CN112229891B - Method for detecting enrofloxacin in water body - Google Patents

Method for detecting enrofloxacin in water body Download PDF

Info

Publication number
CN112229891B
CN112229891B CN202011461753.4A CN202011461753A CN112229891B CN 112229891 B CN112229891 B CN 112229891B CN 202011461753 A CN202011461753 A CN 202011461753A CN 112229891 B CN112229891 B CN 112229891B
Authority
CN
China
Prior art keywords
tapb
pda
cofs
electrode
aunps
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202011461753.4A
Other languages
Chinese (zh)
Other versions
CN112229891A (en
Inventor
丁萍
鲁思宇
开天翰
王珊琳
伍翩
陈翠梅
黄瑞雪
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Central South University
Original Assignee
Central South University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Central South University filed Critical Central South University
Priority to CN202011461753.4A priority Critical patent/CN112229891B/en
Publication of CN112229891A publication Critical patent/CN112229891A/en
Application granted granted Critical
Publication of CN112229891B publication Critical patent/CN112229891B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
    • G01N27/416—Systems
    • G01N27/48—Systems using polarography, i.e. measuring changes in current under a slowly-varying voltage

Landscapes

  • Chemical & Material Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Molecular Biology (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Measuring Or Testing Involving Enzymes Or Micro-Organisms (AREA)

Abstract

The invention discloses a method for detecting enrofloxacin in a water body, which comprises the following steps: reacting terephthalaldehyde and 1,3, 5-tri (4-aminophenyl) benzene to generate TAPB-PDA-COFs; reacting TAPB-PDA-COFs, chloroauric acid and sodium citrate to obtain a TAPB-PDA-COFs/AuNPs composite material; modifying the TAPB-PDA-COFs/AuNPs composite material on the surface of a glassy carbon electrode to prepare a modified electrode; assembling the modified electrodes into a three-electrode system of an electrochemical workstation, detecting the oxidation current in the water body by using a square wave stripping voltammetry method, and calculating the enrofloxacin content in the water body by contrasting with a standard curve. The detection method can qualitatively obtain a detection result by directly observing whether the oxidation current is generated or not in a short time, shortens the detection time of the enrofloxacin, and is a convenient, rapid and sensitive method for detecting the enrofloxacin.

Description

Method for detecting enrofloxacin in water body
Technical Field
The invention belongs to the field of analytical chemistry, and particularly relates to a high-sensitivity method for trace detection of enrofloxacin in a water body.
Background
The third generation quinolone enrofloxacin is only partially metabolized in the body, a part of matrix and metabolite thereof are excreted through urine and feces, and the residues can cause various toxic effects, thereby polluting the environment. The toxicity of enrofloxacin includes allergy, immunopathology, mutagenicity, carcinogenicity, hepatotoxicity, nephropathy, abnormal reproductive function, bone marrow toxicity, even anaphylactic shock of human beings, etc.
At present, the methods for analyzing and detecting antibiotics in the environment mainly comprise high performance liquid chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, capillary electrophoresis, high performance thin layer chromatography and the like. However, the above methods have disadvantages of expensive equipment, complicated sample processing, requiring professional operations and time-consuming, and the like, thereby limiting their wide application. In addition, other methods such as enzyme-linked immunosorbent assay (ELISA) and aptamer sensing technology have the defects of expensive price of kits and aptamer screens, and the like, so that the application of the methods is limited.
Most antibiotics, because of their electrochemical redox activity, can be assayed by directly detecting their electrochemical signals using electrodes. The electrooxidation of enrofloxacin is carried out at an anodic potential, the ethyl group exists on piperazine nitrogen, the alpha carbon atom is easier to be oxidized, so that the enrofloxacin releases one equivalent of acetaldehyde as a byproduct in the oxidation process, and then one equivalent of ciprofloxacin is formed. However, the sensitivity of the electrochemical signal generated when the antibiotic is directly detected on the bare electrode is low, and the accurate determination of the trace enrofloxacin in the sample cannot be met, so that the improvement of the electron transfer rate and the current signal in the electrochemical detection process is particularly important for the accurate determination of the trace enrofloxacin.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a method for detecting enrofloxacin in a water body.
In order to solve the technical problems, the technical scheme provided by the invention is as follows:
a method for detecting enrofloxacin in a water body comprises the following steps:
(1) reacting terephthalaldehyde (PDA) and 1,3, 5-tri (4-aminophenyl) benzene (TAPB), and combining imino bonds to generate TAPB-PDA-COFs;
(2) TAPB-PDA-COFs, chloroauric acid (A), (B), (CHAuCl4·4H2O) and sodium citrate to obtain a TAPB-PDA-COFs/AuNPs composite material;
(3) modifying the TAPB-PDA-COFs/AuNPs composite material on the surface of a Glassy Carbon Electrode (GCE) to prepare a modified electrode;
(4) and assembling the modified electrode, a reference electrode and a counter electrode into a three-electrode system of an electrochemical workstation, detecting the oxidation current in the water body by using a square wave stripping voltammetry (SWV), and calculating the enrofloxacin content in the water body by contrasting with a standard curve.
In the above method, preferably, in the step (1), the mass ratio of terephthalaldehyde to 1,3, 5-tris (4-aminophenyl) benzene is 0.05: 0.095.
preferably, in the step (1), the specific process for obtaining TAPB-PDA-COFs is as follows: adding PDA and TAPB into dimethyl sulfoxide (DMSO), ultrasonically dispersing uniformly, then adding acetic acid under an ultrasonic condition, dispersing uniformly, performing sealed incubation on the obtained solution at room temperature for 30 min, and finally centrifuging, washing and drying to obtain TAPB-PDA-COFs; wherein the volume ratio of the dimethyl sulfoxide to the acetic acid is 0.9: 50. the method adopts a solvent ultrasonic method to prepare in the process of synthesizing TAPB-PDA-COFs, needs less reagents, does not need high temperature and has short reaction time. For imine bond formation, the addition of acetic acid in a homogeneous solution of the monomers results in rapid precipitation of the COFs complexes at room temperature, induces crystallization of the COFs complexes and possesses high yields.
Preferably, in the step (2), the mass ratio of TAPB-PDA-COFs to chloroauric acid and sodium citrate is 30-35: 4: 1.
preferably, in the step (2), the specific process for obtaining the TAPB-PDA-COFs/AuNPs composite material comprises the following steps: ultrasonically dispersing TAPB-PDA-COFs in water, adding a sodium citrate aqueous solution, magnetically stirring and heating until the solution is boiled, rapidly adding chloroauric acid, keeping the solution system boiled, continuously stirring until the solution becomes reddish brown and the color does not change any more, centrifuging, washing and drying to obtain the TAPB-PDA-COFs/AuNPs composite material. The method adopts the sodium citrate aqueous solution as a reducing agent, the synthesized AuNPs have relatively large grain size (more than 10 nm), can be directly and rapidly characterized by an ultraviolet-visible spectrophotometer, and has shorter time for synthesizing the composite material; with other reducing agents such as sodium borohydride, it is difficult to control the reaction time.
Preferably, in the step (3), the specific process of modifying the surface of the glassy carbon electrode by the TAPB-PDA-COFs/AuNPs composite material is as follows: adding the TAPB-PDA-COFs/AuNPs composite material into ultrapure water for ultrasonic treatment to obtain a homogeneous solution; and then dripping the homogeneous phase solution on the surface of a clean and dry glassy carbon electrode, dripping the chitosan solution on the surface of the glassy carbon electrode to fix the compound after the homogeneous phase solution is dried, and drying at room temperature under a dark condition to obtain the TAPB-PDA-COFs/AuNPs/GCE electrode.
Preferably, the concentration of the TAPB-PDA-COFs/AuNPs composite material homogeneous phase solution is 1 mg/mL; the mass concentration of the chitosan solution is 0.5%.
In the method, preferably, in the step (3), the modification amount of the TAPB-PDA-COFs/AuNPs composite material on the surface of the Glassy Carbon Electrode (GCE) is 2-10 muL, wherein the optimal modification amount is 6 muL.
In the above method, preferably, in the step (4), the three-electrode system uses Ag/AgCl (3.0 mol/L KCl) as a reference electrode, a platinum wire electrode as a counter electrode, and a TAPB-PDA-COFs/AuNPs/GCE electrode as a working electrode; the potential range detected by the square wave stripping voltammetry is +400 mV to +1200 mV, the amplitude is 0.075V, and the frequency is 20 Hz.
In the above method, preferably, the water to be detected is added with a PBS buffer solution with pH = 7.
Covalent Organic Frameworks (COFs) are composed of organic structural units containing light elements (such as C, N, O, H and B), namely organic precursors with special groups are connected by means of strong covalent bonds, and the COFs have the advantages of good crystal form, uniform pore size distribution, single pore channel, unique delocalized pi-pi electronic system, insolubility in water and most organic solvents, and certain stability at high temperature. However, most COFs have relatively poor electrochemical activity, and the inherent defect limits the further application of the COFs as an electrochemical modification material. The COFs combined by imine bonds can increase the specific surface area of the composite material, and provide an excellent scaffold for charge transfer and molecular diffusion; and the COFs are combined with gold nanoparticles (AuNPs) with high conductivity, so that the gold nanoparticles show excellent conductivity and stability in an electrochemical sensor, and in addition, the gold nanoparticles can reduce the overpotential of electrochemical reaction and stabilize the reversibility of redox reaction.
Different monomers are selected to synthesize different kinds of COFs, and the structure and the property (2D structure, surface functional group and the like) of the COFs are greatly different. The choice of monomers is therefore critical for the synthesis of COFs and will subsequently also affect the recombination of other nanomaterials with COFs. The synthesized TAPB-PDA-COF has the average pore diameter of 3.195 nm by selecting terephthalaldehyde (PDA) and 1,3, 5-tri (4-aminophenyl) benzene (TAPB) as monomers, the pore diameter is increased to 3.787 nm after AuNPs are introduced, the composite material is shown to be more favorable for electron transfer, the thermal stability of TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs is explored through thermogravimetric analysis (TGA), and the TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs start to show obvious mass loss after 400 ℃, so that the TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs have high thermal stability.
Enrofloxacin (Enrofloxacin, ENR), also known as 1-cyclopropyl-7- (4-ethyl-1-piperazinyl) -6-fluoro-1, 4-dihydro-4-oxo-3-quinolinecarboxylic acid, has an electrochemical oxidation process as shown in formula (1).
Figure 755886DEST_PATH_IMAGE001
Formula (1)
In the electrochemical measurement process, the target substance undergoes an oxidation process, causing electron transfer, thereby generating an electric current and an oxidation peak. The electrooxidation of enrofloxacin is carried out at anodic potential because of the presence of ethyl groups on the piperazine nitrogen, wherein the alpha carbon atom is more easily oxidized, so that during oxidation enrofloxacin releases an equivalent of acetaldehyde as a by-product, and an equivalent of ciprofloxacin is formed, during which electrons are transferred to produce an electrical current response. The TAPB-PDA-COFs/AuNPs composite material is modified on a Glassy Carbon Electrode (GCE), and the TAPB-PDA-COFs has a large specific surface area and a controllable pore size structure, so that an excellent support is provided for charge migration and molecular diffusion in the enrofloxacin oxidation process, the surface area of the GCE can be increased, the surface of the electrode can be loaded with more gold nanoparticles (AuNPs), the AuNPs have advantages in electron conduction, the overpotential of electrochemical reaction can be reduced, and the composite material has excellent conductivity and stability in an enrofloxacin electrochemical sensor. Based on the principle and the advantages, the TAPB-PDA-COF is prepared by a simple solvent ultrasonic method, AuNPs are synthesized in situ on the surface of the TAPB-PDA-COF, and the prepared TAPB-PDA-COFs/AuNPs/GCE is used for detecting enrofloxacin, so that excellent current response can be obtained.
Compared with the prior art, the invention has the advantages that:
(1) in the detection method, TAPB-PDA-COFs and AuNPs are combined to synthesize the composite material TAPB-PDA-COFs/AuNPs, and the electrochemical sensor type detection system of the composite material TAPB-PDA-COFs/AuNPs integrates the advantages of high sensitivity, low detection limit, excellent stability, simple method and the like, can directly determine whether oxidation current is generated or not in a short time, obtains the detection result of enrofloxacin in the water body, and does not need to perform professional preheating and maintenance on instruments, so that the detection method is more convenient.
(2) The sensor constructed by the TAPB-PDA-COFs/AuNPs composite material in the detection method has good specificity to enrofloxacin.
(3) In the composite material TAPB-PDA-COFs/AuNPs adopted by the invention, the COFs has a 2D/3D structure with permanent pores, so that an excellent support for an electrode material is provided for charge migration and molecular diffusion, and the test sensitivity can be improved through signal amplification; the adopted gold nanoparticles not only can reduce the overpotential of the electrochemical reaction, but also can stabilize the reversibility of the oxidation-reduction reaction; the method combines the electrochemical oxidation activity of the enrofloxacin, and realizes the detection of the enrofloxacin in the water body by a square wave stripping voltammetry according to the changed oxidation peak current signals.
In conclusion, the composite material TAPB-PDA-COFs/AuNPs constructed in the detection method is beneficial to charge migration and molecular diffusion in the oxidation process, the sensitivity of detecting enrofloxacin is improved, a detection result can be obtained qualitatively by observing whether oxidation current is generated or not directly in a short time, the detection time of enrofloxacin is shortened, and the method is a convenient, rapid and sensitive method for detecting enrofloxacin, and can be widely used for detecting enrofloxacin in a water body.
Drawings
FIG. 1 is a transmission electron microscope image of the TAPB-PDA-COFs/AuNPs composite material in example 1.
FIG. 2 is a diagram of the analysis of the specific surface area and the pore size of the TAPB-PDA-COFs/AuNPs composite material in example 1.
FIG. 3 is a graph showing the effect of detecting enrofloxacin by modifying electrodes at different incubation times in example 1.
FIG. 4 is a graph showing the effect of detecting enrofloxacin by modifying electrodes at different modification amounts in example 2.
FIG. 5 is a SWV curve for the electrochemical sensor constructed in example 3 over a concentration range of 0.05-120. mu.M.
FIG. 6 is a standard curve of the electrochemical sensor constructed in example 3 in a concentration range of 0.05-120. mu.M.
Fig. 7 is a graph showing the stability of the electrochemical sensor constructed in example 3.
FIG. 8 is a graph showing the thermal stability analysis of TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs in example 3.
Fig. 9 is a graph showing the specificity of the electrochemical sensor constructed in example 3.
Detailed Description
In order to facilitate an understanding of the invention, the invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.
Unless otherwise defined, all terms of art used hereinafter have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention.
Unless otherwise specified, the reagents and materials used in the present invention are commercially available products or products obtained by a known method.
The monomer materials used for synthesizing COFs in the invention are 1,3, 5-tri (4-aminophenyl) benzene (TAPB) and terephthalaldehyde (PDA), which are commercially available.
The electrode used in the present invention is a Glassy Carbon Electrode (GCE). Before the electrode is used, the electrode needs to be carefully cleaned so as to prevent the surface of the electrode from being polluted to influence the electrochemical reaction, thereby generating deviation of the detection result.
Example 1:
the preparation of the modified electrode adopted by the invention for detecting enrofloxacin in the water body and the detection effect of the modified electrode on enrofloxacin under different incubation times are determined as follows:
(1) preparation of TAPB-PDA-COFs: adding PDA (0.05 g) and TAPB (0.095 g) into 50 mL DMSO, and performing ultrasonic treatment for 5 min to obtain uniformly dispersed solution; slowly adding 1.8mL of acetic acid into the uniformly dispersed solution under the ultrasonic condition, and carrying out ultrasonic treatment for 10 min; then the reaction solution is incubated for 30 min in a sealed manner at room temperature; and finally, centrifuging at 10000 rpm for 10 min, washing (washing with tetrahydrofuran and methanol for three times respectively), drying (drying for 6 h at 55 ℃ under vacuum condition), and grinding into powder to obtain TAPB-PDA-COFs powder which is stored at room temperature under drying condition for use.
(2) Preparing a TAPB-PDA-COFs/AuNPs composite material: adding 20 mg of TAPB-PDA-COFs powder prepared in the step (1) into 20 mL of ultrapure water, and ultrasonically dispersing for 10 min; then 2.4 mL of 40 mM sodium citrate aqueous solution was added thereto, heated to boiling with magnetic stirring, and 600. mu.L of 1% HAuCl was rapidly added4·4H2O, keeping the solution boiling, continuing to heat and stir for 15 min until the solution turns reddish brown and the color does not change any more, and finally centrifuging the mixture (10000 rpm centrifugation for 5 min), washing (ultrapure water washing)Three times), the resulting product was dried under vacuum overnight. The Transmission Electron Microscope (TEM) result of the prepared TAPB-PDA-COFs/AuNPs composite material is shown in FIG. 1, the TAPB-PDA-COFs has a sheet structure, which shows that a strong support site can be provided for AuNPs compounds, and the diameter of the synthesized AuNPs is about 15-20 nm. The specific surface area and pore size analysis (BET) results of the TAPB-PDA-COFs/AuNPs composite material are shown in FIG. 2, and the BET surface area of the TAPB-PDA-COF is 54.91 m2 g-1. After introduction of the AuNPs, the BET surface area is 62.29 m2 g-1(ii) a The average pore diameter of TAPB-PDA-COFs is 3.195 nm, and after AuNPs are introduced, the pore diameter is increased to 3.787 nm, which shows that the composite material is more favorable for electron transfer.
(3) TAPB-PDA-COFs/AuNPs composite material modified electrode: polishing the naked GCE on polishing cloth by using alumina slurry with the particle size of 1 μm, 0.3 μm and 0.05 μm to form a mirror surface, performing ultrasonic treatment by using ethanol and ultrapure water, and drying; then, 1.0 mg of TAPB-PDA-COFs/AuNPs was added to 1.0 mL of ultrapure water and subjected to ultrasonic treatment for 30 min to prepare a homogeneous solution. And dripping 6.0 mu L of homogeneous solution on the surface of the pretreated GCE, drying, dripping 3 mu L of 0.5% chitosan solution on the surface of the electrode to fix the compound, and drying at room temperature under a dark condition to obtain the modified electrode.
(4) Electrode incubation time optimization
25 mL of 5 electrolytic cells each containing 0.1M of PBS solution (pH = 7) were taken, and 1 mM of enrofloxacin standard solution was added in the same volume so that the total volume of the liquid in the electrolytic cells became 5 mL, and the resulting enrofloxacin solutions of 5 groups each had a concentration of 100. mu.M. And assembling an Ag/AgC reference electrode, a platinum wire counter electrode and a TAPB-PDA-COFs/AuNPs/GCE working electrode into a three-electrode system. Before detection, TAPB-PDA-COFs/AuNPs/GCE electrodes were incubated with 5 100. mu.M solutions of enrofloxacin in PBS for various periods of time (20 s, 40s, 60s, 80s, 120 s), and SWV measurements were performed (using square wave stripping voltammetry over a potential range of +400 mV to +1200 mV, with an amplitude of 0.075V and a frequency of 20 Hz). As shown in FIG. 3, it is clear that the detection effect is best when the incubation time is 40 seconds. The result shows that the detection time required by the electrochemical sensor does not exceed 1min when detecting the enrofloxacin in the water body, thereby greatly shortening the time for detecting the enrofloxacin by the traditional large-scale instrument.
Example 2:
the invention discloses a method for preparing a modified electrode for detecting enrofloxacin in a water body and a method for determining the detection effect of the modified amount of a working electrode material on enrofloxacin, which comprises the following steps:
(1) preparation of TAPB-PDA-COFs: adding PDA (0.05 g) and TAPB (0.095 g) into 50 mL DMSO, and performing ultrasonic treatment for 5 min to obtain uniformly dispersed solution; then slowly adding 1.8mL of acetic acid under the ultrasonic condition, and carrying out ultrasonic treatment for 10 min; then the reaction solution is incubated for 30 min in a sealed manner at room temperature; and finally, centrifuging at 10000 rpm for 10 min, washing (washing with tetrahydrofuran and methanol for three times respectively), drying (drying for 6 h at 55 ℃ under vacuum condition), and grinding into powder to obtain TAPB-PDA-COFs powder which is stored at room temperature under drying condition for use.
(2) Preparing a TAPB-PDA-COFs/AuNPs composite material: adding 20 mg of TAPB-PDA-COFs powder prepared in the step (1) into 20 mL of ultrapure water, and ultrasonically dispersing for 10 min; then 2.4 mL of 40 mM sodium citrate aqueous solution was added thereto, heated to boiling with magnetic stirring, and 600. mu.L of 1% HAuCl was rapidly added4·4H2O, keeping the solution boiling and continuing to heat and stir for 15 min until the solution becomes reddish brown and the color does not change any more, finally the resulting mixture is centrifuged (10000 rpm for 5 min), washed (ultrapure water for three times), and the final product is dried under vacuum overnight.
(3) TAPB-PDA-COFs/AuNPs composite material modified electrode: polishing the naked GCE on polishing cloth by using alumina slurry with the particle size of 1 μm, 0.3 μm and 0.05 μm to form a mirror surface, performing ultrasonic treatment by using ethanol and ultrapure water, and drying; then, 1.0 mg of TAPB-PDA-COFs/AuNPs was suspended in 1.0 mL of ultrapure water and sonicated for 30 min to prepare a homogeneous solution. When the surface of the electrode is dried, respectively dripping 2.0, 4.0, 6.0, 8.0 and 10.0 mu L of TAPB-PDA-COFs/AuNPs on the surface of 5 pieces of GCE for drying, dripping 3 mu L of 0.5% chitosan solution on the surface of the electrode for fixing a compound, and drying at room temperature under a dark condition to obtain different modified electrodes.
(4) Working electrode material modification optimization
Taking 5 electrolytic cells of 25 mL, respectively containing 0.1M PBS solution (pH = 7), adding 1 mM enrofloxacin standard solution of the same volume to make the total volume of the liquid in the electrolytic cells be 5 mL, and obtaining 5 groups of enrofloxacin solutions with the concentration: 100 μ M. And assembling an Ag/AgC reference electrode, a platinum wire counter electrode and a TAPB-PDA-COFs/AuNPs/GCE working electrode into a three-electrode system. After the TAPB-PDA-COFs/AuNPs/GCE electrode and the enrofloxacin standard solution are incubated for 40s, the detection effect of the reaction system obtained in the embodiment on the enrofloxacin sample is shown in figure 4, and it can be seen from the figure that the detection effect is best when the modification amount of the composite material is 6.0 muL.
Example 3:
the invention relates to a method for detecting enrofloxacin in a water body, which comprises the following steps:
(1) preparation of TAPB-PDA-COFs: adding PDA (0.05 g) and TAPB (0.095 g) into 50 mL DMSO, and performing ultrasonic treatment for 5 min to obtain uniformly dispersed solution; slowly adding 1.8mL of acetic acid into the uniformly dispersed solution under the ultrasonic condition, and carrying out ultrasonic treatment for 10 min; then the reaction solution is incubated for 30 min in a sealed manner at room temperature; and finally, centrifuging at 10000 rpm for 10 min, washing (washing with tetrahydrofuran and methanol for three times respectively), drying (drying for 6 h at 55 ℃ under vacuum condition), and grinding into powder to obtain TAPB-PDA-COFs powder which is stored at room temperature under drying condition for use.
(2) Preparing a TAPB-PDA-COFs/AuNPs composite material: adding 20 mg of TAPB-PDA-COFs powder prepared in the step (1) into 20 mL of ultrapure water, and ultrasonically dispersing for 10 min; then 2.4 mL of 40 mM sodium citrate aqueous solution was added thereto, heated to boiling with magnetic stirring, and 600. mu.L of 1% HAuCl was rapidly added4·4H2O, keeping the solution boiling and continuing to heat and stir for 15 min until the solution becomes reddish brown and the color does not change any more, finally the resulting mixture is centrifuged (10000 rpm for 5 min), washed (ultrapure water for three times), and the final product is dried under vacuum overnight.
The thermal stability of TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs was explored by thermogravimetric analysis (TGA), as shown in FIG. 8. TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs show obvious quality loss at the beginning of extraction at 400 ℃, which shows that the TAPB-PDA-COF/AuNPs and TAPB-PDA-COFs prepared in the modified electrode have high thermal stability.
(3) TAPB-PDA-COFs/AuNPs composite material modified electrode: polishing the naked GCE on polishing cloth by using alumina slurry with the particle size of 1 μm, 0.3 μm and 0.05 μm to form a mirror surface, performing ultrasonic treatment by using ethanol and ultrapure water, and drying; then, 1.0 mg of TAPB-PDA-COFs/AuNPs was added to 1.0 mL of ultrapure water and subjected to ultrasonic treatment for 30 min to prepare a homogeneous solution. And dripping 6.0 mu L of homogeneous solution on the surface of the pretreated GCE, drying, dripping 3 mu L of 0.5% chitosan solution on the surface of the electrode to fix the compound, and drying at room temperature under a dark condition to obtain the modified electrode.
(4) Electrochemical measurement:
taking 25 mL of an electrolytic cell, containing 0.1M PBS solution (pH = 7), adding 1 mM enrofloxacin standard solutions with different volumes to make the total volume of liquid in the electrolytic cell be 5 mL, and obtaining 12 groups of enrofloxacin solutions with the concentrations respectively: 0.05. mu.M, 0.1. mu.M, 0.5. mu.M, 1. mu.M, 10. mu.M, 30. mu.M, 50. mu.M, 70. mu.M, 90. mu.M, 100. mu.M, 120. mu.M.
And assembling an Ag/AgC reference electrode, a platinum wire counter electrode and a TAPB-PDA-COFs/AuNPs/GCE working electrode into a three-electrode system. After TAPB-PDA-COFs/AuNPs/GCE and enrofloxacin standard solution are incubated for 40s, SWV determination is carried out (in a potential range of +400 mV to +1200 mV by square wave stripping voltammetry, and is carried out at an amplitude of 0.075V and a frequency of 20 Hz), an SWV curve is shown in FIG. 5, an obtained standard curve is shown in FIG. 6, and regression equations are respectively y = 0.2405x + 0.3981 (R is shown in FIG. 6)2= 0.993) and y = 0.0982x + 1.7235 (R)2= 0.993). From the results of the 11 blank samples, a detection limit of 0.041 μmol l was calculated using the formula LOD = 3S/K (S is the standard deviation of the 11 blank samples and K is the slope of the standard sample)-1This indicates that the sensor has a lower detection limit.
And (3) stability experiment verification:
7 sets of TAPB-PDA-COF/AuNPs/GCEs electrodes were prepared under the same conditions to detect ENR and stored in a refrigerator at 4 ℃ for 1-7 days. And calculating the proportion of the peak current of 2-7 days in the first day by taking the peak current of the first day as 100 percent. As can be seen in fig. 7, the electrode maintained 90.2% performance over the first 4 days. The stability of the electrode decreased from day five and did not change significantly until day 7 to 79.6%, indicating good stability.
And (3) actual sample determination:
10 μ L of water samples were taken and prepared by standard addition methods into actual sample solutions of enrofloxacin of known concentration (0, 6 and 54 μmolL) with PBS pH =7-1) The prepared solution volume is 5 mL. The detected concentrations were as follows: undetected, 5.97. + -. 0.07. mu. molL-1、53.67±0.50 μmolL-1(ii) a The detection rates obtained were respectively: not detected, 99.5% and 99.4%.
Detection object and specificity verification thereof:
the specificity of the sensor was evaluated by using the same concentrations (1. mu.M and 100. mu.M) of enrofloxacin, ciprofloxacin, norfloxacin, ofloxacin and the above 4 antibiotic standard mixed solution, and as a result, as shown in FIG. 9, it can be clearly seen from FIG. 9 that the current generated by the enrofloxacin solution and the current generated by the mixed antibiotic solution are much larger than those of other antibiotics, which confirms that the sensor constructed by the present invention has good specificity for detecting enrofloxacin.
The foregoing is considered as illustrative of the preferred embodiments of the invention and is not to be construed as limiting the invention in any way. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention should fall within the protection scope of the technical scheme of the present invention, unless the technical spirit of the present invention departs from the content of the technical scheme of the present invention.

Claims (10)

1. A method for detecting enrofloxacin in a water body is characterized by comprising the following steps:
(1) reacting terephthalaldehyde and 1,3, 5-tri (4-aminophenyl) benzene to generate TAPB-PDA-COFs;
(2) reacting TAPB-PDA-COFs, chloroauric acid and sodium citrate to obtain a TAPB-PDA-COFs/AuNPs composite material;
(3) modifying the TAPB-PDA-COFs/AuNPs composite material on the surface of a glassy carbon electrode to prepare a modified electrode;
(4) assembling the modified electrodes into a three-electrode system of an electrochemical workstation, detecting the oxidation current in the water body by using a square wave stripping voltammetry method, and calculating the enrofloxacin content in the water body by contrasting with a standard curve.
2. The method according to claim 1, wherein in the step (1), the mass ratio of terephthalaldehyde to 1,3, 5-tris (4-aminophenyl) benzene is 0.05: 0.095.
3. the method of claim 1, wherein in the step (1), the specific process for obtaining TAPB-PDA-COFs is: adding terephthalaldehyde and 1,3, 5-tri (4-aminophenyl) benzene into dimethyl sulfoxide, performing ultrasonic dispersion uniformly, adding acetic acid under an ultrasonic condition, dispersing uniformly, performing sealed incubation on the obtained solution at room temperature for 20-40 min, and finally centrifuging, washing and drying to obtain TAPB-PDA-COFs.
4. The method of claim 1, wherein in the step (2), the mass ratio of TAPB-PDA-COFs to chloroauric acid and sodium citrate is 30-35: 4: 1.
5. the method of claim 1, wherein in the step (2), the TAPB-PDA-COFs/AuNPs composite material is obtained by the following specific process: ultrasonically dispersing TAPB-PDA-COFs in water, adding a sodium citrate aqueous solution, magnetically stirring and heating to boil, quickly adding chloroauric acid, keeping the solution system boiling, continuously stirring until the solution becomes reddish brown and the color does not change any more, centrifuging, washing and drying to obtain the TAPB-PDA-COFs/AuNPs composite material.
6. The method of any one of claims 1 to 5, wherein in the step (3), the specific process of modifying the TAPB-PDA-COFs/AuNPs composite material on the surface of the glassy carbon electrode comprises the following steps: adding the TAPB-PDA-COFs/AuNPs composite material into ultrapure water for ultrasonic treatment to obtain a homogeneous solution; and then dripping the homogeneous phase solution on the surface of a clean and dry glassy carbon electrode, dripping the chitosan solution on the surface of the glassy carbon electrode to fix the compound after the homogeneous phase solution is dried, and drying at room temperature under a dark condition to obtain the TAPB-PDA-COFs/AuNPs/GCE electrode.
7. The method of claim 6, wherein the homogeneous solution has a concentration of 1 mg/mL; the mass concentration of the chitosan solution is 0.5%.
8. The method of any one of claims 1 to 5, wherein in step (3), the amount of modification of the TAPB-PDA-COFs/AuNPs composite material on the surface of the glassy carbon electrode is 2 to 10 μ L.
9. The method of any one of claims 1 to 5, wherein in step (4), the three-electrode system uses Ag/AgCl as a reference electrode, a platinum wire as a counter electrode, and a TAPB-PDA-COFs/AuNPs/GCE electrode as a working electrode; the potential range detected by the square wave stripping voltammetry is +400 mV to +1200 mV, the amplitude is 0.075V, and the frequency is 20 Hz.
10. The method of claim 9, wherein the body of water to be tested is added with a PBS buffer solution of pH = 7.
CN202011461753.4A 2020-12-14 2020-12-14 Method for detecting enrofloxacin in water body Active CN112229891B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011461753.4A CN112229891B (en) 2020-12-14 2020-12-14 Method for detecting enrofloxacin in water body

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011461753.4A CN112229891B (en) 2020-12-14 2020-12-14 Method for detecting enrofloxacin in water body

Publications (2)

Publication Number Publication Date
CN112229891A CN112229891A (en) 2021-01-15
CN112229891B true CN112229891B (en) 2021-03-16

Family

ID=74124897

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011461753.4A Active CN112229891B (en) 2020-12-14 2020-12-14 Method for detecting enrofloxacin in water body

Country Status (1)

Country Link
CN (1) CN112229891B (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113333024B (en) * 2021-05-31 2022-03-25 云南大学 Magnetic nano enzyme material with peroxidase catalytic activity, kit for detecting norovirus and application thereof
CN114047341B (en) * 2021-11-18 2022-10-18 云南大学 Biological probe and biological immunosensor for detecting bungarus venosus and method for detecting bungarus venosus based on proportional signal
CN117225377B (en) * 2023-08-10 2024-05-03 石家庄市疾病预防控制中心（石家庄市卫生检测中心） Core-shell structure covalent organic framework material, preparation method and application thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109851807A (en) * 2019-01-11 2019-06-07 郑州赫诺瑞信息科技有限公司 Py-M-COF and its electrochemical sensor and application
CN111454459A (en) * 2020-02-28 2020-07-28 南开大学 Covalent organic framework material of bionic photosystem I, preparation and application thereof
CN111650320A (en) * 2020-07-03 2020-09-11 中国检验检疫科学研究院 Detection method and kit for quinolone veterinary drugs based on magnetic solid-phase extraction

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109851807A (en) * 2019-01-11 2019-06-07 郑州赫诺瑞信息科技有限公司 Py-M-COF and its electrochemical sensor and application
CN111454459A (en) * 2020-02-28 2020-07-28 南开大学 Covalent organic framework material of bionic photosystem I, preparation and application thereof
CN111650320A (en) * 2020-07-03 2020-09-11 中国检验检疫科学研究院 Detection method and kit for quinolone veterinary drugs based on magnetic solid-phase extraction

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
A novel AuNPs-doped COFs composite as electrochemical probe for chlorogenic acid detection with enhanced sensitivity and stability;Ting Zhang, et al;《Sensors and Actuators B: Chemical》;20180827;第362-369页 *
Controlled growth of imine-linked two dimensional covalent organic framework;Rebecca L. Li,et al;《Chem. Sci.》;20191031;第3796-3801页 *
Covalent organic framework-based electrochemical aptasensors for the ultrasensitive detection of antibiotics;Minghua Wang,et al;《Biosensors and Bioelectronics》;20190221;第8-16页 *
基于多孔金属及共价有机框架材料的电化学生物传感器在疾病标记物检测中的应用;白茹燕;《中国优秀硕士学位论文全文数据库 医药卫生科技辑》;20180215;第8页 *

Also Published As

Publication number Publication date
CN112229891A (en) 2021-01-15

Similar Documents

Publication Publication Date Title
CN112229891B (en) Method for detecting enrofloxacin in water body
Zhou et al. Two-dimensional oriented growth of Zn-MOF-on-Zr-MOF architecture: A highly sensitive and selective platform for detecting cancer markers
Qiu et al. An electrochemical ratiometric sensor based on 2D MOF nanosheet/Au/polyxanthurenic acid composite for detection of dopamine
Yuan et al. Design and fabrication of an electrochemical sensing platform based on a porous organic polymer for ultrasensitive ampicillin detection
Liu et al. Three-dimensional electrochemical immunosensor for sensitive detection of carcinoembryonic antigen based on monolithic and macroporous graphene foam
Kalambate et al. Mesoporous Pd@ Pt core–shell nanoparticles supported on multi-walled carbon nanotubes as a sensing platform: application in simultaneous electrochemical detection of anticancer drugs doxorubicin and dasatinib
Ensafi et al. Simultaneous determination of guanine and adenine in DNA based on NiFe2O4 magnetic nanoparticles decorated MWCNTs as a novel electrochemical sensor using adsorptive stripping voltammetry
Wu et al. A novel molecularly imprinted electrochemiluminescence sensor for isoniazid detection
Qi et al. Label-free alpha fetoprotein immunosensor established by the facile synthesis of a palladium–graphene nanocomposite
Jia et al. High‐Sensitivity Determination of Lead (II) and Cadmium (II) Based on the CNTs‐PSS/Bi Composite Film Electrode
Li et al. Nonenzymatic immunosensor for detection of carbohydrate antigen 15-3 based on hierarchical nanoporous PtFe alloy
Mazloum‐Ardakani et al. Ultrasensitive electrochemical immunosensor for detection of tumor necrosis factor‐α based on functionalized MWCNT‐Gold Nanoparticle/Ionic Liquid Nanocomposite
Lan et al. Cu (II) metal-organic framework encapsulated in carbon paste electrode for high-performance non-enzymatic glucose sensing
Zhang et al. Lectin-based electrochemical biosensor constructed by functionalized carbon nanotubes for the competitive assay of glycan expression on living cancer cells
Wei et al. A novel impedimetric aptasensor based on AuNPs–carboxylic porous carbon for the ultrasensitive detection of ochratoxin A
CN109100408B (en) Method for detecting glutathione in human serum based on FePc/N, B-rGO modified electrode
Zil’berg et al. A chiral voltammetric sensor based on a paste electrode modified by cyanuric acid for the recognition and determination of tyrosine enantiomers
Zhu et al. Ratiometric electrochemical sensing based on Mo 2 C for detection of acetaminophen
Zil’berg et al. Enantioselective voltammetric sensors based on amino acid complexes of Cu (II), Co (III), and Zn (II)
Zhai et al. Core-shell composite N-doped-Co-MOF@ polydopamine decorated with Ag nanoparticles for nonenzymatic glucose sensors
Xia et al. An electrochemical sensor for the sensitive detection of rutin based on a novel composite of activated silica gel and graphene
Cheng et al. Electrochemical sensor for sensitive detection of luteolin based on multi-walled carbon nanotubes/poly (3, 4-ethylenedioxythiophene)–gold nanocomposites
Khan et al. Molecular imprinted polymer based impedimetric sensor for trace level determination of digoxin in biological and pharmaceutical samples
CN109187687B (en) Preparation of conjugated organic microporous material modified electrode and application of modified electrode as peroxynitroso anion electrochemical sensor
Zou et al. Enzyme biosensors systems based on Co-modification of carbon nanotubes and enzyme for detection of glucose in food

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant
CB03 Change of inventor or designer information
CB03 Change of inventor or designer information

Inventor after: Ding Ping

Inventor after: Lu Siyu

Inventor after: Kaitianhan

Inventor after: Wang Shanlin

Inventor after: Wu Pian

Inventor after: Chen Cuimei

Inventor after: Huang Ruixue

Inventor before: Ding Ping

Inventor before: Lu Siyu

Inventor before: Kaitianhan

Inventor before: Wang Shanlin

Inventor before: Wu Pian

Inventor before: Chen Cuimei

Inventor before: Huang Ruixue