Organic acid detection device and method thereof for selectively identifying organic acid

Abstract

The invention relates to the technical field of organic acid detection, and discloses an organic acid detection device and a method for selectively recognizing organic acid thereof.The organic acid detection device comprises a microbial anode chamber, a cathode chamber, a proton exchange membrane, an external resistor and electric signal acquisition equipment, the method for selectively identifying the organic acid comprises the following steps: setting threshold current of each external resistor; putting a to-be-detected solution containing one or more organic acids into the microbial anode chamber; and obtaining an identification result of the type and / or concentration of the organic acid in the solution to be detected according to the conduction condition of the plurality of external resistors detected by the electric signal acquisition equipment. According to the organic acid detection device based on the MFC configuration, the external resistors with different threshold currents are arranged between the microbial anode chamber and the microbial cathode chamber in parallel, efficient and accurate organic acid detection is achieved, the types of the organic acid are recognized, the concentration of the organic acid is also detected, operation is easy, cost is low, and research on selective recognition of various organic acids is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of organic acid detection, and in particular to an organic acid detection device and a method for selectively identifying organic acids. Background Art

[0002] Organic acids are important components in many biological and environmental samples. Accurate detection and identification of organic acids is of great significance for environmental monitoring, food safety and medical diagnosis. Traditional methods for detecting organic acids include acid-base titration, colorimetry, liquid chromatography, ion chromatography, etc. These methods usually require complex instruments and expensive reagents, and are cumbersome to operate. They still have certain limitations in the selective identification of multiple organic acids, which is not conducive to the realization of efficient and accurate organic acid detection.

[0003] Therefore, a new method and system for selectively identifying organic acids is urgently needed. Summary of the invention

[0004] The present invention provides an organic acid detection device and a method for selectively identifying organic acids, which are used to solve the defect that the traditional organic acid detection method is not conducive to realizing efficient and accurate organic acid detection.

[0005] The present invention provides an organic acid detection device, comprising:

[0006] A microbial anode chamber, a cathode chamber, a proton exchange membrane, and a plurality of external resistors, wherein the microbial anode chamber is used to receive a test solution containing one or more organic acids and oxidize the organic acids in the test solution to generate electrons, the cathode chamber is used to receive electrons and perform a reduction reaction with protons, the proton exchange membrane is used to separate the microbial anode chamber and the cathode chamber and allow protons to pass through, and the plurality of external resistors are arranged to be connected in parallel between the microbial anode chamber and the cathode chamber and selectively allow electrons to pass through;

[0007] An electrical signal acquisition device is used to detect the conduction status of a plurality of external resistors.

[0008] According to an organic acid detection device provided by the present invention, the semiconductor material of the external resistor is any one of the following: silicon, germanium, gallium arsenide, silicon carbide, zinc oxide, and the semiconductor in the external resistor includes a PN junction structure.

[0009] The present invention also provides a method for selectively identifying organic acids using the above-mentioned organic acid detection device, comprising:

[0010] Setting a threshold current of each external resistor in the organic acid detection device, wherein different threshold currents represent different types of organic acids or different concentrations of organic acids of the same type;

[0011] placing a test solution containing one or more organic acids into the microbial anode chamber;

[0012] According to the conduction conditions of several external resistors detected by the electrical signal acquisition device, the identification result of the type and / or concentration of the organic acid in the solution to be tested is obtained.

[0013] According to a method for selectively identifying organic acids provided by the present invention, the different types of organic acids include any one of the following or any combination thereof: acetic acid, citric acid, pyruvic acid and oxalic acid.

[0014] According to a method for selectively identifying organic acids provided by the present invention, the threshold current of each external resistor in the organic acid detection device is set, including:

[0015] For each organic acid, perform the following steps to obtain the threshold current of the external resistor corresponding to each organic acid:

[0016] According to the chemical equation of the redox reaction of organic acids, the number of electrons generated by each organic acid molecule in the oxidation process is obtained;

[0017] Based on Faraday's law, combined with a preset substrate concentration, a preset reaction volume and a preset reaction time, a threshold current of the external resistance corresponding to the organic acid is obtained.

[0018] According to a method for selectively identifying organic acids provided by the present invention, the chemical equation for the redox reaction of acetic acid is:

[0019] CH3COO - +2H2O→2CO2+7H + +8e - ,

[0020] The chemical equation for the redox reaction of citric acid is:

[0021] C6H5O7 3- +9H2O→6CO2+15H + +18e - ,

[0022] The chemical equation for the redox reaction of pyruvate is:

[0023] CH3COCOO - +3H2O→3CO2+5H + +5e - ,

[0024] The chemical equation for the redox reaction of oxalic acid is:

[0025] C2H2O4→2CO2+2H + +2e - .

[0026] According to a method for selectively identifying organic acids provided by the present invention, the number of electrons generated by each acetic acid molecule during the oxidation process is 8, the number of electrons generated by each citric acid molecule during the oxidation process is 18, the number of electrons generated by each pyruvic acid molecule during the oxidation process is 5, and the number of electrons generated by each oxalic acid molecule during the oxidation process is 2.

[0027] According to a method for selectively identifying organic acids provided by the present invention, the calculation expression of the threshold current is:

[0028] I=E q ×96485×V×C×T,

[0029] In the calculation expression of threshold current, I represents the threshold current of external resistance, E q represents the number of electrons, V represents the preset reaction volume, C represents the preset substrate concentration, and T represents the preset reaction time.

[0030] According to a method for selectively identifying organic acids provided by the present invention, the preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, the preset reaction time is 1 hour, and the calculation expression of the threshold current of the external resistance corresponding to acetic acid is: I1=8×96485×0.001×0.01 / 3600≈2.14×10 -2 μA,

[0031] The calculation expression of the threshold current of citric acid corresponding to the external resistance is: I2 = 18 × 96485 × 0.001 × 0.01 / 3600 ≈ 4.83 × 10 -2 μA,

[0032] The calculation expression of the threshold current of pyruvic acid corresponding to the external resistance is: I3 = 5 × 96485 × 0.001 × 0.01 / 3600 ≈ 1.34 × 10 -2 μA,

[0033] The calculation expression of the threshold current of oxalic acid corresponding to the external resistance is: I4 = 2 × 96485 × 0.001 × 0.01 / 3600 ≈ 0.54 × 10 -2 μA.

[0034] According to a method for selectively identifying organic acids provided by the present invention, the preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, the preset reaction time is 1 hour, and the threshold current of the external resistance corresponding to acetic acid is 2×10 -2 μA, the threshold current of citric acid corresponding to the external resistance is 4×10 -2 μA, the threshold current of pyruvic acid corresponding to the external resistance is 1×10 -2μA, the threshold current of oxalic acid corresponding to the external resistance is 0.5×10 -2 μA.

[0035] According to a method for selectively identifying organic acids provided by the present invention, the identification result of the type and / or concentration of the organic acid in the solution to be tested is obtained according to the conduction conditions of a plurality of external resistors detected by an electrical signal acquisition device, including:

[0036] The electrical signals of each external resistor are obtained by an electrical signal acquisition device, and IV spectrum measurement is performed on the electrical signals of each external resistor to obtain the conduction status of each external resistor.

[0037] According to a method for selectively identifying organic acids provided by the present invention, the identification result of the type and / or concentration of the organic acid in the solution to be tested is obtained according to the conduction conditions of a plurality of external resistors detected by an electrical signal acquisition device, including:

[0038] When the conduction status of each external resistor obtained by the electrical signal acquisition device indicates that a certain external resistor in the organic acid detection device is turned on, it means that the type and concentration of the organic acid in the test solution are the type and concentration of the organic acid represented by the turned-on external resistor.

[0039] The present invention provides an organic acid detection device and a method for selectively identifying organic acids. The organic acid detection device is based on an MFC configuration and utilizes external resistors with different threshold currents arranged in parallel between a microbial anode chamber and a cathode chamber to achieve efficient and accurate organic acid detection. The device can identify the type of organic acid and detect the concentration of the organic acid. The device is simple to operate and low in cost, and is conducive to promoting research on selective identification of multiple organic acids. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 The present invention provides a schematic flow chart of a method for selectively identifying organic acids.

[0042] Figure 2 This is a structural example diagram of an organic acid detection device.

[0043] Figure 3 This is a graph showing substrate concentration versus detection signal current. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments, and they should not be understood as limitations on the present invention. 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. In the description of the present invention, it should be understood that the terms used are only for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0045] Figure 1 The present invention provides a schematic flow chart of a method for selectively identifying organic acids.

[0046] See also Figure 1 The present invention provides a method for selectively identifying organic acids, which may include:

[0047] S110, setting a threshold current of each external resistor in the organic acid detection device, wherein different threshold currents represent different types of organic acids or organic acids of the same type but different concentrations.

[0048] S120, placing a test solution containing one or more organic acids into the microbial anode chamber.

[0049] S130, obtaining an identification result of the type and / or concentration of the organic acid in the solution to be tested according to the conduction conditions of the plurality of external resistors detected by the electrical signal acquisition device.

[0050] In one embodiment, the organic acid detection device may include:

[0051] A microbial anode chamber, a cathode chamber, a proton exchange membrane, and a plurality of external resistors, wherein the microbial anode chamber is used to receive a test solution containing one or more organic acids and oxidize the organic acids in the test solution to generate electrons, the cathode chamber is used to receive electrons and perform a reduction reaction with protons, the proton exchange membrane is used to separate the microbial anode chamber and the cathode chamber and allow protons to pass through, and the plurality of external resistors are arranged to be connected in parallel between the microbial anode chamber and the cathode chamber and selectively allow electrons to pass through, wherein the semiconductor material of the external resistor is any one of the following: silicon (Si), germanium (Ge), gallium arsenide (GaAs), silicon carbide (SiC), zinc oxide (ZnO), and the semiconductor in the external resistor includes a PN junction structure;

[0052] An electrical signal acquisition device is used to detect the conduction status of a plurality of external resistors.

[0053] in Figure 2 A structural example of an organic acid detection device is shown.

[0054] In one embodiment, S110 may perform the following steps for each organic acid to obtain a threshold current of an external resistor corresponding to each organic acid:

[0055] According to the chemical equation of the redox reaction of organic acids, the number of electrons generated by each organic acid molecule in the oxidation process is obtained;

[0056] Based on Faraday's law, combined with a preset substrate concentration, a preset reaction volume and a preset reaction time, a threshold current of the external resistance corresponding to the organic acid is obtained.

[0057] Among them, the calculation expression of the threshold current is:

[0058] I=E q ×96485×V×C×T,

[0059] In the calculation expression of threshold current, I represents the threshold current of external resistance, E q represents the number of electrons, V represents the preset reaction volume, C represents the preset substrate concentration, and T represents the preset reaction time.

[0060] In one embodiment, S120 may include:

[0061] The electrical signals of each external resistor are obtained by an electrical signal acquisition device, and the electrical signals of each external resistor are measured by IV spectrum to obtain the conduction status of each external resistor;

[0062] When the conduction status of each external resistor obtained by the electrical signal acquisition device indicates that a certain external resistor in the organic acid detection device is turned on, it means that the type and concentration of the organic acid in the test solution are the type and concentration of the organic acid represented by the turned-on external resistor.

[0063] In this embodiment, the different types of organic acids may include: acetic acid, citric acid, pyruvic acid and oxalic acid.

[0064] The chemical equation for the redox reaction of acetic acid is:

[0065] CH3COO - +2H2O→2CO2+7H + +8e - ,

[0066] The chemical equation for the redox reaction of citric acid is:

[0067] C6H5O7 3- +9H2O→6CO2+15H + +18e - ,

[0068] The chemical equation for the redox reaction of pyruvate is:

[0069] CH3COCOO - +3H2O→3CO2+5H + +5e - ,

[0070] The chemical equation for the redox reaction of oxalic acid is:

[0071] C2H2O4→2CO2+2H + +2e - .

[0072] That is, the number of electrons generated by each acetic acid molecule in the oxidation process is 8, the number of electrons generated by each citric acid molecule in the oxidation process is 18, the number of electrons generated by each pyruvic acid molecule in the oxidation process is 5, and the number of electrons generated by each oxalic acid molecule in the oxidation process is 2.

[0073] In this embodiment, the preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, the preset reaction time is 1 hour, and the calculation expression of the threshold current of the external resistance corresponding to acetic acid is: I1 = 8 × 96485 × 0.001 × 0.01 / 3600 ≈ 2.14 × 10 -2 μA,

[0074] The calculation expression of the threshold current of citric acid corresponding to the external resistance is: I2 = 18 × 96485 × 0.001 × 0.01 / 3600 ≈ 4.83 × 10 -2 μA,

[0075] The calculation expression of the threshold current of pyruvic acid corresponding to the external resistance is: I3 = 5 × 96485 × 0.001 × 0.01 / 3600 ≈ 1.34 × 10 -2 μA,

[0076] The calculation expression of the threshold current of oxalic acid corresponding to the external resistance is: I4 = 2 × 96485 × 0.001 × 0.01 / 3600 ≈ 0.54 × 10 -2 μA.

[0077] That is, the preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, and the preset reaction time is 1 hour. In this embodiment, the threshold current is rounded, and the threshold current corresponding to the external resistance of acetic acid is 2×10 -2 μA, the threshold current of citric acid corresponding to the external resistance is 4×10 -2 μA, the threshold current of pyruvic acid corresponding to the external resistance is 1×10 -2 μA, the threshold current of oxalic acid corresponding to the external resistance is 0.5×10 -2 μA.

[0078] This example adopts Experiment 1 and Experiment 2 to verify the method for selectively identifying organic acids provided by the present invention.

[0079] Experiment 1: Detect the electrical signals of acetic acid, citric acid, pyruvic acid and oxalic acid as substrates at different concentrations of 0.5, 1, 1.5, 2, 2.5, 3, 3.5 mmol / L respectively, and repeat 3 times. The detection current collection values ​​are as follows Figure 3 As shown. Figure 3 It can be seen that the four organic acids cannot be detected at 0.5mmol / L, citric acid can be detected at 1mmol / L but other acids cannot be detected. As the concentration of organic acids increases, the detection current shows a linear correlation trend. It is preliminarily determined that the selective detection of the method for selectively identifying organic acids provided by the present invention is effective.

[0080] Experiment 2: Based on the data of Experiment 1 as the standard curve, combined with the selection and dynamic scanning of semiconductors, effective separation and detection of acetic acid, citric acid, pyruvic acid and oxalic acid were achieved.

[0081] Four threshold currents were set (2×10-2μA, 4×10-2μA, 1×10-2μA, 0.5×10-2μA). Semiconductor materials were selected based on the characteristics of four organic acids: TiO2 with surface modification of Pt was used for acetic acid and pyruvic acid, and CdTe with surface modification of IrO2 was used for citric acid and oxalic acid.

[0082] Testing mixed organic acid solution:

[0083] Prepare a mixed solution of the two acids with a concentration of 2.5 mmol / L (2.5 mmol / L for each acid).

[0084]

[0085] Based on the above data, citric acid, due to its polycarboxylic acid structure, requires a higher threshold current to trigger, and is easier to separate from other organic acids; while for acids with similar response characteristics (such as acetic acid + pyruvic acid), the separation effect is weaker. Users can set the threshold current of each external resistor in the organic acid detection device according to actual needs and use it to selectively identify organic acids.

[0086] The present invention provides an organic acid detection device and a method for selectively identifying organic acids. The organic acid detection device is based on an MFC configuration and utilizes external resistors with different threshold currents arranged in parallel between a microbial anode chamber and a cathode chamber to achieve efficient and accurate organic acid detection. The device can identify the type of organic acid and detect the concentration of the organic acid. The device is simple to operate and low in cost, and is conducive to promoting research on selective identification of multiple organic acids.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An organic acid detection device, comprising: A microbial anode chamber, a cathode chamber, a proton exchange membrane, and a plurality of external resistors, wherein the microbial anode chamber is used to receive a test solution containing one or more organic acids and oxidize the organic acids in the test solution to generate electrons, the cathode chamber is used to receive electrons and perform a reduction reaction with protons, the proton exchange membrane is used to separate the microbial anode chamber and the cathode chamber and allow protons to pass through, and the plurality of external resistors are arranged to be connected in parallel between the microbial anode chamber and the cathode chamber and selectively allow electrons to pass through; An electrical signal acquisition device is used to detect the conduction status of a plurality of external resistors.

2. The organic acid detection device according to claim 2, characterized in that: The semiconductor material of the external resistor is any one of the following: silicon, germanium, gallium arsenide, silicon carbide, zinc oxide, and the semiconductor in the external resistor includes a PN junction structure.

3. A method for selectively identifying organic acids using the organic acid detection device according to claim 1 or 2, comprising the following steps: Setting a threshold current of each external resistor in the organic acid detection device, wherein different threshold currents represent different types of organic acids or different concentrations of organic acids of the same type; placing a test solution containing one or more organic acids into the microbial anode chamber; According to the conduction conditions of several external resistors detected by the electrical signal acquisition device, the identification result of the type and / or concentration of the organic acid in the solution to be tested is obtained.

4. The method for selectively identifying organic acids according to claim 3, characterized in that: The step of setting the threshold current of each external resistor in the organic acid detection device includes: For each organic acid, perform the following steps to obtain the threshold current of the external resistor corresponding to each organic acid: According to the chemical equation of the redox reaction of organic acids, the number of electrons generated by each organic acid molecule in the oxidation process is obtained; Based on Faraday's law, combined with a preset substrate concentration, a preset reaction volume and a preset reaction time, a threshold current of the external resistance corresponding to the organic acid is obtained.

5. The method for selectively identifying organic acids according to claim 4, characterized in that: The calculation expression of threshold current is: I=E q ×96485×V×C×T, In the calculation expression of threshold current, I represents the threshold current of external resistance, E q represents the number of electrons, V represents the preset reaction volume, C represents the preset substrate concentration, and T represents the preset reaction time.

6. The method for selectively identifying organic acids according to claim 5, characterized in that: The one or more organic acids include any one or any combination of the following: acetic acid, citric acid, pyruvic acid, and oxalic acid.

7. The method for selectively identifying organic acids according to claim 6, characterized in that: The preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, and the preset reaction time is 1 hour.

8. The method for selectively identifying organic acids according to claim 7, characterized in that: The calculation expression of the threshold current of acetic acid corresponding to the external resistance is: I1 = 8 × 96485 × 0.001 × 0.01 / 3600 ≈ 2.14 × 10 -2 μA, The calculation expression of the threshold current of citric acid corresponding to the external resistance is: I2 = 18 × 96485 × 0.001 × 0.01 / 3600 ≈ 4.83 × 10 -2 μA, The calculation expression of the threshold current of pyruvic acid corresponding to the external resistance is: I3 = 5 × 96485 × 0.001 × 0.01 / 3600 ≈ 1.34 × 10 -2 μA, The calculation expression of the threshold current of oxalic acid corresponding to the external resistance is: I4 = 2 × 96485 × 0.001 × 0.01 / 3600 ≈ 0.54 × 10 -2 μA, The preset substrate concentration is 1 mmol / L, the preset reaction volume is 10 mL, the preset reaction time is 1 hour, and the threshold current of the external resistance corresponding to acetic acid is 2×10 -2 μA, the threshold current of citric acid corresponding to the external resistance is 4×10 - 2 μA, the threshold current of pyruvic acid corresponding to the external resistance is 1×10 -2 μA, the threshold current of oxalic acid corresponding to the external resistance is 0.5×10 -2 μA.

9. The method for selectively identifying organic acids according to any one of claims 3 to 8, characterized in that: The method of obtaining the identification result of the type and / or concentration of the organic acid in the solution to be tested based on the conduction conditions of the plurality of external resistors detected by the electrical signal acquisition device includes: The electrical signals of each external resistor are obtained by an electrical signal acquisition device, and IV spectrum measurement is performed on the electrical signals of each external resistor to obtain the conduction status of each external resistor.

10. The method for selectively identifying organic acids according to any one of claims 3 to 8, characterized in that: The method of obtaining the identification result of the type and / or concentration of the organic acid in the solution to be tested based on the conduction conditions of the plurality of external resistors detected by the electrical signal acquisition device includes: When the conduction status of each external resistor obtained by the electrical signal acquisition device indicates that a certain external resistor in the organic acid detection device is turned on, it means that the type and concentration of the organic acid in the test solution are the type and concentration of the organic acid represented by the turned-on external resistor.

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