A method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge

Abstract

The present invention discloses a method for evaluating algaecidal efficacy based on in-situ detection of the charge of extracellular polymers, and belongs to the technical field of harmful cyanobacteria treatment in surface water. The charge performance of cyanobacteria extracellular polymers and the surface potential distribution of cyanobacteria cells are detected. The method is based on the detection of changes in the in-situ charge performance of cyanobacteria extracellular polymers, and can evaluate the effect of ultra-low voltage nano-tip enhanced electroporation on algae killing under the influence of extracellular polymers. It is an effective tool for studying the mechanism of killing microorganisms by nano-tip enhanced electroporation, and is conducive to judging the correlation between the in-situ charge performance of cells and the inactivation effect under the action of the electric field. It can clearly, objectively and effectively evaluate the actual effect of the electric field on cells, and has the advantages of simple operation and convenient use in the in-situ detection of the charge of extracellular polymers.

Description

Technical Field

[0001] The invention belongs to the technical field of harmful blue algae treatment in surface water, and specifically relates to a method for evaluating algaecidal efficacy based on in-situ detection of the charge of extracellular polymers. Background Art

[0002] Water environment safety is one of the important conditions for ensuring human life and health. Water shortage and serious water pollution have become environmental issues of great concern to the international community. In particular, the problem of blue-green algae blooms caused by eutrophication of water bodies has attracted much attention. How to effectively prevent and control the eutrophication of lake and reservoir water sources is still one of the important tasks of water pollution control and an important part of ensuring the safety of drinking water in my country.

[0003] At present, the technology of nano-tip enhanced electroporation for cyanobacteria cell inactivation under extremely low voltage conditions is developing rapidly. This technology can achieve good cyanobacteria inactivation effect under extremely low voltage conditions. In the technology of water algal bloom control, nano-tip enhanced electroporation for cell inactivation under extremely low voltage conditions is a promising and efficient microalgae inactivation method with the advantages of low energy consumption, rapid processing, convenient operation, and good inactivation effect. However, the effect of this technology is limited by the extracellular polymers of cyanobacteria. Extracellular polymers wrap around cells as a protective barrier and form a buffer structure on the cell surface. At present, there are still deficiencies in the research on extracellular polymers, especially in the field of in-situ detection of the charge properties of extracellular polymers. There is no systematic and comprehensive characterization method.

[0004] After nanotip enhanced electroporation treatment of cyanobacterial cells, the characterization of the inactivation effect tends to focus on the cell density, maximum photochemical quantum yield, and changes in cell surface morphology of cyanobacteria. Although these traditional macroscopic characterization methods can detect the inactivation effect of nanotip enhanced electroporation technology under extremely low voltage conditions, due to factors such as cell resuscitation and changes in water environment conditions, it is impossible to accurately evaluate the impact of cyanobacterial extracellular polymers, especially during the treatment process, it is difficult to measure the charge properties of extracellular polymers.

[0005] As a cyanobacteria inactivation technology that uses a high-voltage electric field generated by a sharp electrode to break the cell membrane and inactivate it, traditional characterization methods make it difficult to visually detect the surface charge of cyanobacterial extracellular polymers in situ and analyze the ability of extracellular polymers to hinder this technology. A single electrochemical characterization method is also unable to provide effective support for the surface charge of extracellular polymers, which has an adverse impact on the development of this technology. Therefore, the in situ detection of the surface charge of cyanobacterial extracellular polymers is of great significance for the evaluation of the algaecidal efficacy of nanotip enhanced electroporation technology under extremely low voltage conditions and the analysis of the microscopic interface action mechanism. Summary of the invention

[0006] The purpose of the present invention is to solve the problem that traditional characterization methods are difficult to intuitively detect and evaluate the effectiveness of cyanobacteria fire extinguishing technology in situ, and to provide a method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge.

[0007] The specific technical solutions adopted by the present invention are as follows:

[0008] The present invention provides a method for evaluating algaecidal efficacy based on in-situ detection of the charge of extracellular polymers. Multiple groups of algae liquids obtained by an electrochemical algaecidal method are used as algae liquids to be evaluated and in-situ detection is performed. The in-situ detection includes detecting the charge performance of the extracellular polymers of cyanobacteria and the surface potential distribution of cyanobacterial cells, wherein the charge performance is characterized by the capacitive charge and charge transfer resistance of the extracellular polymers of cyanobacteria. The algae liquid to be evaluated has lower capacitive charge and charge transfer resistance than other groups and higher cell surface potential than other groups, which is the group with the best algaecidal efficiency in the algae liquid to be evaluated.

[0009] Preferably, the in-situ detection method of the charge properties of the extracellular polymers of cyanobacteria is as follows:

[0010] S1: The algae solution to be evaluated was mechanically stirred evenly, and electrochemical impedance spectroscopy analysis was performed using a single cyanobacteria culture solution as the background medium; the electrochemical impedance spectroscopy analysis adopted a standard three-electrode working system, with a glassy carbon electrode as the working electrode, a platinum wire electrode as the counter electrode, and a silver-silver chloride electrode as the reference electrode; the detection was carried out under constant potential control and at an open circuit potential to obtain an electrochemical impedance spectrum; the frequency range of the electrochemical test system was 10 6 -10 0 Hz;

[0011] S2: The electrochemical impedance spectrum is fitted using a fitting circuit, in which a constant phase angle element CPE is used to replace the charged capacitor in the equivalent circuit to ensure that the error value of the fitting data is less than 20%, and the data of the capacitance charging and charge transfer resistance of the extracellular polymers of cyanobacteria are obtained.

[0012] Furthermore, before the electrochemical impedance spectroscopy analysis is performed in the above standard three-electrode working system, an inert gas is introduced to expel oxygen in the solution to maintain an inert gas environment.

[0013] Furthermore, the above culture solution is the BG11 liquid culture medium required for the growth of cyanobacteria.

[0014] Preferably, the in situ detection method of the surface potential distribution of cyanobacteria cells is as follows:

[0015] Take cyanobacteria cells, spread them flat in the center of a gold-coated silicon wafer, and freeze-dry them. Use Kelvin probe force microscopy to detect the surface potential distribution of the area around the freeze-dried cyanobacteria cells in a tapping mode, and apply a 0.15V DC bias feedback loop.

[0016] Furthermore, Kelvin probe force microscopy was used to detect the potential distribution in a 5 μm × 5 μm area around the cyanobacterial cells.

[0017] Preferably, the electrochemical algae killing method is a nano-tip enhanced electroporation algae killing technology at an extremely low voltage.

[0018] Furthermore, the conditions of the above-mentioned nano-tip enhanced electroporation algae killing technology at extremely low voltage are as follows: the applied DC voltage is 0.5V-1.5V, and the flow rate in the algae killing device is 4mL / min.

[0019] Furthermore, the cell density of cyanobacteria in the above-mentioned ultra-low voltage nano-tip enhanced electroporation algae killing technology is 10 6 -10 7 Pieces / mL.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides an algaecidal evaluation method based on in situ detection of the charge of extracellular polymers. The method first detects and evaluates the charge performance of the extracellular polymers of cyanobacteria, further detects the charge performance of the extracellular polymers of cyanobacteria in situ, analyzes the surface potential distribution of cyanobacteria cells in situ based on the extracellular polymers, and evaluates the algaecidal effect based on the in situ charge performance of the extracellular polymers.

[0022] The method provided by the present invention is based on the detection of changes in the in-situ charging properties of extracellular polymers of cyanobacteria, and evaluates the effect of ultra-low voltage nano-tip enhanced electroporation on killing algae under the influence of extracellular polymers. The method is an effective tool for studying the mechanism of killing microorganisms by nano-tip enhanced electroporation, is conducive to judging the correlation between the in-situ charging properties of cells and the inactivation effect under the action of the electric field, can clearly, objectively and effectively evaluate the actual effect of the electric field on the cells, and has the advantages of simple operation and easy use in the in-situ detection of the charge of extracellular polymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A flow chart of a method for evaluating algaecidal efficacy based on in-situ detection of extracellular polymer charge provided by the present invention;

[0024] Figure 2 A schematic diagram of an electrochemical impedance spectroscopy fitting circuit provided by the present invention;

[0025] Figure 31 is a comparison chart of algaecidal efficacy in Example 1, wherein (a) is the capacitance charge of the intact Microcystis aeruginosa and the Microcystis aeruginosa solution after the extracellular polymers are removed; (b) is the charge transfer resistance of the intact Microcystis aeruginosa and the Microcystis aeruginosa solution after the extracellular polymers are removed; (c) and (d) are the surface potentials of the intact Microcystis aeruginosa and the Microcystis aeruginosa after the extracellular polymers are removed, respectively; (e) and (f) are the algae mortality rates of the intact Microcystis aeruginosa and the Microcystis aeruginosa after the extracellular polymers are removed, respectively, measured by flow cytometry. DETAILED DESCRIPTION

[0026] The present invention is further described and illustrated below in conjunction with the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly without conflicting with each other.

[0027] Example 1

[0028] This embodiment provides a method for evaluating the efficacy of intact Microcystis aeruginosa and Microcystis aeruginosa with extracellular polymers removed after being treated with nano-tip enhanced electroporation at an extremely low voltage to kill the algae. In this embodiment, the parameters of the nano-tip enhanced electroporation treatment at an extremely low voltage are as follows: the flow rate is 4 mL / min, the direct current is 1.5 V, the cell density of Microcystis aeruginosa is 10 7 / mL. The specific evaluation method is as follows:

[0029] (1) The in situ charging performance detection method of cyanobacterial extracellular polymers is as follows:

[0030] The intact Microcystis aeruginosa solution and the Microcystis aeruginosa solution with the extracellular polymer removed were mechanically stirred evenly, and electrochemical impedance spectroscopy was performed using the culture solution as the background medium, wherein the culture solution was the BG11 liquid culture medium required for the growth of cyanobacteria.

[0031] like Figure 2 As described above, the electrochemical impedance spectroscopy analysis adopts a standard three-electrode working system. Before the test, an inert gas is introduced to expel oxygen from the solution and maintain an inert gas environment. The glassy carbon electrode (WE) is used as the working electrode, the platinum wire electrode (PE) is used as the counter electrode, and the silver-silver chloride electrode is used as the reference electrode. The test is carried out under constant potential control and at an open circuit potential to obtain an electrochemical impedance spectrum. The electrochemical test system is operated at 10 6 -10 0 The test was carried out in a frequency range of Hz, with an amplitude of 0.005s and a rest time of 2s.

[0032] The electrochemical impedance spectrum is fitted using a fitting circuit, in which a constant phase angle element CPE is used to replace the charged capacitor in the equivalent circuit, wherein Rs is the solution resistance, Qdl is the in-situ charge of the extracellular polymers of cyanobacteria, and Rct is the charge transfer resistance of the extracellular polymers of cyanobacteria. The error value of the fitting data is ensured to be less than 20%, and the data of the capacitance charge and charge transfer resistance of the extracellular polymers of cyanobacteria are obtained, as shown in FIG. Figure 3 shown.

[0033] like Figure 3 (a) and Figure 3 As shown in (b), in this embodiment, the capacitance charge of the complete Microcystis aeruginosa solution is 3.17 μF·cm 2 , the charge transfer resistance is 384.91KΩ·cm 2 , the capacitance charge of the solution of Microcystis aeruginosa after the removal of extracellular polymers was 1.28 μF·cm 2 , the charge transfer resistance is 299.11KΩ·cm 2 , the fitting error is less than 20%.

[0034] (2) The in situ detection method of the surface potential distribution of cyanobacteria cells is as follows:

[0035] Take cyanobacteria cells of appropriate density to ensure that they can be spread flat in the center of the gold-coated silicon wafer for freeze drying. Use Kelvin probe force microscopy to detect the surface potential distribution of the 5μm×5μm area around the freeze-dried cyanobacteria cells in the knocking mode, and apply a 0.15V DC bias feedback loop.

[0036] like Figure 3 (c) and Figure 3 As shown in (d), in this embodiment, the difference between the surface potential and the background potential of the intact Microcystis aeruginosa is 25.07 mV, and the difference between the surface potential and the background potential of the Microcystis aeruginosa after the extracellular polymers are removed is 112.57 mV.

[0037] The in situ charging performance and charge transfer resistance of intact Microcystis aeruginosa were greater than those of Microcystis aeruginosa without extracellular polymers, and the surface potential was less than that of Microcystis aeruginosa without extracellular polymers. The surface potential was weakened by nanotip enhanced electroporation under extremely low voltage conditions, indicating that extracellular polymers have significant chargeability. Based on the chargeability of extracellular polymers detected in situ, the algae-killing efficiency of Microcystis aeruginosa without extracellular polymers was higher after nanotip enhanced electroporation under 1.5V voltage.

[0038] The mortality of intact Microcystis aeruginosa and Microcystis aeruginosa with extracellular polymers removed was detected by flow cytometry. Figure 3 (e) and Figure 3(f) The mortality rate of intact Microcystis aeruginosa after treatment was 65.10%, and the mortality rate of Microcystis aeruginosa after removal of extracellular polymers was 87.50%, which can prove that the evaluation method provided in this example is accurate.

[0039] Example 2

[0040] This embodiment provides a method for evaluating the efficacy of intact Microcystis aeruginosa and Microcystis aeruginosa with extracellular polymers removed after being treated with nano-tip enhanced electroporation at an extremely low voltage to kill the algae. In this embodiment, the parameters of the nano-tip enhanced electroporation treatment at an extremely low voltage are as follows: the flow rate is 4 mL / min, the direct current is 0.5 V, the cell density of Microcystis aeruginosa is 10 6 / mL. The specific evaluation method is as follows:

[0041] (1) The in situ charging performance detection method of cyanobacterial extracellular polymers is as follows:

[0042] The intact Microcystis aeruginosa solution and the Microcystis aeruginosa solution with the extracellular polymer removed were mechanically stirred evenly, and electrochemical impedance spectroscopy was performed using the culture solution as the background medium, wherein the culture solution was the BG11 liquid culture medium required for the growth of cyanobacteria.

[0043] like Figure 2 As described above, the electrochemical impedance spectroscopy analysis adopts a standard three-electrode working system. Before the test, an inert gas is introduced to expel oxygen from the solution and maintain an inert gas environment. The glassy carbon electrode (WE) is used as the working electrode, the platinum wire electrode (PE) is used as the counter electrode, and the silver-silver chloride electrode is used as the reference electrode. The test is carried out under constant potential control and open circuit potential to obtain an electrochemical impedance spectrum. The electrochemical test system is operated at 10 6 -10 0 The test was carried out in a frequency range of Hz, with an amplitude of 0.005s and a rest time of 2s.

[0044] The electrochemical impedance spectrum was fitted using a fitting circuit, in which a constant phase angle element CPE was used to replace the charged capacitor in the equivalent circuit, wherein Rs was the solution resistance, Qdl was the in-situ charge of the extracellular polymers of cyanobacteria, and Rct was the charge transfer resistance of the extracellular polymers of cyanobacteria, ensuring that the error value of the fitting data was less than 20%, and the data of the capacitive charging and charge transfer resistance of the extracellular polymers of cyanobacteria were obtained.

[0045] In this embodiment, the capacitance charge of the complete Microcystis aeruginosa solution is 3.06 μF·cm 2 , the charge transfer resistance is 355.20KΩ·cm 2 The capacitance charge of the solution of Microcystis aeruginosa after the removal of extracellular polymers was 1.02 μF·cm 2 , the charge transfer resistance is 285.36KΩ·cm 2, the fitting error is less than 20%.

[0046] (2) The in situ detection method of the surface potential distribution of cyanobacteria cells is as follows:

[0047] Take cyanobacteria cells of appropriate density to ensure that the cyanobacteria cells can be flattened in the center of the gold-coated silicon wafer for freeze drying. Kelvin probe force microscopy is used to detect the surface potential distribution of the 5μm×5μm area around the freeze-dried cyanobacteria cells in the knocking mode, and a 0.15V DC bias feedback loop is applied. In this embodiment, the difference between the surface potential and the background potential of the intact Microcystis aeruginosa is 23.02mV, and the difference between the surface potential and the background potential of the Microcystis aeruginosa without extracellular polymers is 98.56mV.

[0048] The in situ charging performance and charge transfer resistance of intact Microcystis aeruginosa were greater than those of Microcystis aeruginosa without extracellular polymers, and the surface potential was less than that of Microcystis aeruginosa without extracellular polymers. The surface potential was weakened by nanotip enhanced electroporation under extremely low voltage conditions, indicating that extracellular polymers have significant chargeability. Based on the chargeability of extracellular polymers detected in situ, the algae-killing efficiency of Microcystis aeruginosa without extracellular polymers was higher after nanotip enhanced electroporation under 0.5V voltage.

[0049] The mortality of intact Microcystis aeruginosa and Microcystis aeruginosa with extracellular polymers removed was detected by flow cytometry. The mortality of intact Microcystis aeruginosa after treatment was 45.63%, and the mortality of Microcystis aeruginosa with extracellular polymers removed was 68.56%, which can prove that the evaluation method provided in this example is accurate.

[0050] Example 3

[0051] This embodiment provides a method for evaluating the effectiveness of nano-tip enhanced electroporation treatment of Microcystis aeruginosa cultured in medium nutrient level culture medium and rich nutrient level culture medium at extremely low voltage after killing algae. The N and P content of the medium nutrient level culture medium is 0.45 mg / L and 0.03 mg / L, respectively, and the N and P content of the rich nutrient level culture medium is 3 mg / L and 0.2 mg / L, respectively.

[0052] In this embodiment, the parameters of the ultra-low voltage nanotip enhanced electroporation treatment are as follows: the flow rate is 4 mL / min, the direct current is 1.5 V, the cell density of Microcystis aeruginosa is 10 7 / mL. The specific evaluation method is as follows:

[0053] (1) The in situ charging performance detection method of cyanobacterial extracellular polymers is as follows:

[0054] The solution of Microcystis aeruginosa cultured under mesotrophic conditions and the solution of Microcystis aeruginosa cultured under eutrophic conditions were mechanically stirred evenly, and electrochemical impedance spectroscopy was performed using the culture solution as the background medium, wherein the culture solution was the BG11 liquid culture medium required for the growth of cyanobacteria.

[0055] like Figure 2 As described above, the electrochemical impedance spectroscopy analysis adopts a standard three-electrode working system. Before the test, an inert gas is introduced to expel oxygen from the solution and maintain an inert gas environment. A glassy carbon electrode (WE) is used as the working electrode, a platinum wire electrode (PE) is used as the counter electrode, and a silver-silver chloride electrode is used as the reference electrode. The test is carried out under constant potential control and at an open circuit potential to obtain an electrochemical impedance spectrum. The electrochemical test system is operated at 10 6 -10 0 The test was carried out in a frequency range of Hz, with an amplitude of 0.005s and a rest time of 2s.

[0056] The electrochemical impedance spectrum was fitted using a fitting circuit, in which a constant phase angle element CPE was used to replace the charged capacitor in the equivalent circuit, wherein Rs was the solution resistance, Qdl was the in-situ charge of the extracellular polymers of cyanobacteria, and Rct was the charge transfer resistance of the extracellular polymers of cyanobacteria, ensuring that the error value of the fitting data was less than 20%, and the data of the capacitive charging and charge transfer resistance of the extracellular polymers of cyanobacteria were obtained.

[0057] In this embodiment, the capacitance charge of the Microcystis aeruginosa solution under medium nutrition culture conditions is 2.88 μF·cm 2 , the charge transfer resistance is 482.36KΩ·cm 2 The capacitance charge of the Microcystis aeruginosa solution under eutrophic conditions was 2.63 μF·cm 2 , the charge transfer resistance is 356.23KΩ·cm 2 , the fitting error is less than 20%

[0058] (2) The in situ detection method of the surface potential distribution of cyanobacteria cells is as follows:

[0059] Take cyanobacteria cells of appropriate density to ensure that the cyanobacteria cells can be flattened in the center of the gold-coated silicon wafer for freeze drying. Use Kelvin probe force microscopy to detect the surface potential distribution of the 5μm×5μm area around the freeze-dried cyanobacteria cells in the knocking mode, and apply a 0.15V DC bias feedback loop. In this embodiment, the difference between the surface potential and the background potential of Microcystis aeruginosa under mesotrophic culture conditions is 85.74mV, and the difference between the surface potential and the background potential of Microcystis aeruginosa under eutrophic culture conditions is 103.85mV.

[0060] The in situ charging performance and charge transfer resistance of Microcystis aeruginosa cultured under mesotrophic conditions were greater than those of Microcystis aeruginosa cultured under eutrophic conditions, and the surface potential was lower than that of Microcystis aeruginosa cultured under eutrophic conditions. The charge of extracellular polymers was stronger under mesotrophic conditions. Based on the charge of extracellular polymers detected in situ, the algae-killing efficiency of Microcystis aeruginosa cultured under eutrophic conditions was higher after nanotip-enhanced electroporation under extremely low voltage conditions.

[0061] The mortality of intact Microcystis aeruginosa and Microcystis aeruginosa with extracellular polymers removed was detected by flow cytometry. The mortality of Microcystis aeruginosa under mesotrophic culture conditions after treatment was 33.56%, and the mortality of Microcystis aeruginosa under eutrophic culture conditions was 62.34%, which can prove that the evaluation method provided in this embodiment is accurate.

[0062] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. A person skilled in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge, characterized in that: The algae liquids obtained by the electrochemical algae killing method are used as the algae liquids to be evaluated, and in-situ detection is performed; the in-situ detection includes detecting the charging performance of the extracellular polymers of cyanobacteria and the distribution of the electric potential on the surface of the cyanobacteria cells, wherein the charging performance is characterized by the capacitive charging and charge transfer resistance of the extracellular polymers of cyanobacteria; the algae liquid to be evaluated, the one in which the capacitive charging and charge transfer resistance are lower than those of the other groups, and the cell surface potential is higher than that of the other groups, is the group with the best algae killing efficiency in the algae liquid to be evaluated; The in-situ detection method of the charging properties of the extracellular polymers of cyanobacteria is specifically as follows: S1: The algae solution to be evaluated is mechanically stirred uniformly, and an electrochemical impedance spectroscopy analysis is performed using a separate cyanobacteria culture solution as a background medium; the electrochemical impedance spectroscopy analysis adopts a standard three-electrode working system, with a glassy carbon electrode as a working electrode, a platinum wire electrode as a counter electrode, and a silver-silver chloride electrode as a reference electrode; The detection is carried out under constant potential control and open circuit potential to obtain an electrochemical impedance spectrum; the frequency range of the electrochemical test system is 10 6 -10 0 Hz; S2: fitting the electrochemical impedance spectrum using a fitting circuit, in which a constant phase angle element CPE is used to replace the charged capacitor in the equivalent circuit to ensure that the error value of the fitting data is less than 20%, thereby obtaining the data of the capacitance charging and charge transfer resistance of the extracellular polymers of cyanobacteria.

2. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 1, characterized in that: Before the electrochemical impedance spectroscopy analysis is performed in the standard three-electrode working system, an inert gas is introduced to discharge oxygen in the solution to maintain an inert gas environment.

3. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 1, characterized in that: The culture solution is the BG11 liquid culture medium required for the growth of cyanobacteria.

4. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 1, characterized in that: The in-situ detection method of the surface potential distribution of the cyanobacteria cells is specifically as follows: Take cyanobacteria cells and spread them flat in the center of a gold-coated silicon wafer for freeze-drying. Use Kelvin probe force microscopy to detect the surface potential distribution of the area around the freeze-dried cyanobacteria cells in a tapping mode, and apply a 0.15 V DC bias feedback loop.

5. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 4, characterized in that: Kelvin probe force microscopy was used to detect the electric potential distribution in a 5μm×5μm area around cyanobacterial cells.

6. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 1, characterized in that: The electrochemical algae killing method is a nano tip enhanced electroporation algae killing technology under extremely low voltage.

7. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 6, characterized in that: The conditions of the nanotip enhanced electroporation algae killing technology at extremely low voltage are as follows: the applied DC voltage is 0.5 V-1.5 V, and the flow rate in the algae killing device is 4 mL / min.

8. The method for evaluating algaecidal efficacy based on in situ detection of extracellular polymer charge according to claim 7, characterized in that: The cell density of cyanobacteria in the nano-tip enhanced electroporation algae killing technology under extremely low voltage is 10 6 -10 7 Pieces / mL.

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