Preparation method of snowflake-shaped PdCu nano material for detecting chloramphenicol

Abstract

The invention discloses a preparation method of a snowflake-shaped PdCu nano material for detecting chloramphenicol, and the snowflake-shaped PdCu nano material is prepared by adopting palladium chloride hydrate (PdCl2. XH2O) and copper chloride dehydrate (CuCl2. 2H2O) as metal precursors, phloroglucinol as a reducing agent and oleylamine and octadecene as a mixed solvent through a one-pot method. The preparation method disclosed by the invention is simple, low in energy consumption and small in environmental harm; the prepared snowflake-shaped PdCu nano material can be used as an electrochemical sensor, can realize rapid, sensitive and high-selectivity detection on chloramphenicol, and has a potential application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of electrochemical analysis, and particularly relates to a preparation method of snowflake-shaped PdCu nanomaterials for detecting chloramphenicol. Background Art

[0002] Antibiotics are used to treat and prevent bacterial infections in humans and animals. However, the improper use and disposal of antibiotics can have a negative impact on the ecological environment. The World Health Organization (WHO) stated in a declaration that "there is an urgent global need to change the way antibiotics are prescribed and used", which clearly indicates that in order to minimize the problem of antibiotic resistance, it is necessary to use antibiotics correctly, and antibiotic resistance is a major threat to global public health. The accumulation of antibiotics in food and water has also raised growing concerns about food and environmental safety, prompting researchers to develop more efficient methods to analyze residual antibiotics in food and water samples. Chloramphenicol (CAP) is a broad-spectrum antibiotic effective against both Gram-negative and Gram-positive bacteria. It is used to prevent infection of small wounds and can also treat a variety of diseases, including cystic fibrosis, conjunctivitis, cholera, typhoid, plague, and ear and skin infections. Chloramphenicol is also widely used in aquaculture and veterinary medicine. However, chloramphenicol can cause some serious side effects in humans, including aplastic anemia, leukemia, neurotoxic reactions, gray baby syndrome, bone marrow suppression, and allergic reactions. Therefore, the European Union (EU) and many other countries have prohibited the use of chloramphenicol for the treatment of food animals. However, due to its high efficacy, relatively low cost, and easy availability, chloramphenicol is still widely used in developing countries. It is also used to treat and prevent some infectious diseases in bees, birds, and aquaculture. In addition, studies have shown that animal-derived products may contain residual chloramphenicol due to the natural presence of chloramphenicol in the plant materials consumed by animals. For these reasons, accurate and sensitive chloramphenicol detection and analysis methods are needed. Among different detection techniques, electrochemical methods have the advantages of high accuracy, miniaturization, strong practicability, wide analysis range, low cost, fast response, and relatively simple operation, making them more suitable for the routine monitoring of chloramphenicol.

[0003] Currently, the methods for chloramphenicol detection mainly include microbiological method, high performance liquid chromatography, chemiluminescent enzyme immunoassay, etc. However, most of these detection methods have problems such as high cost, complex operation, and long detection time, and cannot well meet the requirements of on-site rapid detection. In this context, it has great practical significance and application value to use snowflake-shaped PdCu nanomaterials for the ultrasensitive electrochemical detection of chloramphenicol. Summary of the Invention

[0004] In view of the technical problems existing in the current traditional detection of chloramphenicol, such as low detection sensitivity and high development cost, the present invention provides a method for preparing snowflake-shaped PdCu nanomaterials for ultrasensitive detection of chloramphenicol, which has the advantages of high sensitivity, simple operation, low cost, short time consumption, low detection limit, and small dosage, and can stand out among numerous methods for detecting chloramphenicol.

[0005] To achieve the above object, the present invention adopts the following technical solutions: A method for preparing snowflake-shaped PdCu nanomaterials, comprising the following steps: Step 1, mix palladium chloride hydrate, copper chloride dihydrate, phloroglucinol anhydrous, oleylamine and octadecene, and ultrasonicate the mixture; Step 2, heat the sample obtained by ultrasonication in Step 1 under oil bath for reflux, and then cool it naturally; Step 3, centrifuge the solution cooled in Step 2, then wash it with cyclohexane and absolute ethanol, and dry it to obtain snowflake-shaped PdCu nanomaterials.

[0006] Furthermore, in Step 1, the dosage ratio of palladium chloride hydrate, copper chloride dihydrate, phloroglucinol anhydrous, oleylamine and octadecene is 0.05 mmol: 0.025 mmol: 0.1 mmol: 4 mL: 1 mL.

[0007] Furthermore, in Step 2, the temperature of the oil bath is 210 °C and the time is 5 h.

[0008] Furthermore, in Step 3, the conditions for centrifugal separation are 8000 rpm / min, and the volume ratio of cyclohexane to absolute ethanol is 1:1.

[0009] Application of the snowflake-shaped PdCu nanomaterials prepared by the above method in the detection of chloramphenicol.

[0010] In an embodiment of the present invention, the above snowflake-shaped PdCu nanomaterials are used as an electrochemical sensor for highly sensitive detection of chloramphenicol.

[0011] Furthermore, the application includes the following steps: Step 1, weigh the snowflake-shaped PdCu nanomaterials ground into fine powder, add them to a mixed solution of absolute ethanol, deionized water and Nafion to prepare a suspension of 5 mg / mL; The dosage ratio of snowflake-shaped PdCu nanomaterials, absolute ethanol, deionized water and Nafion is 5 mg: 800 μL: 150 μL: 50 μL; Step 2, take 25 μL of the suspension and modify it on the polished glassy carbon electrode, and irradiate it under an infrared lamp for 5 min to prepare an electrochemical sensor for detecting chloramphenicol; Step 3: Using cyclic voltammetry, with the electrochemical sensor prepared in Step 2 as the working electrode, a platinum wire as the counter electrode, and a saturated calomel electrode as the reference electrode, set the electrochemical CV detection parameters as follows: starting potential -0.4 V, ending potential +0.3 V, rest time 2 s. The chloramphenicol sample is configured in a 0.1 M PBS (pH = 3) buffer solution to detect the chloramphenicol sample to be measured.

[0012] The snowflake-like PdCu nanomaterial of the present invention is prepared using palladium chloride hydrate (PdCl2·XH2O) and copper chloride dihydrate (CuCl2·2H2O) as metal precursors, phloroglucinol as a reducing agent, and oleylamine and octadecene as a mixed solvent. This snowflake-like PdCu nanomaterial enables the modified electrode to have a large electrochemically active specific surface area, a fast mass transfer rate during the electrochemical process, can improve the reaction activity, and thus can catalyze the process of the chloramphenicol oxidation reaction. Beneficial effects

[0013] The present invention provides a preparation method of a snowflake-like PdCu nanomaterial for ultrasensitive detection of chloramphenicol. Compared with the prior art, it has the following beneficial effects: 1. The present invention uses simple and easily available raw materials, low cost, and low energy consumption to prepare a composite material with good conductivity and a large specific surface area, which can be applied to the electrochemical sensing of chloramphenicol.

[0014] 2. The present invention has a relatively wide linear range of 0.1 - 180 μM when detecting chloramphenicol.

[0015] 3. The present invention has a low detection limit of 0.05 μM when detecting chloramphenicol. Description of the drawings

[0016] Figure 1 It is the SEM image of the snowflake-like PdCu nanomaterial of the present invention.

[0017] Figure 2 It is the DPV graph of the snowflake-like PdCu nanomaterial of the present invention as a modified electrode for detecting chloramphenicol at different concentrations. Detailed implementation manners

[0018] The preferred implementation manners of the present invention will be described in detail below in conjunction with the embodiments. It should be understood that the following embodiments are given only for the purpose of illustration and are not used to limit the scope of the present invention. Those skilled in the art can make various modifications and substitutions to the present invention without departing from the purpose and spirit of the present invention.

[0019] The experimental methods used in the following embodiments are all conventional methods unless otherwise specified.

[0020] The materials, reagents, etc. used in the following examples can be obtained from commercial sources without special instructions.

[0021] The reaction initial substances used in the following examples of the present invention are commercially available palladium chloride hydrate (PdCl2·XH2O), copper chloride dihydrate (CuCl2·2H2O), phloroglucinol, oleylamine, octadecene, etc. The electrolyte in the electrochemical performance test is a CAP solution of 0.1 M PBS (pH = 3), and the above experiments are all carried out at room temperature.

[0022] In the following examples, a scanning electron microscope (SEM) was used to observe the morphology of the prepared multi-channel PdCu nanomaterials. The electrochemical performance test was carried out using a Shanghai Chenhua CHI660E electrochemical workstation, and the electrolyte was a solution of 0.1 M PBS (pH = 3). Example 1

[0023] A preparation method of snowflake-shaped PdCu nanomaterials includes the following steps: Step 1, preparation of materials: First, add 0.05 mmol PdCl2·XH2O, 0.025 mmol CuCl2·2H2O, 0.1 mmol anhydrous phloroglucinol, 4 mL oleylamine, and 1 mL octadecene into a 30 mL round-bottom flask, and ultrasonicate for 30 min with an ultrasonic instrument; Step 2, put the ultrasonically treated sample in step 1 into an oil bath, heat and reflux with a 210 °C oil bath and then cool naturally, and react in the oil bath for 5 h; Step 3, the cooled solution in step 2 is centrifuged quickly at 8000 rpm / min for three times for 10 min, washed 3 times with cyclohexane and absolute ethanol (volume ratio 1:1), and then dried in a 70 °C vacuum drying oven for 12 h to obtain snowflake-shaped PdCu nanomaterials.

[0024] The snowflake-shaped PdCu nanomaterials were characterized by a scanning electron microscope (SEM). As Figure 1 shown, the morphology of the material is snowflake-shaped and its distribution is relatively uniform. The diameter of each snowflake cluster is about 400 nm. Example 2

[0025] Electrochemical sensing of chloramphenicol: The prepared snowflake-shaped PdCu nanomaterials were used as sensors in the electrochemical detection of chloramphenicol. The specific experimental steps are as follows: Step 1, accurately weigh 5 mg of the snowflake-shaped PdCu nanomaterials prepared in Example 1 and ground into fine powder, add them to a mixed solution of 800 μL absolute ethanol, 150 μL deionized water, and 50 μL Nafion, and ultrasonicate for 30 min to disperse the materials evenly to prepare a 5 mg / mL suspension; Step 2: Use a pipette with a volume range of 50 μL to take 25 μL of the suspension in five times with 5 μL each time and modify it onto the polished glassy carbon electrode, and irradiate it under an infrared lamp for 5 min to prepare a supersensitive electrochemical sensor for detecting chloramphenicol.

[0026] Differential pulse voltammetry (DPV) is used for the linear detection of chloramphenicol. It consists of a three-electrode system composed of a working electrode (the glassy carbon electrode modified with the material), a counter electrode (platinum wire), and a reference electrode (saturated calomel electrode). Prepare a series of CAP solutions with a concentration of 0.1 M PBS (pH = 3) with a total volume of 10 mL, and set the electrochemical CV detection parameters: starting potential -0.4 V, ending potential +0.3 V, and resting time 2 s to obtain the working curve, as Figure 2 shown. The snowflake-like PdCu nanomaterial of the present invention is used for detecting chloramphenicol, with a linear range of 0.1 - 180 μM and a lowest detection limit of up to 0.05 μM.

Claims

1. A method for preparing a snowflake-like PdCu nanomaterial, characterized in that, It includes the following steps: Step 1: Mix palladium chloride hydrate, copper chloride dihydrate, phloroglucinol anhydrous, oleylamine, and octadecene, and ultrasonicate the mixture. Step 2: Heat the sample obtained in Step 1 under oil bath reflux and then cool it naturally. Step 3: Centrifuge the solution cooled in Step 2, then wash it with cyclohexane and absolute ethanol, and dry it to obtain snowflake-like PdCu nanomaterials.

2. The preparation method of the snowflake-shaped PdCu nanomaterial according to claim 1, characterized in that, In Step 1, the dosage ratio of palladium chloride hydrate, copper chloride dihydrate, phloroglucinol anhydrous, oleylamine, and octadecene is 0.05 mmol: 0.025 mmol: 0.1 mmol: 4 mL: 1 mL.

3. The preparation method of the snowflake-shaped PdCu nanomaterial according to claim 1, characterized in that, In Step 2, the temperature of the oil bath is 210 °C and the time is 5 h.

4. The preparation method of the snowflake-like PdCu nanomaterial according to claim 1, characterized in that, In Step 3, the conditions for centrifugation are 8000 rpm / min, and the volume ratio of cyclohexane to absolute ethanol is 1:

1.

5. Application of the snowflake-like PdCu nanomaterials prepared by the preparation method according to any one of claims 1 to 4 in detecting chloramphenicol.

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