阅读说明：本技术 一种用于检测双酚a的电化学传感器及其制备方法和应用 (Electrochemical sensor for detecting bisphenol A and preparation method and application thereof ) 是由 朱明山 李志� 胡佳月 查庆兵 于 2020-07-14 设计创作，主要内容包括：本发明属于传感器技术领域,具体公开了一种用于检测双酚A的电化学传感器及其制备方法和应用。所述方法包括以下步骤：取前驱体MIL-100(Fe)分散于乙醇水溶液中,再加入CTAB和Nafion溶液,混合均匀后得到悬浊液,将悬浊液涂在导电基底表面,常温下晾干,得到这种新型的电化学传感器。本发明是以铁的金属有机框架MIL-100(Fe)为基底,将CTAB修饰在MIL-100(Fe)上的电化学传感器,以增强电极吸附BPA和电子输运的能力,从而提高电化学传感器的电催化活性。通过优化沉积电位、沉积时间和pH值,使双酚A的检出限可以达到2×10<Sup>-8</Sup>mol/L。(The invention belongs to the technical field of sensors, and particularly discloses an electrochemical sensor for detecting bisphenol A and a preparation method and application thereof. The method comprises the following steps: and (2) dispersing a precursor MIL-100(Fe) in an ethanol aqueous solution, adding a CTAB (cetyl trimethyl ammonium bromide) solution and a Nafion solution, uniformly mixing to obtain a suspension, coating the suspension on the surface of a conductive substrate, and airing at normal temperature to obtain the novel electrochemical sensor. The electrochemical sensor is an electrochemical sensor which takes an iron metal organic framework MIL-100(Fe) as a substrate and modifies CTAB on the MIL-100(Fe) so as to enhance the BPA adsorption and electron transport capacity of the electrode and improve the electrocatalytic activity of the electrochemical sensor. By optimizing the deposition potential, deposition time and pH value, the detection limit of bisphenol A can reach 2 x 10 ‑8 mol/L。)

1. A preparation method of an electrochemical sensor for detecting bisphenol A is characterized by comprising the following steps:

dispersing metal organic framework MIL-100(Fe) in an ethanol water solution, adding CTAB and Nafion solution, mixing uniformly to obtain a suspension, coating the suspension on the surface of a conductive substrate, and drying to obtain the electrochemical sensor for detecting bisphenol A.

2. The method of claim 1, wherein:

the concentration of the MIL-100(Fe) in the ethanol water solution is 0.2-0.6 mg/mL;

the concentration of CTAB in the ethanol water solution is 0.2-0.8 mg/mL.

3. The method of claim 1, wherein:

the concentration of the MIL-100(Fe) in the ethanol water solution is 0.48 mg/mL;

the concentration of CTAB in the ethanol water solution is 0.4 mg/mL.

4. The production method according to claim 1, 2 or 3, characterized in that:

The volume ratio of ethanol to water in the ethanol water solution is 1-4: 1-4;

the dosage of the Nafion solution meets the condition that 5-10 mu L of Nafion solution is correspondingly added into each 1mL of ethanol water solution; the concentration of the Nafion solution is 4-6 wt%.

5. The method of claim 1, wherein the MIL-100(Fe) is prepared by the method comprising:

mixing Fe³⁺Dissolving salt and benzene tricarboxylic acid in water, uniformly mixing the obtained solution, heating the obtained mixed solution for reaction, cooling a product after the reaction is finished, and purifying to obtain a precursor, namely an iron metal organic framework, namely MIL-100 (Fe).

6. The method of claim 5, wherein:

the molar ratio of the ferric nitrate to the benzene tricarboxylic acid is 0.8-2.0: 0.4 to 1.8;

the molar volume ratio of the ferric nitrate to the water is 0.8-1.2 mmol: 3-7 mL.

7. The method of claim 5, wherein:

the heating reaction is carried out at the temperature of 120-240 ℃ for 6-18 h.

8. The production method according to claim 1, 2 or 3, characterized in that:

the suspension is 25-50 mu L/cm²The amount of the coating is coated on the surface of the conductive substrate;

the conductive substrate is a glassy carbon electrode, a carbon rod electrode or a titanium electrode.

9. An electrochemical sensor for detecting bisphenol A, prepared by the method of any one of claims 1 to 8.

10. Use of the electrochemical sensor for detecting bisphenol a according to claim 9 for detecting bisphenol a.

Technical Field

The invention belongs to the technical field of sensors, and particularly relates to an electrochemical sensor for detecting bisphenol A, and a preparation method and application thereof.

Background

Bisphenol A (BPA) is an organic chemical raw material, which is commonly used for food packaging and containers, and for the production of electronic products. Bisphenol A has a certain embryotoxicity, which causes the damage of immune function and increases the risk of cancer, and has strong toxicity to aquatic organisms. Therefore, a fast, sensitive, and accurate method for detecting bisphenol a is needed for food safety, environmental monitoring, and toxicity evaluation. Electrochemical sensing technology has been widely used for detecting environmental pollutants and biomolecules due to its high sensitivity, easy operation, portability and miniaturization. While the electrochemical sensor also shows satisfactory results in the detection of actual samples. The working electrode is used as the core of the electrochemical sensor and determines the performance of the sensor, the strength, the sensitivity, the stability, the detection limit and the like of an electrochemical signal. Therefore, how to improve the performance of the bisphenol A electrochemical sensor lies in regulating and controlling the interface design between the bisphenol A and the electrode and constructing efficient electron transmission.

Disclosure of Invention

In order to overcome the disadvantages and shortcomings of the prior art, the present invention provides a method for preparing an electrochemical sensor for detecting bisphenol a.

The invention also aims to provide the electrochemical sensor for detecting the bisphenol A, which is prepared by the method.

It is still another object of the present invention to provide an electrochemical sensor for detecting bisphenol a, which is useful for detecting bisphenol a.

The purpose of the invention is realized by the following scheme:

a preparation method of an electrochemical sensor for detecting bisphenol A comprises the following steps:

dispersing metal organic framework MIL-100(Fe) in an ethanol water solution, adding CTAB and Nafion solution, mixing uniformly to obtain a suspension, coating the suspension on the surface of a conductive substrate, and drying to obtain the electrochemical sensor for detecting bisphenol A.

Preferably, the MIL-100(Fe) is prepared by the following method:

mixing Fe³⁺Dissolving salt and benzene tricarboxylic acid in water, uniformly mixing the obtained solution, heating the obtained mixed solution for reaction, and cooling the product after the reaction is finishedAnd purifying to obtain a precursor, namely an iron metal organic framework, namely MIL-100 (Fe).

Wherein, the Fe ³⁺Is at least one of ferric nitrate, ferric chloride, ferric sulfate and the like.

The molar ratio of the ferric nitrate to the benzene tricarboxylic acid is 0.8-2.0: 0.4 to 1.8, preferably 1.0 to 1.4: 0.8 to 1.2; more preferably 1.2: 1.0.

The molar volume ratio of the ferric nitrate to the water is 0.8-1.2 mmol: 3-7 mL; more preferably 1.2 mmol: 5 mL.

The heating reaction is carried out at the temperature of 120-240 ℃ for 6-18 h; more preferably, the temperature is 160-200 ℃, and the time is 10-14 h; most preferably, the temperature is 180 ℃ and the time is 12 h. The purification is to centrifuge, wash and dry the cooled product.

In the preparation method of the electrochemical sensor for detecting bisphenol A,

the concentration of the MIL-100(Fe) in the ethanol water solution is 0.2-0.6 mg/mL, and preferably 0.48 mg/mL. The volume ratio of ethanol to water in the ethanol water solution is 1-4: 1-4, preferably 1-2: 1 to 2. The concentration of CTAB in the ethanol water solution is 0.2-0.8 mg/mL; preferably 0.4 mg/mL;

the dosage of the Nafion solution meets the requirement that 5-10 mu L of Nafion solution is correspondingly added into each 1mL of ethanol water solution. The concentration of the Nafion solution is 4-6 wt%; preferably 5 wt%.

The suspension is 25-50 mu L/cm ²The amount of the coating is coated on the surface of the conductive substrate; the conductive substrate is a glassy carbon electrode, a carbon rod electrode or a titanium electrode and the like.

An electrochemical sensor for detecting bisphenol A is prepared by the method.

The application of the electrochemical sensor for detecting bisphenol A in detecting bisphenol A. Preferably, the method is applied to detection of bisphenol A in dust of electronic waste dump.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the electrochemical sensor is an electrochemical sensor which takes an iron metal organic framework MIL-100(Fe) as a substrate and modifies CTAB on the MIL-100(Fe) so as to enhance the BPA adsorption and electron transport capacity of the electrode and improve the electrocatalytic activity of the electrochemical sensor.

(2) The invention introduces CTAB which is a cationic surfactant, and utilizes the hydrophobic effect of long-chain alkane to adsorb bisphenol A; meanwhile, the MIL-100(Fe) is a porous material with a large surface area, and provides a large number of attachment sites for a CTAB molecular layer, so that the adsorption and enrichment capacity of the hydrophobic end of the CTAB long-chain alkane on the BPA is fully exerted.

(3) The invention optimizes the deposition potential, deposition time and pH value to ensure that the detection limit of bisphenol A can reach 2 multiplied by 10 ^-8mol/L。

Drawings

FIG. 1 shows the preparation of the CTAB/MIL-100(Fe) electrochemical sensor of example 1.

FIG. 2 is a TEM morphology of MIL-100(Fe) prepared in example 1.

FIG. 3 shows the results of the assay of MIL-100(Fe) in example 1 with and without CTAB in a pH 7, 0.1mol/L phosphate buffer at 2X 10^-5Differential pulse voltammetry curve of mol/L bisphenol A.

FIG. 4 shows CTAB/MIL-100(Fe) as an electrochemical sensor in example 1, detected by differential pulse method at 2X 10 in 0.1mol/L phosphate buffer solution with different pH values^-5Results of mol/L bisphenol A.

FIG. 5 shows CTAB/MIL-100(Fe) as an electrochemical sensor in example 1, detected by differential pulse method at different deposition potentials in 0.1mol/L pH 7 phosphate buffer at 2X 10^-5Results of mol/L bisphenol A.

FIG. 6 shows CTAB/MIL-100(Fe) as an electrochemical sensor in example 1, detected by differential pulse method at different deposition times in 0.1mol/L phosphate buffer at pH 7^-5Results of mol/L bisphenol A.

FIG. 7 is a differential pulse voltammetry curve showing the limit of detection of bisphenol A in 0.1mol/L phosphate buffer at pH 7 with CTAB/MIL-100(Fe) as an electrochemical sensor in example 1.

FIG. 8 shows the application of the CTAB/MIL-100(Fe) electrochemical sensor in the detection of electronic garbage dust samples in example 1.

Detailed Description

The present invention will be described in further detail with reference to examples and drawings, but the embodiments of the present invention are not limited thereto.