Construction method and application of noble metal nanocluster electrochemical sensor

Abstract

The invention relates to the technical field of agricultural product detection, and particularly discloses a construction method and application of a noble metal nanocluster electrochemical sensor, and the construction method comprises the following steps: constructing two novel electrochemical biological esterase sensors of NF / KbE-CS / Au24Pd (at) G / GCE and NF / KbE-CS / Au25 (at) G / GCE for detecting profenofos based on an enzyme inhibition action principle; when an electrochemical method is used for detecting profenofos, redox reaction can be directly carried out on the surface of the electrode, micro-scale rapid detection of profenofos can be realized by monitoring the change of an electric signal, complicated sample pretreatment is not needed, the time for analyzing a result is shortened, and the method is more economical and convenient; the technology can be integrated in portable equipment due to the miniaturization potential of the electrochemical sensor, instant analysis can be realized, the detection flexibility and practicability are enhanced, in addition, the electrochemical method also shows good selectivity, interference can be reduced and the analysis accuracy can be improved by optimizing an electrode material and a detection condition, and the application prospect is wide. The profenofos residue can be efficiently, conveniently and quickly detected.

Description

Technical Field

[0001] The invention belongs to the technical field of agricultural product detection, and specifically relates to a construction method and application of a noble metal nanocluster electrochemical sensor. Background Art

[0002] Noble metal nanoclusters are ultrasmall particles composed of noble metal (such as gold, silver, platinum, etc.) atoms, usually with a size of less than a few nanometers, and have unique physical and chemical properties. The size of noble metal nanoclusters is very small, usually less than 3 nanometers, which makes them have a significant size effect. The size effect causes the nanoclusters to exhibit properties that are completely different from those of bulk noble metal materials in terms of optics, electricity, magnetism, and catalysis. Noble metal nanoclusters are cores composed of several to dozens of noble metal atoms, and are core / shell molecular aggregates assembled with organic single molecules (such as thiol compounds) or biological molecules (such as DNA, proteins, etc.) as protective groups. The protective groups not only stabilize the structure of the nanoclusters, but also provide them with a biocompatible surface.

[0003] Quantum size effect: When the size of a nanocluster is close to or smaller than the Fermi wavelength of electrons, it will exhibit a quantum size effect, which will lead to significant changes in the electronic structure and optical properties of the nanocluster, such as the tunability of the fluorescence emission wavelength.

[0004] Photofluorescence: Noble metal nanoclusters have photofluorescence, that is, they can emit fluorescence under the excitation of light. The fluorescence properties are closely related to the size, shape and surface chemical properties of the nanoclusters.

[0005] Spectral tunability: The fluorescence emission wavelength of precious metal nanoclusters can vary with their particle size, thereby obtaining any wavelength in the range from visible light to near-infrared light. This spectral tunability makes nanoclusters widely used in biomedical imaging, optical sensing and other fields.

[0006] High catalytic activity: Noble metal nanoclusters have the characteristics of high surface area, high surface energy and many activation centers, so they have extremely high catalytic activity. They can be used as catalysts or catalyst carriers to accelerate the rate of chemical reactions.

[0007] Selective catalysis: The catalytic performance of precious metal nanoclusters also shows a certain selectivity, that is, they have higher catalytic activity for certain specific chemical reactions; this selective catalysis makes the nanoclusters have higher efficiency and lower by-product generation in catalytic reactions.

[0008] The noble metal nanocluster electrochemical sensor is an electrochemical sensor built based on noble metal nanocluster materials. It has the characteristics of good selectivity, high sensitivity, fast analysis speed, simple operation and the ability to realize online in vivo analysis. The working principle of the noble metal nanocluster electrochemical sensor is based on the electrochemical principle, that is, the electrochemical reaction between the electrode and the electrolyte solution is used to detect the target substance. When the target substance interacts with the noble metal nanoclusters on the surface of the sensor, it will change the charge distribution on the electrode surface or produce current changes, thereby realizing the detection of the target substance.

[0009] With the continuous development of nanotechnology and electrochemical technology, noble metal nanocluster electrochemical sensors will be used in more fields. In the future, people will be committed to developing more sensitive, more selective and more stable sensors to meet the needs of high-precision detection in different fields. At the same time, they will also explore more environmentally friendly and low-cost preparation methods to reduce the production cost of sensors and promote their commercial application. Noble metal nanocluster electrochemical sensors are high-performance sensors with broad application prospects and will play an important role in many fields.

[0010] Organophosphorus pesticides (taking bromophos as an example) are seriously harmful to human body and environment. Therefore, it is very necessary to detect the bromophos content and keep it within a reasonable range. The current detection methods include gas chromatography. The efficient separation ability of this method helps to effectively separate the target analytes from complex matrices, reduce interference, and the analysis results are accurate and reliable. However, the experimental cost is high, the process is complicated, and high requirements are placed on the experimental personnel's operating skills. Another detection method is high performance liquid chromatography-mass spectrometry (HPLC-MS). This method can effectively identify and quantify low concentrations of bromophos residues in complex matrices, and the detection effect is significant, but it requires high instrument purchase and maintenance costs and is not suitable for large-scale detection.

[0011] On this basis, we developed an electrochemical biosensor detection method. When using the electrochemical method to detect bromophos, redox reactions can be carried out directly on the electrode surface. By monitoring the changes in the electrical signal, rapid detection of trace amounts can be achieved. No complicated sample pretreatment is required, which reduces the time for analysis results and is more economical and convenient. In addition, the miniaturization potential of electrochemical sensors enables the technology to be integrated into portable devices, which is conducive to instant analysis and enhances the flexibility and practicality of detection. In addition, the electrochemical method also exhibits good selectivity, and can reduce interference and improve analysis accuracy by optimizing electrode materials and detection conditions. It can efficiently, conveniently and quickly detect bromophos residues. Summary of the invention

[0012] The purpose of the present invention is to provide a method for constructing a noble metal nanocluster electrochemical sensor and its application to solve the problems raised in the above background technology.

[0013] To achieve the above object, the present invention provides the following technical solutions:

[0014] like Figure 1-4 As shown, a method for constructing a noble metal nanocluster electrochemical sensor and its application, comprising: constructing a NF / KbE-CS / Au based on the enzyme inhibition principle to detect bromophos 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE Two new electrochemical bioesterase sensors;

[0015] From the above, we can see that under the optimal conditions, Au 24 Pd clusters outperform Au 25 , indicating that the Pd atom-centered directional doping clusters improve the sensitivity of the determination. Under the optimal conditions, in the range of 1 to 1000 μg / L, the inhibition rate has a good linear relationship with the logarithm of the concentration of bromophos. The linear equation is Y=14.03l gc+19.7994, and the correlation coefficient is R 2 =0.9856;

[0016] Through the setting of the above technical scheme, the NF / KbE-CS / Au detection system for bromophos based on the principle of enzyme inhibition was constructed. 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE's two new electrochemical bioesterase sensors bring many benefits. The following is a detailed analysis of these benefits:

[0017] Enzyme inhibition principle: Both sensors are based on the principle of enzyme inhibition, that is, when bromophos is present, it inhibits the activity of esterase, thereby reducing the production of electrochemically active substances and resulting in a decrease in the electrochemical reaction signal. This principle makes the sensor highly selective and sensitive to bromophos;

[0018] Sensitization effect of nanomaterials: Au 24 Pd and Au 25 Nanomaterials as electrode modification layers can significantly improve the electrochemical performance of sensors and further amplify response signals, thereby increasing detection sensitivity.

[0019] Stability of Nanocomposite Structures: Au 24 Pd@G and Au 25 @G The nanocomposite structure has good stability and biocompatibility, which can protect esterase from interference from environmental factors and maintain its catalytic activity, thereby improving the stability and reproducibility of the sensor;

[0020] Optimization of electrode materials: By optimizing the composition and structure of electrode materials, the stability and reproducibility of the sensor can be further improved to ensure accurate and reliable detection results under different conditions;

[0021] Environmental monitoring: These two sensors can be used in the field of environmental monitoring to detect the residual amount of bromophos in water and soil, providing strong support for environmental protection and food safety;

[0022] Pesticide residue detection: In agricultural products and food, the residue of bromophos is an important safety indicator. These two sensors can achieve rapid and accurate detection of bromophos residue, which helps to protect the health and safety of consumers.

[0023] Expanded to the detection of other pesticides: Electrochemical biosensors based on the principle of enzyme inhibition can not only be used to detect bromophos, but can also be expanded to the detection of other organophosphorus pesticides, providing more options for pesticide residue detection; Innovative electrode design: By introducing nanomaterials and composite structures, these two sensors are innovative in electrode design, providing new ideas and methods for the research and development of electrochemical biosensors.

[0024] like Figure 1-4 As shown, cyclic voltammetry and square wave voltammetry were performed in K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte solution;

[0025] From the above, we can know that: graphene has a large specific surface area, which can provide a good attachment environment for the loading of clusters and plant esterases. 24 The Pd@G composite material has good conductivity and synergistic electrocatalytic effect, which can effectively promote the transfer of electrons and improve the response sensitivity of the sensor;

[0026] By setting up the above technical solution, cyclic voltammetry and square wave voltammetry detection are carried out in the electrolyte solution of K3[Fe(CN)6] / K4[Fe(CN)6], which has the following advantages:

[0027] Cyclic voltammetry has the following benefits:

[0028] Determine the reversibility of electrode reaction: Cyclic voltammetry can clearly show the oxidation peak and reduction peak. By comparing the current and potential of these two peaks, the reversibility of the electrode reaction can be determined. In the K3[Fe(CN)6] / K4[Fe(CN)6] system, since the oxidation and reduction reactions are highly reversible, cyclic voltammetry can accurately reflect this.

[0029] Study the electrode reaction mechanism: Through cyclic voltammetry, we can observe the intermediates that may be formed during the electrode reaction, the properties of phase boundary adsorption and coupled chemical reactions, so as to deeply study the mechanism of the electrode reaction, which is of great significance for understanding the electrochemical behavior of the K3[Fe(CN)6] / K4[Fe(CN)6] system;

[0030] Quantitative analysis: Although cyclic voltammetry is mainly used for mechanism research, under certain conditions, it can also be used for quantitative analysis. By measuring the current values ​​of the oxidation peak and the reduction peak, parameters such as the concentration of the reactants or the effective area of ​​the electrode can be estimated;

[0031] Electrode performance evaluation: Cyclic voltammetry can also be used to evaluate the performance of electrodes. By comparing the cyclic voltammograms of different electrodes under the same conditions, the quality of the electrode and the reversibility of the reaction can be judged;

[0032] Square wave voltammetry has the following benefits;

[0033] High sensitivity: Square wave voltammetry stimulates electrode reactions by applying a square wave voltage and measuring the resulting current response. This method has high sensitivity for detecting low concentrations of reactants or small changes on the electrode surface.

[0034] Fast response: Square wave voltammetry has a fast response speed and can complete a measurement in a shorter time, thereby improving detection efficiency, which is very beneficial for application scenarios that require fast detection;

[0035] Reduce background current: Compared with other electrochemical methods, square wave voltammetry can more effectively reduce the impact of background current, thereby more accurately measuring the reaction current, which helps to improve the accuracy and reliability of the measurement;

[0036] Study of complex electrode reactions: Square wave voltammetry is also suitable for studying complex electrode reaction processes. By changing parameters such as the frequency and amplitude of the square wave voltage, the electrochemical behavior under different reaction conditions can be explored, providing strong support for a deeper understanding of electrode reactions;

[0037] In summary, cyclic voltammetry and square wave voltammetry in K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte solutions have their own unique advantages. These two methods complement each other and together provide powerful tools for electrochemical research.

[0038] like Figure 1-4 As shown, the experimental conditions were optimized by single factor experiment, and then the experimental conditions were optimized by single factor experiment to obtain Au 24 The optimal conditions for Pd are: pH of PBS buffer solution = 7.0, Au 24The loading amount of Pd@G composite material was 5μL. The inhibition time of bromophos was 20min. Under the optimal experimental conditions, the linear range of electrochemical enzyme sensor for detecting bromophos was 1-1000μg / L, and the detection limit was 0.018μg / L.

[0039] By setting up the above technical solution, optimizing the experimental conditions through single factor experiments has the following benefits:

[0040] The core of single-factor experiment is to examine the impact of only one factor on the experimental results each time, which helps to clearly identify which factors have a significant impact on the experimental results. By analyzing each factor one by one, the key factors affecting the experimental results can be more accurately determined, providing direction for subsequent experimental optimization.

[0041] Compared with multi-factor experiments, the design and implementation of single-factor experiments are simpler. Since only one factor level is changed each time, it is easier to control the experimental conditions and reduce the complexity and uncertainty in the experimental process. At the same time, single-factor experiments are also easier to repeat to verify the reliability and stability of the experimental results.

[0042] Single-factor experiments can quickly screen out factors that have a significant impact on the experimental results, thereby avoiding wasting time and resources on unimportant factors. By gradually optimizing the level of each key factor, the optimal experimental conditions can be gradually approached, improving experimental efficiency. In addition, single-factor experiments can also provide basic data for subsequent multi-factor experiments, helping to reduce the scope and complexity of multi-factor experiments.

[0043] Single-factor experiments can reduce experimental costs as much as possible while ensuring experimental results by optimizing the level of each factor one by one. Since only one factor level is changed each time, it is easier to control the amount of experimental materials and the operating time of experimental equipment, thereby reducing experimental costs. At the same time, single-factor experiments can also provide valuable reference data for subsequent scale-up experiments and production, helping to reduce production costs.

[0044] The results of single-factor experiments are more intuitive and easier to understand. Since only one factor is examined at a time, the relationship between the experimental results and the factors can be more easily explained, which helps researchers better understand the experimental phenomena and laws and provides theoretical support for subsequent experimental research.

[0045] In summary, optimizing experimental conditions through single-factor experiments has many benefits. However, it should be noted that single-factor experiments also have their limitations, such as ignoring the interaction between factors. Therefore, in practical applications, appropriate experimental methods should be selected according to the specific research objects and experimental objectives, and combined with multi-factor experiments and other methods for comprehensive analysis and optimization.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] By constructing a NF / KbE-CS / Au system for detecting bromophos based on the principle of enzyme inhibition 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE The role of two new electrochemical bioesterase sensors, NF / KbE-CS / Au 24 The Pd@G / GCE electrochemical bioesterase sensor has good repeatability, stability and anti-interference, a wide linear range and a low detection limit, and has certain practicality in real life.

[0048] On this basis, we have developed an electrochemical biosensor detection method. When using the electrochemical method to detect bromophos, redox reactions can be carried out directly on the electrode surface, and rapid detection of trace amounts can be achieved by monitoring changes in electrical signals. No complicated sample pretreatment is required, which reduces the time for analysis results and is more economical and convenient. In addition, the miniaturization potential of electrochemical sensors enables the technology to be integrated into portable devices, which is conducive to instant analysis and enhances the flexibility and practicality of detection. In addition, the electrochemical method also exhibits good selectivity, and can reduce interference and improve analysis accuracy by optimizing electrode materials and detection conditions. It can efficiently, conveniently and quickly detect bromophos residues. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 is a flow chart of the construction method of the present invention;

[0050] Figure 2 The principle flow chart of the construction method of the present invention is as follows;

[0051] Figure 3 NF / KbE-CS / Au 24 SWV diagrams of Pd@G / GCE under different conditions;

[0052] Figure 4 It is a linear relationship diagram between different concentrations of bromophos and inhibition rate of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] like Figure 1-4As shown, a method for constructing a noble metal nanocluster electrochemical sensor and its application, comprising: constructing a NF / KbE-CS / Au based on the enzyme inhibition principle to detect bromophos 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE Two new electrochemical bioesterase sensors;

[0055] From the above, we can see that under the optimal conditions, Au 24 Pd clusters outperform Au 25 , indicating that the Pd atom-centered directional doping clusters improve the sensitivity of the determination. Under the optimal conditions, in the range of 1 to 1000 μg / L, the inhibition rate has a good linear relationship with the logarithm of the concentration of bromophos. The linear equation is Y=14.03l gc+19.7994, and the correlation coefficient is R 2 =0.9856;

[0056] Through the setting of the above technical scheme, the NF / KbE-CS / Au detection system for bromophos based on the principle of enzyme inhibition was constructed. 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE's two new electrochemical bioesterase sensors bring many benefits. The following is a detailed analysis of these benefits:

[0057] Enzyme inhibition principle: Both sensors are based on the principle of enzyme inhibition, that is, when bromophos is present, it inhibits the activity of esterase, thereby reducing the production of electrochemically active substances and resulting in a decrease in the electrochemical reaction signal. This principle makes the sensor highly selective and sensitive to bromophos;

[0058] Sensitization effect of nanomaterials: Au 24 Pd and Au 25 Nanomaterials as electrode modification layers can significantly improve the electrochemical performance of sensors and further amplify response signals, thereby increasing detection sensitivity.

[0059] Stability of Nanocomposite Structures: Au 24 Pd@G and Au 25 @G The nanocomposite structure has good stability and biocompatibility, which can protect esterase from interference from environmental factors and maintain its catalytic activity, thereby improving the stability and reproducibility of the sensor;

[0060] Optimization of electrode materials: By optimizing the composition and structure of electrode materials, the stability and reproducibility of the sensor can be further improved to ensure accurate and reliable detection results under different conditions;

[0061] Environmental monitoring: These two sensors can be used in the field of environmental monitoring to detect the residual amount of bromophos in water and soil, providing strong support for environmental protection and food safety;

[0062] Pesticide residue detection: In agricultural products and food, the residue of bromophos is an important safety indicator. These two sensors can achieve rapid and accurate detection of bromophos residue, which helps to protect the health and safety of consumers.

[0063] Expanded to the detection of other pesticides: Electrochemical biosensors based on the principle of enzyme inhibition can not only be used to detect bromophos, but can also be expanded to the detection of other organophosphorus pesticides, providing more options for pesticide residue detection; Innovative electrode design: By introducing nanomaterials and composite structures, these two sensors are innovative in electrode design, providing new ideas and methods for the research and development of electrochemical biosensors.

[0064] like Figure 1-4 As shown, cyclic voltammetry and square wave voltammetry were performed in K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte solution;

[0065] From the above, we can know that: graphene has a large specific surface area, which can provide a good attachment environment for the loading of clusters and plant esterases. 24 The Pd@G composite material has good conductivity and synergistic electrocatalytic effect, which can effectively promote the transfer of electrons and improve the response sensitivity of the sensor;

[0066] By setting up the above technical solution, cyclic voltammetry and square wave voltammetry detection are carried out in the electrolyte solution of K3[Fe(CN)6] / K4[Fe(CN)6], which has the following advantages:

[0067] Cyclic voltammetry has the following benefits:

[0068] Determine the reversibility of electrode reaction: Cyclic voltammetry can clearly show the oxidation peak and reduction peak. By comparing the current and potential of these two peaks, the reversibility of the electrode reaction can be determined. In the K3[Fe(CN)6] / K4[Fe(CN)6] system, since the oxidation and reduction reactions are highly reversible, cyclic voltammetry can accurately reflect this.

[0069] Study the electrode reaction mechanism: Through cyclic voltammetry, we can observe the intermediates that may be formed during the electrode reaction, the properties of phase boundary adsorption and coupled chemical reactions, so as to deeply study the mechanism of the electrode reaction, which is of great significance for understanding the electrochemical behavior of the K3[Fe(CN)6] / K4[Fe(CN)6] system;

[0070] Quantitative analysis: Although cyclic voltammetry is mainly used for mechanism research, under certain conditions, it can also be used for quantitative analysis. By measuring the current values ​​of the oxidation peak and the reduction peak, parameters such as the concentration of the reactants or the effective area of ​​the electrode can be estimated;

[0071] Electrode performance evaluation: Cyclic voltammetry can also be used to evaluate the performance of electrodes. By comparing the cyclic voltammograms of different electrodes under the same conditions, the quality of the electrode and the reversibility of the reaction can be judged;

[0072] Square wave voltammetry has the following benefits;

[0073] High sensitivity: Square wave voltammetry stimulates electrode reactions by applying a square wave voltage and measuring the resulting current response. This method has high sensitivity for detecting low concentrations of reactants or small changes on the electrode surface.

[0074] Fast response: Square wave voltammetry has a fast response speed and can complete a measurement in a shorter time, thereby improving detection efficiency, which is very beneficial for application scenarios that require fast detection;

[0075] Reduce background current: Compared with other electrochemical methods, square wave voltammetry can more effectively reduce the impact of background current, thereby more accurately measuring the reaction current, which helps to improve the accuracy and reliability of the measurement;

[0076] Study of complex electrode reactions: Square wave voltammetry is also suitable for studying complex electrode reaction processes. By changing parameters such as the frequency and amplitude of the square wave voltage, the electrochemical behavior under different reaction conditions can be explored, providing strong support for a deeper understanding of electrode reactions;

[0077] In summary, cyclic voltammetry and square wave voltammetry in K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte solutions have their own unique advantages. These two methods complement each other and together provide powerful tools for electrochemical research.

[0078] like Figure 1-4 As shown, the experimental conditions were optimized by single factor experiment, and then the experimental conditions were optimized by single factor experiment to obtain Au 24 The optimal conditions for Pd are: pH of PBS buffer solution = 7.0, Au 24 The loading amount of Pd@G composite material was 5μL. The inhibition time of bromophos was 20min. Under the optimal experimental conditions, the linear range of electrochemical enzyme sensor for detecting bromophos was 1-1000μg / L, and the detection limit was 0.018μg / L.

[0079] By setting up the above technical solution, optimizing the experimental conditions through single factor experiments has the following benefits:

[0080] The core of single-factor experiment is to examine the impact of only one factor on the experimental results each time, which helps to clearly identify which factors have a significant impact on the experimental results. By analyzing each factor one by one, the key factors affecting the experimental results can be more accurately determined, providing direction for subsequent experimental optimization.

[0081] Compared with multi-factor experiments, the design and implementation of single-factor experiments are simpler. Since only one factor level is changed each time, it is easier to control the experimental conditions and reduce the complexity and uncertainty in the experimental process. At the same time, single-factor experiments are also easier to repeat to verify the reliability and stability of the experimental results.

[0082] Single-factor experiments can quickly screen out factors that have a significant impact on the experimental results, thereby avoiding wasting time and resources on unimportant factors. By gradually optimizing the level of each key factor, the optimal experimental conditions can be gradually approached, improving experimental efficiency. In addition, single-factor experiments can also provide basic data for subsequent multi-factor experiments, helping to reduce the scope and complexity of multi-factor experiments.

[0083] Single-factor experiments can reduce experimental costs as much as possible while ensuring experimental results by optimizing the level of each factor one by one. Since only one factor level is changed each time, it is easier to control the amount of experimental materials and the operating time of experimental equipment, thereby reducing experimental costs. At the same time, single-factor experiments can also provide valuable reference data for subsequent scale-up experiments and production, helping to reduce production costs.

[0084] The results of single-factor experiments are more intuitive and easier to understand. Since only one factor is examined at a time, the relationship between the experimental results and the factors can be more easily explained, which helps researchers better understand the experimental phenomena and laws and provides theoretical support for subsequent experimental research.

[0085] In summary, optimizing experimental conditions through single-factor experiments has many benefits. However, it should be noted that single-factor experiments also have their limitations, such as ignoring the interaction between factors. Therefore, in practical applications, appropriate experimental methods should be selected according to the specific research objects and experimental objectives, and combined with multi-factor experiments and other methods for comprehensive analysis and optimization.

[0086] Furthermore, this design application is used to construct and use electrochemical sensors for precious metal nanoclusters. On this basis, we have developed an electrochemical biosensor detection method. When using the electrochemical method to detect propyl bromide, redox reactions can be directly carried out on the electrode surface. By monitoring the changes in electrical signals, rapid detection of trace amounts can be achieved. There is no need for complex sample pretreatment, which reduces the time for analyzing results and is more economical and convenient.

[0087] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for constructing a noble metal nanocluster electrochemical sensor and its application, characterized in that: include: Construction of NF / KbE-CS / Au for detection of profenofos based on enzyme inhibition principle 24 Pd@G / GCE and NF / KbE-CS / Au 25 @G / GCE Two new electrochemical bioesterase sensors; Cyclic voltammetry and square wave voltammetry were performed in K3[Fe(CN)6] / K4[Fe(CN)6] electrolyte solution; The experimental conditions were optimized through single-factor experiments.

2. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: In the range of 1 to 1000 μg / L, the inhibition rate and the logarithm of the concentration of profenofos present a good linear relationship, and the linear equation is Y=14.03lgc+19.7994.

3. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 2, characterized in that: In the range of 1 to 1000 μg / L, the inhibition rate and the logarithm of the concentration of profenofos have a good linear relationship and correlation, and the correlation coefficient R 2 =0.9856.

4. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The pH of the PBS buffer solution is 7.

0.

5. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The bromophos inhibition time is 20 min.

6. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The linear range of the electrochemical enzyme sensor for detecting profenofos is 1 to 1000 μg / L, and the detection limit of the electrochemical enzyme sensor is 0.018 μg / L.

7. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The NF / KbE-CS / Au 24 The Pd@G / GCE electrochemical bioesterase sensor has repeatability, stability and anti-interference properties.

8. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The Au 24 Pd clusters outperform Au 25 Clusters.

9. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The Pd atom center is directionally doped at the center of the cluster.

10. The method for constructing a noble metal nanocluster electrochemical sensor and its application according to claim 1, characterized in that: The Au 24 The loading amount of Pd@G composite material was 5 μL.

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