A biomimetic electrical sensor and a method of making the same

Abstract

This invention belongs to the field of sarcosine detection technology, providing a biomimetic electrosensor, its preparation method, and its application in ultrasensitive sarcosine detection. The method includes the following steps: mixing red blood cell solution and biomimetic active material, co-incubating to obtain biomimetic red blood cells; mixing the biomimetic red blood cells with a conductive polymer (dopamine, pyrrole, aniline, or thiophene), and performing an in-situ polymerization reaction to obtain the biomimetic electrosensor. This invention combines conductive polymers with natural cells, utilizing the excellent conductivity of the conductive polymers, and based on the hyperoxic microenvironment of cells, giving the biomimetic active material better electrocatalytic properties, enabling rapid, sensitive, and efficient monitoring of Sarcosine (Sarcosine). The biomimetic electrosensor has advantages such as fast reaction speed, low cost, easy miniaturization, good biocompatibility, and simple sample pretreatment, providing a new, rapid, accurate, and stable diagnostic tool for the pathogenesis and development of prostate diseases.

Description

Technical Field

[0001] This invention relates to the field of sarcosine detection technology, and in particular to a biomimetic electrical sensor, its preparation method, and its application in ultrasensitive sarcosine detection. Background Technology

[0002] Creatine (Sar) is a tumor metabolite that increases significantly with the progression and metastasis of prostate diseases, and this change is unaffected by other diseases, making Sar a promising biomarker for prostate diseases. Sar concentrations are higher in the urine of prostate cancer patients and lower in the urine of patients with benign prostatic hyperplasia (BPH). Therefore, ultrasensitive detection of Sar can help in the early diagnosis and treatment of prostate diseases and is key to curbing the continued rise in prostate cancer incidence. Given the current limitations of creatine detection methods in terms of speed, convenience, accuracy, and specificity for clinical diagnostic applications, the biomimetic design and development of novel nanosensors for rapid, efficient, and ultrasensitive Sar detection is an important approach to achieving highly sensitive and accurate measurement of the occurrence and development of prostate diseases, and is of great significance. Summary of the Invention

[0003] The purpose of this invention is to overcome the problems existing in the prior art, and to provide a biomimetic electrical sensor, its preparation method, and its application in ultrasensitive detection of sarcosine, so as to achieve ultrasensitive detection of changes in sarcosine (Sar) content during the development of prostate diseases.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for fabricating a biomimetic electrical sensor, comprising the following steps: (1) Mix red blood cell solution and biomimetic substance and incubate together to obtain biomimetic red blood cells; (2) The biomimetic red blood cells are mixed with the conductive polymer and subjected to in-situ polymerization to obtain the biomimetic electrical sensor. The conductive polymer in step (2) includes dopamine, pyrrole, aniline or thiophene.

[0005] Preferably, the red blood cell solution in step (1) contains red blood cells, sodium chloride, and water, wherein the volume fraction of red blood cells in the red blood cell solution is 3.5-4.5%, and the mass fraction of sodium chloride in the red blood cell solution is 0.7-1.1%; the biomimetic substance is riboflavin; The mass-to-volume ratio of the red blood cell solution to the biomimetic substance is 7-11 mL: 7-11 mg.

[0006] Preferably, the co-incubation temperature in step (1) is 2~6℃ and the co-incubation time is 3~12h.

[0007] Preferably, when the conductive polymer in step (2) is dopamine, biomimetic red blood cells, Tris-HCl buffer and dopamine are mixed and in situ polymerized to obtain a biomimetic electrical sensor. The pH of the Tris-HCl buffer is 8-9, and the mass-volume ratio of the Tris-HCl buffer, dopamine and the biomimetic substance in step (1) is 40-50 mL: 5-50 mg: 7-11 mg. The in-situ polymerization reaction is carried out at a temperature of -2 to 2°C for 3 to 12 hours.

[0008] Preferably, when the conductive polymer in step (2) is pyrrole, the biomimetic red blood cells and pyrrole solution are mixed and in situ polymerized to obtain a biomimetic electrical sensor. The pyrrole solution comprises PBS buffer, potassium ferrocyanide, and pyrrole, wherein the pH of the PBS buffer is 6.5-7.5; the concentration of phosphate ions in the pyrrole solution is 0.05-0.15 mol / L, the mass concentration of potassium ferrocyanide in the pyrrole solution is 0.67-2 mg / mL, and the mass concentration of pyrrole in the pyrrole solution is 4-5.33 mg / mL; the mass-to-volume ratio of the pyrrole solution and the biomimetic substance in step (1) is 10-30 mL: 7-11 mg. The in-situ polymerization reaction is carried out at a temperature of 25~35℃ and for a duration of 1.5~2.5h.

[0009] Preferably, when the conductive polymer in step (2) is aniline, biomimetic red blood cells, aniline solution and oxidant solution are mixed and in-situ polymerized to obtain a biomimetic electrical sensor. The aniline solution contains aniline, tartaric acid, and water. The mass concentration of aniline in the aniline solution is 12-16 mg / mL, and the mass concentration of tartaric acid in the aniline solution is 1.5-3.5 mg / mL. The oxidizing agent solution is an ammonium persulfate solution with a mass concentration of 1.67-5 mg / mL. The mass-volume ratio of the aniline solution, the oxidizing agent solution, and the biomimetic substance in step (1) is 4-6 mL: 5-7 mL: 7-11 mg. The in-situ polymerization reaction is carried out at a temperature of -2 to 2°C for 6 to 24 hours.

[0010] Preferably, when the conductive polymer in step (2) is thiophene, biomimetic red blood cells, thiophene solution and ferric chloride are mixed and subjected to in-situ polymerization to obtain a biomimetic electrical sensor. The thiophene solution contains water, thiophene, and sodium dodecyl sulfate. The mass concentration of thiophene in the thiophene solution is 0.833~1.25 mg / mL, and the mass concentration of sodium dodecyl sulfate in the thiophene solution is 4.17~5 mg / mL. The mass-volume ratio of the thiophene solution, ferric chloride, and the biomimetic substance in step (1) is 10~15 mL: 10~15 mg: 7~11 mg. The in-situ polymerization reaction is carried out at a temperature of 25-30°C for 2-8 hours.

[0011] The present invention also provides a biomimetic electrical sensor prepared by the aforementioned method.

[0012] The present invention also provides the application of the aforementioned biomimetic electrical sensor in the ultrasensitive detection of sarcosine.

[0013] The beneficial effects of this invention are: This invention provides a method for preparing a biomimetic electrosensor, comprising the following steps: mixing a red blood cell solution with a biomimetic active substance and co-incubating to obtain biomimetic red blood cells; mixing the biomimetic red blood cells with a conductive polymer (the conductive polymer includes dopamine, pyrrole, aniline, or thiophene) and performing an in-situ polymerization reaction to obtain the biomimetic electrosensor. The biomimetic electrosensor combines a conductive polymer with natural cells, utilizing the excellent conductivity of the conductive polymer, and based on the hyperoxic microenvironment of the cell, the biomimetic active substance exhibits better electrocatalytic activity, enabling rapid, sensitive, and efficient monitoring of Sar-related precipitates (Sar). The biomimetic electrosensor prepared by this invention shows different trends in electrochemical signal intensity at different Sar concentrations, achieving ultrasensitive detection of Sar content. The biomimetic electrosensor of this invention has advantages such as fast reaction speed, low cost, easy miniaturization, good biocompatibility, and simple sample pretreatment. It is a promising tool for Sar detection and analysis, providing a new, rapid, accurate, and stable diagnostic tool for the pathogenesis and development of prostate diseases, thereby ultimately reversing or halting disease progression, and has significant practical implications. Attached Figure Description

[0014] Figure 1 The ultraviolet-visible spectra of the biomimetic electrical sensors obtained in Examples 1-3 and the control samples are shown (Wavelength, Absorbance). Figure 2 The oxygen absorption-release curves (Time, Oxygen, Adding sample, Oxygen release phase) of the biomimetic electrical sensors obtained in Examples 1-3 are shown below. Figure 3Field emission scanning electron microscopy characterization of PDA2@Rf@RBC and RBC; Figure 3 In the image, (a) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 2 μm scale, (b) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 1 μm scale, (c) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 0.5 μm scale, (d) is a field emission scanning electron microscope (FESEM) image of RBC at a 2 μm scale, (e) is a field emission scanning electron microscope (FESEM) image of RBC at a 1 μm scale, and (f) is a field emission scanning electron microscope (FESEM) image of RBC at a 0.5 μm scale. Figure 4 High-resolution transmission electron microscopy characterization images of PDA2@Rf@RBC and RBC; Figure 4 In the image, (a) is a high-resolution transmission electron microscope (TEM) characterization of PDA2@Rf@RBC under a 1 μm scale, (b) is a high-resolution TEM characterization of PDA2@Rf@RBC under a 20 nm scale, (c) is a high-resolution TEM characterization of RBC under a 1 μm scale, and (d) is a high-resolution TEM characterization of RBC under a 20 nm scale. Figure 5 Characterization graphs of electrochemical impedance properties of PDA2@Rf@RBC, Rf, and GCE; Figure 5 In the figure, (a) is the cyclic volt-ampere curve (Potential - voltage, Current - current) of PDA2@Rf@RBC, Rf and GCE, and (b) is the impedance diagram of PDA2@Rf@RBC, Rf and GCE; Figure 6 Electrochemical behavior characterization of different samples and electrochemical response characterization of PDA2@Rf@RBC to Sar; Figure 6 In the figure, (a) is the electrochemical behavior characterization diagram of different samples (Potential—voltage, Current—current), and (b) is the electrochemical response characterization diagram of PDA2@Rf@RBC to Sar (Potential—voltage, Current—current). Figure 7 Differential pulse voltammogram of PDA2@Rf@RBC; Figure 7In the diagram, (a) is a schematic diagram of the DPVs (Potential—voltage, Current—current) of PDA2@Rf@RBC at different Sar concentrations, (b) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (0.01~0.1μmol / L), (c) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (100~1000μmol / L), and (d) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (1000~10000μmol / L). Figure 8 A schematic diagram of the electrochemical stability of PDA2@Rf@RBC (Time—time, Current—current); Figure 9 Characterization diagrams of the electrochemical behavior of different samples; Figure 9 In the figure, (a) is the electrochemical behavior characterization diagram of PPy3@Rf@RBC (Potential—voltage, Current—current), (b) is the electrochemical behavior characterization diagram of PANI2@Rf@RBC (Potential—voltage, Current—current), and (c) is the electrochemical behavior characterization diagram of PTH2@Rf@RBC (Potential—voltage, Current—current). Detailed Implementation

[0015] This invention provides a method for fabricating a biomimetic electrical sensor, comprising the following steps: (1) Mix red blood cell solution and biomimetic substance and incubate together to obtain biomimetic red blood cells; (2) The biomimetic red blood cells are mixed with the conductive polymer and subjected to in-situ polymerization to obtain the biomimetic electrical sensor. The conductive polymer in step (2) includes dopamine, pyrrole, aniline or thiophene.

[0016] In this invention, the red blood cells in step (1) are preferably obtained from fresh whole blood. The centrifugation speed for separation is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and even more preferably 2500 r / min; the centrifugation time for separation is preferably 3-7 min, more preferably 4-6 min, and even more preferably 5 min; the separated red blood cells are washed with physiological saline, and stored after washing for use in step (1); the mass fraction of physiological saline is preferably 0.7-1.1%, more preferably 0.8-1.0%, and even more preferably 0.9%; the temperature of physiological saline is preferably 2-6℃. The preferred temperature for the first step is 3-5℃, more preferably 4℃; the preferred centrifugation speed for washing is 2000-3000 r / min, further preferably 2200-2800 r / min, more preferably 2500 r / min; the preferred number of washings is 4-6 times, more preferably 5 times, and each time the red blood cells are mixed with physiological saline, the volume fraction of red blood cells in the mixed system is preferably 2-6%, further preferably 3-5%, more preferably 4%; the preferred centrifugation time for each washing is 1-5 min, further preferably 2-4 min, more preferably 3 min; the preferred storage temperature is 2-6℃, further preferably 3-5℃, more preferably 4℃.

[0017] In this invention, the red blood cell solution in step (1) preferably contains red blood cells, sodium chloride and water, and the volume fraction of red blood cells in the red blood cell solution is preferably 3.5-4.5%, more preferably 3.7-4.3%, and more preferably 4%; the mass fraction of sodium chloride in the red blood cell solution is preferably 0.7-1.1%, more preferably 0.8-1.0%, and more preferably 0.9%; the biomimetic substance is preferably riboflavin (Rf).

[0018] In this invention, the mass-to-volume ratio of the red blood cell solution and the biomimetic substance in step (1) is preferably 7-11 mL: 7-11 mg, more preferably 8-10 mL: 8-10 mg, and even more preferably 9 mL: 9 mg.

[0019] In this invention, the mixing in step (1) preferably includes the following steps: mixing sodium chloride and water to obtain a sodium chloride solution, suspending red blood cells in the sodium chloride solution to obtain a red blood cell solution; and then adding a biomimetic substance to complete the mixing; the temperature of the sodium chloride solution is preferably 2~6℃, more preferably 3~5℃, and more preferably 4℃.

[0020] In this invention, the co-incubation temperature in step (1) is preferably 2~6℃, more preferably 3~5℃, and even more preferably 4℃; the co-incubation time is preferably 3~12h, more preferably 5~10h, and even more preferably 7~8h.

[0021] In this invention, after co-incubation in step (1), the system is centrifuged to obtain a sample, which is then washed to obtain the biomimetic red blood cells. The centrifugation speed is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and even more preferably 2500 r / min. The centrifugation time is preferably 3-7 min, more preferably 4-6 min, and even more preferably 5 min. The washing reagent is preferably physiological saline, and the mass fraction of physiological saline is preferably 0.7-1.1%, more preferably 0.8-1.0%, and even more preferably 0.9%. The temperature of the physiological saline is preferably 2-6℃, more preferably 3-5℃, and even more preferably 4℃; the centrifugation speed for washing is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and even more preferably 2500 r / min; the number of washings is preferably 2-4 times, and even more preferably 3 times. During each washing, the sample is mixed with the physiological saline, and the volume fraction of the sample in the mixed system is preferably 2-6%, more preferably 3-5%, and even more preferably 4%; the centrifugation time for each washing is preferably 1-5 min, more preferably 2-4 min, and even more preferably 3 min.

[0022] In this invention, when the conductive polymer in step (2) is dopamine, step (2) preferably includes the following steps: mixing biomimetic red blood cells, Tris-HCl buffer and dopamine, and carrying out an in-situ polymerization reaction to obtain a biomimetic electrical sensor.

[0023] In this invention, when the conductive polymer in step (2) is dopamine, the mixing preferably includes the following steps: suspending biomimetic red blood cells in Tris-HCl buffer, and then adding dopamine to complete the mixing.

[0024] In this invention, the pH of the Tris-HCl buffer is preferably 8-9, more preferably 8.2-8.8, and even more preferably 8.45; the mass-volume ratio of the Tris-HCl buffer, dopamine, and the biomimetic substance in step (1) is preferably 40-50 mL: 5-50 mg: 7-11 mg, more preferably 43-47 mL: 10-36 mg: 8-10 mg, and even more preferably 45-46 mL: 20-30 mg: 9 mg.

[0025] In this invention, when the conductive polymer in step (2) is dopamine, the in-situ polymerization reaction is preferably carried out in an ice bath. The temperature of the in-situ polymerization reaction is preferably -2~2℃, more preferably -1~1℃, and more preferably 0℃. The shaking speed of the in-situ polymerization reaction is preferably 200~300r / min, more preferably 220~280r / min, and more preferably 250r / min. The time of the in-situ polymerization reaction is preferably 3~12h, more preferably 5~10h, and more preferably 7~8h.

[0026] In this invention, when the conductive polymer in step (2) is dopamine, after the in-situ polymerization reaction is completed, the resulting solution is centrifuged to obtain a sample. The sample is then washed with physiological saline to obtain the biomimetic electrical sensor. The centrifugation speed is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and even more preferably 2500 r / min. The centrifugation time is preferably 3-7 min, more preferably 4-6 min, and even more preferably 5 min. The mass fraction of the physiological saline used for washing is preferably 0.7-1.1%, and even more preferably 0.8-1.0%. More preferably, the concentration is 0.9%; the temperature of the physiological saline is preferably 2~6℃, further preferably 3~5℃, and more preferably 4℃; the centrifugation speed for washing is preferably 2000~3000 r / min, further preferably 2200~2800 r / min, and more preferably 2500 r / min; the number of washings is preferably 2~4 times, and more preferably 3 times. During each washing, the sample is mixed with physiological saline, and the volume fraction of the sample in the mixed system is preferably 2~6%, further preferably 3~5%, and more preferably 4%; the centrifugation time for each washing is preferably 1~5 min, further preferably 2~4 min, and more preferably 3 min.

[0027] In this invention, when the conductive polymer in step (2) is pyrrole, step (2) preferably includes the following steps: mixing biomimetic red blood cells and pyrrole solution, and carrying out in-situ polymerization reaction to obtain a biomimetic electrical sensor.

[0028] In this invention, the pyrrole solution preferably comprises PBS buffer, potassium ferrocyanide, and pyrrole; the pH value of the PBS buffer is preferably 6.5-7.5, more preferably 6.7-7.3, and even more preferably 7; the concentration of phosphate ions in the pyrrole solution is preferably 0.05-0.15 mol / L, more preferably 0.07-0.13 mol / L, and even more preferably 0.1 mol / L; the mass concentration of potassium ferrocyanide in the pyrrole solution is preferably 0.67-2 mg / mL, more preferably... The preferred concentration is 0.72~1.8 mg / mL, more preferably 1.23~1.5 mg / mL; the preferred mass concentration of pyrrole in the pyrrole solution is 4~5.33 mg / mL, more preferably 4.3~5.3 mg / mL, more preferably 4.47~4.8 mg / mL; the preferred mass-to-volume ratio of the pyrrole solution and the biomimetic substance described in step (1) is 10~30 mL: 7~11 mg, more preferably 15~25 mL: 8~10 mg, more preferably 20 mL: 9 mg.

[0029] In this invention, when the conductive polymer in step (2) is pyrrole, the mixing preferably includes the following steps: suspending biomimetic red blood cells in PBS buffer, and then adding potassium ferrocyanide and pyrrole in sequence to complete the mixing.

[0030] In this invention, when the conductive polymer in step (2) is pyrrole, the temperature of the in-situ polymerization reaction is preferably 25~35℃, more preferably 27~33℃, and even more preferably 30℃; the shaking speed of the in-situ polymerization reaction is preferably 200~300r / min, more preferably 220~280r / min, and even more preferably 250r / min; the time of the in-situ polymerization reaction is preferably 1.5~2.5h, more preferably 1.7~2.3h, and even more preferably 2h.

[0031] In this invention, when the conductive polymer in step (2) is pyrrole, after the in-situ polymerization reaction is completed, the solution obtained from the reaction is centrifuged to obtain a sample, and then the sample is washed with water to obtain the biomimetic electrical sensor; the centrifugation speed is preferably 2000~3000 r / min, more preferably 2200~2800 r / min, and more preferably 2500 r / min; the centrifugation time is preferably 3~7 min, more preferably 4~6 min, and more preferably 5 min; the centrifugation speed for water washing is preferably 2000~3000 r / min, more preferably 2200~2800 r / min, and more preferably 2500 r / min; the number of water washings is preferably 2~4 times, and more preferably 3 times. Each time the sample is washed, it is mixed with water, and the volume fraction of the sample in the mixed system is preferably 2~6%, more preferably 3~5%, and more preferably 4%; the centrifugation time for each water washing is preferably 1~5 min, more preferably 2~4 min, and more preferably 3 min.

[0032] In this invention, when the conductive polymer in step (2) is aniline, step (2) preferably includes the following steps: mixing biomimetic red blood cells, aniline solution and oxidant solution, and carrying out in-situ polymerization reaction to obtain a biomimetic electrical sensor.

[0033] In this invention, when the conductive polymer in step (2) is aniline, the mixing preferably includes the following steps: suspending biomimetic red blood cells in an aniline solution, and then adding a pre-cooled oxidant solution under ice bath conditions to complete the mixing; the temperature of the ice bath is preferably -2~2℃, more preferably -1~1℃, and more preferably 0℃; the temperature of the pre-cooled oxidant solution is preferably -2~2℃, more preferably -1~1℃, and more preferably 0℃.

[0034] In this invention, the aniline solution preferably comprises aniline, tartaric acid, and water. The mass concentration of aniline in the aniline solution is preferably 12-16 mg / mL, more preferably 13-15 mg / mL, and even more preferably 14 mg / mL. The mass concentration of tartaric acid in the aniline solution is preferably 1.5-3.5 mg / mL, more preferably 2-3 mg / mL, and even more preferably 2.4 mg / mL. The oxidizing agent solution is preferably an ammonium persulfate solution with a mass concentration of 1.67-5 mg / mL, more preferably 2-4 mg / mL, and even more preferably 3 mg / mL. The mass-volume ratio of the aniline solution, the oxidizing agent solution, and the biomimetic substance in step (1) is preferably 4-6 mL: 5-7 mL: 7-11 mg, more preferably 4.5-5.5 mL: 5.5-6.5 mL: 8-10 mg, and even more preferably 5 mL: 6 mL: 9 mg.

[0035] In this invention, when the conductive polymer in step (2) is aniline, the in-situ polymerization reaction is preferably carried out in an ice bath, the temperature of the in-situ polymerization reaction is preferably -2~2℃, more preferably -1~1℃, and more preferably 0℃; the time of the in-situ polymerization reaction is preferably 6~24h, more preferably 10~20h, and more preferably 12~15h.

[0036] In this invention, when the conductive polymer in step (2) is aniline, after the in-situ polymerization reaction is completed, the solution obtained from the reaction is centrifuged to obtain a sample, and then the sample is washed with water to obtain the biomimetic electrical sensor; the centrifugation speed is preferably 2000~3000 r / min, more preferably 2200~2800 r / min, and more preferably 2500 r / min; the centrifugation time is preferably 3~7 min, more preferably 4~6 min, and more preferably 5 min; the centrifugation speed for water washing is preferably 2000~3000 r / min, more preferably 2200~2800 r / min, and more preferably 2500 r / min; the number of water washings is preferably 2~4 times, and more preferably 3 times. Each time the sample is washed, it is mixed with water, and the volume fraction of the sample in the mixed system is preferably 2~6%, more preferably 3~5%, and more preferably 4%; the centrifugation time for each water washing is preferably 1~5 min, more preferably 2~4 min, and more preferably 3 min.

[0037] In this invention, when the conductive polymer in step (2) is thiophene, step (2) preferably includes the following steps: mixing biomimetic red blood cells, thiophene solution and ferric chloride, and carrying out an in-situ polymerization reaction to obtain a biomimetic electrical sensor.

[0038] In this invention, when the conductive polymer in step (2) is thiophene, the mixing preferably includes the following steps: suspending biomimetic red blood cells in a thiophene solution, performing ultrasound, and then adding ferric chloride to complete the mixing; the ultrasound time is preferably 0.3~0.7h, more preferably 0.4~0.6h, and more preferably 0.5h.

[0039] In this invention, the thiophene solution preferably comprises water, thiophene, and sodium dodecyl sulfate. The mass concentration of thiophene in the thiophene solution is preferably 0.833~1.25 mg / mL, more preferably 0.9~1.1 mg / mL, and even more preferably 1 mg / mL. The mass concentration of sodium dodecyl sulfate in the thiophene solution is preferably 4.17~5 mg / mL, more preferably 4.3~4.7 mg / mL, and even more preferably 4.5 mg / mL. The mass-volume ratio of the thiophene solution, ferric chloride, and the biomimetic substance in step (1) is preferably 10~15 mL:10~15 mg:7~11 mg, more preferably 11~13 mL:11~13 mg:8~10 mg, and even more preferably 12 mL:12 mg:9 mg.

[0040] In this invention, when the conductive polymer in step (2) is thiophene, the in-situ polymerization reaction is carried out under stirring conditions. The temperature of the in-situ polymerization reaction is preferably 25~30℃, more preferably 27~29℃, and even more preferably 28℃. The time of the in-situ polymerization reaction is preferably 2~8h, more preferably 3~7h, and even more preferably 5~6h.

[0041] In this invention, when the conductive polymer in step (2) is thiophene, after the in-situ polymerization reaction is completed, an excess ethanol solution is added to the system to remove unreacted thiophene; then the system is centrifuged to obtain a sample; the sample is then washed with water and ethanol in sequence to obtain the biomimetic electrical sensor; the volume ratio of ethanol to water in the ethanol solution is preferably 0.5~1.5:0.5~1.5, more preferably 0.7~1.3:0.7~1.3, and more preferably 1:1; the centrifugation speed is preferably 2000~3000 r / min, more preferably 2200~2800 r / min, and more preferably 2500 r / min; the centrifugation time is preferably 3~7 min, more preferably 4~6 min, and more preferably 5 min. The centrifugation speed for water washing and ethanol washing is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and even more preferably 2500 r / min; the number of water washing and ethanol washing is preferably 2-4 times, and even more preferably 3 times. During each water washing, the sample is mixed with water, and the volume fraction of the sample in the resulting system is preferably 2-6%, more preferably 3-5%, and even more preferably 4%; during each ethanol washing, the sample is mixed with ethanol, and the volume fraction of the sample in the resulting system is preferably 2-6%, more preferably 3-5%, and even more preferably 4%; the centrifugation time for each water washing and ethanol washing is preferably 1-5 min, more preferably 2-4 min, and even more preferably 3 min.

[0042] The present invention also provides a biomimetic electrical sensor prepared by the aforementioned method.

[0043] The present invention also provides the application of the aforementioned biomimetic electrical sensor in the ultrasensitive detection of sarcosine.

[0044] In this invention, the response principle of sarcosine is: Sar (sarcosine) + Rf + O2 → H2O2 + Gly (glycine) + CH2O; the biomimetic electrical sensor uses riboflavin (Rf) as the catalytic active center. Rf is an isooxane ring with a conjugated structure, which can complex with the iron porphyrin structure in erythrocytes, thereby improving its redox capacity; the conductive polymer undergoes an in-situ polymerization reaction on the surface of the biomimetic erythrocytes to obtain the conductive oxygen-rich carrier of the biomimetic electrical sensor. The conductive polymer endows the carrier with good conductivity, and the erythrocytes have a natural iron porphyrin structure, which endows the sensor with efficient ability to capture dissolved oxygen to ensure the oxygen environment required in the catalytic process.

[0045] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0046] Example 1

[0047] Red blood cells (RBCs) were isolated from fresh whole blood. The centrifugation speed was set to 2500 rpm for 5 min. The isolated RBCs were then washed with 0.9% physiological saline at 4°C. The washing centrifugation speed was set to 2500 rpm for 5 washes. Each time, the RBCs were mixed with physiological saline, resulting in a RBC volume fraction of 4%. Each washing centrifugation time was 3 min. After washing, the RBCs were stored at 4°C for later use. Sodium chloride and water were mixed to obtain a sodium chloride solution. The prepared red blood cells were taken and suspended in the sodium chloride solution at 4°C to obtain 9 mL of red blood cell solution (the volume fraction of red blood cells in the red blood cell solution was 4%, and the mass fraction of sodium chloride was 0.9%). Then, 9 mg of riboflavin (Rf) was added, and the mixture was incubated at 4°C for 3 hours. After incubation, the system was centrifuged at 2500 r / min for 5 minutes. The centrifuged sample was then washed with 0.9% physiological saline at 4°C, centrifuged at 2500 r / min three times, mixing the sample with the physiological saline each time, resulting in a sample volume fraction of 4% in the mixed system. Each washing was centrifuged for 3 minutes. Biomimetic red blood cells (labeled Rf@RBC) were obtained. Bionic red blood cells were suspended in 45 mL of Tris-HCl buffer at pH 8.45, and then 10 mg of dopamine was added. The mixture was then subjected to in-situ polymerization for 3 h at 0 °C with shaking at 250 r / min. After the reaction, the resulting solution was centrifuged at 2500 r / min for 5 min. The centrifuged sample was then washed with 0.9% physiological saline at 4 °C for 3 times at 2500 r / min. Each time, the sample was mixed with physiological saline, and the volume fraction of the sample in the mixture was 4%. Each centrifugation time was 3 min. The resulting bionic electrical sensor (labeled PDA1@Rf@RBC) was obtained.

[0048] Example 2

[0049] By keeping other conditions unchanged in Example 1 and modifying the amount of dopamine to 36 mg, a biomimetic electrical sensor (labeled as PDA2@Rf@RBC) was obtained.

[0050] Example 3

[0051] By keeping other conditions unchanged in Example 1 and modifying the amount of dopamine to 50 mg, a biomimetic electrical sensor (labeled as PDA3@Rf@RBC) was obtained.

[0052] Example 4

[0053] The biomimetic red blood cells prepared in Example 1 were mixed with 25 mL of pyrrole solution (the pyrrole solution contained PBS buffer at pH 7, potassium ferrocyanide, and pyrrole; the concentration of phosphate ions in the pyrrole solution was 0.1 mol / L, the mass concentration of potassium ferrocyanide was 1.23 mg / mL, and the mass concentration of pyrrole was 4.47 mg / mL). During mixing, the biomimetic red blood cells were first suspended in PBS buffer, and then potassium ferrocyanide and pyrrole were added sequentially to complete the mixing. The mixture was then stirred at 30°C at a shaking speed of 250 rpm. The in-situ polymerization reaction was carried out for 2 hours under the condition of 2 min. After the reaction was completed, the solution obtained from the reaction was centrifuged at a speed of 2500 r / min for 5 min. Then, the sample obtained from the centrifugation was washed with water 3 times at a speed of 2500 r / min. Each time the sample was washed, it was mixed with water, and the volume fraction of the sample in the mixed system was 4%. The centrifugation time for each wash was 3 min, and the biomimetic electrical sensor (labeled as PPy1@Rf@RBC) was obtained.

[0054] Example 5

[0055] By keeping other conditions unchanged in Example 4, and modifying the mass concentration of pyrrole in the pyrrole solution to 5.3 mg / mL, a biomimetic electrical sensor (labeled PPy2@Rf@RBC) was obtained.

[0056] Example 6

[0057] By keeping other conditions unchanged in Example 4, and modifying the mass concentration of pyrrole in the pyrrole solution to 4.8 mg / mL, a biomimetic electrical sensor (labeled PPy3@Rf@RBC) was obtained.

[0058] Example 7

[0059] By keeping other conditions unchanged in Example 4, and modifying the mass concentration of pyrrole in the pyrrole solution to 4.3 mg / mL, a biomimetic electrical sensor (labeled PPy4@Rf@RBC) was obtained.

[0060] Example 8

[0061] The biomimetic red blood cells prepared in Example 1 were suspended in 5 mL of aniline solution (the aniline solution contained aniline, tartaric acid, and water, with a mass concentration of 14 mg / mL for aniline and 2.4 mg / mL for tartaric acid). Then, 6 mL of ammonium persulfate solution pre-cooled to 0°C and with a mass concentration of 3 mg / mL was added under 0°C ice bath conditions. The mixture was subjected to in-situ polymerization in the 0°C ice bath for 6 hours. After the reaction, the resulting solution was centrifuged at 2500 rpm for 5 minutes. The centrifuged sample was then washed three times with water at 2500 rpm. Each time the sample was washed, it was mixed with water, resulting in a sample volume fraction of 4% in the mixed system. Each wash was centrifuged for 3 minutes to obtain the biomimetic electrical sensor (labeled PANI1@Rf@RBC).

[0062] Example 9

[0063] By keeping other conditions unchanged in Example 8 and modifying the in-situ polymerization reaction time to 12 hours, a biomimetic electrical sensor (labeled PANI2@Rf@RBC) was obtained.

[0064] Example 10

[0065] By keeping other conditions unchanged in Example 8 and modifying the in-situ polymerization reaction time to 24 hours, a biomimetic electrical sensor (labeled PANI3@Rf@RBC) was obtained.

[0066] Example 11

[0067] The biomimetic red blood cells prepared in Example 1 were suspended in 12 mL of thiophene solution (the thiophene solution contained water, thiophene, and sodium dodecyl sulfate, with a thiophene concentration of 1 mg / mL and a sodium dodecyl sulfate concentration of 4.5 mg / mL), and sonicated for 0.5 h. Then, 12 mg of ferric chloride was added, and an in-situ polymerization reaction was carried out at 28 °C with stirring for 2 h. After the reaction, excess ethanol solution (ethanol to water volume ratio of 1:1) was added to the system to remove unreacted thiophene. The system was then centrifuged at a speed of 25 rpm. The centrifuge speed was 2500 r / min for 5 min. Then, the sample obtained by centrifugation was washed with water 3 times, with the centrifugation speed set at 2500 r / min. Each time the sample was washed, it was mixed with water, and the volume fraction of the sample in the mixed system was 4%. The centrifugation time for each wash was 3 min. Finally, the sample obtained by washing was washed with ethanol, with the centrifugation speed set at 2500 r / min. Each time the sample was washed, it was mixed with ethanol, and the volume fraction of the sample in the mixed system was 4%. The centrifugation time for each wash was 3 min. The resulting biomimetic electrical sensor (labeled PTH1@Rf@RBC) was obtained.

[0068] Example 12

[0069] By keeping other conditions unchanged in Example 11 and modifying the in-situ polymerization reaction time to 6 hours, a biomimetic electrical sensor (labeled as PTH2@Rf@RBC) was obtained.

[0070] Example 13

[0071] By keeping other conditions unchanged in Example 11 and modifying the in-situ polymerization reaction time to 8 hours, a biomimetic electrical sensor (labeled as PTH3@Rf@RBC) was obtained.

[0072] Keeping other conditions unchanged in Example 1, without adding Rf, and using spare red blood cells instead of biomimetic red blood cells, PDA1@RBC was reacted with dopamine to obtain PDA2@RBC; similarly, PDA2@RBC and PDA3@RBC were obtained. Using a Shimadzu UV-3600 UV-Vis-NIR spectrometer, the biomimetic electrical sensors prepared in Examples 1-3 and the control samples were suspended in water for spectral characterization. The control samples contained PDA1@RBC, PDA2@RBC, PDA3@RBC, red blood cells (RBC) isolated in Example 1, and Rf. The UV-Vis spectral characterization diagrams of the biomimetic electrical sensors obtained in Examples 1-3 and the control samples were obtained, as shown below. Figure 1 As shown; from Figure 1As can be seen, the absorption wavelengths of Rf are 222nm, 268nm, 355nm, and 442nm, respectively. The biomimetic electrical sensors prepared in Examples 1-3 all exhibit characteristic Rf signals, indicating the successful preparation of PDA1@Rf@RBC, PDA2@Rf@RBC, and PDA3@Rf@RBC. Furthermore, due to differences in the amount of dopamine used, the characteristic Rf signals in PDA1@Rf@RBC, PDA2@Rf@RBC, and PDA3@Rf@RBC gradually weaken.

[0073] The oxygen-carrying capacity of the biomimetic electrical sensors prepared in Examples 1-3 was evaluated using a dissolved oxygen meter (Vernier, USA). Specifically, a certain volume of PBS (1×) solution was added to a sealed container, and O2 was introduced. The change in O2 content in the solution was monitored using the dissolved oxygen meter. Simultaneously, the O2 concentration in the solution was controlled (oxygenation was stopped at a certain concentration before saturation), and the same volume of the test samples (PDA1@Rf@RBC, PDA2@Rf@RBC, PDA3@Rf@RBC) was added. The change in O2 concentration in the solution was observed through the sensor signal, resulting in oxygen uptake-release curves for the biomimetic electrical sensors obtained in Examples 1-3, as shown below. Figure 2 As shown. From Figure 2 It can be seen that PDA2@Rf@RBC exhibits significant oxygen uptake behavior and also demonstrates good sustained oxygen release capacity during the oxygen release phase.

[0074] The PDA2@Rf@RBCs prepared in Example 2 were centrifuged and washed 3-5 times with deionized water. An appropriate amount of the cleaned PDA2@Rf@RBCs was mixed evenly with a small amount of deionized water to obtain a PDA2@Rf@RBC solution, which was then set aside. Conductive adhesive was adhered to the sample stage, and an appropriate amount of the above-mentioned evenly dispersed PDA2@Rf@RBC solution was dropped onto the conductive adhesive. The solution was allowed to air dry at room temperature, sputtered with gold, and then measured using a JSM-6701F field emission scanning electron microscope (FETS-SEM) manufactured by Japan Co., Ltd. Furthermore, the same method was used to measure the red blood cells (RBCs) isolated in Example 1, obtaining FETS characterization images of PDA2@Rf@RBCs and RBCs, as shown below. Figure 3 As shown; Figure 3In the image, (a) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 2 μm scale, (b) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 1 μm scale, (c) is a field emission scanning electron microscope (FESEM) image of PDA2@Rf@RBC at a 0.5 μm scale, (d) is a field emission scanning electron microscope (FESEM) image of RBC at a 2 μm scale, (e) is a field emission scanning electron microscope (FESEM) image of RBC at a 1 μm scale, and (f) is a field emission scanning electron microscope (FESEM) image of RBC at a 0.5 μm scale. Figure 3 As can be seen, the surfaces of PDA2@Rf@RBC and natural RBC are significantly different. The surface of natural RBC is smooth, while the surface of PDA2@Rf@RBC is relatively rough due to the coating of conductive polymer PDA nanolayers.

[0075] The PDA2@Rf@RBCs prepared in Example 2 were centrifuged and washed 3-5 times with deionized water. An appropriate amount of the cleaned PDA2@Rf@RBCs was mixed evenly with a small amount of deionized water to obtain a PDA2@Rf@RBC solution, which was then set aside. An appropriate amount of the evenly dispersed PDA2@Rf@RBC solution was dropped onto a copper grid and allowed to air dry at room temperature. Measurements were performed using a Hitachi JEM-2100 transmission electron microscope. Furthermore, the red blood cells (RBCs) isolated in Example 1 were measured using the same method, resulting in high-resolution transmission electron microscopy characterization images of the PDA2@Rf@RBCs and RBCs, as shown below. Figure 4 As shown; Figure 4 In the image, (a) shows the high-resolution transmission electron microscopy (TEM) characterization of PDA2@Rf@RBC at a 1 μm scale, (b) shows the TEM characterization of PDA2@Rf@RBC at a 20 nm scale, (c) shows the TEM characterization of RBC at a 1 μm scale, and (d) shows the TEM characterization of RBC at a 20 nm scale. Figure 4 As can be seen, the rough surface of PDA2@Rf@RBC is a PDA coating formed by nanoparticles with a particle size of about 20nm; while the cell surface of natural RBC is smooth and no nanoparticles are visible on the cell surface.

[0076] The CV method was used in a solution containing 0.1 mol / L KCl and 5.0 mM [Fe(CN)6]. 3- / [Fe(CN)6] 4- The electrochemical properties of the PDA2@Rf@RBC prepared in Example 2 were studied in a solution containing 0.1 mol / L KCl and 5.0 mM [Fe(CN)6]. Furthermore, electrochemical impedance spectroscopy (EIS) was used at room temperature and under open-circuit conditions.3- / [Fe(CN)6] 4- In a solution, within a fixed frequency range of 10 kHz to 1 Hz, the impedance changes of the glassy carbon electrode surface during the electrochemical process were further characterized. The same method was used to measure the impedance of riboflavin (Rf) and blank samples. Riboflavin (Rf) refers to the Rf-modified glassy carbon electrode, and the blank sample refers to the bare glassy carbon electrode (GCE). Electrochemical impedance characterization diagrams of PDA2@Rf@RBC, Rf, and GCE were obtained, as shown below. Figure 5 As shown; Figure 5 In the figure, (a) shows the cyclic voltammetry curves of PDA2@Rf@RBC, Rf, and GCE, and (b) shows the impedance diagrams of PDA2@Rf@RBC, Rf, and GCE. From (a), it can be seen that the bare glassy carbon electrode (GCE) has a clear pair of redox peaks. Compared with GCE, the redox peak current increases after PDA2@Rf@RBC modification, indicating that PDA2@Rf@RBC modification can improve the specific surface area of ​​the electrode. However, after Rf modification on the electrode, the redox peak current decreases because Rf is a material with poor redox activity. From (b), it can be seen that compared with bare GCE, the resistance of PDA2@Rf@RBC / GCE is significantly reduced, while the resistance of Rf / GCE increases. The results indicate that the presence of Rf has a certain resistance to the interfacial reaction between the electrode and the solution, and these results are consistent with those in (a).

[0077] The electrochemical behavior of PDA2@Rf@RBC was investigated using the CV method. Specifically, the modified electrodes of each sample were tested in 0.1M PBS buffer (pH 7.0) at a scan rate of 100 mV·s. -1 The sample contained Rf, Rf@RBC prepared in Example 1, PDA2@RBC, and PDA2@Rf@RBC. The sample was added to a 0.5% Nafion aqueous solution to obtain a mixture. An appropriate amount of the mixture was dropped onto a glassy carbon electrode. After drying, it was tested in a three-electrode system (platinum sheet electrode as counter electrode, Ag / AgCl electrode as reference electrode, and glassy carbon electrode as working electrode). Furthermore, differential pulse voltammetry (DPVs) was used to detect Sar in PBS. The electrochemical behavior of different samples and the electrochemical response of PDA2@Rf@RBC to Sar were characterized, as shown in the figure. Figure 6 As shown; Figure 6In the diagram, (a) shows the electrochemical behavior characterization of different samples, and (b) shows the electrochemical response characterization of PDA2@Rf@RBC to Sar. From (a), it can be seen that there is a pair of redox peaks in the Rf test signal, and the redox peak of PDA2@Rf@RBC has shifted positively, indicating that our synthesized biomimetic electrosensor can improve the redox capability of Rf. Furthermore, the enhanced peak current after PDA modification indicates that the conductive polymer can improve the conductivity of the sensor. From (b), it can be seen that compared with before the addition of 10 nM Sar (black line), the cathode peak current is significantly reduced after the addition of 10 nM Sar (red line). Therefore, reducing the current change (ΔI) can provide a reference for the quantitative analysis of Sar in this work.

[0078] The differential pulse voltammetry (DPV) of PDA2@Rf@RBC was studied for quantitative detection of different concentrations of Sar, resulting in differential pulse voltammograms of PDA2@Rf@RBC. Figure 7 As shown; Figure 7In the figure, (a) is a schematic diagram of the DPVs of PDA2@Rf@RBC at different Sar concentrations, (b) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (0.01~0.1μmol / L), (c) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (100~1000μmol / L), and (d) is a linear graph of the response of PDA2@Rf@RBC at different Sar concentrations (1000~10000μmol / L). In (a), the Sar concentration gradually increases as the arrows point. From (a), it can be seen that the peak current decreases with increasing Sar concentration in the ranges of 0, 10, 30, 50, 60, 70, 80, 90 nM, 0.1, 0.2, 0.5, 1.0, 5.0, 10 μM, and 0.1, 0.5, 0.6, 0.7, 0.8, 1.0, 3.0, 4.0, 8.0, 10 mM. Therefore, this work uses a reduction in current change (ΔI) for Sar quantification. From (b) to (d), it can be seen that ΔI exhibits a good linear correlation with Sar concentration in the ranges of 0.01–0.1 μmol / L, 100–1000 μmol / L, and 1000–10000 μmol / L. The linear regression equations are as follows: ΔI(μA)=(58.318±1.291)C+(1.3752±0.087), with a correlation coefficient of 0.997; ΔI(μA)=0.00137C+(9.703±0.026), with a correlation coefficient of 0.996; ΔI(μA)=(8.083E-5)C+(11.091±0.013), with a correlation coefficient of 0.996. It is evident that PDA2@Rf@RBC has a relatively low detection range, while the sensor is environmentally friendly, low-cost, easy to test, and highly stable, overcoming the shortcomings of traditional sensors such as high cost and poor stability.

[0079] To test the electrocatalytic stability of PDA2@Rf@RBC, the chronoamperometry (It) method was used in a three-electrode test system (platinum sheet electrode as counter electrode, Ag / AgCl electrode as reference electrode, and PDA2@Rf@RBC-modified glassy carbon electrode as working electrode) in 0.1M PBS buffer (pH 7.0). The test time was set to 12 h, and the electrochemical stability diagram of PDA2@Rf@RBC was obtained, as shown in the figure. Figure 8 As shown. From Figure 8 As can be seen, the current of PDA2@Rf@RBC remained stable after 40,000 s of operation. The test results indicate that PDA2@Rf@RBC has good electrochemical stability.

[0080] Electrochemical behavior of PPy3@Rf@RBC, PANI2@Rf@RBC, and PTH2@Rf@RBC was investigated using CV. Specifically, the electrodes modified with each sample were tested in 0.1M PBS buffer (pH 7.0) at a scan rate of 100 mV·s. -1 A sample was added to a 0.5% Nafion aqueous solution to obtain a mixture. An appropriate amount of this mixture was dropped onto a glassy carbon electrode. After drying, the mixture was tested in a three-electrode system (platinum sheet electrode as the counter electrode, Ag / AgCl electrode as the reference electrode, and glassy carbon electrode as the working electrode). Electrochemical behavior characterization diagrams of different samples were obtained, as shown below. Figure 9 As shown; Figure 9 In the diagram, (a) represents the electrochemical behavior characterization of PPy3@Rf@RBC, (b) represents the electrochemical behavior characterization of PANI2@Rf@RBC, and (c) represents the electrochemical behavior characterization of PTH2@Rf@RBC. Figure 9 As can be seen, the addition of pyrrole, aniline, and thiophene resulted in a positive shift in the redox peaks of Rf, indicating that the synthesized biomimetic electrosensor can improve the redox capability of Rf. Furthermore, the redox current of Rf was enhanced to varying degrees, suggesting that in-situ polymerization of the conductive polymer can improve the conductivity of the sensor.

[0081] As shown in the above embodiments, this invention provides a method for preparing a biomimetic electrosensor, comprising the following steps: mixing a red blood cell solution and a biomimetic living substance, and co-incubating to obtain biomimetic red blood cells; mixing the biomimetic red blood cells with a conductive polymer (the conductive polymer includes dopamine, pyrrole, aniline, or thiophene), and performing an in-situ polymerization reaction to obtain the biomimetic electrosensor. The biomimetic electrosensor combines a conductive polymer with natural cells, utilizing the excellent conductivity of the conductive polymer, and based on the hyperoxic microenvironment of the cell, the biomimetic living substance exhibits better electrocatalytic activity, enabling rapid, sensitive, and efficient monitoring of Sar (Sar) levels. The biomimetic electrosensor prepared by this invention shows different trends in electrochemical signal intensity when the Sar concentration varies, achieving ultrasensitive detection of Sar content. The biomimetic electrical sensor of this invention has advantages such as fast response speed, low cost, easy miniaturization, good biocompatibility, and simple sample pretreatment. It is a promising Sar detection and analysis tool that can provide a new, fast, accurate, and stable diagnostic tool for the pathogenesis and development of prostate diseases, thereby achieving the ultimate goal of reversing or stopping disease progression, which has important practical significance.

[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a biomimetic electrical sensor, characterized by, Includes the following steps: (1) Mix red blood cell solution and biomimetic substance and incubate together to obtain biomimetic red blood cells; (2) The biomimetic red blood cells are mixed with the conductive polymer and subjected to in-situ polymerization to obtain the biomimetic electrical sensor. The conductive polymer in step (2) includes dopamine, pyrrole, aniline, or thiophene; The biomimetic substance is riboflavin; The mass-to-volume ratio of the red blood cell solution to the biomimetic substance is 7-11 mL: 7-11 mg. The biomimetic electrical sensor is used for ultrasensitive detection of sarcosine. The red blood cell solution in step (1) contains red blood cells, sodium chloride and water. The volume fraction of red blood cells in the red blood cell solution is 3.5-4.5%, and the mass fraction of sodium chloride in the red blood cell solution is 0.7-1.1%. The co-incubation temperature in step (1) is 2~6℃, and the co-incubation time is 3~12h.

2. The method for fabricating the biomimetic electrical sensor as described in claim 1, characterized in that, When the conductive polymer in step (2) is dopamine, biomimetic red blood cells, Tris-HCl buffer and dopamine are mixed and in situ polymerized to obtain a biomimetic electrical sensor. The pH of the Tris-HCl buffer is 8-9, and the mass-volume ratio of the Tris-HCl buffer, dopamine and the biomimetic substance in step (1) is 40-50 mL: 5-50 mg: 7-11 mg. The in-situ polymerization reaction is carried out at a temperature of -2 to 2°C for 3 to 12 hours.

3. The method for fabricating the biomimetic electrical sensor as described in claim 1, characterized in that, When the conductive polymer in step (2) is pyrrole, the biomimetic red blood cells and pyrrole solution are mixed and in situ polymerized to obtain a biomimetic electrical sensor. The pyrrole solution comprises PBS buffer, potassium ferrocyanide and pyrrole, wherein the pH of the PBS buffer is 6.5-7.5; The concentration of phosphate ions in the pyrrole solution is 0.05~0.15mol / L, the mass concentration of potassium ferrocyanide in the pyrrole solution is 0.67~2mg / mL, and the mass concentration of pyrrole in the pyrrole solution is 4~5.33mg / mL; the mass-volume ratio of the pyrrole solution and the biomimetic substance in step (1) is 10~30mL:7~11mg; The in-situ polymerization reaction is carried out at a temperature of 25~35℃ and for a duration of 1.5~2.5h.

4. The method for fabricating the biomimetic electrical sensor as described in claim 1, characterized in that, When the conductive polymer in step (2) is aniline, biomimetic red blood cells, aniline solution and oxidant solution are mixed and in-situ polymerized to obtain a biomimetic electrical sensor. The aniline solution contains aniline, tartaric acid, and water. The mass concentration of aniline in the aniline solution is 12-16 mg / mL, and the mass concentration of tartaric acid in the aniline solution is 1.5-3.5 mg / mL. The oxidizing agent solution is ammonium persulfate solution, and the mass concentration of ammonium persulfate solution is 1.67-5 mg / mL. The mass-volume ratio of the aniline solution, the oxidizing agent solution, and the biomimetic substance in step (1) is 4-6 mL: 5-7 mL: 7-11 mg. The in-situ polymerization reaction is carried out at a temperature of -2 to 2°C for 6 to 24 hours.

5. The method for fabricating the biomimetic electrical sensor as described in claim 1, characterized in that, When the conductive polymer in step (2) is thiophene, biomimetic red blood cells, thiophene solution and ferric chloride are mixed and subjected to in-situ polymerization to obtain a biomimetic electrical sensor. The thiophene solution comprises water, thiophene, and sodium dodecyl sulfate, wherein the mass concentration of thiophene in the thiophene solution is 0.833~1.25 mg / mL, and the mass concentration of sodium dodecyl sulfate in the thiophene solution is 4.17~5 mg / mL; the mass-volume ratio of thiophene solution, ferric chloride, and the biomimetic substance in step (1) is 10~15 mL: 10~15 mg: 7~11 mg; The in-situ polymerization reaction is carried out at a temperature of 25~30℃ for 2~8 hours.

6. The biomimetic electrical sensor prepared by the method of any one of claims 1 to 5.

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