A zinc modified mesoporous Y-type molecular sieve, an electrochemical sensor and a preparation method and application thereof in detecting the content of acetaminophen

Abstract

The application discloses a preparation method of zinc modified mesoporous Y type molecular sieve, and the preparation method comprises the following steps: using Bola type surfactant [C5H5-N + -(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N + -C5H5]·2[Br ‑ ] as a template agent and cooperating with specific raw material proportion to prepare mesoporous NaY type molecular sieve; ion exchange is carried out on the NaY type molecular sieve by immersing the NaY type molecular sieve in an ammonium salt solution and a zinc salt solution in sequence, drying and calcining to obtain the zinc modified mesoporous Y type molecular sieve. The zinc modified mesoporous Y type molecular sieve prepared by the application has a large specific surface area, a high pore volume and excellent conductivity, the detection range of the electrochemical sensor for detecting the content of acetaminophen in the application is 0.066-10000 micromole / L, the detection limit can reach 0.01 micromole / L, meanwhile, the zinc modified mesoporous Y type molecular sieve has excellent detection sensitivity, stability, reproducibility and selectivity, can realize accurate determination of acetaminophen in drugs, and the electrochemical sensor prepared by the application has the advantages of simple structure, convenient operation, low detection cost and wide application prospect.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of electrochemical sensors, and particularly relates to a zinc-modified mesoporous Y-type molecular sieve, an electrochemical sensor, a preparation method thereof and application thereof in detecting the content of acetaminophen. BACKGROUND

[0002] Acetaminophen (PC) is also known as paracetamol, which is an organic compound (chemical formula C8H9NO2) and a commonly used fever and pain reliever. PC is mainly used for fever caused by common cold or influenza and is also used for relieving mild to moderate pain such as headache, arthralgia, migraine, toothache, muscle pain, neuralgia and menstrual pain. PC is an internationally recognized common medicine that is the safest and most effective for the human body. Although the reasonable use of PC (0.3-0.5 g for an adult once, and no more than 2 g per day) is safe and effective, a small dose of PC cannot reach the minimum dosage for treating the above diseases, which affects the medical effect. Excessive and long-term use of PC can cause serious side effects, and secretory interference substances caused by the drug can affect the endocrine system of the human body. For example, a high dose of PC can cause accumulation of toxic metabolites, leading to liver toxicity or kidney toxicity, and other organ systems such as hearing and brain may also be affected. Therefore, it is of important practical significance for the quality control of PC in various medicines in the pharmaceutical industry to develop a simple operation, high sensitivity and low cost technology for detecting the content of PC in medicines.

[0003] At present, there are many methods for detecting the content of PC, each of which has certain advantages and disadvantages. For example, the common spectrophotometry (UV-Vis) for determining the content of PC has the advantages of simple operation and wide detection range, but has the disadvantages of low accuracy and poor sensitivity. Nuclear magnetic resonance (NMRS) is often used for qualitative analysis of PC and can determine the molecular structure and charge distribution of PC, but cannot be used for quantitative analysis. Liquid chromatography (HPLC) has higher accuracy than the previous methods, but is time-consuming, labor-intensive and expensive. Capillary electrophoresis (HPCE) has the advantages of multiple operation modes and small sample size, but is also time-consuming, labor-intensive and expensive. The above methods not only have high requirements for instruments, but also have cumbersome sample pretreatment, which is not convenient for real-time monitoring.

[0004] An electrochemical sensor can quickly and sensitively detect target information, and directly or indirectly convert the target information into an electrical signal, so as to realize qualitative and quantitative analysis of the target. The electrochemical sensor has the advantages of high sensitivity, simple structure and low price and has good development prospects in the field of analysis and detection. The sensitivity of the electrochemical sensor mainly depends on the performance of the sensitive element. The sensitivity, detection limit and detection range of the electrochemical sensor for detecting PC still need to be improved.

[0005] Y-type mesoporous molecular sieves have good hydrothermal stability, unique pore structure and high specific surface area, making them ideal matrix materials for constructing electrochemical sensors. The detection performance of electrochemical sensors is closely related to the surface area, pore volume and conductivity of the molecular sieve. Templates play a vital role in the synthesis of molecular sieves. They can regulate the specific surface area of ​​the molecular sieve material by regulating the crystallinity and pore structure and size of the molecular sieve. The specific surface area and pore volume of the mesoporous Y-type molecular sieves prepared by the templates used in the prior art are still insufficient, resulting in unsatisfactory detection accuracy and sensitivity in their application in electrochemical sensors for detecting acetaminophen. Summary of the Invention

[0006] The primary purpose of the present invention is to overcome the defects and shortcomings of existing acetaminophen detection technology, such as complex equipment, high detection cost, low detection accuracy and poor detection sensitivity. The present invention provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The method adopts a new template agent and a specific template agent dosage to prepare the Y-type molecular sieve and performs metallic zinc modification on the Y-type molecular sieve, so that the prepared zinc-modified mesoporous Y-type molecular sieve has the characteristics of large specific surface area, high adsorption capacity and good conductivity. When used in an electrochemical sensor for detecting acetaminophen content, it can achieve the effects of high detection accuracy, high detection sensitivity and wide detection range. In addition, the electrochemical sensor prepared by the method has a simple structure, is easy to operate and has low detection cost.

[0007] The second object of the present invention is to provide a zinc-modified mesoporous Y-type molecular sieve.

[0008] A third object of the present invention is to provide an electrochemical sensor.

[0009] A fourth object of the present invention is to provide an application of an electrochemical sensor in detecting acetaminophen content.

[0010] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0011] A method for preparing a zinc-modified mesoporous Y-type molecular sieve comprises the following steps:

[0012] S1. Silica sol, sodium metaaluminate, a pH regulator and a template are mixed in water to obtain an aluminosilicate gel, wherein the template is a Bola-type surfactant [C5H5-N + -(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N + -C5H5]·2[Br - ];

[0013] S2. The aluminosilicate gel obtained in step S1 was heated to react. After the reaction, the product was collected by filtration and washing, and the product was dried and calcined to obtain a mesoporous NaY molecular sieve;

[0014] S3. The mesoporous NaY molecular sieve of step S2 is ion exchanged with an ammonium salt solution to obtain an NH4Y molecular sieve; the NH4Y molecular sieve is ion exchanged with a zinc salt solution. After the reaction, the precipitate is collected, dried, and calcined to obtain a mesoporous ZnY molecular sieve, which is the zinc-modified mesoporous Y molecular sieve;

[0015] Wherein, in step S1, the molar ratio of silica sol, sodium aluminate, pH regulator, template and water is (2-6):(0.5-3):(2-8):(0.06-0.50):(50-250).

[0016] The template agent Bola type surfactant introduced in the present invention is a long-chain amphiphilic bifunctional template agent with a molecular structure of [C5H5-N+-(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N+-C5H5]·2[Br-], recorded as C ph-10-6 The long chains in its structure guide the formation of mesopores, open the pores of the Y-type molecular sieve, shorten the diffusion path of the sample molecules to be detected, and reduce their diffusion resistance. ph-10-6 As a template, Y-type molecular sieves with mesoporous structures can be prepared in one step, greatly increasing the specific surface area and mesopore volume of the Y-type molecular sieve. Furthermore, metallic zinc has good electrical conductivity. Modifying the mesoporous Y-type molecular sieve with metallic zinc can enhance its conductivity, thereby enhancing its electrocatalytic activity as a working electrode in electrochemical sensors.

[0017] The larger the specific surface area of ​​the molecular sieve, the higher the adsorption capacity, which can promote more active sites to participate in the reaction, allowing more target molecules to be rapidly adsorbed in a short period of time, thereby improving the reactivity and selectivity of the molecular sieve. The appropriate ratio of silica sol, sodium metaaluminate, pH adjuster, template agent and water can make the prepared Y-type molecular sieve have a larger specific surface area and adsorption capacity.

[0018] Preferably, in step S1, the molar ratio of silica sol, sodium metaaluminate, pH regulator, template and water is (3-5):(1-2):(3-6):(0.08-0.30):(80-150).

[0019] More preferably, in step S1, the molar ratio of silica sol, sodium metaaluminate, pH adjuster, template and water is 3:1:5:0.15:100.

[0020] Preferably, the pH regulator in the step S1 is at least one of sodium hydroxide, potassium hydroxide, and sodium bicarbonate.

[0021] Preferably, the mixing mode in the step S1 is magnetic stirring, the temperature of the magnetic stirring is 25-50℃, and the time of the magnetic stirring is 2-6h.

[0022] In the preparation of the NaY type molecular sieve, a suitable reaction temperature can make the prepared Y type molecular sieve have a larger specific surface area and adsorption capacity. If the reaction temperature is too high, the crystallization rate of the molecular sieve will be too fast, leading to the generation of impurities. If the reaction temperature is too low, the energy for the growth of the molecular sieve is not enough, and the crystallization rate is too slow, which can lead to the occurrence of amorphous crystallization and the failure to form a mesoporous Y type molecular sieve with good structure.

[0023] Preferably, the reaction temperature in the step S2 is 110-150℃, and the reaction time is 24-48h.

[0024] Preferably, the drying temperature in the step S2 is 80-120℃, and the drying time is 12-24h.

[0025] Preferably, the calcination temperature in the step S2 is 550-600℃, and the calcination time is 5-6h.

[0026] Preferably, the ammonium salt of the ammonium salt solution in the step S3 is at least one of ammonium chloride and ammonium nitrate.

[0027] Preferably, the reaction temperature for the ion exchange between the mesoporous NaY type molecular sieve and the ammonium salt solution in the step S3 is 60-100℃, and the reaction time is 4-6h.

[0028] Preferably, the zinc salt of the zinc salt solution in the step S3 is at least one of zinc chloride and zinc nitrate.

[0029] In the ion exchange process between the NH4Y type molecular sieve and the zinc salt solution, a suitable concentration of the zinc salt solution and a suitable reaction time can make the prepared mesoporous ZnY type molecular sieve have excellent electrical conductivity and maintain a large specific surface area. If the concentration of the zinc salt solution is too high, the molecular sieve channels will be excessively blocked, reducing the specific surface area of the molecular sieve and thus reducing the electrical conductivity of the molecular sieve. If the concentration of the zinc salt solution is too low, the zinc content of the molecular sieve after ion exchange will be too low, and the electrical conductivity will be poor.

[0030] Preferably, the concentration of the zinc salt solution in the step S3 is 0.001-0.1 mol / L.

[0031] More preferably, the concentration of the zinc salt solution in the step S3 is 0.01 mol / L.

[0032] Preferably, the reaction temperature for the ion exchange between the mesoporous NH4Y molecular sieve and the zinc salt solution in step S3 is 60-100°C.

[0033] If the ion exchange time in the zinc salt solution is too long, it will lead to blockage of the molecular sieve pores and a certain etching effect on the molecular sieve surface, which will reduce the specific surface area of ​​the molecular sieve and thus reduce the conductivity of the molecular sieve; if the ion exchange time is too short, the exchange is insufficient, which will lead to too little zinc content in the molecular sieve framework, thereby reducing the conductivity of the molecular sieve.

[0034] Preferably, the time for the ion exchange reaction between the NH4Y molecular sieve and the zinc salt solution in step S3 is 8 to 24 hours.

[0035] Preferably, the drying temperature in step S3 is 80-120° C., and the drying time is 12-24 hours.

[0036] Preferably, the calcination temperature in step S3 is 550-600° C., and the calcination time is 5-6 hours.

[0037] The present invention also protects a zinc-modified mesoporous Y-type molecular sieve, which is prepared by the above preparation method.

[0038] The present invention also protects an electrochemical sensor, which is prepared by the following steps:

[0039] S1. Polishing, washing, and drying the glassy carbon electrode to obtain a pretreated glassy carbon electrode;

[0040] S2. The zinc-modified mesoporous Y-type molecular sieve material is dispersed in a solvent to obtain a zinc-modified Y-type molecular sieve suspension;

[0041] S3. Take the zinc-modified mesoporous Y-type molecular sieve suspension treated in step S2 and drop it onto the pretreated glassy carbon electrode, and air-dry the solvent to obtain the electrochemical sensor.

[0042] Preferably, the solvent in step S2 is at least one of ethanol, propylene glycol, and Nafion solution.

[0043] During the preparation of electrochemical sensors, the appropriate concentration and drop-coating amount of the molecular sieve suspension can ensure excellent detection performance. The concentration of the molecular sieve suspension affects the dispersion of the ZnY molecular sieve on the electrode. If the concentration of the molecular sieve suspension is too high or the drop-coating amount of the molecular sieve suspension is too large, the adsorption sites on the electrode will be saturated, limiting its adsorption and reaction capacity for acetaminophen and reducing the sensor's detection sensitivity. If the concentration of the molecular sieve suspension is too low or the drop-coating amount of the molecular sieve suspension is too small, the adsorption sites on the electrode will be reduced, and the adsorption and reaction capacity for acetaminophen will be weak, thus reducing the detection sensitivity and accuracy of the electrochemical sensor.

[0044] Preferably, the concentration of the zinc-modified Y-type molecular sieve in the suspension is 10-30 mg / mL.

[0045] Preferably, in step S3, the volume of the zinc-modified mesoporous Y-type molecular sieve suspension dropwise coated onto the pretreated glassy carbon electrode is 15 to 25 μL.

[0046] The present invention also protects the use of the electrochemical sensor in detecting the content of acetaminophen.

[0047] Preferably, the application is application in detecting the content of acetaminophen in drugs.

[0048] Compared with the prior art, the present invention has the following beneficial effects:

[0049] (1) The preparation method of the zinc-modified mesoporous Y-type molecular sieve of the present invention adopts a new template agent and matches a specific raw material ratio, so that the prepared zinc-modified mesoporous Y-type molecular sieve has the characteristics of large specific surface area and high adsorption capacity, which can promote more active sites to participate in the reaction, allowing more target molecules to be quickly adsorbed in a short time; improve the catalytic rate of the reaction, and at the same time modify the metal zinc to the mesoporous Y-type molecular sieve, so that the molecular sieve material has excellent conductivity, and increases its electrocatalytic activity of the working electrode in the electrochemical sensor. The total specific surface area of ​​the mesoporous Y-type molecular sieve prepared by the preparation method of the present invention is greater than 500m 2 / g, and the total pore volume is greater than 0.2m 3 / g.

[0050] (2) The present invention utilizes the characteristics of the prepared zinc-modified mesoporous Y-type molecular sieve, such as large specific surface area, high pore volume, and excellent conductivity, to modify a layer of zinc-modified mesoporous Y-type molecular sieve material on the surface of a glassy carbon electrode to construct an electrochemical sensor based on the zinc-modified mesoporous Y-type molecular sieve. The electrochemical sensor prepared by the present invention has a wide linear detection range for detecting acetaminophen, which is 0.066-10000 μmol / L, and a low detection limit of 0.01 μmol / L. It has excellent sensing characteristics such as detection sensitivity, stability, reproducibility, and selectivity, and can achieve accurate determination of acetaminophen in drugs.

[0051] (3) The electrochemical sensor prepared by the present invention is simple to prepare and easy to operate. It can reduce the detection cost when used to detect the content of acetaminophen in drugs and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is the X-ray diffraction pattern of the mesoporous NaY molecular sieve prepared in Example 1.

[0053] Figure 2 This is a field emission scanning electron microscope image of the mesoporous NaY molecular sieve prepared in Example 1.

[0054] The magnification of Figure (a) is 6000 times, and the magnification of Figure (b) is 25000 times.

[0055] Figure 3 This is the nitrogen adsorption-desorption isotherm of the mesoporous NaY molecular sieve prepared in Example 1, and the inset is the BJH pore size distribution diagram of the molecular sieve.

[0056] Figure 4 Cyclic voltammetry curves of the electrochemical sensors prepared in Example 17(a), Example 22(b), and Example 23(c), respectively, in a 0.1 mol / L PBS solution (pH=7) containing 500 μmol / L acetaminophen.

[0057] Figure 5 These are the cyclic voltammetry curves of the electrochemical sensor prepared in Example 17 in 0.1 mol / L PBS solutions containing 500 μmol / L acetaminophen at different pH values.

[0058] Figure 6 Cyclic voltammetry curves of the electrochemical sensor prepared in Example 17 at different scan rates in a 0.1 mol / L PBS (pH=7.0) solution containing 500 μmol / L acetaminophen.

[0059] Figure 7Cyclic voltammograms of the electrochemical sensor prepared in Example 17 in a 0.1 mol / L PBS solution (pH=7) containing 500 μmol / L acetaminophen (a) and in a 0.1 mol / L PBS solution (pH=7) without acetaminophen (b).

[0060] Figure 8 The selectivity of the electrochemical sensor prepared in Example 17 for detecting acetaminophen.

[0061] Figure 9 Reproducibility of the electrochemical sensor prepared in Example 17 for detecting acetaminophen.

[0062] Figure 10 The electrochemical sensor prepared in Example 17 was used to detect the stability of acetaminophen.

[0063] Figure 11 The differential pulse voltammetry curves of the electrochemical sensor prepared in Example 17 in the presence of acetaminophen at different concentrations are shown in the inset. The linear relationship between the square root of the peak current of the differential pulse voltammetry curve and the square root of the corresponding concentration is shown in the inset. DETAILED DESCRIPTION

[0064] In order to more clearly and completely describe the technical solution of the present invention, the present invention is further described in detail through specific embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope of the rights of the present invention.

[0065] The self-made Bola type surfactant [C5H5-N + -(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N + -C5H5]·2[Br - ] can be synthesized by the following method:

[0066] S1. Dissolve 20 mmol of 4,4'-dihydroxybiphenyl in 80 mL of anhydrous ethanol containing 20 mmol of potassium hydroxide. Then, slowly add 100 mmol of 1,10-dibromodecane under a nitrogen atmosphere and reflux at 80°C for 20 h. After cooling to room temperature, filter while hot. Wash the solid sample repeatedly with hot ethanol several times and dry it in a vacuum oven at 50°C for 12 h to obtain BrCH2-(CH2)8CH2-O-(p-C6H4)2-O-CH2(CH2)8-CH2Br, denoted as C ph-10 .

[0067] S2. Add 20mmolC ph-10and 250 mmol of pyridine were dissolved in a mixed solution of acetonitrile and toluene (each 26 mL) in a volume ratio of 1:1, and the product was refluxed at 70°C for 10 h. After the product was cooled to room temperature, it was filtered and washed with ether, and dried in a vacuum oven at 50°C for 12 h to obtain the bolaform surfactant [C5H5-N + -(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N + -C5H5]·2[Br - ] and is denoted as C ph-10-6 .

[0068] The equipment used in the embodiments of the present application is as follows:

[0069] An X-ray diffractometer of D8 Advance type produced by Bruker, Germany, was used to detect the X-ray diffraction pattern of the sample;

[0070] A field emission scanning electron microscope of SU8220 type produced by Hitachi, Japan, was used to characterize the structure of the sample;

[0071] A full-automatic specific surface and porosity analyzer BET of Micromeritics ASAP 2460 type produced by Micromeritics, USA, was used to detect the nitrogen adsorption-desorption isotherm of the sample;

[0072] An electrochemical workstation of CHI660E type produced by Shanghai Chenhua Instrument Co., Ltd. was used to detect the content of acetaminophen.

[0073] The raw material information used in the present application is as follows:

[0074] The acetaminophen standard sample was purchased from Acmec Ltd;

[0075] Compound amphenicol amphetamine tablets were purchased from Enwei Pharmaceutical Co., Ltd;

[0076] Sodium metaaluminate was purchased from Aladdin Biochemical Technology Co., Ltd;

[0077] Zinc chloride was purchased from Meril;

[0078] Phosphate buffer solution (PBS, 0.1 mol / L) with different pH values was prepared by K2HPO4 and KH2PO4 in different proportions;

[0079] All the reagents used in the present application are analytical pure reagents, and the solutions are prepared with deionized water.

[0080] (I) Preparation of zinc-modified mesoporous Y molecular sieve:

[0081] Example 1

[0082] The embodiment provides a preparation method of a zinc-modified mesoporous Y-type molecular sieve, and the specific preparation steps are as follows:

[0083] S1. 0.43 g of a template agent (Bola-type surfactant C ph-10-6 ) is dissolved in 7.27 g of deionized water, 0.80 g of sodium hydroxide, 0.33 g of sodium metaaluminate and 2.45 g of silica sol are sequentially added, and magnetic stirring is carried out at 40℃ for 4 h to obtain an aluminosilicate gel, and the molar ratio of the silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:1:5:0.15:100.

[0084] S2. The aluminosilicate gel obtained in step S1 is transferred into a stainless steel autoclave with a teflon liner, and is reacted at 130℃ for 36 h, and after filtration, the product is washed with deionized water and collected, dried at 80℃ for 12 h, and then calcined at 550℃ for 6 h to obtain a mesoporous NaY-type molecular sieve;

[0085] S3. The mesoporous NaY-type molecular sieve obtained in step S2 is subjected to ion exchange with a 1 mol / L NH4Cl solution under the condition that the solid-liquid ratio is 1:20, the reaction temperature is 80℃, and the reaction time is 4 h, and the above step is repeated three times to obtain a mesoporous NH4Y-type molecular sieve; the mesoporous NH4Y-type molecular sieve is subjected to ion exchange with a 0.01 mol / L ZnCl2 solution under the condition that the solid-liquid ratio is 1:50, the reaction temperature is 80℃, and the reaction time is 24 h, and the precipitate is collected by centrifugal separation, dried at 80℃ for 12 h, and then calcined at 550℃ for 6 h to obtain the zinc-modified mesoporous Y-type molecular sieve;

[0086] In step S3, the solid-liquid ratio of the mesoporous NaY-type molecular sieve to the NH4Cl solution and the solid-liquid ratio of the mesoporous NH4Y-type molecular sieve to the ZnCl2 solution are all the ratio of the mass of the molecular sieve to the volume of the salt solution.

[0087] Figure 1 The X-ray diffraction pattern of the mesoporous NaY-type molecular sieve prepared in step S1 of the embodiment is shown in the following figure. Figure 1 It can be known from the figure that the NaY-type molecular sieve prepared in the embodiment 1 presents the characteristic diffraction peaks of the Y-type molecular sieve in the XRD wide-angle region (2θ is 5°-50°), and presents a primary characteristic diffraction peak in the XRD low-angle region (2θ is 0°-5°), which indicates that the prepared Y-type molecular sieve has a mesoporous structure.

[0088] Figure 2 The electric field emission scanning electron microscope image of the mesoporous NaY-type molecular sieve prepared in step S1 of the embodiment is shown in the following figure. In the figure, (a) is a 6000-fold magnification, and (b) is a 25000-fold magnification. Figure 2It can be seen that the structure of the NaY molecular sieve prepared in Example 1 is the same as that of the traditional Y molecular sieve, showing a typical octahedral shape, uniform particle size, and a significantly open pore structure. The surface is rough, which increases the specific surface area of ​​the Y molecular sieve and is beneficial to improving the catalytic rate of the reaction.

[0089] Figure 3 The nitrogen adsorption and desorption isotherms of the mesoporous NaY molecular sieve prepared in step S1 of this embodiment are shown in the figure, and the inset is the BJH pore size distribution diagram of the molecular sieve. Figure 3 It can be seen that the nitrogen adsorption and desorption isotherm of the mesoporous NaY molecular sieve prepared in Example 1 has a hysteresis loop when P / P0>0.5, indicating that the prepared Y-type molecular sieve has a mesoporous structure. From the BJH pore size distribution diagram in the illustration, it can be observed that the sample has a narrow peak around 4nm, indicating that the molecular sieve has a uniform mesopore size. At the same time, the pore structure parameters are summarized based on the test results. The total specific surface area of ​​the molecular sieve reaches 745.6021m 2 / g, and the total pore volume is 0.299402m 3 / g, the high specific surface area and large adsorption capacity make the molecular sieve have highly exposed active sites, which is conducive to the catalytic reaction.

[0090] Example 2

[0091] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that: in step S1, the amount of template added is 0.287 g, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template and water is 3:1:5:0.10:100, and the total specific surface area of ​​the prepared molecular sieve is 633.6722 m 2 / g, and the total pore volume is 0.2238m 3 / g.

[0092] Example 3

[0093] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 5:1:5:0.15:100, and the total specific surface area of ​​the prepared molecular sieve is 708.1537 m 2 / g, and the total pore volume is 0.2624m 3 / g.

[0094] Example 4

[0095] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:2:5:0.15:100, and the total specific surface area of ​​the prepared molecular sieve is 655.3935 m 2 / g, and the total pore volume is 0.2598m 3 / g.

[0096] Example 5

[0097] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:1:4:0.15:100, and the total specific surface area of ​​the prepared molecular sieve is 594.6568 m 2 / g, and the total pore volume is 0.2155m 3 / g.

[0098] Example 6

[0099] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:1:6:0.15:100, and the total specific surface area of ​​the prepared molecular sieve is 723.9345 m 2 / g, and the total pore volume is 0.2813m 3 / g.

[0100] Example 7

[0101] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:1:5:0.15:80, and the total specific surface area of ​​the prepared molecular sieve is 582.1196 m 2 / g, and the total pore volume is 0.2239m 3 / g.

[0102] Example 8

[0103] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 3:1:5:0.15:140, and the total specific surface area of ​​the prepared molecular sieve is 673.6394 m 2 / g, and the total pore volume is 0.2427m 3 / g.

[0104] Example 9

[0105] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that the reaction temperature of the aluminosilicate gel in step S2 is 110°C, and the total specific surface area of ​​the prepared molecular sieve is 689.9564 m 2 / g, and the total pore volume is 0.2466m 3 / g.

[0106] Example 10

[0107] This embodiment provides a method for preparing zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that the reaction temperature of the aluminosilicate gel in step S2 is 150°C. The total specific surface area of ​​the prepared molecular sieve is 713.5821m 2 / g, and the total pore volume is 0.2630m 3 / g.

[0108] Example 11

[0109] This embodiment provides a method for preparing zinc-modified mesoporous Y-type molecular sieves. The preparation process is basically the same as the preparation steps in Example 1, except that the reaction time of the aluminosilicate gel in step S2 is 24 hours. The total specific surface area of ​​the prepared molecular sieve is 612.3885m 2 / g, and the total pore volume is 0.2129m 3 / g.

[0110] Example 12

[0111] This embodiment provides a method for preparing zinc-modified mesoporous Y-type molecular sieves. The preparation process is basically the same as the preparation steps in Example 1, except that the reaction time of the aluminosilicate gel in step S2 is 48 hours. The total specific surface area of ​​the prepared molecular sieve is 676.9159 m 2 / g, and the total pore volume is 0.2418m 3 / g.

[0112] Table 1

[0113]

[0114]

[0115] Example 13

[0116] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is substantially the same as the preparation steps in Example 1, except that the concentration of the zinc salt solution in step S3 is 0.001 mol / L.

[0117] Example 14

[0118] This embodiment provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is substantially the same as the preparation steps in Example 1, except that the concentration of the zinc salt solution in step S3 is 0.1 mol / L.

[0119] Example 15

[0120] This embodiment provides a preparation method of zinc-modified mesoporous Y-type molecular sieve, and its preparation process is basically the same as the preparation steps of Example 1, except that: in step S3, the time for the ion exchange reaction between the NH4Y-type molecular sieve and the zinc salt solution is 8 hours.

[0121] Example 16

[0122] This embodiment provides a method for preparing zinc-modified mesoporous Y-type molecular sieve, and its preparation process is basically the same as the preparation steps of Example 1, except that: in step S3, the time for the ion exchange reaction between the NH4Y-type molecular sieve and the zinc salt solution is 16 hours.

[0123] (2) Preparation of electrochemical sensors:

[0124] Example 17

[0125] This embodiment provides an electrochemical sensor, and the specific preparation steps are as follows:

[0126] S1. Polish a 3 mm diameter glassy carbon electrode with 0.3 μm and 0.05 μm Al2O3 polishing powders. Rinse the surface with deionized water. Then, ultrasonicate in deionized water and anhydrous ethanol for 30 min each. Blow dry at room temperature to obtain a pretreated glassy carbon electrode.

[0127] S2. Take 20 mg of the zinc-modified mesoporous Y-type molecular sieve material obtained in Example 1 and dispersed in 1 mL of ethanol and ultrasonicated for 30 min to obtain a uniformly dispersed molecular sieve suspension having a concentration of 20 mg / mL;

[0128] S3. 20 μL of the molecular sieve suspension is dropped onto the pretreated glassy carbon electrode obtained in step S1, and the ethanol is naturally air-dried at room temperature to obtain the electrochemical sensor based on the zinc-modified mesoporous Y-type molecular sieve.

[0129] Figure 4The cyclic voltammetry curves of the electrochemical sensors prepared in Example 17(a), Example 22(b) and Example 23(c) respectively in a 0.1 mol / L PBS solution (pH=7) containing 500 μmol / L acetaminophen are shown. Figure 5 It can be seen that if the amount of molecular sieve suspension applied is too much, the adsorption sites on the electrode will be saturated and the electrochemical response will not change much; if the amount of molecular sieve suspension applied is too little, there will be fewer adsorption sites on the electrode, and the adsorption and catalytic ability of acetaminophen in the solution will be weak, thereby reducing the detection sensitivity and accuracy of the electrochemical sensor.

[0130] Example 18

[0131] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the zinc-modified mesoporous Y-type molecular sieve material used in step S2 is replaced with the zinc-modified mesoporous Y-type molecular sieve material prepared in Example 13. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 46.35 μA.

[0132] Example 19

[0133] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the zinc-modified mesoporous Y-type molecular sieve material used in step S2 is replaced with the zinc-modified mesoporous Y-type molecular sieve material prepared in Example 14. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 72.59 μA.

[0134] Example 20

[0135] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the zinc-modified mesoporous Y-type molecular sieve material used in step S2 is replaced with the zinc-modified mesoporous Y-type molecular sieve material prepared in Example 15. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 61.28 μA.

[0136] Example 21

[0137] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the zinc-modified mesoporous Y-type molecular sieve material used in step S2 is replaced with the zinc-modified mesoporous Y-type molecular sieve material prepared in Example 16. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 70.52 μA.

[0138] Example 22

[0139] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the volume of the molecular sieve suspension drop-coated on the glassy carbon electrode in step S3 is 25 μL. The electrochemical sensor prepared using this method was tested by cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 70.98 μA.

[0140] Example 23

[0141] This example provides a method for preparing an electrochemical sensor. The preparation process is essentially the same as that of Example 17, except that the volume of the molecular sieve suspension drop-coated on the glassy carbon electrode in step S3 is 15 μL. The electrochemical sensor prepared using this method was tested by cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 43.52 μA.

[0142] Example 24

[0143] This example provides an electrochemical sensor, prepared using a process essentially identical to that of Example 17, except that the concentration of the molecular sieve suspension in step S2 was changed to 10 mg / mL. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 55.69 μA.

[0144] Example 25

[0145] This example provides an electrochemical sensor, prepared using a process essentially identical to that of Example 17, except that the concentration of the molecular sieve suspension in step S2 was changed to 30 mg / mL. The electrochemical sensor prepared using this method was subjected to cyclic voltammetry in a 0.1 mol / L PBS solution (pH 7) containing 500 μmol / L acetaminophen, yielding a detection current of 74.88 μA.

[0146] Table 2

[0147]

[0148] Comparative Example 1

[0149] This comparative example provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that: in step S1, the amount of template added is 0.143 g, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template and water is 3:1:5:0.05:100, and the total specific surface area of ​​the prepared molecular sieve is 498.3656 m 2 / g, with a total volume of 0.1639m 3 / g.

[0150] Comparative Example 2

[0151] This comparative example provides a method for preparing a zinc-modified mesoporous Y-type molecular sieve. The preparation process is basically the same as the preparation steps in Example 1, except that in step S1, the molar ratio of silica sol, sodium metaaluminate, sodium hydroxide, template agent and water is 1:1:5:0.15:100, and the total specific surface area of ​​the prepared molecular sieve is 452.1655 m 2 / g, total volume is 0.1229m 3 / g.

[0152] Performance Testing

[0153] (1) Optimization of acetaminophen content detection conditions

[0154] The test was performed using a three-electrode system of an electrochemical workstation. The electrochemical sensor prepared in Example 17 was used as the working electrode, denoted as a ZnY / GCE electrode, a saturated calomel electrode was used as the reference electrode, and a platinum wire electrode was used as the counter electrode. Cyclic voltammetry was performed in a PBS buffer solution containing acetaminophen to investigate the effects of pH value and scan rate on the acetaminophen current.

[0155] The electrochemical sensor prepared in Example 17 was placed in a 0.1 mol / PBS buffer solution containing 500 μmol / acetaminophen under different pH conditions. The cyclic voltammetry test curves were as follows: Figure 5 As shown;

[0156] Depend on Figure 5It can be seen that during the oxidation process of acetaminophen, the separation of electrons and protons leads to the formation of its oxidation products. When the pH value ranges from 5.8 to 7.0, the potential ranges from 0.42V to 0.31V, and the anodic peak current gradually increases. When the pH value ranges from 7.0 to 8.6, the potential ranges from 0.31V to 0.27V, and the anodic peak current gradually decreases. The peak potential shifts toward negative values ​​throughout the entire process, indicating that protons are involved in the oxidation process of acetaminophen. The results show that in 0.1mol / LPBS (pH=7.0), the oxidation peak of acetaminophen reaches the maximum current response, that is, the optimal pH value used in the detection is 7.0.

[0157] The electrochemical sensor prepared in Example 17 was placed in a 0.1 mol / L PBS (pH = 7.0) solution containing 500 μmol / L acetaminophen. The cyclic voltammetry test curve was as shown in FIG. Figure 6 As shown;

[0158] Depend on Figure 6 As can be seen, as the scan rate changes from 40mV / s to 220mV / s, the anodic and cathodic currents of acetaminophen increase with increasing scan rate. Furthermore, the oxidation peak potential shifts continuously toward the positive direction, while the reduction peak potential shifts toward the negative direction. A potential difference of 0.16V (<0.2V) exists between the oxidation and reduction peaks of acetaminophen. These results indicate that acetaminophen undergoes a quasi-reversible redox process on the ZnY / GCE electrode. Furthermore, a scan rate that is too slow during the experiment results in a longer reaction time, while a scan rate that is too fast results in increased instability during electrode detection. The optimal scan rate selected for this experiment was 100mV / s.

[0159] (2) Electrochemical performance test of electrochemical sensors

[0160] The three-electrode system of the electrochemical workstation was used for testing. The electrochemical sensor prepared in Example 17 was used as the working electrode, the saturated calomel electrode was used as the reference electrode, and the platinum wire electrode was used as the counter electrode. Cyclic voltammetry was performed in a 0.1 mol / L PBS buffer solution (pH = 7) containing acetaminophen and a 0.1 mol / L PBS buffer solution (pH = 7) not containing 500 μmol / L acetaminophen. The initial potential was 0 V, the scan rate was 100 mV / s, and the sampling interval was 0.001 V. The results are shown in FIG. Figure 7 shown.

[0161] Depend on Figure 7As can be seen, in a blank electrolyte solution without acetaminophen, the working electrode exhibited almost no redox peaks. However, after adding 500 μmol / L acetaminophen, a clear redox peak signal appeared at a potential of 0.40 V, demonstrating good electrochemical performance and the reversibility of the reaction.

[0162] (3) Selectivity test of electrochemical sensors

[0163] The three-electrode system of the electrochemical workstation was used for testing. The electrochemical sensor prepared in Example 17 was used as the working electrode, denoted as the ZnY / GCE electrode, the saturated calomel electrode was used as the reference electrode, and the platinum wire electrode was used as the counter electrode. To a 0.1 mol / L PBS buffer solution (pH = 7) containing 500 μmol / L acetaminophen, 50 times the concentration of acetaminophen, Al 3+ 、Co 2+ 、Cu 2+ , K + 、Na + 、Ti 4+ and Zn 2+ The solution was subjected to cyclic voltammetry test to compare the electrochemical response of these interfering substances with that of acetaminophen solution to verify the selectivity of the ZnY / GCE electrode. The test results are as follows: Figure 8 shown.

[0164] Depend on Figure 8 It can be seen that the electrochemical responses of these interfering substances are very weak compared with the electrochemical response of acetaminophen solution, and the detection sensitivity of the modified electrode is much higher than that of the tested interfering substances, indicating that the prepared sensor has good selectivity.

[0165] (4) Reproducibility test of electrochemical sensors

[0166] The electrochemical sensor prepared in Example 17 was used as the working electrode, denoted as the ZnY / GCE electrode, a saturated calomel electrode as the reference electrode, and a platinum wire electrode as the counter electrode. In a 0.1 mol / L PBS buffer solution (pH = 7) containing 500 μmol / L acetaminophen, the acetaminophen solution was measured multiple times at different times using the same ZnY / GCE electrode and the volt-ampere value was recorded to verify the reproducibility of the modified electrode. The test results are shown in Figure 2. Figure 9 shown.

[0167] Depend on Figure 9 It can be seen that the difference between the current values ​​measured 8 times is small, indicating that the ZnY / GCE electrode has good reproducibility.

[0168] (5) Stability test of electrochemical sensors

[0169] The three-electrode system of the electrochemical workstation was used for the test. The electrochemical sensor prepared in Example 17 was used as the working electrode, denoted as the ZnY / GCE electrode, the saturated calomel electrode was used as the reference electrode, and the platinum wire electrode was used as the counter electrode. - 3 mol / L Fe(CN)6 3- / 4- and 0.1 mol / L KCl solution, 100 segments were scanned at a scan rate of 100 mV / s, and the stability of the sensor was tested by cyclic voltammetry. The test results are as follows: Figure 10 shown.

[0170] Depend on Figure 10 It can be seen that after multiple cycles of scanning, the CV curve of the sensor remains basically unchanged, indicating that the prepared sensor has good stability.

[0171] (6) Detection of acetaminophen standard solutions with different concentrations

[0172] The three-electrode system of the electrochemical workstation was used for testing. The electrochemical sensor prepared in Example 17 was used as the working electrode, denoted as the ZnY / GCE electrode, the saturated calomel electrode was used as the reference electrode, and the platinum wire electrode was used as the counter electrode. Differential pulse voltammetry was used to detect 0.1 mol / L PBS solutions containing different concentrations of acetaminophen. The initial potential was 0 V, the potential increment was 0.004 V, the amplitude was 0.025 V, the pulse width was 50 ms, and the pulse period was 200 ms. The test results are shown in FIG. Figure 11 shown.

[0173] Depend on Figure 11 It can be seen that in the potential range of 0 to 0.7 V, the dotted line is the oxidation peak formed by the blank background curve of the ZnY / GCE electrode. When the concentration of PC is increased from 6.6×10 -8 mol / L~1.0×10 -2 mol / L, the peak current increases with the increase of acetaminophen concentration. The illustration shows the linear relationship between the peak current and the square root of the corresponding concentration, R 2 =0.9995. The results show that the ZnY / GCE electrode has a wide detection range and a very low detection limit, with a detection range of 6.6×10 -8 mol / L~1.0×10 -2 mol / L, and the detection limit was 0.01μmol / L.

[0174] (7) Detection of acetaminophen content in drugs

[0175] The three-electrode system of the electrochemical workstation was used for the test, the electrochemical sensor prepared by the example 17 was used as the working electrode, recorded as ZnY / GCE electrode, saturated calomel electrode was used as the reference electrode, platinum wire electrode was used as the counter electrode, the solution prepared by the medicine compound paracetamol and amantadine tablet was used to replace the standard solution of paracetamol for the detection by the differential pulse voltammetry, and the test results were shown in table 3.

[0176] From table 3, the recovery rate of the detection was between 96.8% and 101.6% when the solution was tested four times in parallel, and the relative standard deviation RSD was 2.1%, which indicated that the repeatability of the ZnY / GCE electrode for determining the content of paracetamol in the actual medicine was higher.

[0177] Table 3

[0178]

[0179]

[0180] Obviously, the above examples of the present application are only examples for clearly illustrating the present application, and are not the limitation to the embodiments of the present application. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for preparing a zinc-modified mesoporous Y-type molecular sieve, characterized in that: The following steps are involved: S1. Silica sol, sodium metaaluminate, a pH regulator and a template are mixed in water to obtain an aluminosilicate gel, wherein the template is a Bola-type surfactant [C5H5-N + -(CH2) 10 -O-(p-C6H4)2-O-(CH2) 10 -N + -C5H5]·2[Br - ]; S2. The aluminosilicate gel obtained in step S1 was heated to react. After the reaction, the product was collected by filtration and washing, and the product was dried and calcined to obtain a mesoporous NaY molecular sieve; S3. The mesoporous NaY molecular sieve of step S2 is ion exchanged with an ammonium salt solution to obtain an NH4Y molecular sieve; the NH4Y molecular sieve is ion exchanged with a zinc salt solution. After the reaction, the precipitate is collected, dried, and calcined to obtain a mesoporous ZnY molecular sieve, which is the zinc-modified mesoporous Y molecular sieve; Wherein, in step S1, the molar ratio of silica sol, sodium aluminate, pH regulator, template and water is (2-6):(0.5-3):(2-8):(0.06-0.50):(50-250).

2. The method for preparing the zinc-modified mesoporous Y-type molecular sieve according to claim 1, characterized in that: In the step S1, the molar ratio of silica sol, sodium aluminate, pH regulator, template and water is (3-5):(1-2):(3-6):(0.08-0.30):(80-150).

3. The method for preparing the zinc-modified mesoporous Y-type molecular sieve according to claim 1, characterized in that: The reaction temperature in step S2 is 110-150°C.

4. The method for preparing the zinc-modified mesoporous Y-type molecular sieve according to claim 1, characterized in that: The concentration of the zinc salt solution in step S3 is 0.001-0.1 mol / L.

5. The method for preparing the zinc-modified mesoporous Y-type molecular sieve according to claim 1, characterized in that: In step S3, the time for the ion exchange reaction between the NH4Y molecular sieve and the zinc salt solution is 4 to 24 hours.

6. A zinc-modified mesoporous Y-type molecular sieve, characterized in that: The compound is prepared by the preparation method according to any one of claims 1 to 5.

7. An electrochemical sensor, characterized in that Prepared by the following steps: S1. Polishing, washing, and drying the glassy carbon electrode to obtain a pretreated glassy carbon electrode; S2. The zinc-modified mesoporous Y-type molecular sieve material according to claim 6 is dispersed in a solvent to obtain a zinc-modified Y-type molecular sieve suspension; S3. Take the zinc-modified mesoporous Y-type molecular sieve suspension treated in step S2 and drop it onto the pretreated glassy carbon electrode, and air-dry the solvent to obtain the electrochemical sensor.

8. The electrochemical sensor according to claim 7, characterized in that The concentration of the zinc-modified Y-type molecular sieve in the suspension is 10-30 mg / mL.

9. The electrochemical sensor according to claim 7, characterized in that: In step S3, the volume of the zinc-modified mesoporous Y-type molecular sieve suspension dropwise coated on the pretreated glassy carbon electrode is 15 to 25 μL.

10. Use of the electrochemical sensor according to any one of claims 7 to 9 in detecting acetaminophen content.

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