Bionic electric sensor, preparation method thereof and application of bionic electric sensor in ultrasensitive detection of sarcosine

Abstract

The invention belongs to the technical field of sarcosine detection, and provides a bionic electric sensor, a preparation method thereof and application of the bionic electric sensor in ultrasensitive detection of sarcosine. The method comprises the following steps: mixing a red blood cell solution and a bionic active substance, and carrying out co-incubation to obtain bionic red blood cells, and mixing the bionic red blood cells with a conductive polymer (dopamine, pyrrole, aniline or thiophene), and carrying out an in-situ polymerization reaction to obtain the bionic electric sensor. The conductive polymer is combined with natural cells, the excellent conductivity of the conductive polymer is utilized, and meanwhile, based on the high-oxygen microenvironment of the cells, the bionic active substance has better electrocatalytic property and can be used for rapid, sensitive and efficient monitoring of Sar. The bionic electric sensor has the advantages of being high in reaction speed, low in cost, easy to miniaturize, good in biocompatibility, simple in sample pretreatment and the like, and a novel, rapid, accurate and stable diagnostic tool can be provided for the morbidity and development law of prostate diseases.

Description

Technical Field

[0001] The invention relates to the technical field of creatine detection, and in particular to a bionic electrical sensor and a preparation method thereof, and application of the bionic electrical sensor in ultra-sensitive detection of creatine. Background Art

[0002] Sarcosine (Sar) is a tumor metabolite. As prostate disease worsens and metastasizes, Sar increases significantly, and this change is not affected by other diseases, making Sar a promising marker for prostate disease. Among them, Sar has a higher concentration in the urine of patients with prostate cancer, and a lower concentration in the urine of patients with benign prostatic hyperplasia. Therefore, ultrasensitive detection of Sar can help achieve early diagnosis and treatment of prostate disease and is the key to curbing the continued increase in the incidence of prostate cancer. In view of the fact that the current sarcosine detection methods still lack the rapidity, convenience, accuracy and specificity for clinical diagnostic applications, bionic design and development of new nanosensors for rapid, efficient and ultrasensitive detection of Sar is an important way to achieve highly sensitive and accurate determination of the occurrence and development of prostate disease, which is of great significance. Summary of the invention

[0003] The purpose of the present invention is to overcome the problems existing in the prior art, provide a bionic electrical sensor and a preparation method thereof and an application in ultra-sensitive detection of sarcosine, so as to achieve ultra-sensitive detection of changes in sarcosine Sar content during the development of prostate disease.

[0004] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0005] The present invention provides a method for preparing a bionic electrical sensor, comprising the following steps:

[0006] (1) mixing a red blood cell solution and a biomimetic active substance, and co-incubating them to obtain biomimetic red blood cells;

[0007] (2) mixing the bionic red blood cells with the conductive polymer and performing an in-situ polymerization reaction to obtain the bionic electrical sensor;

[0008] The conductive polymer in step (2) includes dopamine, pyrrole, aniline or thiophene.

[0009] Preferably, the red blood cell solution in step (1) comprises 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%, the mass fraction of sodium chloride in the red blood cell solution is 0.7-1.1%; and the biomimetic active substance is riboflavin;

[0010] The mass volume ratio of the red blood cell solution and the biomimetic active substance is 7-11 mL:7-11 mg.

[0011] Preferably, the co-incubation temperature in step (1) is 2 to 6° C., and the co-incubation time is 3 to 12 hours.

[0012] Preferably, when the conductive polymer in step (2) is dopamine, the biomimetic red blood cells, Tris-HCl buffer and dopamine are mixed and subjected to in-situ polymerization reaction to obtain a biomimetic electrical sensor;

[0013] The pH of the Tris-HCl buffer is 8-9, and the mass volume ratio of the Tris-HCl buffer, dopamine and the biomimetic active substance in step (1) is 40-50 mL: 5-50 mg: 7-11 mg;

[0014] The temperature of the in-situ polymerization reaction is -2 to 2°C, and the time of the in-situ polymerization reaction is 3 to 12 hours.

[0015] Preferably, when the conductive polymer in step (2) is pyrrole, the bionic red blood cells and the pyrrole solution are mixed and subjected to in-situ polymerization reaction to obtain a bionic electrical sensor;

[0016] The pyrrole solution comprises PBS buffer, potassium ferrocyanide and pyrrole, wherein the pH value 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 volume ratio of the pyrrole solution to the biomimetic active substance in step (1) is 10-30 mL:7-11 mg;

[0017] The temperature of the in-situ polymerization reaction is 25-35° C., and the time of the in-situ polymerization reaction is 1.5-2.5 hours.

[0018] Preferably, when the conductive polymer in step (2) is aniline, the biomimetic red blood cells, aniline solution and oxidant solution are mixed to perform an in-situ polymerization reaction to obtain a biomimetic electrical sensor;

[0019] The aniline solution comprises aniline, tartaric acid and water, wherein 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 oxidant solution is an ammonium persulfate solution, and the mass concentration of the ammonium persulfate solution is 1.67-5 mg / mL; the mass volume ratio of the aniline solution, the oxidant solution and the biomimetic active substance in step (1) is 4-6 mL: 5-7 mL: 7-11 mg;

[0020] The temperature of the in-situ polymerization reaction is -2 to 2°C, and the time of the in-situ polymerization reaction is 6 to 24 hours.

[0021] Preferably, when the conductive polymer in step (2) is thiophene, the biomimetic red blood cells, thiophene solution and ferric chloride are mixed to perform an in-situ polymerization reaction to obtain a biomimetic electrical sensor;

[0022] 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 the thiophene solution, ferric chloride and the biomimetic active substance in step (1) is 10-15 mL: 10-15 mg: 7-11 mg;

[0023] The temperature of the in-situ polymerization reaction is 25-30° C., and the time of the in-situ polymerization reaction is 2-8 hours.

[0024] The invention also provides a bionic electric sensor prepared by the preparation method of the bionic electric sensor.

[0025] The invention also provides application of the bionic electrical sensor in ultra-sensitive detection of sarcosine.

[0026] The beneficial effects of the present invention are:

[0027] The present invention provides a method for preparing a bionic electrical sensor, comprising the following steps: mixing a red blood cell solution and a bionic active substance, co-incubating, and obtaining a bionic red blood cell; mixing the bionic red blood cell with a conductive polymer (the conductive polymer includes dopamine, pyrrole, aniline or thiophene), and performing an in-situ polymerization reaction to obtain a bionic electrical sensor. The bionic electrical sensor combines the conductive polymer with the natural cell, utilizes the excellent conductive property of the conductive polymer, and based on the high oxygen microenvironment of the cell, the bionic active substance has better electrocatalytic property, and can be used for rapid, sensitive and efficient monitoring of Sar. The bionic electrical sensor prepared by the present invention has different trends in the change of electrochemical signal intensity when the concentration of Sar is different, and can realize ultra-sensitive detection of Sar content. The bionic electrical sensor of the present invention has the advantages of fast reaction speed, low cost, easy miniaturization, good biocompatibility, simple sample pretreatment, etc., and is a very promising Sar detection and analysis tool, which can provide a new, rapid, accurate and stable diagnostic tool for the incidence and development of prostate diseases, thereby achieving the purpose of ultimately reversing or preventing the progression of the disease, and has important practical significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The UV-visible spectra of the bionic electrical sensors obtained in Examples 1 to 3 and the control samples (Wavelength—wavelength, Absorbance—absorbance);

[0029] Figure 2The oxygen absorption-release curve diagram of the bionic electrical sensor obtained in Examples 1 to 3 (Time—time, Oxygen—oxygen, Adding sample—adding sample, Oxygen release phase—oxygen release phase);

[0030] Figure 3 Field emission scanning electron microscopy characterization images of PDA2@Rf@RBC and RBC; Figure 3 In the figure, (a) is a field emission scanning electron microscopy characterization image of PDA2@Rf@RBC at a 2μm scale, (b) is a field emission scanning electron microscopy characterization image of PDA2@Rf@RBC at a 1μm scale, (c) is a field emission scanning electron microscopy characterization image of PDA2@Rf@RBC at a 0.5μm scale, (d) is a field emission scanning electron microscopy characterization image of RBC at a 2μm scale, (e) is a field emission scanning electron microscopy characterization image of RBC at a 1μm scale, and (f) is a field emission scanning electron microscopy characterization image of RBC at a 0.5μm scale;

[0031] Figure 4 High-resolution transmission electron microscopy characterization images of PDA2@Rf@RBC and RBC; Figure 4 In the figure, (a) is a high-resolution transmission electron microscopy characterization image of PDA2@Rf@RBC at a scale of 1 μm, (b) is a high-resolution transmission electron microscopy characterization image of PDA2@Rf@RBC at a scale of 20 nm, (c) is a high-resolution transmission electron microscopy characterization image of RBC at a scale of 1 μm, and (d) is a high-resolution transmission electron microscopy characterization image of RBC at a scale of 20 nm;

[0032] Figure 5 The electrochemical impedance spectroscopy characteristics of PDA2@Rf@RBC, Rf and GCE are shown in Figure 2. Figure 5 In the figure, (a) is the cyclic voltammogram (Potential—voltage, Current—current) of PDA2@Rf@RBC, Rf and GCE, and (b) is the impedance diagram of PDA2@Rf@RBC, Rf and GCE;

[0033] Figure 6 Characterization of electrochemical behavior of different samples and electrochemical response of PDA2@Rf@RBC to Sar; Figure 6 In the figure, (a) is a characterization diagram of the electrochemical behavior of different samples (Potential—voltage, Current—current), and (b) is a characterization diagram of the electrochemical response of PDA2@Rf@RBC to Sar (Potential—voltage, Current—current);

[0034] Figure 7is the differential pulse voltammogram of PDA2@Rf@RBC; Figure 7 In the figure, (a) is a schematic diagram of the DPVs of PDA2@Rf@RBC in different Sar concentrations (Potential—voltage, Current—current), (b) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (0.01-0.1 μmol / L), (c) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (100-1000 μmol / L), (d) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (1000-10000 μmol / L);

[0035] Figure 8 Schematic diagram of electrochemical stability of PDA2@Rf@RBC (Time—time, Current—current);

[0036] Fig. 9 Characterization diagram of electrochemical behavior of different samples; Fig. 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 DESCRIPTION

[0037] The present invention provides a method for preparing a bionic electrical sensor, comprising the following steps:

[0038] (1) mixing a red blood cell solution and a biomimetic active substance, and co-incubating them to obtain biomimetic red blood cells;

[0039] (2) mixing the bionic red blood cells with the conductive polymer and performing an in-situ polymerization reaction to obtain the bionic electrical sensor;

[0040] The conductive polymer in step (2) includes dopamine, pyrrole, aniline or thiophene.

[0041] In the present invention, the red blood cells in step (1) are preferably separated from fresh whole blood, and the centrifugal speed of separation is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and more preferably 2500 r / min; the centrifugal time of separation is preferably 3-7 min, more preferably 4-6 min, and more preferably 5 min; the separated red blood cells are washed with physiological saline, and after washing, they are stored for step (1); the mass fraction of the physiological saline is preferably 0.7-1.1%, more preferably 0.8-1.0%, and more preferably 0.9%; the temperature of the physiological saline is preferably 2-6°C, and the separation is carried out at 40°C. The centrifugal speed for washing is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, more preferably 2500 r / min; the number of washes is preferably 4-6 times, more preferably 5 times, and the red blood cells are mixed with physiological saline during each wash, and the volume fraction of red blood cells in the mixed system is preferably 2-6%, more preferably 3-5%, more preferably 4%; the centrifugal time for each wash is preferably 1-5 min, more preferably 2-4 min, more preferably 3 min; the storage temperature is preferably 2-6 ° C, more preferably 3-5 ° C, more preferably 4 ° C.

[0042] In the present invention, the red blood cell solution in step (1) preferably comprises 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%; and the biomimetic active substance is preferably riboflavin (Rf).

[0043] In the present invention, the mass volume ratio of the red blood cell solution and the biomimetic active substance in step (1) is preferably 7-11 mL:7-11 mg, more preferably 8-10 mL:8-10 mg, and more preferably 9 mL:9 mg.

[0044] In the present invention, the mixing in step (1) preferably comprises 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 biomimetic active substances to complete the mixing; the temperature of the sodium chloride solution is preferably 2 to 6°C, more preferably 3 to 5°C, and more preferably 4°C.

[0045] In the present invention, the co-incubation temperature in step (1) is preferably 2-6°C, more preferably 3-5°C, and more preferably 4°C; the co-incubation time is preferably 3-12h, more preferably 5-10h, and more preferably 7-8h.

[0046] In the present invention, after the co-incubation in step (1) is completed, the system is centrifuged to obtain a sample, and then the sample is washed to obtain the bionic red blood cells; the centrifugal speed is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and more preferably 2500 r / min; the centrifugal time is preferably 3-7 min, more preferably 4-6 min, and more preferably 5 min; the washing reagent is preferably physiological saline, and the mass fraction of the physiological saline is preferably 0.7-1.1%, more preferably 0.8-1.0%, and more preferably 0.9%; The temperature of the physiological saline is preferably 2-6°C, more preferably 3-5°C, and more preferably 4°C; the centrifugal speed for washing is preferably 2000-3000 r / min, more preferably 2200-2800 r / min, and more preferably 2500 r / min; the number of washes is preferably 2-4 times, and more preferably 3 times. During each wash, 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 more preferably 4%; the centrifugation time for each wash is preferably 1-5 min, more preferably 2-4 min, and more preferably 3 min.

[0047] In the present invention, when the conductive polymer in step (2) is dopamine, step (2) preferably comprises the following steps: mixing bionic red blood cells, Tris-HCl buffer and dopamine, and performing an in-situ polymerization reaction to obtain a bionic electrical sensor.

[0048] In the present invention, when the conductive polymer in step (2) is dopamine, the mixing preferably comprises the following steps: suspending the bionic red blood cells in Tris-HCl buffer, then adding dopamine to complete the mixing.

[0049] In the present invention, the pH of the Tris-HCl buffer is preferably 8-9, more preferably 8.2-8.8, and more preferably 8.45; the mass volume ratio of the Tris-HCl buffer, dopamine and the biomimetic active 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 more preferably 45-46 mL: 20-30 mg: 9 mg.

[0050] In the present invention, when the conductive polymer in step (2) is dopamine, the in-situ polymerization reaction is preferably carried out in an ice bath, and the temperature of the in-situ polymerization reaction is preferably -2 to 2°C, more preferably -1 to 1°C, and more preferably 0°C; the shaking speed of the in-situ polymerization reaction is preferably 200 to 300 r / min, more preferably 220 to 280 r / min, and more preferably 250 r / min; the time of the in-situ polymerization reaction is preferably 3 to 12 h, more preferably 5 to 10 h, and more preferably 7 to 8 h.

[0051] In the present invention, when the conductive polymer in step (2) is dopamine, after the in-situ polymerization reaction is completed, the solution obtained by the reaction is centrifuged to obtain a sample, and then the sample is washed with physiological saline to obtain the bionic electrical sensor; the centrifugal speed is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the centrifugal time is preferably 3-7min, more preferably 4-6min, and more preferably 5min; the mass fraction of the physiological saline used for washing is preferably 0.7-1.1%, and more preferably 0.8-1.0%, More preferably, it is 0.9%; the temperature of the physiological saline is preferably 2-6°C, further preferably 3-5°C, and more preferably 4°C; the centrifugal speed for washing is preferably 2000-3000r / min, further preferably 2200-2800r / min, and more preferably 2500r / min; the number of washes is preferably 2-4 times, and more preferably 3 times. During each wash, the sample is mixed with the 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 centrifugal time for each wash is preferably 1-5min, further preferably 2-4min, and more preferably 3min.

[0052] In the present invention, when the conductive polymer in step (2) is pyrrole, step (2) preferably comprises the following steps: mixing the bionic red blood cells and the pyrrole solution, and performing an in-situ polymerization reaction to obtain a bionic electrical sensor.

[0053] In the present invention, the pyrrole solution preferably comprises a PBS buffer, potassium ferrocyanide and pyrrole; the pH value of the PBS buffer is preferably 6.5 to 7.5, more preferably 6.7 to 7.3, and more preferably 7; the concentration of phosphate ions in the pyrrole solution is preferably 0.05 to 0.15 mol / L, more preferably 0.07 to 0.13 mol / L, and more preferably 0.1 mol / L; the mass concentration of potassium ferrocyanide in the pyrrole solution is preferably 0.67 to 2 mg / mL, and more preferably Preferably, the 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 mass volume ratio of the pyrrole solution to the biomimetic active substance in step (1) is preferably 10-30 mL:7-11 mg, more preferably 15-25 mL:8-10 mg, more preferably 20 mL:9 mg.

[0054] In the present invention, when the conductive polymer in step (2) is pyrrole, the mixing preferably comprises the following steps: suspending the biomimetic red blood cells in PBS buffer, and then sequentially adding potassium ferrocyanide and pyrrole to complete the mixing.

[0055] In the present invention, when the conductive polymer in step (2) is pyrrole, the temperature of the in-situ polymerization reaction is preferably 25-35°C, more preferably 27-33°C, and more preferably 30°C; the shaking speed of the in-situ polymerization reaction is preferably 200-300 r / min, more preferably 220-280 r / min, and more preferably 250 r / min; the time of the in-situ polymerization reaction is preferably 1.5-2.5 h, more preferably 1.7-2.3 h, and more preferably 2 h.

[0056] In the present invention, when the conductive polymer in step (2) is pyrrole, after the in-situ polymerization reaction is completed, the solution obtained by the reaction is centrifuged to obtain a sample, and then the sample is washed with water to obtain the bionic electrical sensor; the centrifugal speed is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the centrifugal time is preferably 3-7min, more preferably 4-6min, and more preferably 5min; the centrifugal speed for washing is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the number of washings is preferably 2-4 times, and more preferably 3 times. During each washing, the sample 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 centrifugal time for each washing is preferably 1-5min, more preferably 2-4min, and more preferably 3min.

[0057] In the present invention, when the conductive polymer in step (2) is aniline, step (2) preferably comprises the following steps: mixing the bionic red blood cells, aniline solution and oxidant solution, and performing an in-situ polymerization reaction to obtain a bionic electrical sensor.

[0058] In the present invention, when the conductive polymer in step (2) is aniline, the mixing preferably comprises the following steps: suspending the 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 to 2°C, more preferably -1 to 1°C, and more preferably 0°C; the temperature of the pre-cooled oxidant solution is preferably -2 to 2°C, more preferably -1 to 1°C, and more preferably 0°C.

[0059] In the present invention, the aniline solution preferably comprises aniline, tartaric acid and water, and the mass concentration of aniline in the aniline solution is preferably 12-16 mg / mL, more preferably 13-15 mg / mL, and 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 more preferably 2.4 mg / mL; the oxidant solution is preferably an ammonium persulfate solution, and the mass concentration of the ammonium persulfate solution is 1.67-5 mg / mL, more preferably 2-4 mg / mL, and more preferably 3 mg / mL; the mass volume ratio of the aniline solution, the oxidant solution and the biomimetic active 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 more preferably 5 mL:6 mL:9 mg.

[0060] In the present invention, when the conductive polymer in step (2) is aniline, the in-situ polymerization reaction is preferably carried out in an ice bath, and the temperature of the in-situ polymerization reaction is preferably -2 to 2°C, more preferably -1 to 1°C, and more preferably 0°C; the time of the in-situ polymerization reaction is preferably 6 to 24h, more preferably 10 to 20h, and more preferably 12 to 15h.

[0061] In the present invention, when the conductive polymer in step (2) is aniline, after the in-situ polymerization reaction is completed, the solution obtained by the reaction is centrifuged to obtain a sample, and then the sample is washed with water to obtain the bionic electrical sensor; the centrifugal speed is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the centrifugal time is preferably 3-7min, more preferably 4-6min, and more preferably 5min; the centrifugal speed for washing is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the number of washings is preferably 2-4 times, and more preferably 3 times. During each washing, the sample 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 centrifugal time for each washing is preferably 1-5min, more preferably 2-4min, and more preferably 3min.

[0062] In the present invention, when the conductive polymer in step (2) is thiophene, step (2) preferably comprises the following steps: mixing bionic red blood cells, thiophene solution and ferric chloride, and performing in-situ polymerization reaction to obtain a bionic electrical sensor.

[0063] In the present invention, when the conductive polymer in step (2) is thiophene, the mixing preferably comprises the following steps: suspending the bionic 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 to 0.7 h, more preferably 0.4 to 0.6 h, and more preferably 0.5 h.

[0064] In the present 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 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 more preferably 4.5 mg / mL; the mass volume ratio of thiophene solution, ferric chloride and the biomimetic active 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 more preferably 12 mL: 12 mg: 9 mg.

[0065] In the present invention, when the conductive polymer in step (2) is thiophene, the in-situ polymerization reaction is carried out under stirring, and the temperature of the in-situ polymerization reaction is preferably 25-30°C, more preferably 27-29°C, and more preferably 28°C; the time of the in-situ polymerization reaction is preferably 2-8h, more preferably 3-7h, and more preferably 5-6h.

[0066] In the present invention, when the conductive polymer in step (2) is thiophene, after the in-situ polymerization reaction is completed, an excess of ethanol solution is added to the system to remove unreacted thiophene; the system is then centrifuged to obtain a sample; the sample is washed with water and ethanol in sequence to obtain the bionic 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 speed of centrifugal separation is preferably 2000-3000r / min, more preferably 2200-2800r / min, and more preferably 2500r / min; the time of centrifugal separation is preferably 3-7min, more preferably 4-6min, and more preferably 5min n; the centrifugal speed of water washing and ethanol washing is independently preferably 2000-3000r / min, further preferably 2200-2800r / min, more preferably 2500r / min; the number of water washing and ethanol washing is independently preferably 2-4 times, more preferably 3 times, each time the water washing, the sample is mixed with water, and the volume fraction of the sample in the mixed system is preferably 2-6%, more preferably 3-5%, more preferably 4%; each time the ethanol washing, the sample is mixed with ethanol, and the volume fraction of the sample in the mixed system is preferably 2-6%, further preferably 3-5%, more preferably 4%; the centrifugal time of each water washing and ethanol washing is independently preferably 1-5min, further preferably 2-4min, more preferably 3min.

[0067] The invention also provides a bionic electric sensor prepared by the preparation method of the bionic electric sensor.

[0068] The invention also provides application of the bionic electrical sensor in ultra-sensitive detection of sarcosine.

[0069] In the present invention, the response principle of sarcosine is: Sar (sarcosine) + Rf + O2 → H2O2 + Gly (glycine) + CH2O; the bionic electrical sensor uses riboflavin (Rf) as the catalytic active center, and Rf is an isocyanine ring with a conjugated structure, which can be complexed with the iron porphyrin structure in erythrocytes to improve its redox ability; the conductive polymer undergoes an in-situ polymerization reaction on the surface of the bionic erythrocytes to obtain a conductive oxygen-rich carrier of the bionic electrical sensor, and the conductive polymer gives the carrier good conductivity. The natural iron porphyrin structure in the erythrocytes gives the sensor the ability to efficiently capture dissolved oxygen to ensure the oxygen environment required in the catalytic process.

[0070] The technical solutions provided by the present invention are described in detail below in conjunction with the embodiments, but they should not be construed as limiting the protection scope of the present invention.

[0071] Example 1

[0072] Separate red blood cells (RBC) from fresh whole blood, set the separation centrifugal speed to 2500 r / min, the time to 5 min, wash the separated red blood cells with physiological saline of 0.9% at a temperature of 4°C, set the washing centrifugal speed to 2500 r / min, wash 5 times, mix the red blood cells with the physiological saline each time, the volume fraction of red blood cells in the mixed system is 4%, and the centrifugal time for each washing is 3 min; store at 4°C after washing for future use;

[0073] Sodium chloride and water are mixed to obtain a sodium chloride solution, and the above-mentioned spare red blood cells are taken and suspended in a sodium chloride solution at a temperature of 4°C to obtain 9mL of red blood cell solution (the volume fraction of red blood cells in the red blood cell solution is 4%, and the mass fraction of sodium chloride is 0.9%); then 9mg of riboflavin (Rf) is added, and the mixture is incubated at 4°C for 3h. After the incubation, the system is centrifuged, and the speed of the centrifugation is set to 2500r / min for 5min; then, the sample obtained by centrifugation is washed with physiological saline at a temperature of 4°C and a mass fraction of 0.9%, and the centrifugal speed of the washing is set to 2500r / min. The number of washings is 3 times. During each washing, the sample is mixed with physiological saline, and the volume fraction of the sample in the mixed system is 4%; the centrifugation time for each washing is 3min; and bionic red blood cells (labeled as Rf@RBC) are obtained;

[0074] The bionic red blood cells were suspended in 45 mL of Tris-HCl buffer with a pH of 8.45, and then 10 mg of dopamine was added. The in-situ polymerization reaction was carried out in an ice bath at 0°C with a shaking speed of 250 r / min for 3 hours. After the reaction, the solution obtained by the reaction was centrifuged at a speed of 2500 r / min for 5 minutes. Then, the sample obtained by centrifugation was washed with physiological saline at a temperature of 4°C and a mass fraction of 0.9%. The centrifugal speed of the washing was set to 2500 r / min, and the number of washings was 3 times. During each washing, the sample was mixed with physiological saline, and the volume fraction of the sample in the mixed system was 4%. The centrifugal time for each washing was 3 minutes, and a bionic electrical sensor (marked as PDA1@Rf@RBC) was obtained.

[0075] Example 2

[0076] The other conditions in Example 1 were kept unchanged, and the dosage of dopamine was changed to 36 mg to obtain a biomimetic electrical sensor (labeled as PDA2@Rf@RBC).

[0077] Example 3

[0078] The other conditions in Example 1 were kept unchanged, and the dosage of dopamine was changed to 50 mg to obtain a biomimetic electrical sensor (labeled as PDA3@Rf@RBC).

[0079] Example 4

[0080] The bionic red blood cells prepared in Example 1 were mixed with 25 mL of a pyrrole solution (the pyrrole solution contained a PBS buffer solution with a pH value of 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 the mixing, the bionic red blood cells were first suspended in the PBS buffer solution, and then potassium ferrocyanide and pyrrole were added in sequence to complete the mixing; the mixture was stirred at 30° C. and a shaking speed of 250 r / min. The in-situ polymerization reaction was carried out under the condition of 400 ℃ and 800 ℃ for 2 hours. After the reaction, the solution obtained by the reaction was centrifuged at a speed of 2500 r / min and a time of 5 min. Then, the sample obtained by centrifugation was washed with water for 3 times at a speed of 2500 r / min. During each washing, the sample was mixed with water. The volume fraction of the sample in the mixed system was 4%. The centrifugation time for each washing was 3 min, and a bionic electrical sensor (marked as PPy1@Rf@RBC) was obtained.

[0081] Example 5

[0082] The other conditions in Example 4 were kept unchanged, and the mass concentration of pyrrole in the pyrrole solution was changed to 5.3 mg / mL to obtain a biomimetic electrical sensor (labeled as PPy2@Rf@RBC).

[0083] Example 6

[0084] The other conditions in Example 4 were kept unchanged, and the mass concentration of pyrrole in the pyrrole solution was changed to 4.8 mg / mL to obtain a biomimetic electrical sensor (labeled as PPy3@Rf@RBC).

[0085] Example 7

[0086] The other conditions in Example 4 were kept unchanged, and the mass concentration of pyrrole in the pyrrole solution was changed to 4.3 mg / mL to obtain a biomimetic electrical sensor (labeled as PPy4@Rf@RBC).

[0087] Example 8

[0088] The bionic red blood cells prepared in Example 1 were suspended in 5 mL of aniline solution (the aniline solution contained aniline, tartaric acid and water, and the mass concentration of aniline in the aniline solution was 14 mg / mL, and the mass concentration of tartaric acid was 2.4 mg / mL). Then, 6 mL of ammonium persulfate solution precooled to 0°C and having a mass concentration of 3 mg / mL was added under 0°C ice bath conditions. The mixture was subjected to in-situ polymerization in an ice bath at 0°C, and the reaction time was set to 6 h. After the reaction was completed, the solution obtained by the reaction was centrifuged, and the speed of the centrifugation was set to 2500 r / min for 5 min. Then, the sample obtained by centrifugation was washed with water 3 times, and the centrifugal speed of the washing was set to 2500 r / min. During each washing, the sample was mixed with water, and the volume fraction of the sample in the mixed system was 4%; the centrifugation time for each washing was 3 min, and a bionic electrical sensor (labeled as PANI1@Rf@RBC) was obtained.

[0089] Example 9

[0090] The other conditions in Example 8 were kept unchanged, and the time of the in-situ polymerization reaction was changed to 12 h to obtain a biomimetic electrical sensor (labeled as PANI2@Rf@RBC).

[0091] Example 10

[0092] The other conditions in Example 8 were kept unchanged, and the time of the in-situ polymerization reaction was changed to 24 h to obtain a biomimetic electrical sensor (labeled as PANI3@Rf@RBC).

[0093] Embodiment 11

[0094] The bionic 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, the mass concentration of thiophene in the thiophene solution was 1 mg / mL, and the mass concentration of sodium dodecyl sulfate was 4.5 mg / mL), and ultrasonicated for 0.5 h. Then, 12 mg of ferric chloride was added, and an in-situ polymerization reaction was carried out at a temperature of 28° C. and under stirring. The reaction time was set to 2 h. After the reaction was completed, an excess of ethanol solution (the volume ratio of ethanol to water in the ethanol solution was 1:1) was added to the system to remove unreacted thiophene. The system was centrifuged and the speed of the centrifugal separation was set to 25. 00r / min, the time is 5min; then, the sample obtained by centrifugation is washed with water for 3 times, and the centrifugal speed for washing is set to 2500r / min. During each washing, the sample is mixed with water, and the volume fraction of the sample in the mixed system is 4%; the centrifugal time for each washing is 3min, and finally the sample obtained by water washing is washed with ethanol, and the centrifugal speed for washing is set to 2500r / min. During each washing, the sample is mixed with ethanol, and the volume fraction of the sample in the mixed system is 4%; the centrifugal time for each washing is 3min, and a bionic electrical sensor (marked as PTH1@Rf@RBC) is obtained.

[0095] Example 12

[0096] The other conditions in Example 11 were kept unchanged, and the time of the in-situ polymerization reaction was changed to 6 h to obtain a biomimetic electrical sensor (labeled as PTH2@Rf@RBC).

[0097] Example 13

[0098] The other conditions in Example 11 were kept unchanged, and the time of the in-situ polymerization reaction was changed to 8 h to obtain a biomimetic electrical sensor (labeled as PTH3@Rf@RBC).

[0099] The other conditions in Example 1 are kept unchanged, Rf is not added, and spare red blood cells are selected to replace the bionic red blood cells, and react with dopamine to obtain PDA1@RBC; similarly, PDA2@RBC and PDA3@RBC are obtained; the bionic electrical sensors prepared in Examples 1 to 3 and the control samples are suspended in water for spectral characterization using a Shimadzu UV-3600 ultraviolet-visible-near infrared spectrometer, and the control samples contain PDA1@RBC, PDA2@RBC, PDA3@RBC, the red blood cells (RBC) separated in Example 1, and Rf, and the ultraviolet-visible spectral characterization diagrams of the bionic electrical sensors obtained in Examples 1 to 3 and the control samples are obtained, as shown in FIG. Figure 1 shown; from Figure 1It can be seen that the absorption wavelengths of Rf are 222nm, 268nm, 355nm and 442nm respectively. The bionic electrical sensors prepared in Examples 1 to 3 all have characteristic signals of Rf, indicating that PDA1@Rf@RBC, PDA2@Rf@RBC and PDA3@Rf@RBC were successfully prepared. In addition, due to the different dosages of dopamine, the characteristic signals of Rf in PDA1@Rf@RBC, PDA2@Rf@RBC and PDA3@Rf@RBC gradually weakened.

[0100] The oxygen carrying capacity of the bionic electrical sensors prepared in Examples 1 to 3 was evaluated using a dissolved oxygen tester (Vernier, USA). Specifically, a certain volume of PBS (1×) solution was added to a closed container, O2 was introduced, and the change of the O2 content in the solution was monitored using the dissolved oxygen tester; at the same time, the concentration of O2 in the solution was controlled (oxygen was stopped at a certain concentration before saturation), and the same volume of the sample to be tested (PDA1@Rf@RBC, PDA2@Rf@RBC, PDA3@Rf@RBC) was added, and the change of the O2 concentration in the solution was observed through the sensor signal to obtain the oxygen absorption-release curve of the bionic electrical sensors obtained in Examples 1 to 3, as shown in FIG. Figure 2 As shown. Figure 2 It can be seen that PDA2@Rf@RBC has obvious oxygen absorption behavior and has good continuous oxygen release ability during the oxygen release stage.

[0101] The PDA2@Rf@RBC prepared in Example 2 was washed 3 to 5 times by centrifugation with secondary water. An appropriate amount of the washed PDA2@Rf@RBC was mixed with a small amount of secondary water to obtain a PDA2@Rf@RBC solution for later use. The conductive glue was adhered to the sample table, and an appropriate amount of the above-mentioned evenly dispersed PDA2@Rf@RBC solution was dripped on the conductive glue. It was naturally dried at room temperature. After gold spraying, it was measured using a JSM-6701F field emission scanning electron microscope produced by Japan Co., Ltd. In addition, the red blood cells (RBC) separated in Example 1 were measured using the same method to obtain field emission scanning electron microscope characterization images of PDA2@Rf@RBC and RBC, as shown in the figure. Figure 3 As shown; Figure 3In the figure, (a) is a field emission scanning electron microscopy image of PDA2@Rf@RBC at a 2μm scale, (b) is a field emission scanning electron microscopy image of PDA2@Rf@RBC at a 1μm scale, (c) is a field emission scanning electron microscopy image of PDA2@Rf@RBC at a 0.5μm scale, (d) is a field emission scanning electron microscopy image of RBC at a 2μm scale, (e) is a field emission scanning electron microscopy image of RBC at a 1μm scale, and (f) is a field emission scanning electron microscopy image of RBC at a 0.5μm scale. Figure 3 As can be seen from the figure, the surface of PDA2@Rf@RBC and natural RBC are significantly different. The surface of natural RBC is smooth, while the surface of PDA2@Rf@RBC becomes rough due to the coating of the conductive polymer PDA nanolayer.

[0102] The PDA2@Rf@RBC prepared in Example 2 was washed 3 to 5 times by centrifugation with secondary water. An appropriate amount of the washed PDA2@Rf@RBC was mixed with a small amount of secondary water to obtain a PDA2@Rf@RBC solution for later use. An appropriate amount of the above-mentioned evenly dispersed PDA2@Rf@RBC solution was dripped onto a copper mesh, dried naturally at room temperature, and measured using a JEM-2100 transmission electron microscope manufactured by Hitachi. In addition, the red blood cells (RBC) separated in Example 1 were measured using the same method to obtain high-resolution transmission electron microscope characterization images of PDA2@Rf@RBC and RBC, as shown in FIG. Figure 4 As shown; Figure 4 In the figure, (a) is a high-resolution transmission electron microscopy image of PDA2@Rf@RBC at a 1μm scale, (b) is a high-resolution transmission electron microscopy image of PDA2@Rf@RBC at a 20nm scale, (c) is a high-resolution transmission electron microscopy image of RBC at a 1μm scale, and (d) is a high-resolution transmission electron microscopy image of RBC at a 20nm scale. Figure 4 It can be seen that the rough surface of PDA2@Rf@RBC is a PDA coating formed by nanoparticles with a particle size of about 20 nm; while the cell surface of natural RBC is smooth and no nanoparticles can be seen on the cell surface.

[0103] The CV method was used in the presence of 0.1 mol / L KCl, 5.0 mM [Fe(CN)6] 3- / [Fe(CN)6] 4- The electrochemical properties of PDA2@Rf@RBC prepared in Example 2 were studied in a solution containing 0.1 mol / L KCl, 5.0 mM [Fe(CN)6]3- / [Fe(CN)6] 4- In the solution, the impedance change of the glassy carbon electrode surface during the electrochemical process was further characterized in the fixed frequency range of 10kHz to 1Hz. The same method was used to measure riboflavin (Rf) and blank samples. Riboflavin (Rf) is the glassy carbon electrode modified with Rf, and the blank sample is the bare glassy carbon electrode (GCE). The electrochemical impedance characteristics characterization diagram of PDA2@Rf@RBC, Rf and GCE was obtained, as shown in Figure 5 As shown; Figure 5 In the figure, (a) is the cyclic voltammetry curve of PDA2@Rf@RBC, Rf and GCE, and (b) is the impedance diagram of PDA2@Rf@RBC, Rf and GCE. As can be seen from (a), there is a pair of clear redox peaks on the bare glassy carbon electrode (GCE); compared with GCE, the redox peak current increases after PDA2@Rf@RBC modification, indicating that the specific surface area of ​​the electrode can be improved after PDA2@Rf@RBC modification. However, after Rf is modified on the electrode, the redox peak current decreases because Rf is a material with poor redox activity. As can be seen from (b), compared with bare GCE, the resistance of PDA2@Rf@RBC / GCE is significantly reduced, and the resistance of Rf / GCE increases. The results show 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 the results in (a).

[0104] The electrochemical behavior of PDA2@Rf@RBC was studied by CV method. Specifically, the electrodes modified with each sample were tested in 0.1 M PBS buffer (pH 7.0) with a scan rate of 100 mV·s -1 , wherein the sample includes Rf, Rf@RBC prepared in Example 1, PDA2@RBC, and PDA2@Rf@RBC. The sample is added to a 0.5% Nafion aqueous solution to obtain a mixed solution. An appropriate amount of the mixed solution is dropped on a glassy carbon electrode. After drying, the mixture is tested in a three-electrode system (a platinum electrode as a counter electrode, an Ag / AgCl electrode as a reference electrode, and a glassy carbon electrode as a working electrode). In addition, differential pulse voltammetry (DPVs) is used to detect Sar in PBS to obtain electrochemical behavior characterizations of different samples and electrochemical response characterization diagrams of PDA2@Rf@RBC to Sar, as shown in FIG. Figure 6 As shown; Figure 6In the figure, (a) is a characterization diagram of the electrochemical behavior of different samples, and (b) is a characterization diagram of the electrochemical response of PDA2@Rf@RBC to Sar. As can be seen from (a), 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 the biomimetic electrical sensor we synthesized can improve the redox ability of Rf. In addition, after PDA modification, the peak current enhancement indicates that the conductive polymer can improve the conductivity of the sensor. As can be seen from (b), compared with before the addition of 10nM Sar (black line), the cathode peak current is significantly reduced after the addition of 10nM Sar (red line). Therefore, the reduction of current change (ΔI) can be used to provide a reference for the quantitative analysis of Sar in this work.

[0105] The DPVs of PDA2@Rf@RBC were studied for quantitative detection of Sar at different concentrations, and the differential pulse voltammograms of PDA2@Rf@RBC were obtained, as shown in Figure 7 As shown; Figure 7In the figure, (a) is a schematic diagram of the DPVs of PDA2@Rf@RBC in different Sar concentrations, (b) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (0.01~0.1μmol / L), (c) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (100~1000μmol / L), and (d) is a linear graph of the response of PDA2@Rf@RBC in different Sar concentrations (1000~10000μmol / L). In (a), as the arrows in the figure point, the Sar concentration gradually increases; from (a), it can be seen that in the ranges of 0, 10, 30, 50, 60, 70, 80, 90nM, 0.1, 0.2, 0.5, 1.0, 5.0, 10μM and 0.1, 0.5, 0.6, 0.7, 0.8, 1.0, 3.0, 4.0, 8.0, 10mM, the peak current decreases with the increase of Sar concentration. Therefore, in this work, the reduction of current change (ΔI) was used for Sar quantification. From (b) to (d), it can be seen that ΔI and Sar concentration show a good linear correlation in the range of 0.01 to 0.1μmol / L, 100 to 1000μmol / L, and 1000 to 10000μmol / L. The linear regression equations are: 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 can be seen that PDA2@Rf@RBC has a lower detection range. At the same time, the sensor is green, environmentally friendly, low-cost, easy to test, and highly stable, overcoming the shortcomings of traditional sensors with high cost and poor stability.

[0106] In order to test the electrocatalytic stability of PDA2@Rf@RBC, the electrochemical stability of PDA2@Rf@RBC was tested in a three-electrode test system (platinum electrode as counter electrode, Ag / AgCl electrode as reference electrode, PDA2@Rf@RBC modified glassy carbon electrode as working electrode) using the chronoamperometry (It) method in 0.1 M 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. Figure 8 It can be seen that the current of PDA2@Rf@RBC remains stable after running for 40,000 seconds. The test results show that PDA2@Rf@RBC has good electrochemical stability.

[0107] The electrochemical behaviors of PPy3@Rf@RBC, PANI2@Rf@RBC, and PTH2@Rf@RBC were studied by CV method. Specifically, the electrodes modified with each sample were tested in 0.1 M PBS buffer (pH 7.0) with a scan rate of 100 mV·s -1 , take the sample and add it to 0.5% Nafion aqueous solution to obtain a mixed solution, take an appropriate amount of the mixed solution and drop it on the glassy carbon electrode. After drying, test it in a three-electrode system (platinum electrode as counter electrode, Ag / AgCl electrode as reference electrode and glassy carbon electrode as working electrode) to obtain electrochemical behavior characterization diagrams of different samples, such as Fig. 9 As shown; Fig. 9 In the figure, (a) is the electrochemical behavior characterization diagram of PPy3@Rf@RBC, (b) is the electrochemical behavior characterization diagram of PANI2@Rf@RBC, and (c) is the electrochemical behavior characterization diagram of PTH2@Rf@RBC. Fig. 9 It can be seen that after adding pyrrole, aniline and thiophene, the redox peaks of Rf all shifted positively to a certain extent, indicating that the synthesized biomimetic electrical sensor can improve the redox ability of Rf. In addition, the redox current of Rf was enhanced to varying degrees, indicating that the in-situ polymerization of conductive polymers can improve the conductivity of the sensor.

[0108] It can be seen from the above embodiments that the present invention provides a method for preparing a bionic electrical sensor, comprising the following steps: mixing a red blood cell solution and a bionic active substance, co-incubating, to obtain bionic red blood cells; mixing the bionic red blood cells with a conductive polymer (the conductive polymer includes dopamine, pyrrole, aniline or thiophene), performing an in situ polymerization reaction, and obtaining a bionic electrical sensor. The bionic electrical sensor combines a conductive polymer with a natural cell, utilizes the excellent conductive properties of the conductive polymer, and based on the high oxygen microenvironment of the cell, enables the bionic active substance to have better electrocatalytic properties, which can be used for rapid, sensitive and efficient monitoring of Sar. The bionic electrical sensor prepared by the present invention has different trends in the change of the electrochemical signal intensity when the concentration of Sar is different, and can achieve ultra-sensitive detection of the Sar content. The bionic electrical sensor of the present invention has the advantages of fast response speed, low cost, easy miniaturization, good biocompatibility, and simple sample pretreatment. It is a very promising Sar detection and analysis tool, which can provide a new, fast, accurate and stable diagnostic tool for the incidence and development of prostate diseases, thereby achieving the ultimate purpose of reversing or preventing the progression of the disease, and has important practical significance.

[0109] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a bionic electric sensor, characterized in that: It includes the following steps: (1) mixing a red blood cell solution and a biomimetic active substance, and co-incubating them to obtain biomimetic red blood cells; (2) mixing the bionic red blood cells with the conductive polymer and performing an in-situ polymerization reaction to obtain the bionic electrical sensor; The conductive polymer in step (2) includes dopamine, pyrrole, aniline or thiophene.

2. The method for preparing the bionic electric sensor according to claim 1, characterized in that: The red blood cell solution in step (1) comprises 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%; and the biomimetic active substance is riboflavin; The mass volume ratio of the red blood cell solution and the biomimetic active substance is 7-11 mL:7-11 mg.

3. The method for preparing the bionic electric sensor according to claim 1 or 2, characterized in that: The co-incubation temperature in step (1) is 2 to 6° C., and the co-incubation time is 3 to 12 hours.

4. The method for preparing the bionic electric sensor according to claim 3, characterized in that: When the conductive polymer in step (2) is dopamine, the biomimetic red blood cells, Tris-HCl buffer and dopamine are mixed and subjected to in-situ polymerization reaction 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 active substance in step (1) is 40-50 mL: 5-50 mg: 7-11 mg; The temperature of the in-situ polymerization reaction is -2 to 2°C, and the time of the in-situ polymerization reaction is 3 to 12 hours.

5. The method for preparing the bionic electric sensor according to claim 1 or 4, characterized in that: When the conductive polymer in step (2) is pyrrole, the bionic red blood cells and the pyrrole solution are mixed and subjected to in-situ polymerization reaction to obtain a bionic electrical sensor; The pyrrole solution comprises PBS buffer, potassium ferrocyanide and pyrrole, wherein the pH value 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 volume ratio of the pyrrole solution to the biomimetic active substance in step (1) is 10-30 mL:7-11 mg; The temperature of the in-situ polymerization reaction is 25-35° C., and the time of the in-situ polymerization reaction is 1.5-2.5 hours.

6. The method for preparing the bionic electric sensor according to claim 5, characterized in that: When the conductive polymer in step (2) is aniline, the bionic red blood cells, the aniline solution and the oxidant solution are mixed to perform an in-situ polymerization reaction to obtain a bionic electrical sensor; The aniline solution comprises aniline, tartaric acid and water, wherein 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 oxidant solution is an ammonium persulfate solution, and the mass concentration of the ammonium persulfate solution is 1.67-5 mg / mL; the mass volume ratio of the aniline solution, the oxidant solution and the biomimetic active substance in step (1) is 4-6 mL: 5-7 mL: 7-11 mg; The temperature of the in-situ polymerization reaction is -2 to 2°C, and the time of the in-situ polymerization reaction is 6 to 24 hours.

7. The method for preparing the bionic electric sensor according to claim 6, characterized in that: In step (2), when the conductive polymer is thiophene, the bionic red blood cells, thiophene solution and ferric chloride are mixed to perform an in-situ polymerization reaction to obtain a bionic 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 the thiophene solution, ferric chloride and the biomimetic active substance in step (1) is 10-15 mL: 10-15 mg: 7-11 mg; The temperature of the in-situ polymerization reaction is 25-30° C., and the time of the in-situ polymerization reaction is 2-8 hours.

8. A bionic electric sensor prepared by the method for preparing a bionic electric sensor according to any one of claims 1 to 7.

9. Use of the bionic electrical sensor according to claim 8 in ultrasensitive detection of sarcosine.

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