PdRu / NC in S3 is as follows: Dissolve the NC prepared in S2 in water, then add PdCl2 and RuCl3·H2O to the mixture; stir the mixture for 12 hours and add NaBH4, then keep stirring for 12 hours, and then collect PdRu / NC by centrifugation, wash with water, and dry in vacuum.

3. The noble metal PdRu / NC / GCE caffeic acid electrochemical sensor according to claim 1, characterized in that: The specific operation of the synthesis of PdRu / NC / GCE in S4 is as follows: The GCE is polished on a polishing cloth containing Al2O3 powder and then washed. Dissolve the PdRu / NC material prepared in S3 in ultrapure water, drop the PdRu / NC dispersion on the GCE, and dry it under infrared light to obtain PdRu / NC / GCE.

4. The application of the noble metal PdRu / NC / GCE caffeic acid electrochemical sensor according to claim 1, characterized in that: The electrochemical sensor can be used to detect caffeic acid in daily food.

Images