CN111426736B - Preparation method of CoAl-LDH/PANI modified electrode - Google Patents
Preparation method of CoAl-LDH/PANI modified electrode Download PDFInfo
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- CN111426736B CN111426736B CN202010462325.7A CN202010462325A CN111426736B CN 111426736 B CN111426736 B CN 111426736B CN 202010462325 A CN202010462325 A CN 202010462325A CN 111426736 B CN111426736 B CN 111426736B
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- 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
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
- G01N27/308—Electrodes, e.g. test electrodes; Half-cells at least partially made of carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y40/00—Manufacture or treatment of nanostructures
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
- C08G73/02—Polyamines
- C08G73/026—Wholly aromatic polyamines
- C08G73/0266—Polyanilines or derivatives thereof
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/13—Energy storage using capacitors
Abstract
The invention discloses a preparation method of a CoAl-LDH/PANI modified electrode, which comprises the following specific steps: s1, preparation of hydrotalcite-like LDH: with hydrophobic ionic liquid BmimPF 6 Preparing a mixed salt microemulsion A and an alkali microemulsion B by taking a TX-100 and water microemulsion system as media, and preparing 3 CoAl-LDH samples by adopting a double microemulsion coprecipitation method according to different water contents in the microemulsions; s2, preparing polyaniline PANI: preparing PANI by adopting a double microemulsion method; s3, preparing CoAl-LDH/PANI; s4, preparation of CoAl-LDH/PANI modified electrode. The invention discloses a preparation method of a CoAl-LDH/PANI modified electrode, and the preparation of the modified electrode is carried out, so that the electrochemical activity of the electrode is increased, and the simultaneous determination of pesticides carbaryl and isoprocarb by the CoAl-LDH/PANI modified electrode is realized.
Description
Technical Field
The invention relates to the field of modified electrode preparation, in particular to a preparation method of a CoAl-LDH/PANI modified electrode.
Background
The carbaryl and isoprocarb belong to carbamate pesticides and are widely applied to the control of agricultural pests. However, because of pesticide residues, the carbamate substances enter human bodies to cause adverse reactions such as headache, vomit, diarrhea, urinary incontinence, bronchospasm, dyspnea and the like, and even threaten the lives of human beings. Therefore, a rapid, high-sensitivity and high-selectivity detection method is urgently needed to be established. The analysis technologies commonly used at present comprise gas chromatography/mass spectrometry, high performance liquid chromatography/mass spectrometry and fluorescent biological probes, and although the methods have high sensitivity, selectivity and accuracy for the determination of pesticides, the methods have the defects of expensive instruments, complex sample pretreatment process, incapability of being used for on-site real-time detection and the like, so that the application of the methods is limited. Compared with the prior art, the electrochemical method has the advantages of fast response, simple manufacture, high sensitivity, good selectivity, convenient operation, low cost and the like. Therefore, the establishment of the electrochemistry for simultaneously detecting the carbaryl and the isoprocarb with high sensitivity, high selectivity and good stability has important significance. However, the key to improving the sensitivity and stability of electrochemical detection is the design and synthesis of electrode modifying materials.
Hydrotalcite-like materials are a new class of two-dimensional layered nanomaterials. The catalyst has larger theoretical specific surface area, flexible and adjustable electronic performance and better catalytic activity, and is widely applied to the field of electrochemical sensing. However, the hydrotalcite-like materials prepared by coprecipitation, hydrothermal synthesis and other methods generally have large and non-uniform particle sizes and are in a block shape, which causes great loss of active area and active sites, and the simple small-particle size hydrotalcite-like materials are easy to aggregate and have poor electrical conductivity in the application process, which greatly limits the application of the materials. Therefore, the preparation of hydrotalcite-like composite materials becomes an effective method.
Conductive polyaniline is a widely used conductive polymer material, and is widely used in the fields of electronics, optics, electrochemistry and the like due to the characteristics of high conductivity, low cost, high chemical durability, good environmental stability, easy synthesis and the like. However, polyaniline prepared by the traditional synthesis method is often large in size and unstable in the application process, and the conductivity and the electrochemical catalytic performance of the polyaniline are influenced.
In order to solve the defects existing when the materials are used independently, the invention respectively synthesizes the CoAl-LDH nano-sheet and the polyaniline fiber by adopting an inverse microemulsion method, then prepares a CoAl-LDH/PANI nano-sheet compound by an ultrasonic physical mixing method, prepares a modified electrode and is used for simultaneously detecting the carbaryl and the isoprocarb. The CoAl-LDH nanosheet prepared by adopting the reverse microemulsion method is thin in thickness, small and uniform in size, smaller in PANI size and regular in appearance. The prepared CoAl-LDH/PANI nanosheet composite not only can fully utilize the large specific surface area and fully exposed active sites of the CoAl-LDH nanosheets, but also improves the conductivity of the material by doping PANI. Due to the interaction between the two, the problem of mutual aggregation is inhibited, the stability in the PANI application process is enhanced, and the specific surface area and the dispersity of the material are improved. Fully exerts the synergistic effect of the CoAl-LDH nanosheets and the PANI, and makes up for the defects of the CoAl-LDH nanosheets and the PANI when the CoAl-LDH nanosheets and the PANI are used independently. The detection platform for the carbaryl and the isoprocarb prepared by the CoAl-LDH/PANI nanosheet composite can adsorb more carbaryl and isoprocarb molecules to the surface of an electrode, improves the electrocatalytic activity of two detection objects, improves the detection sensitivity, and has important significance for establishing a novel high-sensitivity electrochemical detection method.
Disclosure of Invention
In view of the above, the invention provides a preparation method of a CoAl-LDH/PANI modified electrode, which comprises the steps of preparing hydrotalcite-like LDH and polyaniline PANI to form CoAl-LDH/PANI/GCE, preparing the modified electrode, increasing the electrochemical activity of the electrode, and successfully fixing a CoAl-LDH/PANI film on the surface of the electrode.
In order to achieve the purpose, the technical scheme adopted by the invention is as follows:
a preparation method of a CoAl-LDH/PANI modified electrode comprises the following specific steps:
s1, preparation of hydrotalcite-like LDH:
with hydrophobic ionic liquid BmimPF 6 Taking TX-100 and a water microemulsion system as media to prepare a mixed salt microemulsion A and an alkali microemulsion B, wherein the water phase of the mixed salt microemulsion A is Co (NO) 3 ) 2 ·6H 2 O、Al(NO 3 ) 3 ·9H 2 The water phase of the alkali microemulsion B is NaOH water solution;
according to different water contents in the microemulsion, a double microemulsion coprecipitation method is adopted, the alkali microemulsion B is dropwise added into the mixed salt microemulsion A, the mixed salt microemulsion A is mixed and stirred for 12 hours at room temperature, the mixture is kept stand and aged for 12 hours, centrifuged for 10 minutes at 10000r, sequentially washed by ethanol and water,obtaining a jelly-like CoAl-LDH gel: CoAl-LDH 0.25 ，CoAl-LDH 0.2 And CoAl-LDH 0.1 ；
S2, preparation of polyaniline PANI:
preparing an aniline microemulsion A and an initiator microemulsion B by adopting the microemulsion system; adopting a double-microemulsion method, dropwise adding an initiator microemulsion B into an aniline microemulsion A under the ice-water bath condition, stirring and mixing, reacting for 8 hours, centrifuging at 10000r for 10 minutes, and washing with ethanol and water in sequence to obtain emerald PANI;
s3, preparation of CoAl-LDH/PANI:
mixing CoAl-LDH and PANI according to the mass ratio of 1:1 of CoAl-LDH to PANI, performing ultrasonic mixing reaction on ethanol dispersion of a CoAl-LDH sample and PANI ethanol dispersion for 6h, centrifuging at 10000r for 10min, washing with deionized water to obtain the CoAl-LDH respectively 0.25 /PANI，CoAl-LDH 0.2 Per PANI and CoAl-LDH 0.1 /PANI；
Weighing CoAl-LDH 0.1 With CoAl-LDH 0.1 Respectively preparing CoAl-LDH with PANI mass ratio of 1:2 and 2:1 0.1 /PANI 1/2 And CoAl-LDH 0.1 /PANI 2/1 The mass ratio of the obtained product to CoAl-LDH to PANI is 1:1 0.1 /PANI 1/1 Comparing;
s4, preparation of CoAl-LDH/PANI modified electrode:
polishing and grinding a glassy carbon electrode GCE with the diameter of 3mm to a mirror surface by using alumina powder, respectively carrying out ultrasonic washing in a mixed solution of dilute nitric acid and ethanol, and washing by using deionized water; preparing an ethanol dispersion liquid with the concentration of 1mg/mL by using the CoAl-LDH/PANI sample, transferring 2 mu L of CoAl-LDH/PANI dispersion liquid by using a liquid transfer gun, dripping the CoAl-LDH/PANI dispersion liquid on the surface of the treated GCE, and drying at room temperature under a clean state to obtain the modified electrode CoAl-LDH/PANI/GCE.
Preferably, in the step S1, the three-component contents of the mixed salt microemulsion a and the alkali microemulsion B are the same; the water content of microemulsion A was different, and the water phase of microemulsion A was 0.2M Co (NO) 3 ) 2 ·6H 2 O, 0.1M Al (NO) 3 ) 3 ·9H 2 Aqueous mixed salt solution of O, aqueous phase of microemulsion B0.7M aqueous NaOH solution.
Preferably, in the step S1, CoAl-LDH is prepared 0.25 ，CoAl-LDH 0.2 、CoAl-LDH 0.1 The volume percentages of the microemulsion system for the three samples are respectively: LDH 0.25 BmimPF of 6 TX-100, water 1.25:36.25: 12.5; LDH 0.2 BmimPF of 6 TX-100, water is 1.25:38.75: 10; LDH 0.1 BmimPF of 6 TX-100, water 1.25:43.75: 5; the total volume is 50mL, and the volume ratio of the water content in the three microemulsion systems is 0.25, 0.2 and 0.1 respectively.
Preferably, in the step S2, the volume ratio of the components of the microemulsion system is BmimPF 6 TX-100 and water 0.025:0.725: 0.25.
Preferably, in step S2, the preparation method of the aniline microemulsion a is as follows: the preparation method of the aniline microemulsion A comprises the following steps: 0.2 to 0.8mL of aniline solution is taken, 1 to 1.6mL of concentrated hydrochloric acid and 7.05mL of deionized water are added, after uniform ultrasonic mixing, 26.1mL of TX-100 and 0.5 to 1.3mL of BMIMPF are added 6 Stirring uniformly; the preparation method of the initiator microemulsion B comprises the following steps: accurately weighing 0.3-0.9g ammonium persulfate to be dissolved in 3.5mL deionized water, adding 9.50-10.50mL TX-100 and 0.35mL BmimPF 6 And (5) stirring uniformly.
The application of the preparation method of the CoAl-LDH/PANI modified electrode is characterized in that the modified electrode prepared by the method is used for simultaneously detecting pesticides carbaryl and isoprocarb.
By adopting the technical scheme, the invention has the following beneficial effects:
the electrode material of the CoAl-LDH/PANI nanosheet composite modified electrode is prepared by respectively preparing the CoAl-LDH nanosheets and the conductive PANI by adopting a reverse microemulsion method and then by adopting an ultrasonic physical mixing method, and the preparation method is simple.
The CoAl-LDH/PANI nanosheet composite modified electrode plays a synergistic effect of CoAl-LDH and PANI in the aspect of electrocatalysis of carbaryl and isoprocarb: the CoAl-LDH nanosheet obtained by the reverse microemulsion method is thin, small and uniform in size, fully exposed at an active site, and simultaneously provides a support for the load of PANI in the composite; the conductive PANI obtained by the method is small in size, has better stability, conductivity and electrochemical catalytic performance, and improves the conductivity of the composite material by doping; the synergistic effect of the two improves the stability of PANI, inhibits the aggregation of the PANI and the modified electrode, and improves the adsorption and capture capacity of the modified electrode on the detected object.
The CoAl-LDH/PANI nanosheet composite modified electrode has the advantages that a wider linear range (0.001-150 mu M) and a lower detection limit (6.8 nM isoprocarb 8.1nM) are obtained in the aspect of simultaneous detection of the carbaryl and the isoprocarb, the oxidation peak potential difference is larger, so that simultaneous detection of the carbaryl and the isoprocarb can be well realized, the detection method is good in stability and high in sensitivity.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required in the description of the embodiments are briefly introduced below, the drawings in the description below are merely the embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.
FIG. 1 is a CoAl-LDH 0.25 、CoAl-LDH 0.2 、CoAl-LDH 0.1 PANI and CoAl-LDH 0.1 Scanning electron microscopy of/PANI;
FIG. 2 is a CoAl-LDH 0.1 PANI and CoAl-LDH 0.1 A Fourier infrared spectrogram of/PANI;
FIG. 3 is CoAl-LDH 0.1 PANI and CoAl-LDH 0.1 X-ray diffraction pattern of/PANI;
FIG. 4 shows different materials in [ Fe (CN) ] 6 ] 3-/4- Cyclic voltammogram (a) and impedance plot (B) in solution;
FIG. 5 shows different materials at 5mM [ Fe (CN) ] containing 0.1M KCl 6 ] 3-/4- Cyclic voltammogram (a) and impedance plot (B) in solution;
FIG. 6 shows different materials at 5mM [ Fe (CN) ] containing 0.1M KCl 6 ] 3-/4- Cyclic voltammetric behavior in solution (a) and effect on peak current (B);
FIG. 7 is a CV diagram of different materials in 0.2M KOH solution without carbaryl and isoprocarb (A) and 0.2M KOH with 0.1mM carbaryl and 0.1mM isoprocarb (B);
FIG. 8 is CoAl-LDH 0.1 Electrochemical behavior of/PANI/GCE in a blank (a), in KOH solution (0.2M) containing 0.1mM carbaryl (c), 0.1mM isoprocarb (b) and a mixture of 0.1mM carbaryl and isoprocarb (d);
FIG. 9 shows different CoAl-LDHs 0.1 Influence of PANI concentration and modification amount on peak current;
FIG. 10 is a graph of the effect of the enrichment time (A) and the enrichment potential (B) on peak current;
FIG. 11 is a CV curve (A) and the effect on peak current (B) of simultaneous detection of carbaryl and isoprocarb in different concentrations of KOH solution (a to e: 0.1, 0.2, 0.3, 0.4, 0.5M);
FIG. 12 shows the concentration of carbaryl and isoprocarb in CoAl-LDH 0.1 DPV plots on/PANI/GCE;
FIG. 13 shows the concentration of carbaryl in CoAl-LDH 0.1 Current response (0.001 to 150 μ M) for/PANI/GCE (A) and linear relationship of peak current to concentration (B);
FIG. 14 shows different concentrations of isoprocarb in CoAl-LDH 0.1 Current response (0.001 to 150 μ M) for/PANI/GCE (A) and linear relationship of peak current to concentration (B);
FIG. 15 is a DPV graph of common phenols, pesticides and carbaryl, isoprocarb, in KOH solution (0.2M);
FIG. 16 is CoAl-LDH 0.1/ PANI/GCE anti-interference detection;
FIG. 17 shows GCE (a), CoAl-LDH 0.25 /GCE(b)，CoAl-LDH 0.2 (ii)/GCE (c) and CoAl-LDH 0.1 (d) in 5.0mM [ Fe (CN) ]containing 0.1M KCl 6 ] 3-/4- Cyclic voltammetry behavior in solution (a) and alternating impedance profile (B);
FIG. 18 shows GCE (a), CoAl-LDH 0.25 /GCE(b)，CoAl-LDH 0.2 (ii)/GCE (c) and CoAl-LDH 0.1 CV diagram in KOH solution (0.2M) containing 0.1mM carbaryl and 0.1mM isoprocarb;
FIG. 19 is a CoAl-LDH 0.1 The mixture was subjected to GCE in blank (a), containing 0.1mM carbaryl (b), containing 0.1mM isoprocarb(c) And electrochemical behavior of 0.1mM carbaryl and isoprocarb mix (d) in KOH solution (0.2M);
FIG. 20 is a graph of different CoAl-LDHs 0.1 The effect of the modifier on the peak current;
FIG. 21 is a graph of the effect of different concentrations of KOH solutions;
FIG. 22 is CoAl-LDH 0.1 The influence of the enrichment time (A) and the enrichment potential (B) on the peak currents of carbaryl and isoprocarb;
FIG. 23 shows the concentration of carbaryl in CoAl-LDH 0.1 Current response (0.05 to 150 μ M) for the/GCE (A) and linear relationship of peak current to concentration (B);
FIG. 24 shows different concentrations of isoprocarb in CoAl-LDH 0.1 Current response (0.05 to 150. mu.M) of/GCE (A) and linear relationship of peak current to concentration (B).
Detailed Description
The technical solutions in the embodiments of the present invention are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The method is adopted to prepare the CoAl-LDH/PANI/GCE for the electrode, and data in the CoAl-LDH/PANI/GCE are optimized, and the specific preparation and experimental processes are as follows:
a preparation method of CoAl-LDH/PANI/GCE for an electrode comprises the following specific steps:
s1, preparing hydrotalcite-like LDH reagent:
selection of hydrophobic ionic liquid BmimPF 6 TX-100 and water microemulsion system, A, B two microemulsions are prepared, the water phase of microemulsion A is Co (NO) 3 ) 2 ·6H 2 O、Al(NO 3 ) 3 ·9H 2 Preparing 3 LDH samples according to different proportions of the three components of the microemulsion B by using a NaOH solution as a water phase of the microemulsion B;
the three components of the microemulsion A, B have the same content, and the water phases have different compositions; microemulsion A had an aqueous phase of 0.2M Co (N)O 3 ) 2 ·6H 2 O, 0.1M Al (NO) 3 ) 3 ·9H 2 O solution, wherein the water phase of the microemulsion B is 0.7M NaOH solution;
the 3 LDH samples were LDH 0.25 ，LDH 0.2 ，LDH 0.1 The proportion is as follows according to volume percentage: LDH 0.25 BmimPF of 6 TX-100, water 1.25:36.25: 12.5; LDH 0.2 BmimPF of 6 TX-100, water 1.25:38.75: 10; LDH 0.1 BmimPF of 6 TX-100, water is 1.25:43.75: 5;
s2, preparation of CoAl LDH:
dropwise adding the microemulsion B into the microemulsion A by adopting a double microemulsion method, mixing and stirring at room temperature for 12h, standing and aging for 12h, centrifuging at 10000r for 10min, and sequentially washing with ethanol and water to obtain a jelly-like LDH gel: CoAl-LDH 0.25 ，CoAl-LDH 0.2 And CoAl-LDH 0.1 ；
S3, preparing a polyaniline PANI reagent:
preparing microemulsions A and B by adopting the microemulsion system, taking 0.2-0.8mL of aniline solution, adding 1-1.6mL of concentrated hydrochloric acid and 7.05mL of deionized water, ultrasonically mixing, adding 26.1mL of TX-100 and 0.5-1.3mL of BmimPF6, uniformly stirring to obtain microemulsion A, weighing 0.3-0.9g of ammonium persulfate, dissolving in 3.5mL of deionized water, adding 9.50-10.50mL of TX-100 and 0.35mL of BmimPF6, and uniformly stirring to obtain microemulsion B;
s4, preparation of PANI:
dropwise adding the microemulsion B into the microemulsion A by adopting a double-microemulsion method under the ice-water bath condition, stirring and mixing, reacting for 8 hours, centrifuging at 10000r for 10min, and sequentially washing with ethanol and water to obtain emerald PANI;
s5, preparation of CoAl-LDH/PANI:
mixing the CoAl-LDH and the PANI in proportion, and performing ultrasonic mixing for 6 hours to obtain the CoAl-LDH 0.25 /PANI，CoAl-LDH 0.2 Per PANI and CoAl-LDH 0.1 /PANI, 10000r centrifugal washing for 10min, researching the doping amount ratio of LDH and PANI, respectively selecting the mass ratio of CoAl-LDH 0.1 /PANI＝1:2，CoAl-LDH 0.1 2:1 with CoAl-LDH in the above conditions 0.1 Carrying out ultrasonic hybridization on the/PANI (1:1) to obtain CoAl-LDH0.1/PANI nano compounds with different proportions;
s6, preparing CoAl-LDH/PANI/GCE:
polishing and grinding a glassy carbon electrode GCE with the diameter of 3mm by using alumina powder, ultrasonically washing in a mixed solution of dilute nitric acid and ethanol, washing by using deionized water, and washing by using CoAl-LDH 0.1 the/PANI is prepared into 1mg/mL solution, and 2 mu L of Co-Al is transferred by a liquid transfer gun 0.1 Coating the suspension liquid of-LDH/PANI on the surface of a polished glassy carbon electrode, keeping the surface clean, drying at room temperature, and obtaining the CoAl-LDH for the electrode 0.1 /PANI/GCE。
Structure and shape characterization analysis
(1) Scanning electron microscope SEM is shown in FIG. 1, as shown in the figure, (A), (B) and (C) are SEM of hydrotalcite prepared by reversed-phase microemulsion according to different mixture ratios, and it can be seen from the figure that the CoAl-LDH prepared by the method presents a sheet structure and has a thickness of several nanometers. The size of the hydrotalcite prepared is smaller and more uniform as the proportion of the aqueous phase in the formulation is reduced, and the size of (C) is the smallest, about 100 nm. Graph (D) is an SEM of hydrochloric acid doped conductive PANI, from which it can be seen that the synthetic PANI exhibits a relatively smooth nanotube shape with dimensions around 200 nm. (E) Is CoAl-LDH 0.1 SEM of/PANI. The figure shows that CoAl-LDH in the complex 0.1 The lamellar structure of the sheet is destroyed to some extent and its surface is covered with a relatively uniform fibrillated nano-thin PANI layer. Attached to CoAl-LDH compared to PANI alone 0.1 The PANI size of the surface is smaller.
(2) The Fourier infrared spectrum (FT-IR) is shown in FIG. 2 and is CoAl-LDH 0.1 PANI and CoAl-LDH 0.1 Infrared spectrum of/PANI. In the infrared spectrum of LDH, at 3439cm -1 the-OH characteristic stretching vibration peak of the hydroxyl group of the hydrotalcite-like layer or the interlayer water molecule appears. 1637cm -1 The left and right peaks correspond to bending vibration of crystal water, and are 1362cm -1 Due to CO 3 2- C-O stretching vibration peak in (1). Furthermore, less than 1100cm -1 The absorption band of (A) is due to hydrotalcite-like interlayer M-O and O-M-OCharacteristic lattice vibration peak of (1). In the infrared spectrum of PANI, at 3435cm -1 The absorption peak is broad and strong, which not only indicates the-NH stretching vibration of amino group and imino group, but also may contain moisture. At 2921 and 2851cm -1 The absorption peaks at the left and right correspond to-NH 2 Vibration of-C 6 H 4 NH 2+ C 6 H 4 -a group. At 1560 and 1466cm -1 The absorption peaks at (a) are attributed to C ═ N and C ═ C stretching vibrations which are the quinone ring and the benzene ring. At 1292cm -1 Is caused by C-N stretching of the benzene compound. At 1115cm -1 The absorption peak at (a) is the stretch band of N ═ Q ═ N, which is the characteristic absorption peak of polyaniline base. At 869cm -1 The absorption peak of (2) is the C-H stretching vibration of the benzene ring. CoAl-LDH 0.1 FT-IR spectra of/PANI nanocomposites showed characteristic absorption peaks for PANI and LDH, respectively, indicating successful preparation of CoAl-LDH 0.1 /PANI nano-composite.
(3) The X-ray diffraction (XRD) patterns are shown in FIG. 3, which are respectively CoAl-LDH 0.1 PANI and CoAl-LDH 0.1 XRD spectrum of/PANI. Analysis can show that LDH exhibits CoAl-LDH at 2 theta 11.9 ° (003), 23.4 ° (006), 34.5 ° (012), 38.8 ° (015), 50.1 ° (018), 61.1 ° (110) and 62.5 ° (113) 0.1 And the nanometer sheet diffraction peak shows that the nanometer composite maintains the layered structure of hydrotalcite-like compound. In the XRD pattern of PANI, two broad diffraction peaks at 20.96 ° (020) and 25.82 ° (200) at 2 θ are due to periodic parallelism and periodic perpendicularity of the polymer chains. While the peak at 17.58 ° 2 θ may be caused by Ammonium Persulfate (APS), a reagent added in PANI synthesis. Simultaneous CoAl-LDH 0.1 The XRD pattern of/PANI shows that the diffraction peaks near 2 θ of 8.85 ° (003), 14.74 ° (006), 60.1 ° (110) and 62.2 ° (113) are associated with hydrotalcite-like compounds. In addition, the diffraction peak that can be observed at 25.38 ° (200) is attributed to PANI. The diffraction peaks for APS initiators were assigned 2 θ -17.58 ° (-101) and 29.48 ° (121). Combined with FT-IR, the successful preparation of CoAl-LDH is more proved 0.1 /PANI。
(II) electrochemical characterization analysis
CoAl-LDH for the examples 0.1 Electrochemical testing was performed on/PANI/GCEThe method comprises the following steps:
inserting a three-electrode system in KOH solution to obtain CoAl-LDH 0.1 The method comprises the steps of taking/PANI/GCE as a working electrode, researching electrochemical behaviors of carbaryl and isoprocarb with different modification amounts and different concentrations of KOH solution by using CV within a potential range of 0-0.8V, measuring DPV and i-t of the carbaryl and isoprocarb solutions with different concentrations under the optimal experimental condition, and finally measuring a recovery rate experiment.
(1) Electrochemical characterization of glassy carbon electrodes modified with different materials
As shown in FIG. 4, (A) shows GCE (a), CoAl-LDH 0.1 /GCE(b)，PANI/GCE(c)，CoAl-LDH 0.1 (d) at 5mM [ Fe (CN) 6 ] 3-/4- (1:1) Cyclic voltammograms at a scan rate of 100mV/s in solution. GCE (curve a) exhibited a pair of reversible redox peaks with a peak potential difference (. DELTA.Ep) of 119 mV. When the target product CoAl-LDH 0.1 After the/PANI compound is modified on a glassy carbon electrode, the electrode CoAl-LDH is modified 0.1 The increase in peak current, Δ Ep, of/PANI/GCE (curve d) was 109mV due to the increased electron transfer rate of the hydrotalcite-like compound due to its large specific surface area and the high conductivity of polyaniline, indicating that CoAl-LDH 0.1 the/PANI complex attracts more easily [ Fe (CN) 6 ] 3-/4- 。
Fig. 4(B) shows an impedance plot for three different electrodes. The semi-circle of the electrode in the high frequency region indicates that the electron transfer process is kinetically controlled, while the straight line portion in the low frequency region indicates diffusion controlled. A large semicircle appears in the impedance diagram (curve a) of the bare glassy carbon electrode, which indicates that the electron transfer resistance of the surface of the bare glassy carbon electrode is relatively large. When the target product CoAl-LDH 0.1 the/PANI is modified on the surface of the electrode, and the measured semicircle of the high-frequency region is smaller, so that the impedance value of the modified electrode is obviously reduced (curve d). This result is consistent with the current response in fig. 4 (a). These results indicate that CoAl-LDH 0.1 The electrochemical activity of the electrode is increased by the PANI material due to the high conductivity of polyaniline, and in addition, the characterization result of electrochemical impedance also indicates that the CoAl-LDH has a certain degree of description 0.1 the/PANI film was successfully immobilized on the electrode surface.
(2) Electrochemical characterization of hydrotalcite and polyaniline hybridization modified electrode with different water contents
As shown in FIG. 5, FIG. 5 shows a bare electrode (GCE) and three CoAl-LDH/polyaniline nanosheet composite material modified electrodes (CoAl-LDH) prepared by utilizing a reverse microemulsion method and obtained by hybridizing CoAl-LDH and polyaniline with different water phase ratios 0.25 /PANI/GCE，CoAl-LDH 0.2 /PANI/GCE，CoAl-LDH 0.1 /PANI/GCE) at 5mM [ Fe (CN) with 0.1M KCl 6 ] 3-/4- Cyclic voltammogram (a) and impedance plot (B) in solution. From FIG. 5(A), CoAl-LDH can be obtained 0.1 The current response (curve d) of the/PANI composite material modified electrode in the iron standard is obviously higher than that of the CoAl-LDH 0.25 /PANI composite material modified electrode (curve b) and CoAl-LDH 0.2 the/PANI (curve c) composite material modified electrode. This may be related to the size of the CoAl-LDH prepared with different ratios of the inverse microemulsion. CoAl-LDH 0.1 In the PANI, the size of hydrotalcite combined with polyaniline is smaller, the exposure of active sites is more sufficient, and the doping of polyaniline is relatively uniform. CoAl-LDH in FIG. 5(B) 0.1 The impedance value of/PANI/GCE (curve d) is significantly less than that of CoAl-LDH 0.25 (PANI/GCE (curve b) and Coal-LDH 0.2 The result of the electrode modified by the/PANI/GCE (curve d) composite material is consistent with that of FIG. 5(A), and the CoAl-LDH is well proved 0.1 the/PANI composite material has better electrochemical performance.
(3)CoAl-LDH 0.1 Electrochemical characterization of modified electrode with different doping ratio from PANI
Fig. 6 is an optimization of the doping ratio. Expressed as CoAl-LDH 0.1 (ii)/GCE (a), PANI/GCE (b) and CoAl-LDH with different doping ratios 0.1 /PANI/GCE(CoAl-LDH 0.1 :PANI＝2:1(c)，CoAl-LDH 0.1 :PANI＝1:1(d)，CoAl-LDH 0.1 PANI 2:1(e)) in 5.0mM [ Fe (CN) containing 0.1M KCl 6 ] 3-/4- Cyclic voltammetric behavior in solution (a) and effect on peak current (B).
As can be seen from the figure, CoAl-LDH 0.1 And PANI have a certain influence on the performance of the composite material. As shown in FIG. 6, CoAl-LDH 0.1 And PANIWhen the doping ratio is 1:1, the performance of the composite material modified electrode is best. The possible reason is that when PANI is too low, doping is not uniform, and when PANI is too high, certain active sites are covered, so that the performance of the composite material is reduced.
(4) Electrochemical behavior of carbaryl and isoprocarb on different modified electrodes
FIG. 7 shows (A) GCE (a), CoAl-LDH 0.1 /GCE(b)，PANI/GCE(c)，CoAl-LDH 0.1 CV diagram of/PANI/GCE (d) in 0.2M KOH solution (A) without carbaryl and isoprocarb and in 0.2M KOH with 0.1mM carbaryl and 0.1mM isoprocarb (B). Is a CV diagram measured in a 0.2M KOH solution without carbaryl and isoprocarb. It can be seen from the figure that all electrodes did not have any redox peak, which indicates that the modified material itself has no electrochemical activity and no electrochemical oxidation or reduction action occurs on the electrodes. Fig. 7(B) is a cyclic voltammogram of the scan after the carbaryl and isoprocarb are added (the concentration is 0.1mM), it can be seen that the carbaryl and isoprocarb have oxidation reactions on the surfaces of the three electrodes, a distinct oxidation peak appears, and no reduction peak appears, which indicates that the carbaryl and isoprocarb have an irreversible electrochemical oxidation process on the electrodes.
Comparative GCE (a), CoAl-LDH 0.1 The modified electrodes have oxidation peaks of carbaryl and isoprocarb at the potentials of about 0.214V and 0.371V, and the peak current is gradually increased. Therefore, the hydrotalcite-like compound and the polyaniline modified material play a certain promotion role in the oxidation of the carbaryl and the isoprocarb on the electrode. When CoAl-LDH 0.1 the/PANI composite material is modified on the surface of the glassy carbon electrode, and the oxidation peak current is further maximized. We believe that CoAl-LDH 0.1 The specific surface area of the electrode is increased, and more carbaryl and isoprocarb can be adsorbed. In addition, the addition of polyaniline enhances the electrical conductivity of the electrode, and is favorable for accelerating the electron transmission from carbaryl and isoprocarb to the surface of the electrode. Thus, CoAl-LDH 0.1 the/PANI can promote the electrocatalytic oxidation process of the carbaryl and the isoprocarb.
(5) Carbaryl and isoprocarb in CoAl-LDH 0.1 Electrochemical behavior of/PANI/GCE
FIG. 8 is a study of CoAl-LDH 0.1 Electrochemical behavior of/PANI/GCE in blank KOH solution (0.2M), containing 0.1mM carbaryl, 0.1mM isoprocarb and containing 0.1mM mixture of carbaryl and isoprocarb, respectively. Wherein the CoAl-LDH 0.1 Electrochemical behavior of/PANI/GCE in KOH solution (0.2M) in blank (a), with 0.1mM carbaryl (c), with 0.1mM isoprocarb (b), and with a mixture of 0.1mM carbaryl and isoprocarb (d).
The peak position of the carbaryl is detected to be 0.212V separately, and the peak position of the isoprocarb is detected to be 0.378V. This is substantially consistent with the peak position of carbaryl and isoprocarb detected simultaneously in the mixed solution, indicating that no other chemical reaction occurred between carbaryl and isoprocarb during the mixed solution detection. Besides, in the mixed solution containing the carbaryl and the isoprocarb, the difference between the oxidation peak potentials of the carbaryl and the isoprocarb is 0.214V and 0.371V, which indicates that the two substances can be well detected simultaneously in the mixed solution of the carbaryl and the isoprocarb.
The data optimization process is as follows:
(1) effect of modification concentration and modification amount
FIG. 9 shows different CoAl-LDHs 0.1 Influence of concentration and modification amount of PANI on Peak Current
Prepared CoAl-LDH 0.1 the/PANI composite materials are respectively prepared into suspensions with the concentrations of 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0mg/mL, 2 mu L of the suspensions are taken to be modified on the surface of a naked electrode, and the influence of the composite material concentration on the electrochemical oxidation of the carbaryl (fold line a) and the isoprocarb (fold line b) is examined. As shown in FIG. 9(A), the concentration was 0.5-1.0mg/mL, and the oxidation peak current was increased with the increase in concentration. When the concentration exceeds 1mg/L, the peak current decreases with increasing concentration. Therefore, 1mg/mL is the optimum modification concentration. Fig. 9(B) is a diagram illustrating optimization of the modification amount of the electrode. As can be seen from the figure, the thickness of the modified membrane is influential on the peak current when CoAl-LDH 0.1 When the content of the/PANI is increased from 0 to 10 mu L, the peak current generated by the carbaryl and the isoprocarb is gradually increased, and when the modification amount is more than 10 mu L, the current is obviously reduced. Therefore, 10. mu.L was selected as the maximumThe amount of modification is preferred. When the modification amount is small, the covering amount of the modification liquid on the surface of the electrode is incomplete; when the modification amount is too large, the electrode material is easily dispersed unevenly on the surface of the electrode and the formed modification film is too thick, which affects the electron transfer, resulting in the reduction of oxidation peak current of carbaryl and isoprocarb.
FIG. 10 is a graph showing the effect of the enrichment time (A) and the enrichment potential (B) on the peak current
The graph shows the effect of the accumulation time and the accumulation potential on the peak current. The peak current gradually increased as the enrichment time increased from 0-120s, and then slowly increased with increasing time, tending to plateau. Likewise, peak current appeared to be maximum at-0.2V for the enrichment potential. Therefore, the experiment selects the enrichment time of 120s and the enrichment potential of-0.2V.
(2) Effect of different concentration of KOH solution
The carbaryl and isoprocarb belong to carbamate pesticides, which are unstable and easily hydrolyzed under alkaline conditions, and the hydrolysis process is shown in the following formula. The hydrolysis products are the corresponding phenols and the electrochemical signal is stronger than that measured directly for carbaryl and isoprocarb. According to previous reports, the hydrolysis speed of the carbamate pesticide is increased by about ten times for every pH increase, so that electrochemical detection of carbaryl and isoprocarb is carried out at a higher pH value. The concentration of the KOH solution was investigated, and as shown in FIG. 11, the peak currents of carbaryl and isoprocarb increased with increasing concentration when the KOH solution concentration was 0.1 to 0.2M, and decreased with increasing KOH concentration when the KOH solution concentration was 0.2 to 0.5M. The possible reason is that too high a concentration of alkali may have a certain destructive effect on the material of the modified electrode, resulting in a reduced performance of the modified electrode. A0.2M KOH solution was chosen for the optimal buffer concentration.
(3) Differential Pulse Voltammetry (DPV) study
Study by differential pulse voltammetryCarbamate and isoprocarb with different concentrations in CoAl-LDH 0.1 The electrochemical signal on the electrode is modified by/PANI/GCE. FIG. 12 represents the concentration of carbaryl and isoprocarb in CoAl-LDH 0.1 The concentrations of the a-h curves were 0.01, 0.05, 0.10, 0.50, 1.0, 3.0, 5.0 and 10.0. mu.M in the DPV plot on/PANI/GCE, respectively. The inset is a linear plot of peak current versus concentration. As can be seen from fig. 12, as the concentrations of carbaryl and isoprocarb increased, the oxidation peak currents increased simultaneously. The oxidation peak currents of carbaryl and isoprocarb are linear in the range of 0.01 to 10. mu.M, and FIG. 12(B) is an enlarged view of the change in oxidation peak current in the concentration range of 0.01 to 0.5. mu.M, from which it can be seen that the linear relationship still exists in this concentration range. Calculating a regression equation: carbaryl Ipa (μ a) ═ 1.116C (μ M) -2.046 (R) 2 0.998), isoprocarb Ipa (μ a) — 1.030C (μ M) -0.481 (R) 2 0.996), the detection limits for carbaryl and isoprocarb were calculated to be 8.9 and 9.7nM, respectively.
FIG. 13 represents the concentration of carbaryl in CoAl-LDH 0.1 Current response (0.001 to 150. mu.M) and peak current-concentration linearity of the/PANI/GCE, as shown by CoAl-LDH with stepwise additions of carbaryl at different concentrations 0.1 The current response of the/PANI/GCE is between 0.001 and 150 mu M, and the current response of the modified electrode is gradually enhanced along with the increase of the concentration of the carbaryl. The inset shows the current response of 0.001-1 μ M, which can be seen with the addition of 0.001 μ M carbaryl. The graph B is a linear relationship between the concentration of carbaryl and the current, and shows better linearity in the concentration range of 0.001-150 μ M, and the regression equation is obtained as Ipa (μ A) ═ 1.292C (μ M) +0.125 (R) 2 0.9998), the detection limit was calculated to be 6.8 nM.
Table 1 shows the comparison of detection limits of carbaryl and isoprocarb at different modified electrodes
Wherein the CPE: a carbon paste electrode; SPE: screen printing electrode
As shown in Table 1, compared with the electrochemical detection methods reported in many literatures, the method has wider linear range and lower detection limit when used for simultaneously detecting carbaryl and isoprocarb.
FIG. 14 represents different concentrations of isoprocarb in CoAl-LDH 0.1 Current response (0.001 to 150. mu.M) and peak current to concentration linearity of/PANI/GCE. The figure shows that CoAl-LDH is gradually added into isoprocarb with different concentrations 0.1 The current response of the/PANI/GCE is gradually enhanced along with the increase of the concentration of the isoprocarb in the concentration range of 0.001-150 mu M. The inset shows the current response of 0.001-0.5. mu.M, and it can be seen that there is also a current response when 0.001. mu.M carbaryl is added. Graph B is a linear plot of isoprocarb concentration versus current, showing better linearity at concentrations ranging from 0.001 to 150 μ M, and the regression equation is given by Ipa (μ A) 1.039C (μ M) +0.121 (R) 2 0.9997), the detection limit was calculated to be 8.1 nM.
(4) Interference
The interference of some common phenols and pesticides on the detection of carbaryl and isoprocarb is studied, and as shown in fig. 15, when 100 times of fenobucarb, carbofuran, diazinon, propoxur, metolcarb, bisphenol a and 2, 4-dichlorophenol are added into a mixed solution of carbaryl and isoprocarb, the detection of carbaryl and isoprocarb is not greatly influenced. The peak positions of fenobucarb and metolcarb are similar to those of carbaryl and isoprocarb, but the oxidation peak current is lower than that of both carbaryl and isoprocarb. The peak positions of other pesticides and phenols are a certain distance away from the peak positions of carbaryl and isoprocarb, so that the pesticides and the phenols can be easily distinguished.
The interference of some common phenols and pesticides on the detection of carbaryl and isoprocarb is studied, and as shown in fig. 16, when 100 times of bisphenol a and 2, 4-dichlorophenol are added to 70 μ M of carbaryl and 70 μ M of isoprocarb respectively, no particularly large current change is generated, and the influence of the two phenols on the detection is very small. When 100 times of fenobucarb, carbofuran, propoxur, metolcarb and diazinon are added, the current response changes slightly. In summary, the modified electrode shows better anti-interference capability when detecting carbaryl and isoprocarb.
(5) Sample detection
In view of CoAl-LDH 0.1 Excellent performance of/PANI/GCE, the electrodes were applied to detect carbaryl and isoprocarb in real samples of cucumber, apple and spinach purchased from Yan jiashan market (shandong Qingdao). 10g of cucumber, apple and spinach are respectively weighed and mashed into a small beaker, 10.0mL of absolute ethyl alcohol is added into the beaker for soaking for 10 hours, the mixture is centrifuged for 5 minutes at 8000r, and supernatant is collected to determine the concentration of the carbaryl and the isoprocarb by a standard addition method. Table 2 the detection of carbaryl and isoprocarb in the real samples showed recovery rates ranging from 98.8% to 100.4%, indicating that the electrochemically modified electrode is reliable for use in the real sample detection.
TABLE 2
a cucumber, apple and spinach are purchased in the Yan jiashan market; b five replicates
(6) Electrochemical characterization of CoAl-LDH modified electrodes with different water contents
FIG. 17 shows GCE (a), CoAl-LDH 0.25 /GCE(b)，CoAl-LDH 0.2 /GCE(c)，CoAl-LDH 0.1 (d) at 5mM [ Fe (CN) 6 ] 3-/4- (1:1) Cyclic voltammogram in solution. The current of the modified electrode has an enhanced response compared to the bare electrode current. CoAl-LDH 0.1 The current of the/GCE is about CoAl-LDH 0.25 (ii) GCE and CoAl-LDH 0.2 1.21 times and 1.13 times of/GCE. The possible reason is that CoAl-LDH 0.1 Is of a size comparable to CoAl-LDH 0.25 And CoAl-LDH 0.2 Small, active site exposure is greater. Graph (B) gives an impedance plot for the different modified electrodes. When the target product CoAl-LDH 0.1 The electrode surface is modified, and the measured semicircle of the high-frequency region is smaller, so that the impedance value of the modified electrode is obviously reduced (curve d). This result is consistent with the current response in graph (a). These results indicate that CoAl-LDH 0.1 The electrochemical activity of the electrode is increased, and in addition, the characterization result of the electrochemical impedance is also changed from oneTo a certain extent, indicating CoAl-LDH 0.1 The film was successfully immobilized on the electrode surface.
(7) Electrochemical behavior of carbaryl and isoprocarb on different electrodes
The cyclic voltammogram of the scan after the carbaryl and isoprocarb (both concentration are 0.1mM) are added into the KOH solution with the concentration of 0.2M is shown in fig. 18, and it can be seen that both the carbaryl and the isoprocarb have oxidation reaction on the surfaces of the four electrodes, and obvious oxidation peaks and no reduction peaks appear, which indicates that the carbaryl and the isoprocarb have an irreversible electrochemical oxidation process on the electrodes.
FIG. 18 shows a CoAl-LDH 0.1 Electrochemical behavior of/GCE in KOH solution (0.2M) in blank (a), containing 0.1mM carbaryl (b), containing 0.1mM isoprocarb (c) and a mixture of 0.1mM carbaryl and isoprocarb (d).
GCE(a)，CoAl-LDH 0.25 /GCE(b)，CoAl-LDH 0.2 /GCE(c)，CoAl-LDH 0.1 The modified electrode of/GCE (d) shows oxidation peaks of carbaryl and isoprocarb at the potentials of about 0.203V and 0.361V, and the peak current is gradually increased. The hydrotalcite-like modified material plays a certain role in promoting the oxidation of the carbaryl and the isoprocarb on the electrode. When CoAl-LDH 0.1 The maximum response of/GCE to carbaryl and isoprocarb. Thus, CoAl-LDH 0.1 Can promote the electrocatalytic oxidation process of the carbaryl and the isoprocarb.
(8) Carbaryl and isoprocarb in CoAl-LDH 0.1 Electrochemical behavior on/GCE
FIG. 19 is a study of CoAl-LDH 0.1 The electrochemical behavior of/GCE in blank KOH solution (0.2M), containing 0.1mM carbaryl, 0.1mM isoprocarb and containing 0.1mM mixture of carbaryl and isoprocarb, respectively. In the blank KOH solution (0.2M), the modified electrode has no electrochemical response, and it can be seen that the modified electrode itself does not undergo any electrochemical oxidation or reduction processes in the solution. The peak position of the carbaryl alone is detected to be 0.207V, and the peak position of the isoprocarb is detected to be 0.359V. This is substantially consistent with the peak positions of carbaryl and isoprocarb detected simultaneously in the mixed solution, indicating that carbaryl and isoprocarb were detected during the mixed solution detection processNo other chemical reactions occurred. Besides, in the mixed solution containing the carbaryl and the isoprocarb, the difference between the oxidation peak potentials of the carbaryl and the isoprocarb is 0.203V and 0.361V, and the difference between the oxidation peak potentials of the carbaryl and the isoprocarb is 0.158V, which indicates that the two substances can be well detected simultaneously in the mixed solution of the carbaryl and the isoprocarb.
The optimization result of the modification amount of the electrode is shown in FIG. 20, and it can be seen from the graph that the thickness of the modified membrane has an influence on the peak current when CoAl-LDH 0.1 When the modified amount of the compound (2) is increased from 0 to 4 mu L, the peak current generated by the carbaryl and the isoprocarb is gradually increased, and when the modified amount is 4 to 10 mu L, the current is obviously reduced. Therefore, 4. mu.L was selected as the optimum modification amount.
(9) Effect of different concentration of KOH solution
Carbaryl and isoprocarb belong to carbamate pesticides, which are unstable and easily hydrolyzed under alkaline conditions, and the hydrolysis products are corresponding phenols, as shown in fig. 21, the concentration of a KOH solution is studied, and the detection response is the largest in a 0.2M KOH solution, so that a 0.2M KOH solution is selected as the optimal buffer solution concentration.
The effect of the enrichment time and the enrichment potential on the peak current is shown in FIG. 22. The peak current gradually increased as the enrichment time increased from 0-90s, and then slowly increased with increasing time, tending to plateau. Likewise, the peak current appeared to be maximum at-0.1V for the enrichment potential. Therefore, the enrichment time was chosen to be 90s, and the enrichment potential was-0.1V.
FIG. 23 shows the CoAl-LDH effect when different concentrations of carbaryl were added stepwise 0.1 The current response of the/GCE is between 0.05 and 150 mu M, and the current response of the modified electrode is gradually enhanced along with the increase of the concentration of the carbaryl. The graph B is a linear relationship between the concentration of carbaryl and the current, and shows better linearity in the concentration range of 0.05-150 μ M, and the regression equation is obtained as Ipa (μ A) is 0.12c (μ M) +0.115 (R) 2 0.9997), the detection limit was calculated to be 0.016 μ M.
FIG. 24 is a graph of CoAl-LDH when different concentrations of isoprocarb were added stepwise 0.1 Current response of/GCEAt 0.05-150 μ M, the current response of the modified electrode gradually increased with increasing concentration of isoprocarb. Graph B is a linear plot of isoprocarb concentration versus current, showing better linearity over the concentration range of 0.05-150 μ M, and the regression equation is found to be Ipa (μ A) 0.101c (μ M) +0.199 (R) 2 0.9995), the detection limit was calculated to be 0.021 μ M.
In conclusion, the CoAl-LDH nanosheets and the conductive PANI are prepared respectively by adopting a reverse microemulsion method, then the CoAl-LDH/PANI nanosheet composite is prepared by adopting an ultrasonic physical mixing method, the modified electrode is prepared by adopting a dripping method, and the simultaneous detection of the carbaryl and the isoprocarb is realized. As the CoAl-LDH nanosheet obtained by the reverse microemulsion method has the advantages of thin thickness, small size and uniformity, the active site is fully exposed; and meanwhile, the obtained PANI has good dispersibility, the composite PANI is used as a conductive support body, CoAl-LDH nano sheets are uniformly fixed on the substrate, the doping of the PANI improves the conductivity of the material, the dispersibility of the CoAl-LDH nano sheets is improved, the combination of the PANI and the CoAl-LDH nano sheets fully exerts the synergistic effect of the CoAl-LDH nano sheets, the mutual aggregation is inhibited, the stability of the PANI and the CoAl-LDH nano sheets is ensured, the electrochemical active sites are increased, and the adsorption and capture capacity of the modified electrode on a detected object is improved. Therefore, the CoAl-LDH/PANI nanosheet composite modified electrode obtains a wider linear range (0.001-150 mu M) and a lower detection limit (6.8 nM isoprocarb 8.1nM) in the aspect of simultaneous detection of the carbaryl and the isoprocarb, and realizes high-sensitivity and high-selectivity simultaneous detection of the carbaryl and the isoprocarb.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (6)
1. A preparation method of a CoAl-LDH/PANI modified electrode is characterized by comprising the following specific steps:
s1, preparation of hydrotalcite-like LDH:
with hydrophobic ionic liquid BmimPF 6 TX-100 and an aqueous microemulsion system as media to prepare a mixed salt microemulsion A and an alkali microemulsion B, wherein the aqueous phase of the mixed salt microemulsion A is Co (NO) 3 ) 2 ·6H 2 O、Al(NO 3 ) 3 ·9H 2 The water phase of the alkali microemulsion B is NaOH water solution;
according to different water contents in the microemulsions, a double-microemulsion co-deep sedimentation method is adopted, the alkali microemulsion B is dropwise added into the mixed salt microemulsion A, the mixed salt microemulsion A is mixed and stirred for 12 hours at room temperature, the mixture is kept stand and aged for 12 hours, centrifuged for 10 minutes at 10000 revolutions, and sequentially washed by ethanol and water to obtain jelly-shaped CoAl-LDH gel: CoAl-LDH 0.25 ，CoAl-LDH 0.2 And CoAl-LDH 0.1 ；
S2, preparing polyaniline PANI:
preparing an aniline microemulsion A and an initiator microemulsion B by adopting the microemulsion system; dropwise adding the initiator microemulsion B into the aniline microemulsion A by adopting a double-microemulsion method under the ice-water bath condition, stirring and mixing, reacting for 8 hours, centrifuging at 10000r for 10min, and sequentially washing with ethanol and water to obtain emerald PANI;
s3, preparation of CoAl-LDH/PANI:
mixing CoAl-LDH and PANI according to the mass ratio of 1:1 of CoAl-LDH to PANI, performing ultrasonic mixing reaction on ethanol dispersion of a CoAl-LDH sample and PANI ethanol dispersion for 6h, centrifuging at 10000r for 10min, washing with deionized water to obtain the CoAl-LDH respectively 0.25 /PANI，CoAl-LDH 0.2 Per PANI and CoAl-LDH 0.1 /PANI；
Weighing CoAl-LDH 0.1 With CoAl-LDH 0.1 Respectively preparing CoAl-LDH with PANI mass ratio of 1:2 and 2:1 0.1 /PANI 1/2 And CoAl-LDH 0.1 /PANI 2/1 The mass ratio of the obtained product to CoAl-LDH to PANI is 1:1 0.1 /PANI 1/1 Comparing;
s4, preparation of CoAl-LDH/PANI modified electrode:
polishing and grinding a glassy carbon electrode GCE with the diameter of 3mm to a mirror surface by using alumina powder, respectively carrying out ultrasonic washing in a mixed solution of dilute nitric acid and ethanol, and washing with deionized water; preparing an ethanol dispersion liquid with the concentration of 1mg/mL by using the CoAl-LDH/PANI sample, transferring 2 mu L of CoAl-LDH/PANI dispersion liquid by using a liquid transfer gun, dripping the CoAl-LDH/PANI dispersion liquid on the surface of the treated GCE, and drying at room temperature under a clean state to obtain the modified electrode CoAl-LDH/PANI/GCE.
2. The method for preparing the CoAl-LDH/PANI modified electrode as claimed in claim 1, wherein the three component contents of the mixed salt microemulsion A and the alkali microemulsion B are the same in step S1; the water content of microemulsion A was different, and the water phase of microemulsion A was 0.2M Co (NO) 3 ) 2 ·6H 2 O, 0.1M Al (NO) 3 ) 3 ·9H 2 O, microemulsion B, the aqueous phase of which is 0.7M aqueous NaOH.
3. The method for preparing a CoAl-LDH/PANI modified electrode as claimed in claim 1, wherein in step S1, preparing CoAl-LDH 0.25 ，CoAl-LDH 0.2 、CoAl-LDH 0.1 The volume percentages of the microemulsion system in the three samples are respectively as follows: LDH 0.25 BmimPF of 6 TX-100, water 1.25:36.25: 12.5; LDH 0.2 BmimPF of 6 TX-100, water is 1.25:38.75: 10; LDH 0.1 BmimPF of 6 TX-100, water 1.25:43.75: 5; the total volume is 50mL, and the volume ratio of the water content in the three microemulsion systems is 0.25, 0.2 and 0.1 respectively.
4. The method for preparing the CoAl-LDH/PANI modified electrode as claimed in claim 1, wherein the volume ratio of each component of the microemulsion system in step S2 is BmimPF 6 TX-100 and water 0.025:0.725: 0.25.
5. The method of claim 1The preparation method of the CoAl-LDH/PANI modified electrode is characterized in that in the step S2, the preparation method of the aniline microemulsion A comprises the following steps: adding 1-1.6mL concentrated hydrochloric acid and 7.05mL deionized water into 0.2-0.8mL aniline solution, mixing uniformly by ultrasonic wave, adding 26.1mL TX-100 and 0.5-1.3mLBmimPF 6 Stirring uniformly; the preparation method of the initiator microemulsion B comprises the following steps: accurately weighing 0.3-0.9g ammonium persulfate to be dissolved in 3.5mL deionized water, adding 9.50-10.50mL TX-100 and 0.35mL BmimPF 6 And (4) stirring uniformly.
6. The use of the method for preparing a CoAl-LDH/PANI modified electrode as claimed in any one of claims 1 to 5, wherein the modified electrode prepared by the method is used for simultaneously detecting the pesticides carbaryl and isoprocarb.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103756756A (en) * | 2014-01-17 | 2014-04-30 | 青岛科技大学 | LDH/polyaniline nano composite material electrorheological fluid and preparation method thereof |
| CN104998609A (en) * | 2015-06-18 | 2015-10-28 | 青岛科技大学 | Method for preparing small-grain-size ultra-thin hydrotalcite nano-sheets without surface active agents through reversed-phase microemulsion |
| CN105032342A (en) * | 2015-06-18 | 2015-11-11 | 青岛科技大学 | Preparation method of stratiform bimetallic oxide sorbent capable of effectively removing low-concentrated phosphate radical |
| CN107219283A (en) * | 2017-06-14 | 2017-09-29 | 青岛科技大学 | A kind of method of photic electrochemical gaging glutathione |
| CN108774562A (en) * | 2018-07-23 | 2018-11-09 | 青岛科技大学 | A kind of MOF-Ti/ polyaniline nano-composite materials ER fluid and preparation method thereof |
| CN111153420A (en) * | 2020-01-14 | 2020-05-15 | 北京化工大学 | Magnesium-aluminum hydrotalcite nanotube and preparation method thereof |
-
2020
- 2020-05-27 CN CN202010462325.7A patent/CN111426736B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103756756A (en) * | 2014-01-17 | 2014-04-30 | 青岛科技大学 | LDH/polyaniline nano composite material electrorheological fluid and preparation method thereof |
| CN104998609A (en) * | 2015-06-18 | 2015-10-28 | 青岛科技大学 | Method for preparing small-grain-size ultra-thin hydrotalcite nano-sheets without surface active agents through reversed-phase microemulsion |
| CN105032342A (en) * | 2015-06-18 | 2015-11-11 | 青岛科技大学 | Preparation method of stratiform bimetallic oxide sorbent capable of effectively removing low-concentrated phosphate radical |
| CN107219283A (en) * | 2017-06-14 | 2017-09-29 | 青岛科技大学 | A kind of method of photic electrochemical gaging glutathione |
| CN108774562A (en) * | 2018-07-23 | 2018-11-09 | 青岛科技大学 | A kind of MOF-Ti/ polyaniline nano-composite materials ER fluid and preparation method thereof |
| CN111153420A (en) * | 2020-01-14 | 2020-05-15 | 北京化工大学 | Magnesium-aluminum hydrotalcite nanotube and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| Quaternarization strategy to ultrathin lamellar graphitic C3N4 ionic liquid nanostructure for enhanced electrochemical 2,4-Dichlorophenol sensing;Tianrong Zhan 等;《Sensors & Actuators: B. Chemical》;20181213;第283卷;第463-471页 * |
| 离子液体掺杂聚苯胺/纳米铜修饰电极制备及其在过氧化氢测定中的应用;何世伟 等;《分析化学》;20130531;第41卷(第05期);第766-770页 * |
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