A method for preparing a lung cancer exosome sensing electrode

Abstract

This invention belongs to the field of electrochemical detection technology and relates to a lung cancer exosome detection sensor based on a platinum-iron nanowire-coated Prussian blue composite material. Using platinum acetylacetonate as the platinum source, iron acetylacetonate as the iron source, and ethylene glycol as the reducing agent, a platinum-iron nanowire structure was synthesized via a hydrothermal method, followed by ultrasonic etching with dilute hydrochloric acid solution. Potassium ferrocyanide was added dropwise to the etched solution using a micro-synthesis method to obtain the composite material. The composite material solution was then drop-coated onto a bare gold working electrode and dried at room temperature. The electrode was immersed in a PNA probe solution, allowing the PNA probe to spontaneously graft onto the material, and then stored in a refrigerator. This aptamer electrode enables rapid trace detection of lung cancer exosome markers and can be used for early lung cancer detection in medicine.

Description

Technical Field

[0001] This invention belongs to the field of electrochemical technology and relates to a method for preparing a lung cancer exosome sensing electrode. Background Technology

[0002] Exosomes are tiny vesicles with a lipid bilayer membrane structure that can be secreted by most cells in the body. They are widely distributed in body fluids, including blood, tears, urine, saliva, and breast milk, and are rich in bioactive molecules such as nucleic acids, proteins, and lipids. Exosomes frequently travel between cells, providing a bridge for intercellular communication. They have become a hot topic of innovation in research on disease biomarkers, disease mechanisms, and drug development. Exosomes play important roles in the physiological and pathological processes of immunity, including antigen presentation, tumor growth and migration, and tissue repair. Furthermore, exosomes secreted by different cells have different compositions and functions, making them valuable biomarkers for disease diagnosis.

[0003] Currently, lung cancer detection methods mainly include general laboratory tests, imaging examinations, and histological examinations. These methods either require expensive and bulky equipment, are time-consuming and complex to operate, or are harmful to the human body and have significant side effects. Therefore, how to achieve safe, accurate, and efficient detection of lung cancer is a problem we currently face. In recent years, electrochemical sensing for cancer detection has received increasing attention, but its original bare electrode detection is difficult to achieve rapid and sensitive detection. Electrochemical biosensing is a novel technology that converts the target molecule and its reaction signal into an electrical signal, such as capacitance, current, potential, and conductivity, through the specific recognition between biomolecules, thereby achieving rapid and accurate detection of the target analyte. Summary of the Invention

[0004] This invention addresses the problems existing in traditional lung cancer detection systems by proposing a lung cancer exosome detection method based on a platinum-iron nanowire-encapsulated Prussian blue composite material. The purpose of this invention is to fabricate an exosome sensing electrode for the detection of lung cancer markers, thus overcoming the problem of poor sensing performance in existing methods.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] A method for detecting lung cancer exosomes based on platinum-iron nanowires encapsulated with Prussian blue composite material, the specific steps of which are as follows.

[0007] (1) Preparation of Platinum Iron Rice Noodles

[0008] Using platinum acetylacetonate as the platinum source, iron acetylacetonate as the iron source, and ethylene glycol as the reducing agent, a mixed solvent was prepared by mixing potassium hydroxide, DMF (N,N-dimethylformamide), ethylene glycol, oleylamine, and heptanol. Platinum acetylacetonate and iron acetylacetonate were dissolved in the mixed solvent to prepare a reaction solution. The reaction solution was stirred overnight at room temperature and then transferred to a hydrothermal reactor. A platinum-iron nanowire solution was obtained after the hydrothermal synthesis reaction. The platinum-iron nanowire solution was centrifuged and washed to obtain platinum-iron nanowire precipitate.

[0009] (2) Preparation of platinum-iron nanowire-coated Prussian blue composite material

[0010] The obtained platinum-iron nanowire precipitate was dispersed in water; a portion of the dispersion was placed in a dilute hydrochloric acid solution and ultrasonically etched; potassium ferrocyanide solution was added dropwise to the dilute hydrochloric acid dispersion using a micro-rate synthesis method, and the reaction yielded a composite material of platinum-iron nanowires coated with Prussian blue; the solution was centrifuged and washed to obtain the composite material precipitate.

[0011] (3) Fabrication of exosome sensing electrodes for lung cancer

[0012] A composite material of platinum-iron nanowires coated with Prussian blue was added to a suspension of water and chitosan to prepare a mixed solution. The mixture of the composite material was then drop-coated onto the surface of the working electrode and dried at room temperature. The surface of the working electrode was then rinsed with ultrapure water to obtain a lung cancer aptamer sensing electrode modified with platinum-iron-coated Prussian blue composite material.

[0013] As a further improvement of the present invention, in step (1), the concentration of potassium hydroxide in the solvent is 0.5-1M; the volume ratio of each component in the solvent is DMF: ethylene glycol: oleylamine: heptanol = 2:1:4:1; the molar concentrations of platinum acetylacetonate and iron acetylacetonate in the reaction solution are the same; the hydrothermal synthesis temperature is 180-200℃, the hydrothermal synthesis time is 6-10h; the centrifugation rate is 8000r / min, and the centrifugation time is 6min.

[0014] As a further improvement of the present invention, in step (2), the concentration of the dilute hydrochloric acid solution is 0.1-0.5M; the concentration of the platinum-iron nanowire dispersion is 5-8mg / mL; the concentration of the potassium ferrocyanide solution is 10-15mM; the volume ratio of the dispersion, dilute hydrochloric acid solution, and potassium ferrocyanide solution is 1:10:3; the etching time is 0.5-1h; the micro-synthesis reaction is carried out at room temperature and pressure; the dropping rate of the micro-synthesis method is 250-300μL / min; the micro-drop reaction time is 0.5-3h; after the micro-drop is completed, the reaction can be stirred for 5min, then washed with deionized water; the centrifugation rate is 8000r / min; and the centrifugation time is 6min.

[0015] As a further improvement of the present invention, the mass concentration of chitosan in the suspension in step (3) is 1-5%, the mass concentration of platinum-iron nanowires coated with Prussian blue in the composite material mixture solution is 8-15 mg / L, the amount of working electrode coating is 2-5 μL, and the room temperature drying time is 30-50 min.

[0016] This invention provides a lung cancer exosome detection sensor based on platinum-iron nanowire-coated Prussian blue composite material, comprising a lung cancer exosome sensing electrode and a detection marker. The lung cancer exosome electrode uses a gold electrode as the working electrode, a glassy carbon electrode as the counter electrode, and a platinum wire electrode as the reference electrode. The working electrode surface is covered with platinum-iron nanowire-coated Prussian blue composite material. The lung cancer exosome marker is miR-139-5p extracted from exosomes (commercially available).

[0017] In the synthesis of the platinum-iron nanowire-coated Prussian blue composite material of this invention, strict control of hydrochloric acid etching time and micro-synthesis time is required. Etching with dilute hydrochloric acid leads to the formation of free iron ions on the surface of the platinum-iron nanowires, providing conditions for subsequent in-situ growth. Controlling the micro-synthesis time ensures more uniform in-situ growth of Prussian blue on the nanowire surface, preventing agglomeration. In this sensor-modified material, the platinum-iron nanowires exhibit high conductivity, resulting in lower electron transport resistance during sensor detection, shortening the response time. Furthermore, the addition of Prussian blue makes the signal peak more pronounced during the detection process, further enhancing detection performance. Additionally, the sensor detects markers extracted from lung cancer exosomes, achieving good detection results with minimal harm to the human body. The sensor prepared in this invention utilizes base pairing to generate sensing signals for even small amounts of markers, enabling trace detection. Therefore, this invention uses platinum-iron nanowires wrapped in Prussian blue composite material with high conductivity and high catalytic activity as electrode modification material, and exosome extract miR-139-5p as detection marker, to achieve highly sensitive and specific detection of lung cancer.

[0018] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0019] The platinum-iron nanowire-Prussian blue composite material synthesized in this invention has significant advantages. The platinum-iron nanowires possess high conductivity, effectively reducing electron transfer resistance; simultaneously, Prussian blue is a natural catalase with excellent catalytic activity and biocompatibility, enabling better biosensing detection. The combination of these two materials solves the problems of low sensitivity and poor conductivity inherent in electrochemical sensing, while also providing better biocompatibility for subsequent detection. It overcomes the issues of long detection times and significant side effects associated with traditional methods, meeting the clinical requirements for lung cancer exosome detection and making it suitable for large-scale application. Attached Figure Description

[0020] Figure 1 This is a scanning electron microscope image of the platinum-iron nanowires synthesized by hydrothermal method in Example 1.

[0021] Figure 2 This is a scanning electron microscope image of platinum-iron nanowires coated with Prussian blue synthesized by the micro-synthesis method in Example 1.

[0022] Figure 3 This is a TEM scan of platinum-iron nanowires coated with Prussian blue synthesized by the micro-rate synthesis method in Example 1.

[0023] Figure 4 This is a DPV scan of the lung cancer aptamer sensor prepared in Example 1 with different markers. Detailed Implementation

[0024] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described below with reference to specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0025] Numerous specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways than those described herein, and therefore the invention is not limited to the specific embodiments disclosed in the following specification.

[0026] Unless otherwise specified, the preparation process of the lung cancer exosome electrode in the following examples is as follows: Platinum-iron nanowire alloy material with nanowire structure was synthesized via a hydrothermal method using platinum acetylacetonate as the platinum source, iron acetylacetonate as the iron source, and ethylene glycol as the reducing agent (all reagents were purchased from Sinopharm Chemical Reagent Co., Ltd.). A portion of the platinum-iron nanowires was dispersed in a dilute hydrochloric acid solution and ultrasonically etched. Potassium ferrocyanide was added dropwise to the etched solution using a micro-synthesis method to obtain a composite material of platinum-iron nanowires coated with Prussian blue. A certain amount of the composite material was dispersed in a mixed solution of ultrapure water and chitosan to obtain a composite material mixed solution. Using a gold electrode as the working electrode, a glassy carbon electrode as the counter electrode, and a platinum wire electrode as the reference electrode, a certain amount of the composite material mixed solution was drop-coated onto a bare gold working electrode and dried at room temperature for 12 hours. The electrode was immersed in a PNA probe solution to allow the PNA probe to spontaneously graft onto the material, and then stored in a refrigerator at 4°C. Figure 4The DPV characterization method was as follows: First, a phosphate-buffered saline (PBS) solution with a pH of 7.4 was prepared. The three electrodes were then immersed in an electrolytic cell filled with the PBS. The working electrode, reference electrode, and counter electrode, after being immersed in the PNA probe solution, were connected to the interfaces on an electrochemical workstation. The amount of labeled material was varied by adding different concentrations of the labeled material to the electrolytic cell. Finally, the potential window was set to -0.6 to 0 V, and DPV scans were performed at different concentrations of the labeled material. The electrochemical workstation received the current signal generated by the hybridization reaction.

[0027] The PNA probe sequence was 5'-CACAAAT T CGGT TCTACAGG GTA-3', and the detection marker sequence was 5'-UAGCUUAUCAGACUGAUGUUGA-3' (both purchased from Sangon Biotech (Shanghai) Co., Ltd.). The PNA probe was prepared into a 100 μM solution using the purchased DNA preservation solution, and a portion of the solution was diluted to 2 μM for electrode soaking. The concentration range of the detected markers in the following examples is 10. -18 -10 -8 M was detected by adding substances from low to high concentrations using the standard method.

[0028] Example 1

[0029] This embodiment provides a method for preparing a lung cancer exosome sensor based on platinum-iron nanowires encapsulated with Prussian blue composite material, the steps of which are as follows.

[0030] (1) Weigh 1.02g of potassium hydroxide and dissolve it in a mixed solvent (10mL LDMF + 5mL ethylene glycol + 20mL oleylamine + 5mL heptanol), and sonicate for half an hour until the solvent is clear; then weigh 0.059g of platinum acetylacetone and 0.053g of iron acetylacetone and add them to the mixed solution, and stir magnetically at 200 rpm overnight (more than 12h). Then put the reaction solution into a reaction vessel and hydrothermally react at 180℃ for 8h; after the reaction is completed, centrifuge, discard the upper liquid, leave the solid, and then centrifuge (wash) twice with n-hexane, and then centrifuge (wash) three times with ethanol. The centrifugation conditions are all 8000r / min and 6min. After centrifugation, discard the upper liquid to obtain platinum-iron nanowire precipitate. Figure 1 Electron microscopy characterization revealed that the synthesized platinum-iron nanowires exhibited a uniform linear structure.

[0031] (2) The platinum-iron nanowire precipitate obtained in step (1) was dispersed in 20 mL of deionized water. 10 mL of the dispersion was placed in 100 mL of 0.1 M dilute hydrochloric acid solution and ultrasonically etched for 1 h. 0.422 g of potassium ferrocyanide was weighed and dissolved in 100 mL of deionized water. A 10 mM potassium ferrocyanide solution was added dropwise to the etched mixture at a rate of 250 μL / min using a micro-synthesis method. After 1 h of addition, the mixture was stirred for another 5 min at a stirring rate of 250 rpm. After the reaction was completed, the mixture was centrifuged, the supernatant was removed, and the precipitate was washed three times with deionized water. The centrifugation speed in this step was 8000 rpm, and the centrifugation time was 6 min. After centrifugation, the upper liquid was discarded to obtain the platinum-iron nanowire-coated Prussian blue composite material precipitate. Figure 2 Electron microscopy results showed that Prussian blue nanoparticles were attached to the surface of the nanowires; by Figure 3 TEM results showed that Prussian blue was uniformly coated on the surface of platinum-iron nanowires.

[0032] (3) The composite material prepared in step (2) was dispersed in deionized water to prepare a 5 mg / mL dispersion. 2 μL of the dispersion was dropped onto the gold electrode and dried at room temperature for 12 h. The gold electrode was then immersed in a 2 μM PNA probe solution for 20 h (the electrode should be fully submerged) to allow the probe to spontaneously graft onto the material surface. The solution for storing the PNA probe consisted of 10 mM Tris-HCl, 10 mM disodium ethylenediaminetetraacetate, 0.1 M sodium chloride, and 0.286 g TCEP. The grafted probe was then rinsed with deionized water to obtain the lung cancer aptamer electrode, which was stored in a refrigerator at 4 °C.

[0033] (4) Using the gold electrode after the above soaking as the working electrode, the silver chloride electrode as the reference electrode, and the platinum electrode as the counter electrode, differential pulse voltammetry (DPV) was used to detect the labeled substances at different concentrations. A fixed concentration was selected for hybridization time investigation, and detection was performed every five minutes until the DPV curve stabilized, which was the response time of the sensor to the labeled substance. According to the detection results, the detection response time of the aptamer sensor to the labeled substance was 15 min. By investigating the detection linear range of the labeled substance, the results showed that the detection limit reached 3*10 -9 pM. This indicates that the sensor has a fast response time and a low detection limit.

[0034] Depend on Figure 1 SEM characterization showed that the platinum-iron nanowires synthesized in step (1) had a good linear structure and the nanowires were relatively uniform in thickness, which facilitated the subsequent Prussian blue treatment.

[0035] Depend on Figure 2SEM characterization showed that Prussian blue was successfully coated on the surface of the nanowires in the platinum-iron nanowire-coated Prussian blue composite material synthesized in step (2).

[0036] Depend on Figure 3 TEM characterization showed that Prussian blue was more uniformly attached to the surface of the nanowires in the composite material synthesized in step (2), which is beneficial to improving the redox ability of the material.

[0037] Depend on Figure 4 The DPV characterization shows that the prepared lung cancer aptamer sensor has a wide detection range and a low detection limit, which is beneficial for trace detection of lung cancer markers.

[0038] Three concentrations of the labeled sample were prepared in serum using the standard addition method for real sample testing. The results of the real sample testing are shown in Table 1.

[0039] Table 1. Test results of real samples

[0040]

[0041] Table 1 shows the actual sample detection results. When the labeled samples of any three concentrations were prepared in serum using the standard addition method, the sensor's detection results for the actual samples showed a high degree of consistency with the theoretical calculation results, indicating that the lung cancer aptamer sensor has extremely high accuracy in the detection of lung cancer exosomes.

[0042] Example 2

[0043] This embodiment provides a method for detecting lung cancer exosomes based on a platinum-iron nanowire-encapsulated Prussian blue composite material. Unless otherwise specified, this embodiment is consistent with Embodiment 1. The steps are as follows.

[0044] (1) Weigh 1.02g of potassium hydroxide and dissolve it in a mixed solvent (10mL LDMF + 5mL ethylene glycol + 20mL oleylamine + 5mL heptanol). Sonicate for half an hour until the solvent is clear. Then weigh 0.059g of platinum acetylacetone and 0.053g of iron acetylacetone and add them to the mixed solution. Stir magnetically at 200 rpm overnight (more than 12 hours). Then put the reaction solution into the reaction vessel and hydrothermally react at 200℃ for 6 hours. After the reaction is completed, wash twice with n-hexane and then three times with ethanol. Then centrifuge at 8000 rpm for 6 minutes. After centrifugation, discard the upper liquid to obtain platinum-iron nanowire precipitate.

[0045] (2) The platinum-iron nanowire precipitate obtained in (1) was dispersed in 20 mL of deionized water. 10 mL of the dispersion was placed in 100 mL of 0.1 M dilute hydrochloric acid solution and ultrasonically etched for 1 h. 0.422 g of potassium ferrocyanide was weighed and dissolved in 100 mL of deionized water. A 10 mM potassium ferrocyanide solution was added dropwise to the etched mixture at a rate of 400 μL / min using a micro-synthesis method. The micro-reaction time was 0.5 h. The mixture was then washed three times with deionized water and centrifuged. The centrifugation speed was 8000 r / min and the centrifugation time was 6 min. After centrifugation, the supernatant was discarded to obtain the platinum-iron nanowire-coated Prussian blue composite material precipitate.

[0046] (3) The composite material prepared in (2) was dispersed in deionized water to prepare a 5 mg / mL dispersion. 2 μL of the dispersion was dropped onto the gold electrode and dried at room temperature for 12 h. The gold electrode was then immersed in a 2 μM PNA probe solution for 12 h to allow the probe to spontaneously graft onto the material surface. The solution for storing the PNA probe consisted of 10 mM Tris-HCl, 10 mM disodium ethylenediaminetetraacetate, 0.1 M sodium chloride, and 0.286 g TCEP. The grafted probe was rinsed with deionized water to prepare the lung cancer aptamer electrode, which was then stored in a refrigerator at 4 °C.

[0047] (4) Using the gold electrode after the above soaking as the working electrode, the silver chloride electrode as the reference electrode, and the platinum electrode as the counter electrode, differential pulse voltammetry (DPV) was used to detect the labeled substances at different concentrations. A fixed concentration was selected to investigate the hybridization time. Detection was performed every five minutes until the DPV curve stabilized, which was taken as the response time of the sensor to the labeled substance. According to the detection results, the detection response time of the aptamer sensor to the labeled substance was 18 minutes. By investigating the linear range of the labeled substance detection, the results showed that the detection limit reached 3*10 -9 pM. This indicates that the sensor has a fast response time and a low detection limit.

[0048] Example 3

[0049] This embodiment provides a method for detecting lung cancer exosomes based on a platinum-iron nanowire-encapsulated Prussian blue composite material. Unless otherwise specified, this embodiment is consistent with Embodiment 1. The steps are as follows.

[0050] (1) Weigh 1.02g of potassium hydroxide and dissolve it in a mixed solvent (10mL LDMF + 5mL ethylene glycol + 20mL oleylamine + 5mL heptanol). Sonicate for half an hour until the solvent is clear. Then weigh 0.059g of platinum acetylacetone and 0.053g of iron acetylacetone and add them to the mixed solution. Stir magnetically at 200 rpm overnight (more than 12 hours). Then put the reaction solution into the reaction vessel and hydrothermally react at 200℃ for 6 hours. After the reaction is completed, wash twice with n-hexane and then three times with ethanol. Then centrifuge at 8000 rpm for 6 minutes. After centrifugation, discard the upper liquid to obtain platinum-iron nanowire precipitate.

[0051] (2) The platinum-iron nanowire precipitate obtained in (1) was dispersed in 20 mL of deionized water. 10 mL of the dispersion was placed in 100 mL of 0.1 M dilute hydrochloric acid solution and ultrasonically etched for 1 h. 0.422 g of potassium ferrocyanide was weighed and dissolved in 100 mL of deionized water. A 10 mM potassium ferrocyanide solution was added dropwise to the etched mixture at a rate of 150 μL / min using a micro-synthesis method. The micro-reaction time was 2 h. Afterward, the mixture was washed three times with deionized water and then centrifuged. The centrifugation speed was 8000 r / min and the centrifugation time was 6 min. After centrifugation, the supernatant was discarded to obtain the platinum-iron nanowire-coated Prussian blue composite material precipitate.

[0052] (3) The composite material prepared in (2) was dispersed in deionized water to prepare a 5 mg / mL dispersion. 2 μL of the dispersion was dropped onto the gold electrode and dried at room temperature for 12 h. The gold electrode was then immersed in a 2 μM PNA probe solution for 48 h to allow the probe to spontaneously graft onto the material surface. The solution for storing the PNA probe consisted of 10 mM Tris-HCl, 10 mM disodium ethylenediaminetetraacetate, 0.1 M sodium chloride, and 0.286 g TCEP. The grafted probe was rinsed with deionized water to prepare the lung cancer aptamer electrode, which was then stored in a refrigerator at 4 °C.

[0053] (4) Using the gold electrode after the above soaking as the working electrode, the silver chloride electrode as the reference electrode, and the platinum electrode as the counter electrode, differential pulse voltammetry (DPV) was used to detect the labeled substances at different concentrations. A fixed concentration was selected for hybridization time investigation, and detection was performed every five minutes until the DPV curve stabilized, which was the response time of the sensor to the labeled substance. According to the detection results, the detection response time of the aptamer sensor to the labeled substance was 15 min. By investigating the detection linear range of the labeled substance, the results showed that the detection limit reached 3*10 -9 pM. This indicates that the sensor has a fast response time and a low detection limit.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments for application in other fields. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing a lung cancer exosome sensing electrode, characterized by, The steps are as follows: (1) Preparation of platinum-iron nanowires Potassium hydroxide, DMF, ethylene glycol, oleylamine and heptanol are mixed to obtain a mixed solution A, and then acetylacetone platinum and acetylacetone iron are added to obtain a reaction solution. After stirring at room temperature overnight, the reaction solution is transferred into a hydrothermal kettle for hydrothermal synthesis reaction to obtain a platinum-iron nanowire solution. The solution is centrifuged and washed to obtain a platinum-iron nanowire precipitate; (2) Preparation of platinum-iron nanowire wrapped Prussian blue composite material The platinum-iron nanowire precipitate is dispersed in water to obtain a dispersion solution. The dispersion solution is added to a dilute hydrochloric acid solution, ultrasonic etching is performed, and a potassium ferrocyanide solution is added dropwise to perform a micro-rate synthesis reaction to obtain a platinum-iron nanowire wrapped Prussian blue composite material. The composite material is centrifuged and washed to obtain a composite material precipitate; (3) The composite material precipitate is added to a suspension liquid composed of water and chitosan to obtain a mixed solution B. The working electrode of a bare carbon chip is washed with ultrapure water, and the mixed solution B is added dropwise to the surface of the working electrode. The working electrode is dried at room temperature, and then the surface of the working electrode is washed with ultrapure water to obtain a sensing electrode. The sensing electrode is immersed in a PNA probe solution to allow the PNA probe to spontaneously graft onto the material. Subsequently, the PNA probe solution is stored at 5-8°C. The concentration of the PNA probe solution is 2 μM. The sequence of the PNA probe is 5'-CACAAAT T CGGT TCTACAGG GTA-3', and the sequence of the detection marker is 5'-UAGCUUAUCAGACUGAUGUUGA-3'.

2. The method for preparing the lung cancer exosome sensing electrode according to claim 1, characterized in that, In step (1), the volume ratio of DMF, ethylene glycol, oleylamine and heptanol is 2:1:4:

1. The concentration of potassium hydroxide in the mixed solution A is 0.5-1.0 M. The concentration of acetylacetone platinum and acetylacetone iron in the reaction solution is 5-10 mM. The hydrothermal synthesis temperature is 180-200°C, and the hydrothermal synthesis time is 6-10 h.

3. The method for preparing the lung cancer exosome sensing electrode according to claim 1, characterized in that, In step (2), the concentration of the dilute hydrochloric acid solution is 0.1-0.5 M. The concentration of the platinum-iron nanowire dispersion solution is 5-8 mg / mL. The concentration of the potassium ferrocyanide solution is 10-15 mM. The volume ratio of the dispersion solution, the dilute hydrochloric acid solution and the potassium ferrocyanide solution is 1:10:

3. The ultrasonic etching time is 0.5-1 h. The dropping speed of the potassium ferrocyanide solution is 250-300 μL / min. The micro-rate synthesis reaction time is 0.5-3 h.

4. The method for preparing the lung cancer exosome sensing electrode according to claim 1, characterized in that, In step (3), the mass fraction of chitosan in the suspension liquid is 1-5%. The mass concentration of the composite material precipitate in the mixed solution B is 8-15 mg / mL. The drop coating amount is 2-5 μL. The room temperature drying time is 30-50 min.

Images