CN114858891B - Method for constructing electrochemical sensor biological sensing element based on magnetic force - Google Patents
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Abstract
The microbial electrochemical sensor (MEB) takes an electrochemical active biological film as a biological sensing element, has the advantages of high sensitivity, simple operation system, easy integration and the like, and has wide application prospect in the research fields of clinical diagnosis, medical examination, environmental monitoring and the like. However, the incubation time of the electrochemically active biological membrane is long, and the culture process is complicated. In order to solve the problem, the invention provides a method for quickly constructing a biological sensing element of a microbial electrochemical sensor based on magnetic force, which does not depend on a mature electrochemical active biological film as the sensing element, and omits a complicated and time-consuming starting link of MEB. The invention can breakthrough the rapid construction of the biological sensing element of the microbial electrochemical sensor, rapidly establish a strong stable baseline signal and has important significance for realizing the instant detection of MEB.
Description
Technical Field
The invention relates to the technical field of microbial electrochemistry, in particular to a method for quickly constructing a biological sensing element of a microbial electrochemical sensor based on magnetic force.
Background
The biosensor is a product of organically combining a bioactive material with a physicochemical transducer, has the advantages of strong specificity, high sensitivity, rapid detection and the like, and has wide application prospects in the fields of clinical diagnosis, medical examination, environmental monitoring and the like. The first biosensor was an enzyme electrode, and selective detection of a target can be achieved based on the specific action of an enzyme on a substrate. Thereafter, other immobilized biosensing materials (e.g., antibodies, antigens, nucleic acids) and the like are also applied to the biosensor as a molecular recognition element. However, the preparation of these biomolecular recognition originals often requires complex operating systems, expensive instrumentation and extremely high levels of professional operation, limiting the practical use of biosensors. At the same time, most biosensors rely on identifying light signals for detection. For example, real-time fluorescent quantitative PCR techniques and immunolabeling fiber optic biosensors are commonly used. However, the detection light signal is easily interfered by the ambient light and the background value, so that false negative or false positive occurs, and the detection accuracy of the biosensor is reduced, so that the application of the biosensor using the identification light signal as a detection means in practice is limited.
With the continued development of microbial electrochemical sensors (Microbial Electrochemical Sensor, MEB), it is expected to solve the above-mentioned problems. MEB is a sensor which uses electrochemical active microorganisms (Electrochemical Actively Bacteria, EAB) as a core sensing element and can directly convert information of substances to be detected into electric signals for detection. MEB relies on the formation of electrode biofilm structures and has electrochemical activity microorganisms to perform electronic exchange with solid-phase electrodes while performing catalytic reaction, and EAB can be used as a molecular recognition element and a transducer to convert physical information or chemical information expressed by biological activity into an electric signal for output. Meanwhile, EAB is taken as an intact natural cell, does not need complex molecular biology techniques such as genetic engineering, protein separation, purification, reconstruction and the like, has lower technical threshold and use cost, and is considered as the most promising biosensor technique at present.
To date, MEB technology has been reported for the first time, researchers mostly used natural biofilms formed by EAB as sensing and transduction elements, and natural biofilms have self-repairing and self-renewing capabilities. For example, in the field of environmental monitoring, the utilization of mature and stable biological membranes is beneficial to realizing on-line and in-situ monitoring of water quality toxicity. However, the incubation and formation of the biological membrane are complex processes, and often require a culture time of several days or even weeks (usually 1-4 weeks), so that the prior art cannot meet the requirement of immediate detection in special occasions.
In order to solve the problem of long incubation time of natural biological membranes, the university of bloom Liang Peng professor team recently reported that the preparation of artificial biological membranes by sodium alginate and EAB greatly reduces the formation time of biological membranes, and can complete the preparation of biological membranes and the detection of water toxicity within 60 minutes. However, artificial biological membranes are similar to natural biological membranes, and complex multi-layer and three-dimensional structures are unfavorable for toxic pollutant permeation and mass transfer. In order to thoroughly avoid the influence of the characteristics of the biological film on the toxicity of the water quality detected by the EAB, liu Gongjiao of the university of aviation, beijing, is based on the formation process of the biological film, and the technology for detecting the toxicity of the water quality by using the non-film-forming EAB is reported for the first time. Compared with natural and artificial biological membranes, the technology does not need to incubate the biological membranes, and the non-film-forming EAB has a scattered monolayer structure, thereby being more beneficial to the rapid detection of water toxicity. Meanwhile, the team also compares with the traditional EAB biological film, and the result shows that the non-film-forming EAB has more than 30 times higher sensitivity than the biological film in detecting toxic pollutants, and the detection of trace toxic pollutants is successfully realized. However, research on water toxicity detection technology by using non-film-forming EAB is still in a starting stage at present, the preparation process of the non-film-forming EAB is simple physical adsorption, and the defects of low adsorption capacity, poor adhesive force, difficulty in adapting to water flow and the like exist, so that impurities in the water body can compete with electrochemical active microorganisms for non-specific adsorption sites, and bacteria desorption is caused. Therefore, the non-film-forming EAB prepared by physical passive adsorption has a problem in practical use, and research on EAB and electrode controllable adsorption is urgently needed.
The inventor recently discovers through experiments that when nano-scale magnetic particles and electrochemical active microorganisms are cultured together, magnetic force can be applied to rapidly adsorb the magnetic particles to deposit on the surface of a working electrode, and meanwhile, the electrochemical active microorganisms attached to the surface of the magnetic particles are driven to the surface of the working electrode together, so that after the electrochemical active microorganisms are adsorbed on the surface of the working electrode together, the extracellular electronic transfer process can be completed, and obvious electrochemical activity is shown.
Therefore, in order to overcome the practical application bottleneck that the traditional MEB depends on a mature biological film and solve the problem that the MEB cannot be detected immediately, the invention reports a method for quickly constructing a biological sensing element of a microbial electrochemical sensor based on magnetic force.
Disclosure of Invention
A method for quickly constructing a microbial electrochemical sensor biosensing element based on magnetic force is characterized in that nano-scale magnetic particles are used as carriers of electrochemical active microorganisms, an electrochemical active microorganism suspension attached to the surfaces of the magnetic particles is added into an electrochemical system, specific magnetic force is applied to drive the magnetic particles to be deposited on the surfaces of working electrodes, and the magnetic force drives the electrochemical active microorganisms to move to the surfaces of the working electrodes simultaneously due to the fact that the electrochemical active microorganisms are attached to the surfaces of the magnetic particles; the electrochemical active microorganisms on the surface of the working electrode can form a three-dimensional structure similar to a biological film with magnetic particles, wherein the magnetic particles are not only frames of the three-dimensional structure, but also fix the microorganisms; when the electrochemical active microorganisms breathe outside the cell, electrons are collected by magnetic particles with good conductivity and transferred to the working electrode, and accordingly, the electrochemical system generates current, so that the electrochemical sensor can be used as a microbial electrochemical sensor, and the lengthy incubation process of natural biological films is avoided, namely, the biological sensing element of the microbial electrochemical sensor is quickly constructed through magnetic force.
The magnetic particles are ferroferric oxide, are spherical in shape and have the particle size of 10nm-100nm.
The electrochemically active microorganism was Shewanella oneidensis MR-1.
The absorbance value of the suspension at 600nm is 1.0-2.0, and the suspension contains magnetic particles in the range of 10mg/L-100mg/L, and the electrochemically active microorganism is in logarithmic growth phase.
The magnetic force is generated by a pulse magnetic field generator, and the magnetic field intensity is in the range of 10mT-400 mT.
The electrochemical system adopts a flat plate-shaped structure, and a hollow cavity is arranged in the electrochemical system and comprises a cell body, a cell cover, a working electrode, a counter electrode and a reference electrode, as shown in figure 1; as shown in fig. 2, the length, width, height and wall thickness of the cell body are respectively 84mm 54mm 12mm 2mm; as shown in fig. 3, the outer length, the outer width, the outer height and the wall thickness of the pool cover are respectively 88mm by 58mm by 5mm by 2mm; the working electrode is carbon fiber cloth, the counter electrode is a platinum wire electrode, and the reference electrode is an Ag/AgCl electrode.
The method can quickly construct the biological sensing element of the microbial electrochemical sensor based on magnetic force, and quickly generate strong stable baseline signals, and has important significance for realizing the instant detection of MEB.
The method comprises the following specific operation flows:
(1) The magnetic particles and Shewanella oneidensis MR-1 are co-cultured by utilizing a Luria-Bertani culture medium, wherein the culture mode is aerobic culture, the ambient temperature is set to 22.0+/-0.5 ℃, the rotating speed is 180RPM, and the inoculation amount is 0.2 percent by volume;
(2) After 15h-20h of incubation, shewanella oneidensis MR-1 co-incubated with magnetic particles was already in
The absorbance value of the suspension at 600nm is 1.0-2.0 in logarithmic growth phase or stationary phase, and the suspension is preserved for standby;
(3) An electrochemical system is assembled in a clean workbench, the working volume of the electrochemical system is 40mL, the electrochemical system comprises a working electrode, a counter electrode and a reference electrode, wherein the working electrode is 30 mm-50 mm carbon fiber cloth, the counter electrode is 1 mm-37 mm platinum wire electrode, the reference electrode is Ag/AgCl electrode, a pulse magnetic field generator is coupled under Chi Shen, the cell body of the electrochemical system is of a rectangular flat plate structure, the cell body and the cell cover are made of organic glass materials, and the electrochemical system can operate in a sealing mode;
(4) Connecting the three electrodes with an electrochemical workstation or a potentiostat;
(5) Shewanella oneidensis MR-1 suspension co-cultured with magnetic particles is added to an electrochemical system, and then an equal volume of electrolyte DM containing 1g NaHCO per liter of electrolyte DM is added to the electrochemical system 3 、0.13g KCl、0.027g CaCl 2 ·2H 2 O、0.2g MgCl 2 ·6H 2 O, 5.85g NaCl and 7.2g HEPES.
(6) The potential of the working electrode is set to be 0.5V, the intensity of an applied magnetic field is 240mT, an i-t curve is monitored, and after a bioelectric signal is stable, namely, a biomembrane with electrochemical activity is quickly constructed through magnetic force, so that the bioelectrochemical sensor can be further used as a biosensing element of a microbial electrochemical sensor.
Advantageous effects
The invention creatively deposits the magnetic particles attached with Shewanella oneidensis MR-1 on the surface of the working electrode based on magnetic force, thereby rapidly constructing the biological sensing element of the microbial electrochemical sensor. Namely, magnetic particles are driven to be deposited on the surface of the working electrode by applying specific magnetic force, and the electrochemically active microorganisms are simultaneously driven to move to the surface of the working electrode by the magnetic force due to the adhesion of the electrochemically active microorganisms on the surface of the magnetic particles; the electrochemical active microorganisms on the surface of the working electrode can form a three-dimensional structure similar to a biological film with magnetic particles, wherein the magnetic particles are not only frames of the three-dimensional structure, but also fix the microorganisms; when the electrochemical active microorganisms breathe outside the cell, electrons are collected by magnetic particles with good conductivity and transferred to the working electrode, and accordingly, the electrochemical system generates current, so that the electrochemical sensor can be used as a microbial electrochemical sensor, and the lengthy incubation process of natural biological films is avoided, namely, the biological sensing element of the microbial electrochemical sensor is quickly constructed through magnetic force. By implementing the method, the application scene of the microbial electrochemical sensor can be further widened on the basis of the research and application of the existing microbial electrochemical sensor, and the instant detection requirement is met.
The existing research has reported that high-sensitivity and low-cost monitoring of heavy metals in wastewater and nitrate in water can be realized through MEB. However, prior studies have required up to 1 to several weeks of sensor start-up procedures for incubating mature biofilms before detection of both indicators, which clearly does not meet the requirements for both indicator maneuver and emergency detection in real scenarios. Based on the method, the biological sensing element of the microbial electrochemical sensor can be rapidly prepared, and the defects existing in the prior art are overcome.
Furthermore, the use of non-film-forming EABs to detect water biotoxicity has been reported based on biofilm formation processes. Compared with natural and artificial biological membranes, the technology does not need to incubate the biological membranes, but the preparation process of the non-film-forming EAB is simple physical adsorption, and has the defects of low adsorption capacity, poor adhesive force, difficulty in adapting to the flow of water bodies and the like, and impurities in the water bodies can compete with electrochemical active microorganisms for non-specific adsorption sites, so that bacteria desorption is caused. Based on the method, the magnetic particles which are adsorbed with the electrochemical active microorganisms are deposited on the surface of the working electrode, and the electrochemical active microorganisms on the surface of the working electrode can form a three-dimensional structure similar to a biological film with the magnetic particles, wherein the magnetic particles are not only frames of the three-dimensional structure, but also fix the microorganisms, so that the controllable adsorption of EAB and the electrode is realized. The stability and the adhesive force of the early biological film are obviously enhanced, the biological attachment capacity of the working electrode is obviously increased, and the defect of the non-film-forming EAB detection technology is overcome.
Therefore, compared with the reported researches of the microbial electrochemical sensor, the research can overcome the defects in the existing researches, solve the actual problems and has good application prospect.
Drawings
(1) FIG. 1 is a schematic diagram of the structural composition of an electrochemical system;
(2) FIG. 2 is a schematic diagram of the overall dimensions of the cell body;
(3) FIG. 3 is a schematic view of the overall dimensions of the cell cover;
(4) FIG. 4 is a schematic diagram of a method for rapidly constructing a microbial electrochemical sensor biosensor element based on magnetic force;
(5) FIG. 5 is a schematic illustration of co-cultivation of magnetic particles with Shewanella oneidensis MR-1;
(6) FIG. 6 is a schematic diagram of the coupling of an electrochemical system to a pulsed magnetic field generator;
(7) FIG. 7 shows the applied magnetic field-MA (Fe) of a suspension of magnetic particles co-cultured with Shewanella oneidensis MR-1 in an electrochemical system 3 O 4 +MR-1), magnetic particles and Shewanella oneidensis MR-1, the co-culture suspension did not exert magnetic field-Control (Fe 3 O 4 An i-t curve of +MR-1), shewanella oneidensis MR-1 bacterial suspension applied magnetic field MA (MR-1), shewanella oneidensis MR-1 bacterial suspension without applied magnetic field MR-1 in electrolyte DM;
(8) Fig. 8 is a: stable baseline signal current intensity characterization; b: characterization of the time required to reach a stable baseline signal after application of the magnetic force; c: characterization of the working electrode-carried biomass;
(9) FIG. 9 is a scanning electron microscope image of magnetic particle morphology and Shewanella oneidensis MR-1 morphology attached to the working electrode surface after magnetic force is applied;
Detailed Description
Embodiment one:
the method for quickly constructing the biological sensing element of the microbial electrochemical sensor based on the magnetic force is shown in fig. 4, and the method can be used for quickly constructing the biological sensing element and quickly establishing a strong stable baseline signal.
Firstly, using nanoscaleThe magnetic particles were co-cultured with Shewanella oneidensis MR-1 as shown in FIG. 5. Nano-scale ferroferric oxide magnetic particles (SS-F20 1317-61-9) were purchased from addi metal materials limited and sterilized for storage, shewanella oneidensis MR-1 (ATCC 700, 550) was purchased from american type strain collection and stored at-80 ℃. Before use, shewanella oneidensis MR-1 was taken out of the-80℃refrigerator, and inoculated into Luria-Bertani medium (A, B) at a ratio of 0.2% after gradient heating. After inoculation, medium A was supplemented with 25mg/L of magnetic particles and medium B was supplemented with no magnetic particles and incubated overnight at 180RPM in an environment at 22 ℃. After Shewanella oneidensis MR-1 reached the plateau (OD 600 And 2) for constructing a biosensing element of a microbial electrochemical sensor.
Next, 4 identical three-electrode microbial electrochemical systems were assembled, numbered (1): MA (Fe) 3 O 4 +MR-1)、②：Control(Fe 3 O 4 +mr-1), (3): MA (MR-1), (4): MR-1. Each microbial electrochemical system has a working volume of 40mL, and comprises 30 mm/50 mm carbon fiber cloth as a working electrode, a platinum wire with a diameter of 1mm and a length of 37mm as a counter electrode, and an Ag/AgCl electrode (0.205 Vvs. standard hydrogen electrode) as a reference electrode. Before the microbial electrochemical system is assembled, all components are sterilized, wherein the Ag/AgCl electrode is subjected to ultraviolet irradiation and 75% ethanol soaking sterilization, and the other components are subjected to high-temperature sterilization. Directly below the cell body of each microbial electrochemical system, a pulse magnetic field generator is coupled, as shown in fig. 6. After the microbial electrochemical system is assembled, in a clean workbench, (1) the microbial electrochemical system (2) is added into 20mL of suspension of magnetic particles co-cultured with Shewanella oneidensis MR-1 in the culture medium A and 20mL of electrolyte DM, and (3) the microbial electrochemical system (4) is added into Shewanella oneidensis MR-1 of bacterial suspension and 20mL of electrolyte DM in the culture medium B. The three electrodes of the microbial electrochemical system are connected with a potentiostat, a working electrode is applied with 0.5V potential, and an i-t curve is monitored. At 40min, (1) (3) the microbial electrochemical system applied a magnetic field of 240mT for 80min, and (2) (4) the microbial electrochemical system did not apply a magnetic field, and the i-t curve was continuously monitored.
As shown in FIG. 7, the microbial electrochemical systems (1), (2), (3) and (4) are not applied with magnetic fields for the first 40min, and the current is unstable and the intensity is weaker and tends to decrease rapidly; at 40min, no magnetic field was applied to the microbial electrochemical system (1) (3) for 80min and no magnetic field was applied to the microbial electrochemical system (2) (4). It can be observed that (1) (3) the microbial electrochemical system current increases significantly, followed by a steady baseline signal, (2) (4) the microbial electrochemical system current decreases continuously, followed by a steady baseline signal, and (1) the microbial electrochemical system reaches a strong steady baseline signal faster than (2) (3) (4) the microbial electrochemical system. The experiment is repeated for 4 times, and statistical analysis shows that the baseline signal intensity of the microbial electrochemical system (1) is significantly different from that of the microbial electrochemical system (2) (3) (4) and the time required for reaching the stable baseline signal after the magnetic field is applied, the microbial electrochemical system (1) reaches the strong stable baseline signal (about 600 microamps) after the magnetic field is applied for about 30min, and the microbial electrochemical system (2) (3) (4) needs 50-60min to reach the relatively stable baseline signal, as shown in fig. 8a and 8 b. Meanwhile, the observation of the microbial electrochemical system (1) and (3) shows that the microbial electrochemical system (1) added with the magnetic particles and Shewanella oneidensis MR-1 co-culture suspension can reach a strong stable baseline signal faster than the microbial electrochemical system (3) although the magnetic field has an acceleration effect on electricity generation of Shewanella oneidensis MR-1. The experiment proves that the magnetic force-based biological sensing element of the microbial electrochemical sensor can be quickly constructed, and a strong stable baseline signal can be quickly achieved, so that the method has important significance for realizing the instant detection of MEB.
Subsequently, the bioadhesion of the working electrode of the microbial electrochemical system of (1) (2) (3) (4) was measured by microbial ATP bioluminescence. Firstly, under the condition that the magnetic fields applied by the microbial electrochemical systems (1) and (3) are ensured, removing liquid in the four microbial electrochemical systems, secondly, removing the magnetic fields applied by the microbial electrochemical systems (1) and (3), and sequentially taking out working electrodes of the microbial electrochemical systems (1), 2, 3 and 4). The surface of the working electrode was slowly rinsed with buffer for sampling and the bioadhesion was determined using an NHD PROFILE 1 3560 10x bioluminescence meter in the united states, and the experiment was performed in 4 replicates. The biological attachment amount of the working electrode of the microbial electrochemical system of (1) (2) (3) (4) is compared and is found through statistical analysis, as shown in fig. 8 c: (1) the biological attachment capacity of the working electrode of the microbial electrochemical system is obviously different from that of the working electrode of the microbial electrochemical system (2) (3) (4), and the biological attachment capacity is about 40 times of that of the working electrode of the microbial electrochemical system. The method has the advantages that the magnetic particles can be rapidly adsorbed on the surface of the working electrode based on magnetic force, further more Shewanella oneidensis MR-1 attached to the surface of the magnetic particles can be driven to rapidly move to the surface of the working electrode, the biological attachment capacity of electrochemical active microorganisms attached to the surface of the working electrode is remarkably increased, rapid construction of a biological sensing element of a microbial electrochemical sensor is facilitated, and further a strong stable baseline signal is rapidly established.
Embodiment two:
the microbial electrochemical system (1) was repeated in the same manner as in example 1, and the morphology of the magnetic particles attached to the surface of the working electrode and Shewanella oneidensis MR-1 were examined by using a scanning electron microscope (Scanning Electron Microscope, SEM) technique. The magnetic particles were subjected to sampling, fixing, dehydration, air-drying and metal spraying, and then observed by SEM (JSM-5800, JEOL, japan). After the working electrode is subjected to magnetic field application for 80min, the morphology of magnetic particles and Shewanella oneidensis MR-1 on the surface of the working electrode is observed by using SEM (JSM-5800, JEOL, japan) after sampling, fixing, dehydrating, air drying and metal spraying.
As can be seen from SEM pictures (fig. 9a to 9 d), the magnetic particles have a uniform size and good roundness. Shewanella oneidensis MR-1 was scattered on the electrode surface and showed no significant aggregation of the microbial population compared to the reported SEM pictures of the biofilm. The electrochemical active microorganisms and the magnetic particles on the surface of the working electrode form a three-dimensional structure similar to a biological film, wherein the magnetic particles are not only frames of the three-dimensional structure, but also fix the microorganisms, so that a stable early biological film is formed. Therefore, when the electrochemical active microorganisms breathe outside the cell, electrons are collected by the magnetic particles with good electric conduction performance and transferred to the working electrode, and accordingly, the electrochemical system generates current, so that the electrochemical sensor can be used as a microbial electrochemical sensor, and the lengthy incubation process of the natural biological film is avoided. Further elucidates the mechanism of quickly constructing the biological sensing element of the microbial electrochemical sensor based on magnetic force, and has important significance for realizing the instant detection of the microbial electrochemical sensor.
Claims (5)
1. A method for quickly constructing a microbial electrochemical sensor biosensing element based on magnetic force is characterized in that: the nano-scale magnetic particles are used as carriers of electrochemical active microorganisms, the electrochemical active microorganism suspension attached to the surfaces of the magnetic particles is added into an electrochemical system, specific magnetic force is applied to drive the magnetic particles to deposit on the surfaces of the working electrodes, and the electrochemical active microorganisms are attached to the surfaces of the magnetic particles, so that the magnetic force drives the electrochemical active microorganisms to move to the surfaces of the working electrodes; the electrochemical active microorganisms on the surface of the working electrode can form a three-dimensional structure similar to a biological film with magnetic particles, wherein the magnetic particles are not only frames of the three-dimensional structure, but also fix the microorganisms; when the electrochemical active microorganisms breathe outside the cells, electrons are collected by magnetic particles with good electric conduction performance and transferred to a working electrode, and accordingly, an electrochemical system generates current, and the electrochemical sensor can be used as a microbial electrochemical sensor; the method comprises the following specific steps:
(1) The magnetic particles and Shewanella oneidensis MR-1 are co-cultured by utilizing a Luria-Bertani culture medium, wherein the culture mode is aerobic culture, the ambient temperature is set to 22.0+/-0.5 ℃, the rotating speed is 180RPM, and the inoculation amount is 0.2 percent by volume;
(2) After 15h to 20h of culture, shewanella oneidensis MR-1 co-cultured with the magnetic particles is in the logarithmic phase or the stationary phase, the absorbance value of the suspension at 600nm is 1.0 to 2.0, and the suspension is preserved for standby;
(3) An electrochemical system is assembled in a clean workbench, the working volume of the electrochemical system is 40mL, the electrochemical system comprises a working electrode, a counter electrode and a reference electrode, wherein the working electrode is 30 mm-50 mm carbon fiber cloth, the counter electrode is 1 mm-37 mm platinum wire electrode, the reference electrode is Ag/AgCl electrode, a pulse magnetic field generator is coupled under Chi Shen, the cell body of the electrochemical system is of a rectangular flat plate structure, the cell body and the cell cover are made of organic glass materials, and the electrochemical system can operate in a sealing mode;
(4) Connecting the three electrodes with an electrochemical workstation or a potentiostat;
(5) Adding Shewanella oneidensis MR-1 suspension co-cultured with magnetic particles to an electrochemical system, and adding an equal volume of electrolyte DM to the electrochemical system, wherein each liter of electrolyte DM comprises 1g NaHCO3, 0.13g KCl, 0.027g CaCl2.2H2O, 0.2g MgCl2.6H2O, 5.85g NaCl and 7.2g HEPES;
(6) Setting the potential of a working electrode to be 0.5V, applying a magnetic field with the strength of 240mT, monitoring an i-t curve, and quickly constructing a biological film with electrochemical activity by magnetic force after a bioelectric signal is stable, so as to be used as a biological sensing element of the microbial electrochemical sensor;
the magnetic particles are ferroferric oxide, are spherical in shape and have the particle size of 10nm-100nm.
2. The method of claim 1, wherein the suspension has an absorbance at 600nm of 1.0 to 2.0, comprises 10mg/L to 100mg/L of magnetic particles, and the electrochemically active microorganism is in a logarithmic growth phase.
3. The method of claim 1, wherein the electrochemical system is in a plate-like structure, and the inside of the electrochemical system is a hollow chamber, and the electrochemical system comprises a cell body, a cell cover, a working electrode, a counter electrode and a reference electrode, wherein the outer length, the outer width and the outer height of the cell body are respectively 84mm x 54mm x 12mm x 2mm, the outer length, the outer width and the outer height of the cell cover are respectively 88mm x 58mm x 5mm x 2mm, the working electrode is a carbon fiber cloth, the counter electrode is a platinum wire electrode, and the reference electrode is an Ag/AgCl electrode.
4. The method of claim 1, wherein the magnetic force is generated using a pulsed magnetic field generator.
5. The method of claim 1, wherein the conditions for extracellular respiration of the electrochemically active microorganism are a working electrode potential of 0.5V.
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| WO2010117844A2 (en) * | 2009-03-31 | 2010-10-14 | University Of Maryland Biotechnology Institute | Generating electrical power by coupling aerobic microbial photosynthesis to an electron-harvesting system |
| CN106442664A (en) * | 2016-12-09 | 2017-02-22 | 江苏大学 | Pyocyanin bioelectricity chemical detection method |
| WO2020031090A1 (en) * | 2018-08-06 | 2020-02-13 | King Abdullah University Of Science And Technology | Single metal atom or bimetallic alloy heterogeneous catalysts on a carbonaceous support produced by metal precursor deposition on exoelectrogen bacteria and pyrolyzing |
| CN113358722A (en) * | 2021-04-12 | 2021-09-07 | 北京航空航天大学 | Method for realizing rapid detection of water toxicity based on suspended electrochemical active microorganisms |
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| WO2010117844A2 (en) * | 2009-03-31 | 2010-10-14 | University Of Maryland Biotechnology Institute | Generating electrical power by coupling aerobic microbial photosynthesis to an electron-harvesting system |
| CN106442664A (en) * | 2016-12-09 | 2017-02-22 | 江苏大学 | Pyocyanin bioelectricity chemical detection method |
| WO2020031090A1 (en) * | 2018-08-06 | 2020-02-13 | King Abdullah University Of Science And Technology | Single metal atom or bimetallic alloy heterogeneous catalysts on a carbonaceous support produced by metal precursor deposition on exoelectrogen bacteria and pyrolyzing |
| CN113358722A (en) * | 2021-04-12 | 2021-09-07 | 北京航空航天大学 | Method for realizing rapid detection of water toxicity based on suspended electrochemical active microorganisms |
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