Electrochemical sensor for high-sensitivity detection of niclosamide and preparation method

Abstract

The invention belongs to the field of electrochemical sensors, and relates to an electrochemical sensor for high-sensitivity detection of niclosamide and a preparation method. The surface of a glassy carbon electrode (GCE) is modified with an SMMS / WCT / SCCB nano composite material prepared from monodisperse star-shaped mesoporous silica nano microspheres, superconductive carbon black and high-purity whisker carbon nanotubes, and an SMMS / WCT / SCCB / GCE working electrode is formed. The preparation method comprises the following steps: firstly, uniformly dispersing SCCB and WCT which are equal in mass in an N, N-dimethylformamide solution through magnetic stirring in an ultrasonic environment; then, adding SMMS into the solution, and carrying out ultrasonic dispersion to obtain a uniformly mixed black SMMS (at) WCT (at) SCCB turbid liquid; and finally, dispensing the SMMS-coated WCT-coated SCCB mixture uniform suspension onto the surface of the GCE, and drying under an infrared lamp to prepare the working electrode SMMS-coated WCT-coated SCCB / GCE modified by the SMMS-coated WCT-coated SCCB nano composite material. Based on the synergistic interaction effect generated by SMMS, WCT and SCCB, the SMMS / WCT / SCCB / GCE sensor is high in sensitivity, the detection limit can reach 10.44 nM, and the niclosamide sensing detection performance is excellent.

Description

Technical Field

[0001] The invention belongs to the field of electrochemical sensors and relates to an electrochemical sensor for high-sensitivity detection of niclosamide and a preparation method thereof. Background Art

[0002] Niclosamide is a salicylamide derivative that can act as an eel killer and molluscicide, and also has a killing effect on Oncomelania snails and Schistosoma japonicum cercariae. The substance has a good killing effect on many types of snails, beef tapeworms, pork tapeworms, fish tapeworms, broad-segmented tapeworms, short-segmented tapeworms, cercariae, etc. In the agricultural field, the substance is mainly used to kill the golden apple snails (also known as large bottle snails and apple snails) in rice fields. In public health prevention and control, it is used to kill Oncomelania snails (intermediate hosts of Schistosoma japonicum). The substance can quickly produce metabolic changes in water and has a short action time. It can be used to kill unwanted fish in commercial fish ponds. Because it has only a short half-life in water, it only takes a few days after using this fish killer to put new fish. It should be noted that improper use of this substance can cause adverse reactions, such as dizziness, chest tightness, chest pain, fatigue, gastrointestinal discomfort, fever, itching, etc.

[0003] At present, traditional niclosamide detection and analysis technologies mainly involve high performance liquid chromatography, bioassay, titration, UV-visible spectrophotometry, etc. These analytical techniques have played an important role in the detection of niclosamide. However, these analytical techniques also have some disadvantages, such as: expensive detection and analysis hardware equipment, large equipment space volume, complex specialized operations, long detection and analysis cycle, and it is difficult to achieve portable field detection of outdoor niclosamide. In contrast, the electrochemical sensor detection method has the advantages of high efficiency, sensitivity, low cost and easy miniaturization. In recent years, electrochemical sensing detection technology has gradually developed, but the electrochemical sensing detection technology for niclosamide is still immature and needs further improvement. Therefore, it is particularly urgent to develop a low-cost, fast and highly sensitive electrochemical sensing detection technology for niclosamide.

[0004] The Chinese invention patent (publication number: CN115728365A) provides an electrochemical sensor for highly sensitive detection of niclosamide and a detection method thereof, wherein the electrochemical sensor is composed of a GCE glassy carbon electrode surface modified with an ECP-600JD / ZIF-67 nanocomposite prepared from Ketjen black carbon black nanoparticles ECP-600J and metal organic framework material ZIF-67. ECP-600JD is uniformly dispersed in a DMF solution, and then an equal amount of ZIF-67 is added to the above solution, and a uniform mixed suspension is obtained by ultrasonic dispersion. Finally, 5 μL of the above uniform suspension is dropwise applied to the surface of the glassy carbon electrode and dried under an infrared lamp to obtain a working electrode modified with ECP-600JD / ZIF-67 nanocomposite. The disadvantage of this method is that the ECP-600JD Ketjen black carbon black nanoparticles are used. There are still certain shortcomings in enhancing the charge transfer efficiency by forming a conductive network with a branched morphology through "point-to-point" contact. Moreover, ZIF-67 is a metal-organic framework material with high production cost and limited specific surface area of ​​its porous structure. There is still much room for improvement in the adsorption and enrichment of the detected substances on the electrode surface.

[0005] The information disclosed in this background section is only intended to enhance understanding of the overall background of the invention and should not be taken as an acknowledgement or any form of suggestion that the information constitutes the prior art known to a person skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide an electrochemical sensor for highly sensitive detection of niclosamide and a preparation method thereof. The electrochemical sensor prepared by the method can effectively overcome the shortcomings of traditional detection methods, such as expensive detection and analysis hardware equipment, large equipment space volume, complex specialized operations, long detection and analysis cycle, and difficulty in realizing portable on-site detection of niclosamide outdoors. The electrochemical sensor has the advantages of low cost, high speed, high sensitivity, small space volume, easy to carry, and easy to realize portable on-site detection of niclosamide outdoors.

[0007] In order to achieve the above object, the technical solution of the present invention is:

[0008] The invention discloses an electrochemical sensor for highly sensitive detection of niclosamide. The SMMS@WCT@SCCB nanocomposite material prepared by monodisperse stellate mesoporous silica nanospheres (SMMS), superconducting carbon black (SCCB) and high-purity whisker carbon nanotubes (WCT) is modified on the surface of a glassy carbon electrode (GCE) to form a SMMS@WCT@SCCB / GCE working electrode. The SMMS@WCT@SCCB / GCE working electrode, an auxiliary electrode and a reference electrode are placed in an electrolytic cell to form an electrochemical sensor for highly sensitive detection of carbendazim.

[0009] In the electrochemical sensor for highly sensitive detection of niclosamide, the content range of each component in the SMMS@WCT@SCCB nanocomposite material is as follows: SMMS accounts for 30-50% by mass, WCT accounts for 25-35% by mass, and SCCB accounts for 25-35% by mass.

[0010] In the electrochemical sensor for highly sensitive detection of niclosamide, the thickness of the SMMS@WCT@SCCB nanocomposite material on the surface of GCE is 80 to 200 μm.

[0011] The method for preparing the electrochemical sensor for highly sensitive detection of niclosamide comprises the following steps:

[0012] (1) Preparation of SMMS@WCT@SCCB uniform suspension: First, equal masses of SCCB and WCT were added to N,N-dimethylformamide (DMF) solution, and continuous magnetic stirring was performed under ultrasonic environment to obtain a uniformly dispersed black WCT@SCCB suspension; then, a certain amount of SMMS was added to the above solution, and the SMMS addition ratio was 50% of the total mass of SMMS, SCCB and WCT, and ultrasonic dispersion and mixing were performed again to obtain a uniformly mixed SMMS@WCT@SCCB suspension;

[0013] (2) Preparation of SMMS@WCT@SCCB / GCE working electrode: The above-mentioned SMMS@WCT@SCCB uniform suspension was droplet-coated onto the pre-polished GCE surface and dried under an infrared lamp to obtain the SMMS@WCT@SCCB / GCE working electrode;

[0014] (3) Preparation of an electrochemical sensor for highly sensitive detection of niclosamide: Using a platinum wire electrode as an auxiliary electrode and a saturated calomel electrode as a reference electrode, the SMMS@WCT@SCCB / GCE working electrode, auxiliary electrode and reference electrode were placed in a three-electrode glass electrolytic cell to form an electrochemical sensor for highly sensitive detection of niclosamide.

[0015] Furthermore, in the step (1), the ultrasonic dispersion time is 60 to 180 minutes, and the ultrasonic power is 180W.

[0016] Furthermore, in step (2), the infrared lamp drying time is 5 to 15 minutes.

[0017] Furthermore, in step (2), in order to construct the target working electrode, the surface of the glassy carbon electrode is pretreated by wet sand grinding, and the surface of the glassy carbon electrode is polished by ultrasonic cleaning to obtain a glassy carbon electrode with a clean surface and free of impurities.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The SMMS@WCT@SCCB nanocomposite material used in the present invention has a "stone-rebar-mortar" type microstructure. As a sensor working electrode sensitizer, it can overcome the shortcomings of conventional working electrode electrolytes with weak adsorption capacity, low charge transport efficiency, and weak enrichment of niclosamide molecules on the working electrode surface.

[0020] (2) The SMMS used in the present invention is a monodisperse stellate mesoporous silica nanosphere. Compared with conventional mesoporous silica, the pore structure of the monodisperse stellate mesoporous silica nanosphere has more complex and abundant connected pores, and has the advantages of large pore size and high porosity. The large pore size can accommodate larger molecules and larger guest molecules, and the high porosity can provide a larger specific surface area and pore volume, which is conducive to the adsorption and loading of a large amount of substances, and significantly improves the enrichment of niclosamide molecules on the electrode surface.

[0021] (3) The WCT used in the present invention is a whisker carbon nanotube. Compared with conventional carbon nanotubes, whisker carbon nanotubes are not easy to entangle, have better dispersibility and less metal impurities, can maintain a high-speed ion conduction pathway in electrochemically active substances, and the electron and ion transmission will not be interrupted, thereby enhancing the charge transport efficiency. In addition, the whisker carbon nanotube microstructure is a multi-layer hollow structure with extremely high electrolyte adsorption capacity, which is conducive to the penetration and infiltration of the electrode liquid on the surface of the working electrode, and can enhance the charge transport efficiency while promoting the efficient enrichment of niclosamide molecules.

[0022] (4) The SCCB used in the present invention is a superconducting carbon black nanoparticle, which acts as a "mortar" in the "stone-rebar" type microstructure of SMMS@WCT on the working electrode surface, making the composite material more compact and stable. Thanks to the "stone-rebar-mortar" type microstructure of SMMS@WCT@SCCB, the charge transport channel on the working electrode surface is uninterrupted, which can provide higher ion and electron transport efficiency and further enhance the electrochemical sensing performance.

[0023] (5) The SMMS@WCT@SCCB nanocomposite material used in the present invention can fully utilize the advantages of the "stone-steel" type microstructure of the above-mentioned material, showing a synergistic effect and significantly improving the conductivity and niclosamide enrichment capacity of the working electrode modified coating.

[0024] (5) The sensor prepared based on the SMMS@WCT@SCCB nanocomposite material of the present invention has the advantages of being simple, efficient, low cost, highly sensitive, and easy to carry in detecting niclosamide, and can easily realize portable on-site detection of niclosamide outdoors. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1CV curves of niclosamide detected by the SMMS@WCT@SCCB / GCE sensor and the unmodified sensor prepared in Example 1 of the present invention. In the figure, the abscissa E represents the potential (V vs SCE), and the ordinate I represents the current (μA).

[0026] Figure 2 This is the DPV curve of niclosamide detected by the SMMS@WCT@SCCB / GCE sensor prepared in Example 1 of the present invention. In the figure, the abscissa E represents the potential (V vs SCE), and the ordinate I represents the current (μA). DETAILED DESCRIPTION

[0027] In the specific implementation process, the present invention proposes an electrochemical sensor for highly sensitive detection of niclosamide and a preparation method thereof, wherein the SMMS@WCT@SCCB / GCE working electrode is composed of a SMMS@WCT@SCCB nanocomposite prepared from monodispersed stellate mesoporous silica nanospheres (SMMS), superconducting carbon black (SCCB) and high-purity whisker carbon nanotubes (WCT) and modified on the surface of a glassy carbon electrode (GCE). First, equal masses of SCCB and WCT are uniformly dispersed in a N,N-dimethylformamide (DMF) solution by magnetic stirring under an ultrasonic environment; then, a certain amount of SMMS is added to the above solution, and a uniform suspension of the SMMS@WCT@SCCB mixture is obtained by ultrasonic dispersion; finally, the uniform suspension of the SMMS@WCT@SCCB mixture is drop-coated on the surface of the GCE and dried under an infrared lamp to obtain a working electrode SMMS@WCT@SCCB / GCE modified with the SMMS@WCT@SCCB nanocomposite.

[0028] In the present invention, the technical indicators of monodisperse stellar mesoporous silica nanospheres (SMMS) are as follows: average particle size 80nm, pore volume ~1.4mL / g, pore diameter 2.9nm. The technical indicators of superconducting carbon black (SCCB) are as follows: grain size 23-28nm, specific surface area 405-435m 2 / g. The technical indicators of high-purity whisker carbon nanotubes (WCT) are as follows: outer diameter 20-200nm (mostly concentrated in 50-100nm), purity: >97wt%, length 1-15μm.

[0029] The present invention is further described below with reference to specific embodiments.

[0030] Example 1

[0031] In this embodiment, a method for preparing an electrochemical sensor for highly sensitive detection of niclosamide comprises the following steps:

[0032] (1) Preparation of SMMS@WCT@SCCB uniform suspension: 20 mg of SCCB (10 mg) and WCT (10 mg) of equal mass were added to 10 mL of N,N-dimethylformamide (DMF) solution, and continuous magnetic stirring (120 mins) was performed under ultrasonic environment to obtain a uniformly dispersed black WCT@SCCB suspension. Subsequently, a certain amount of SMMS was added to the above solution, the amount of SMMS added was 20 mg, and ultrasonic dispersion (60 mins) was performed again to mix uniformly to obtain a uniformly mixed SMMS@WCT@SCCB suspension.

[0033] (2) Preparation of SMMS@WCT@SCCB / GCE working electrode: 5 μL of the above SMMS@WCT@SCCB uniform suspension was dropleted onto the pre-polished and cleaned GCE surface. The shape and size of the GCE were: CHI104 glassy carbon disk electrode diameter 3 mm, and dried under an infrared lamp for 6 mins to obtain the SMMS@WCT@SCCB / GCE working electrode.

[0034] Among them, the thickness of SMMS@WCT@SCCB nanocomposite on the GCE surface is 80-200 μm.

[0035] (3) Preparation of highly sensitive electrochemical sensor for detecting niclosamide: The above-mentioned SMMS@WCT@SCCB / GCE working electrode, auxiliary electrode (platinum wire electrode) and reference electrode (saturated calomel electrode) were placed in a three-electrode glass electrolytic cell to form an electrochemical sensor for niclosamide detection. The detection limit can reach 10.44 nM, which has excellent electrochemical sensing detection performance for niclosamide.

[0036] The CV curves of the SMMS@WCT@SCCB / GCE sensor prepared in this example and the unmodified sensor for detecting niclosamide are shown in Figure 1 The DPV curve of the prepared SMMS@WCT@SCCB / GCE sensor for detecting niclosamide is shown in Figure 2 .

[0037] Depend on Figure 1It can be seen that the CV curves of these sensors detecting niclosamide all show an irreversible reduction peak and a pair of redox peaks. According to the electrochemical behavior of nitro compounds, the irreversible reduction peak of niclosamide can be attributed to the irreversible reduction of the nitro group to hydroxylamine, and the redox peak can be attributed to the reversible redox behavior of the hydroxylamine group. It should be noted that the CV peak current of the unmodified sensor is weak. In contrast, the SMMS@WCT@SCCB / GCE sensor presents an obvious CV curve, which is closely related to the synergistic effect of the SMMS@WCT@SCCB nanocomposite. SMMS is a monodisperse stellate mesoporous silica nanosphere. Compared with conventional mesoporous silica, the pore structure of monodisperse stellate mesoporous silica nanospheres has more complex and abundant connected pores, and has the advantages of large pore size and high porosity. Large pore size can accommodate larger molecules and larger guest molecules. High porosity can provide a larger specific surface area and pore volume, which is conducive to the adsorption and loading of a large number of substances, and significantly improves the enrichment of chloranilamide molecules on the electrode surface. WCT is a whisker carbon nanotube. Compared with conventional carbon nanotubes, whisker carbon nanotubes are not easy to entangle, have better dispersion and fewer metal impurities, and can maintain a high-speed ion conduction pathway in electrochemically active substances, enhancing the charge transport efficiency. In addition, the whisker carbon nanotube microstructure is a multi-layer hollow structure with extremely high electrolyte adsorption capacity, which is conducive to the penetration and infiltration of the electrode liquid on the working electrode surface, enhancing the charge transport efficiency and promoting the efficient enrichment of chloranilamide molecules. SCCB is a superconducting carbon black nanoparticle, which acts as a "mortar" in the "stone-steel" type microstructure of SMMS@WCT on the working electrode surface, making the construction of the composite material more compact and stable. Thanks to the "stone-rebar-mortar" microstructure of SMMS@WCT@SCCB, the charge transport channel on the working electrode surface is uninterrupted, which can provide higher ion and electron transport efficiency and further enhance the electrochemical sensing performance. Based on the synergistic effect of the "stone-rebar-mortar" microstructure SMMS@WCT@SCCB nanocomposite material, the SMMS@WCT@SCCB / GCE sensor exhibits excellent niclosamide detection and analysis performance.

[0038] Depend on Figure 2It can be seen that the linear niclosamide concentration range of the DPV test of SMMS@WCT@SCCB / GCE sensor for detecting niclosamide is 0.01μM to 20μM. The research results show that the concentration of niclosamide has a significant effect on the peak current response of the DPV curve. With the increase of niclosamide concentration, the peak current response of the DPV curve for detecting niclosamide gradually increases, and the two show a positive correlation. Based on the fitted linear relationship between the niclosamide concentration and the peak current response of the DPV curve, the linear regression equation of the response can be obtained, and then the detection limit of the prepared SMMS@WCT@SCCB / GCE sensor for niclosamide is calculated and analyzed to be 10.44nM, indicating that the above-prepared sensor has excellent niclosamide sensing and detection performance.

[0039] Example 2

[0040] In this embodiment, a method for preparing an electrochemical sensor for highly sensitive detection of niclosamide comprises the following steps:

[0041] (1) Preparation of SMMS@WCT@SCCB uniform suspension: 30 mg of SCCB (15 mg) and WCT (15 mg) of equal mass were added to 15 mL of N,N-dimethylformamide (DMF) solution, and continuous magnetic stirring (180 mins) was performed under ultrasonic environment to obtain a uniformly dispersed black SMMS@WCT suspension. Subsequently, a certain amount of SMMS was added to the above solution, the amount of SMMS added was 30 mg, and ultrasonic dispersion (90 mins) was used again to mix evenly to obtain a uniformly mixed SMMS@WCT@SCCB suspension.

[0042] (2) Preparation of WCT@SMMS / GCE working electrode: 5 μL of the above SMMS@WCT@SCCB uniform suspension was dropleted onto the pre-polished and cleaned GCE surface. The shape and size of the GCE were: CHI104 glassy carbon disk electrode diameter 3 mm, and dried under an infrared lamp for 6 mins to obtain the SMMS@WCT@SCCB / GCE working electrode.

[0043] Among them, the thickness of SMMS@WCT@SCCB nanocomposite on the GCE surface is 80-200 μm.

[0044] (3) Preparation of highly sensitive electrochemical sensor for detecting niclosamide: The above-mentioned SMMS@WCT@SCCB / GCE working electrode, auxiliary electrode (platinum wire electrode) and reference electrode (saturated calomel electrode) were placed in a three-electrode glass electrolytic cell to form an electrochemical sensor for niclosamide detection, which has excellent electrochemical sensing detection performance for niclosamide.

[0045] The implementation results show that the sensor prepared by the present invention has low cost, high efficiency, high sensitivity, small space occupation volume, easy to carry, and easy to realize outdoor field detection. Based on the synergistic effect of SMMS, WCT and SCCB, the SMMS@WCT@SCCB / GCE sensor has high sensitivity, low detection limit, and excellent niclosamide sensing detection performance.

[0046] The exemplary embodiments are chosen and described for the purpose of explaining certain principles of the invention and their practical applications, thereby enabling those skilled in the art to make and utilize various exemplary embodiments of the invention as well as various alternatives and modifications.

Claims

1. An electrochemical sensor for highly sensitive detection of niclosamide, characterized in that: The SMMS@WCT@SCCB nanocomposite material prepared by monodisperse stellar mesoporous silica nanospheres (SMMS), superconducting carbon black (SCCB) and high-purity whisker carbon nanotubes (WCT) was modified on the surface of glassy carbon electrode (GCE) to form the SMMS@WCT@SCCB / GCE working electrode. The SMMS@WCT@SCCB / GCE working electrode, auxiliary electrode and reference electrode were placed in an electrolytic cell to form an electrochemical sensor for highly sensitive detection of carbendazim.

2. An electrochemical sensor for highly sensitive detection of niclosamide according to claim 1, characterized in that: In the SMMS@WCT@SCCB nanocomposite material, the content range of each component is as follows: SMMS accounts for 30-50% by mass, WCT accounts for 25-35% by mass, and SCCB accounts for 25-35% by mass.

3. An electrochemical sensor for highly sensitive detection of niclosamide according to claim 1, characterized in that: The thickness of SMMS@WCT@SCCB nanocomposites on the GCE surface is 80-200 μm.

4. The method for preparing an electrochemical sensor for highly sensitive detection of niclosamide according to any one of claims 1 to 3, characterized in that: The following steps are involved: (1) Preparation of SMMS@WCT@SCCB uniform suspension: First, equal masses of SCCB and WCT were added to N,N-dimethylformamide (DMF) solution, and continuous magnetic stirring was performed under ultrasonic environment to obtain a uniformly dispersed black WCT@SCCB suspension; then, a certain amount of SMMS was added to the above solution, and the SMMS addition ratio was 50% of the total mass of SMMS, SCCB and WCT, and ultrasonic dispersion and mixing were performed again to obtain a uniformly mixed SMMS@WCT@SCCB suspension; (2) Preparation of SMMS@WCT@SCCB / GCE working electrode: The above-mentioned SMMS@WCT@SCCB uniform suspension was droplet-coated onto the pre-polished GCE surface and dried under an infrared lamp to obtain the SMMS@WCT@SCCB / GCE working electrode; (3) Preparation of an electrochemical sensor for highly sensitive detection of niclosamide: Using a platinum wire electrode as an auxiliary electrode and a saturated calomel electrode as a reference electrode, the SMMS@WCT@SCCB / GCE working electrode, auxiliary electrode and reference electrode were placed in a three-electrode glass electrolytic cell to form an electrochemical sensor for highly sensitive detection of niclosamide.

5. The method for preparing an electrochemical sensor for highly sensitive detection of niclosamide according to claim 1, characterized in that: In the step (1), the ultrasonic dispersion time is 60 to 180 minutes, and the ultrasonic power is 180W.

6. The method for preparing an electrochemical sensor for highly sensitive detection of niclosamide according to claim 1, characterized in that: In the step (2), the infrared lamp drying time is 5 to 15 minutes.

7. The method for preparing an electrochemical sensor for highly sensitive detection of niclosamide according to claim 1, characterized in that: In the step (2), in order to construct the target working electrode, the surface of the glassy carbon electrode is pretreated by wet sand grinding, and the surface of the glassy carbon electrode is polished by ultrasonic cleaning to obtain a glassy carbon electrode with a clean surface and free of impurities.

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