Imprinted sensor based on gold nanoparticles, preparation method and application thereof

Abstract

The invention discloses an imprinted sensor based on gold nanoparticles, a preparation method and an application thereof. The method comprises the following steps: 1)placing a target electrode in a first mixing solution containing Na2SO4 and HAuCl4 and performing electrochemical deposition to prepare the gold nanoparticles for modifying the electrode; 2)under existence of a buffer solution, placing the electrode modified by the gold nanoparticles in a second mixing solution containing o-phenylenediamine and 2,4-dichlorphenoxyacetic acid, employing a cyclic voltammetry method for scanning to prepare a polymer membrane for modifying the electrode; and 3)placing the electrode modified by the polymer membrane in ethanol or an ethanol solution for eluting to prepare the imprinted sensor based on gold nanoparticles; wherein the target electrode is glassy carbon electrode or ITO electrode. The imprinted sensor can detect the 2,4-dichlorophenoxyacetic acid in a sensitive mode.

Description

technical field

[0001] The invention relates to the field of imprinted sensors, in particular to an imprinted sensor based on gold nanoparticles and its preparation method and application. Background technique

[0002] 2,4-Dichlorophenoxyacetic acid is a commonly used herbicide, similar to auxin or other plant growth regulators, it can stimulate growth and promote plant metabolism, but it has certain toxicity and is easy to remain on the surface of plants, which is harmful to human Food safety issues have caused serious impacts, so the analysis and detection of 2,4-dichlorophenoxyacetic acid is particularly important. As people pay more and more attention to food safety issues, there are more and more detection methods for 2,4-dichlorophenoxyacetic acid, such as high performance liquid chromatography and chemiluminescence. Although these methods can realize the detection of 2,4-dichlorophenoxyacetic acid, these methods have defects such as complicated operation, long reacti...

Examples

preparation example Construction

[0032] The invention provides a method for preparing an imprinted sensor based on gold nanoparticles, the method comprising the following steps:

[0033] 1) Place the target electrode in a 2 SO 4 and HAuCl 4 Electrochemical deposition is carried out in the first mixed solution to prepare the procedure of gold nano-modified electrode;

[0034] 2) In the presence of a buffer solution, the gold nano-modified electrode is placed in a second mixed solution containing o-phenylenediamine and 2,4-dichlorophenoxyacetic acid and scanned by cyclic voltammetry to prepare a polymer The process of modifying the electrode with the film;

[0035] 3) placing the polymer membrane modified electrode in ethanol or an ethanol solution for eluting to prepare an imprinted sensor based on gold nanoparticles;

[0036] Wherein, the target electrode is a glassy carbon electrode or an ITO electrode.

[0037] like figure 1 As shown, the present invention first contains Na on the target electrode 2 ...

Embodiment 1

[0053] 1) Pretreatment of glassy carbon electrodes

[0054] The surface of the glassy carbon electrode was polished with alumina powder with a particle size of 0.3 μm, and ultrasonically treated in ethanol and secondary aqueous solution. Then put the treated glassy carbon electrode into 0.6mmol / L [Fe(CN) 6 ] 3- / [Fe(CN) 6 ] 4- CV detection was carried out in the solution so that the peak difference ΔEp between the oxidation peak and the reduction peak was 75mV, and then dried at 25°C.

[0055] 2) Preparation of gold nano-modified electrodes

[0056] Put the pretreated glassy carbon electrode into 0.1mol / L Na 2 SO 4 and 30mmol / L of HAuCl 4 In the first mixed solution, the electrodeposition was performed under the condition of -0.6V for 600s to obtain a gold nanoparticle modified electrode.

[0057] EDS detection was performed on the gold nano-modified electrode, and the results were as follows: Figure 16 shown by Figure 16 It can be seen that the gold nano-modified ...

Embodiment 2

[0065] According to the method of Example 1, the difference is that the electrochemical deposition time is respectively 400s, 500s, 700s, 800s and 900s to make MIP / Au / GCE, then the MIP / Au in Example 1 and Example 2 / GCE in 0.6mmol / L [Fe(CN) 6 ] 3- / [Fe(CN) 6 ] 4- solution for 1.5 x 10 -8 mol / L 2,4-D solution for DPV detection, wherein the detection potential is -0.2 ~ 0.5V, the detection results are as follows Figure 7 shown by Figure 7 It is known that the MIP / Au / GCE prepared at the electrochemical deposition time of 600s is the most sensitive to 2,4-D.

technical field

[0001] The invention relates to the field of imprinted sensors, in particular to an imprinted sensor based on gold nanoparticles and its preparation method and application. Background technique

[0002] 2,4-Dichlorophenoxyacetic acid is a commonly used herbicide, similar to auxin or other plant growth regulators, it can stimulate growth and promote plant metabolism, but it has certain toxicity and is easy to remain on the surface of plants, which is harmful to human Food safety issues have caused serious impacts, so the analysis and detection of 2,4-dichlorophenoxyacetic acid is particularly important. As people pay more and more attention to food safety issues, there are more and more detection methods for 2,4-dichlorophenoxyacetic acid, such as high performance liquid chromatography and chemiluminescence. Although these methods can realize the detection of 2,4-dichlorophenoxyacetic acid, these methods have defects such as complicated operation, long reacti...

Examples

preparation example Construction

[0032] The invention provides a method for preparing an imprinted sensor based on gold nanoparticles, the method comprising the following steps:

[0033] 1) Place the target electrode in a 2 SO 4 and HAuCl 4 Electrochemical deposition is carried out in the first mixed solution to prepare the procedure of gold nano-modified electrode;

[0034] 2) In the presence of a buffer solution, the gold nano-modified electrode is placed in a second mixed solution containing o-phenylenediamine and 2,4-dichlorophenoxyacetic acid and scanned by cyclic voltammetry to prepare a polymer The process of modifying the electrode with the film;

[0035] 3) placing the polymer membrane modified electrode in ethanol or an ethanol solution for eluting to prepare an imprinted sensor based on gold nanoparticles;

[0036] Wherein, the target electrode is a glassy carbon electrode or an ITO electrode.

[0037] like figure 1 As shown, the present invention first contains Na on the target electrode 2 ...

Embodiment 1

[0053] 1) Pretreatment of glassy carbon electrodes

[0054] The surface of the glassy carbon electrode was polished with alumina powder with a particle size of 0.3 μm, and ultrasonically treated in ethanol and secondary aqueous solution. Then put the treated glassy carbon electrode into 0.6mmol / L [Fe(CN) 6 ] 3- / [Fe(CN) 6 ] 4- CV detection was carried out in the solution so that the peak difference ΔEp between the oxidation peak and the reduction peak was 75mV, and then dried at 25°C.

[0055] 2) Preparation of gold nano-modified electrodes

[0056] Put the pretreated glassy carbon electrode into 0.1mol / L Na 2 SO 4 and 30mmol / L of HAuCl 4 In the first mixed solution, the electrodeposition was performed under the condition of -0.6V for 600s to obtain a gold nanoparticle modified electrode.

[0057] EDS detection was performed on the gold nano-modified electrode, and the results were as follows: Figure 16 shown by Figure 16 It can be seen that the gold nano-modified ...

Embodiment 2

[0065] According to the method of Example 1, the difference is that the electrochemical deposition time is respectively 400s, 500s, 700s, 800s and 900s to make MIP / Au / GCE, then the MIP / Au in Example 1 and Example 2 / GCE in 0.6mmol / L [Fe(CN) 6 ] 3- / [Fe(CN) 6 ] 4- solution for 1.5 x 10 -8 mol / L 2,4-D solution for DPV detection, wherein the detection potential is -0.2 ~ 0.5V, the detection results are as follows Figure 7 shown by Figure 7 It is known that the MIP / Au / GCE prepared at the electrochemical deposition time of 600s is the most sensitive to 2,4-D.

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