Integrated electrochemical detection equipment for pretreatment and detection of mycotoxin

Abstract

The invention relates to the technical field of food safety detection, in particular to mycotoxin pretreatment and detection integrated electrochemical detection equipment which comprises a preprocessor, a substrate electrode and a signal transmission structure, the substrate electrode is arranged at the lower end of the preprocessor, and the signal transmission structure is connected with the substrate electrode. The preprocessor is used for mixing a solution to be detected and a pretreatment reagent, and is also used for providing an electrode modification channel; the substrate electrode is used for electrochemical detection to obtain an electrochemical signal; the signal transmission structure is used for transmitting the electrochemical signal to an upper computer, so that the upper computer adopts a differential pulse voltammetry (DPV) or an alternating current impedance (EIS) method to quantitatively analyze the concentration of the mycotoxin based on the change of the electrochemical signal. The invention discloses miniaturized and full-automatic integrated electrochemical detection equipment, which realizes on-site rapid and accurate detection of fungaltoxin through collaborative design of a modular preprocessor and a high-sensitivity substrate electrode.

Description

Technical Field

[0001] The present invention relates to the technical field of food safety detection, and in particular to an electrochemical detection device for integrating mycotoxin pretreatment and detection. Background Art

[0002] Mycotoxins are metabolites produced by fungi that can contaminate crops, food, and feed products, as well as condiments used by humans. There are currently 300 known mycotoxins, many of which are highly carcinogenic and teratogenic.

[0003] At present, traditional detection methods (such as HPLC and ELISA) rely on large laboratory equipment, which are complex to operate, time-consuming and costly; most existing portable electrochemical sensors lack automated preprocessing modules and require manual sample crushing, extraction, filtration and toxin enrichment, which can easily introduce errors; the integration of microfluidic technology and electrochemical detection is insufficient, making it difficult to achieve one-stop "sample in - result out" detection. Summary of the Invention

[0004] The purpose of the present invention is to provide an electrochemical detection device for integrated mycotoxin pretreatment and detection, so as to achieve on-site rapid and accurate mycotoxin detection.

[0005] To achieve the above objectives, the present invention provides an electrochemical detection device for integrated mycotoxin pretreatment and detection, the electrochemical detection device comprising:

[0006] A pre-processor, used to mix the solution to be detected and the pre-treatment reagent, and also used to provide an electrode modification channel;

[0007] A substrate electrode is provided corresponding to the pre-processor and disposed at the lower end of the pre-processor, and is used for electrochemical detection to obtain electrochemical signals;

[0008] The signal transmission structure is connected to the substrate electrode and is used to transmit the electrochemical signal to the host computer so that the host computer uses differential pulse voltammetry (DPV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the concentration of fungal toxins based on the changes in the electrochemical signal.

[0009] Optionally, the substrate electrode comprises:

[0010] A working electrode area, a reference electrode area, a counter electrode area, a first circuit channel, a second circuit channel and a third circuit channel; the working electrode area is in the shape of a circular ring, and the counter electrode area and the reference electrode area are both arc-shaped; the reference electrode area and the counter electrode area are respectively surrounded by the outside of the working electrode area, and there is a gap between the reference electrode area and the counter electrode area, the reference electrode area is connected to the first circuit channel, the working electrode area is connected to the second circuit channel, and the counter electrode area is connected to the third circuit channel.

[0011] Optionally, with the center of the sample loading hole as the center of the circle, the inner edge of the working electrode area is 10 mm away from the center of the circle, and the outer edge of the working electrode area is 12 mm away from the center of the circle; the inner edge of the counter electrode area is 13 mm away from the center of the circle, and the outer edge of the counter electrode area is 14 mm away from the center of the circle; the inner edge of the reference electrode area is 14 mm away from the center of the circle, and the outer edge of the reference electrode area is 15 mm away from the center of the circle.

[0012] Optionally, the reference electrode region is in the shape of a quarter of a circle, and the counter electrode region is in the shape of a half of a circle.

[0013] Optionally, the substrate electrode further comprises:

[0014] The color development areas are respectively arranged on the inner and outer sides of the working electrode area, the reference electrode area and the counter electrode area.

[0015] Optionally, the first circuit channel, the second circuit channel and the third circuit channel have the same shape, and the width of the middle channel of each circuit channel is smaller than the width of the channels at both ends.

[0016] Optionally, the distances between adjacent circuit paths are equal.

[0017] Optionally, the preprocessor includes: two electrode modification channels and a liquid mixing channel, the two electrode modification channels are respectively located directly above each electrode area; the liquid mixing channel corresponds to the area inside the working electrode area, and is injected into each electrode area through the lowest horizontal guide tube.

[0018] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0019] The present invention discloses an electrochemical detection device for integrated mycotoxin pretreatment and detection, comprising: a preprocessor, a substrate electrode, and a signal transmission structure. The substrate electrode is disposed at the lower end of the preprocessor, and the signal transmission structure is connected to the substrate electrode. The preprocessor is used to mix a solution to be detected and a pretreatment reagent, and is also used to provide an electrode modification channel. The substrate electrode is used for electrochemical detection to obtain an electrochemical signal. The signal transmission structure is used to transmit the electrochemical signal to a host computer, so that the host computer uses differential pulse voltammetry (DPV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the mycotoxin concentration based on changes in the electrochemical signal. The present invention discloses a miniaturized, fully automatic, integrated electrochemical detection device that achieves rapid and accurate on-site detection of mycotoxins through the collaborative design of a modular preprocessor and a highly sensitive substrate electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 This is a schematic diagram of the assembly of an electrochemical detection device according to an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a preprocessor according to an embodiment of the present invention;

[0023] Figure 3 Three views of the preprocessor structure according to an embodiment of the present invention;

[0024] Figure 4 This is a physical diagram of the substrate electrode structure according to an embodiment of the present invention;

[0025] Figure 5 Schematic diagram of the substrate electrode structure according to an embodiment of the present invention;

[0026] Among them, 1. Preprocessor, 11. Electrode modification channel, 12. Liquid mixing channel, 2. Base electrode, 21. Working electrode area, 22. Reference electrode area, 23. Counter electrode area, 24. First circuit channel, 25. Second circuit channel, 26. Third circuit channel, 27. Color development area, 28. Sample addition hole, 29. Center of circle, 3. Signal transmission structure. DETAILED DESCRIPTION

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making creative efforts are within the scope of protection of the present invention.

[0028] The purpose of the present invention is to provide an electrochemical detection device for integrated mycotoxin pretreatment and detection, so as to achieve on-site rapid and accurate mycotoxin detection.

[0029] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Figure 1 This is a schematic diagram of the assembly of an electrochemical detection device according to an embodiment of the present invention; Figure 2 Schematic diagram of the structure of the preprocessor according to an embodiment of the present invention, wherein (a) is a model diagram of the preprocessor and (b) is a physical diagram of the preprocessor; Figure 3 Three views of the preprocessor structure according to an embodiment of the present invention, wherein (a) is a front view of the preprocessor, (b) is a left view of the preprocessor, and (c) is a top view of the preprocessor; Figure 4 This is a physical diagram of the substrate electrode structure according to an embodiment of the present invention; Figure 5 FIG. 1 is a schematic diagram of the structure of the substrate electrode according to an embodiment of the present invention; FIG. Figure 1-5 As shown, the present invention discloses an electrochemical detection device for integrated pretreatment and detection of fungi toxins, including: a preprocessor 1, a substrate electrode 2 and a signal transmission structure 3, the substrate electrode 2 is arranged at the lower end of the preprocessor 1, and the signal transmission structure 3 is connected to the substrate electrode 2; the preprocessor 1 is used to mix the solution to be detected and the pretreatment reagent, and is also used to provide an electrode modification channel 11; the substrate electrode 2 is used for electrochemical detection to obtain electrochemical signals; the signal transmission structure 3 is used to transmit the electrochemical signals to a host computer, so that the host computer adopts differential pulse voltammetry DPV or electrochemical impedance spectroscopy EIS to quantitatively analyze the fungal toxin concentration based on the change of the electrochemical signal.

[0031] like Figure 4-5As shown, the substrate electrode 2 of the present invention includes: a working electrode area 21, a reference electrode area 22, a counter electrode area 23, a coloring area 27, a first circuit channel 24, a second circuit channel 25 and a third circuit channel 26; the coloring area 27 is respectively arranged on the inner and outer sides of the working electrode area 21, the reference electrode area 22 and the counter electrode area 23; the working electrode area 21 is a circular ring, and the counter electrode area 23 and the reference electrode area 22 are both arc-shaped; the reference electrode area 22 and the counter electrode area 23 are respectively surrounded by the outside of the working electrode area 21, and there is a gap between the reference electrode area 22 and the counter electrode area 23, the reference electrode area 22 is connected to the first circuit channel 24, the working electrode area 21 is connected to the second circuit channel 25, and the counter electrode area 23 is connected to the third circuit channel 26.

[0032] The present invention discloses that the working electrode area 21, the counter electrode area 23 and the reference electrode area 22 are integrated into a base electrode 2, which facilitates the subsequent direct placement of the preprocessor 1 on the base electrode 2 for subsequent use and portability.

[0033] Furthermore, the present invention sets the reference electrode region 22 to be in a quarter arc shape, and sets the counter electrode region 23 to be in a half arc shape, which can better wrap the working electrode region 21 inside.

[0034] Furthermore, the present invention uses the center of the sample loading hole 28 (here, the sample loading hole is obtained by the projection of the preprocessor 1) as the circle center 29. The inner edge of the working electrode area 21 is 10 mm from the circle center 29, and the outer edge of the working electrode area 21 is 12 mm from the circle center 29. The inner edge of the counter electrode area 23 is 13 mm from the circle center 29, and the outer edge of the counter electrode area 23 is 14 mm from the circle center 29. The inner edge of the reference electrode area 22 is 14 mm from the circle center 29, and the outer edge of the reference electrode area 22 is 15 mm from the circle center 29. The diameter of the sample loading hole 28 is 4 mm. The distances of the arc-shaped working electrode area, counter electrode area, and reference electrode area from the circle center can be increased or decreased by 1-3 mm as needed. At the same time, it is necessary to ensure that the working electrode area is on the inside and that the different electrode areas do not contact each other.

[0035] The first, second, and third circuit channels 24, 25, and 26 disclosed herein have identical shapes. The width of the middle channel of each circuit channel is smaller than the width of the channels at both ends, and the distance between adjacent circuit channels is equal. Adjacent circuit channels are spaced 2 mm apart, and the length of the middle channel is 18 mm. The channel at one end connected to each zone is 5 mm long, and the channel at the other end is 6 mm long.

[0036] like Figure 2-Figure 3As shown, the pre-processor 1 disclosed in the present invention includes: two electrode modification channels 11 and a liquid mixing channel 12. The two electrode modification channels 11 are located directly above each electrode area. The liquid mixing channel 12 corresponds to the area inside the working electrode area 21 and is injected into each electrode area through the lowest horizontal guide tube. The liquid mixing channel 12 includes two injection holes. Liquid is injected through the injection holes, mixed, and then flows out. After mixing through multiple circular arcs, it is injected into each electrode area through the lowest horizontal guide tube.

[0037] The present invention discloses that two electrode modification channels 11 are respectively arranged on the outside of the preprocessor 1, and the liquid mixing channel 12 is arranged on the inside of the preprocessor 1. The working electrode area can be modified by injecting nanomaterials into the electrode modification channels 11.

[0038] The pre-processor 1 in the present invention is made of photosensitive resin and is printed using an MP-100-6L 3D printer.

[0039] Example 1: Detection of zearalenone (ZEN) in vinegar samples:

[0040] Electrode surface modification: using a composite nanomaterial of copper oxide and graphite oxide as a modification reagent, injecting it into the outer electrode modification channel 11, waiting for 10 minutes to complete the modification of the working electrode area;

[0041] The vinegar sample and the purifier are added to the inner injection hole, and are automatically purified and mixed through the liquid mixing channel 12. After mixing, they flow into the working electrode area 21, the reference electrode area 22 and the counter electrode area 23 of the base electrode 2;

[0042] The substrate electrode 2 performs electrochemical detection to obtain an electrochemical signal;

[0043] The signal transmission structure 3 transmits the electrochemical signal to the host computer, so that the host computer uses differential pulse voltammetry (DPV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the concentration of fungal toxins based on the change of the electrochemical signal.

[0044] Example 2 is the detection of ochratoxin A (OTA) in wheat flour samples:

[0045] Sample preparation: wheat flour sample was collected, added to 90% acetonitrile-water solution, shaken gently and allowed to stand for 3 minutes, and the supernatant was collected;

[0046] Electrode surface modification: Use a composite nanomaterial of nickel oxide and multi-walled carbon nanotubes as an electrode modifier, inject it into the corresponding electrode area through the outer electrode modification channel 11, wait for 10 minutes, and complete the modification of the working electrode area;

[0047] The supernatant of the wheat flour sample and the acidified acetonitrile-water solution containing the purifier are added to the inner injection hole, and automatically extracted and purified through the liquid mixing channel 12, and finally moved to the working electrode area 21, reference electrode area 22 and counter electrode area 23 of the base electrode 2;

[0048] The substrate electrode 2 performs electrochemical detection to obtain an electrochemical signal;

[0049] The signal transmission structure 3 transmits the electrochemical signal to the host computer, so that the host computer uses differential pulse voltammetry (DPV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the concentration of fungal toxins based on the change of the electrochemical signal.

[0050] Example 3: Detection of vomitoxin (DON) in corn flour samples:

[0051] Sample preparation: collect corn flour sample, add polyethylene glycol-water solution, shake gently to evenly mix, let it stand for 5 minutes, and collect the supernatant;

[0052] Electrode surface modification: Use N / O co-doped porous carbon sheet nanomaterial as the electrode modifier, inject it into the corresponding electrode area through the outer electrode modification channel 11, wait for 10 minutes, and complete the modification of the working electrode area;

[0053] The supernatant of the corn flour sample and the acidified acetonitrile-water solution containing the purifier are added to the inner injection hole, and automatically extracted and purified through the liquid mixing channel 12, and finally moved to the working electrode area 21, the reference electrode area 22 and the counter electrode area 23 of the base electrode 2;

[0054] The substrate electrode 2 performs electrochemical detection to obtain an electrochemical signal;

[0055] The signal transmission structure 3 transmits the electrochemical signal to the host computer, so that the host computer uses square wave voltammetry (SWV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the concentration of fungal toxins based on the change of the electrochemical signal.

[0056] The processing process of the base electrode 2 is as follows:

[0057] 1. Use acetone, alcohol and water to ultrasonically clean the silicon oxide wafer;

[0058] 2. Sputter titanium on the cleaned silicon oxide wafer for 5 minutes, then sputter gold for 10 minutes;

[0059] 3. Use alcohol and water to clean the gold sheet;

[0060] 4. Spin-coat positive photoresist on the cleaned gold sheet;

[0061] 5. Heat the etched gold sheet at 120°C for 1 minute and 30 seconds;

[0062] 6. Attach the heated gold sheet to the mask and expose (1.4V, 14s);

[0063] 7. Develop the exposed structure with developer (50s), then rinse with water and dry with nitrogen.

[0064] 8. Place the developed structure into the gold etchant and etch for 15 seconds, then rinse with water and dry with nitrogen;

[0065] 9. Place the gold-etched structure into titanium etchant and etch for 20 seconds, then rinse with water and dry with nitrogen.

[0066] 10. Glue washing: Soak the etched structure in acetone for 30 seconds to obtain the base electrode 2.

[0067] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0068] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. An electrochemical detection device for integrated mycotoxin pretreatment and detection, characterized in that: The electrochemical detection equipment comprises: A pre-processor, used to mix the solution to be detected and the pre-treatment reagent, and also used to provide an electrode modification channel; A substrate electrode is provided corresponding to the pre-processor and disposed at the lower end of the pre-processor, and is used for electrochemical detection to obtain electrochemical signals; The signal transmission structure is connected to the substrate electrode and is used to transmit the electrochemical signal to the host computer so that the host computer uses differential pulse voltammetry (DPV) or electrochemical impedance spectroscopy (EIS) to quantitatively analyze the concentration of fungal toxins based on the changes in the electrochemical signal.

2. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 1, characterized in that: The substrate electrode comprises: A working electrode area, a reference electrode area, a counter electrode area, a first circuit channel, a second circuit channel and a third circuit channel; the working electrode area is in the shape of a circular ring, and the counter electrode area and the reference electrode area are both arc-shaped; the reference electrode area and the counter electrode area are respectively surrounded by the outside of the working electrode area, and there is a gap between the reference electrode area and the counter electrode area, the reference electrode area is connected to the first circuit channel, the working electrode area is connected to the second circuit channel, and the counter electrode area is connected to the third circuit channel.

3. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 2, characterized in that: With the center of the sample addition hole as the center of the circle, the inner edge of the working electrode area is 10 mm away from the center of the circle, and the outer edge of the working electrode area is 12 mm away from the center of the circle; the inner edge of the counter electrode area is 13 mm away from the center of the circle, and the outer edge of the counter electrode area is 14 mm away from the center of the circle; the inner edge of the reference electrode area is 14 mm away from the center of the circle, and the outer edge of the reference electrode area is 15 mm away from the center of the circle.

4. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 2, characterized in that: The reference electrode area is in the shape of a quarter of a circle, and the counter electrode area is in the shape of a half of a circle.

5. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 2, characterized in that: The substrate electrode further comprises: The color development areas are respectively arranged on the inner and outer sides of the working electrode area, the reference electrode area and the counter electrode area.

6. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 2, characterized in that: The first circuit channel, the second circuit channel, and the third circuit channel have the same shape, and the width of the middle channel of each circuit channel is smaller than the width of the channels at both ends.

7. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 6, characterized in that: The distances between adjacent circuit paths are equal.

8. The electrochemical detection device for integrated mycotoxin pretreatment and detection according to claim 2, characterized in that: The preprocessor includes: two electrode modification channels and a liquid mixing channel, the two electrode modification channels are respectively located directly above each electrode area; the liquid mixing channel corresponds to the area inside the working electrode area, and is injected into each electrode area through the lowest horizontal guide tube.

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