Memristor for detecting pleural effusion and preparation method thereof

Abstract

The invention belongs to the technical field of in-vitro diagnostic devices, and particularly relates to a memristor for detecting pleural effusion and a preparation method of the memristor. The memristor comprises a transparent glass electrode, an inorganic oxide layer and a metal electrode which are sequentially formed from bottom to top, the transparent glass electrode is an FTO electrode or an ITO electrode, and the inorganic oxide layer comprises a Fe2O3 oxide layer and a SiO2 oxide layer which are arranged from bottom to top. The inorganic oxide composite functional layer with the memristive effect is formed by the Fe2O3 / SiO2 oxide composite layer, the interior of the inorganic oxide composite functional layer is polarized after the inorganic oxide composite functional layer is in contact with malignant pleural effusion or tuberculous pleural effusion, so that the bioelectric effect is generated, the detection sensitive layer is formed, and good matching is formed through the work function of the transparent glass electrode and the Fe2O3 / SiO2 oxide composite layer, so that the detection sensitivity is improved. The electrochemical performance is excellent, and the huge potential for detecting TPE or MPE is shown.

Description

Technical Field

[0001] The present invention belongs to the technical field of in vitro diagnostic devices, and particularly relates to a memristor for detecting pleural effusion and a preparation method thereof. Background Art

[0002] Pleural effusion refers to the abnormal accumulation of fluid in the pleural cavity. Normally, the pleural cavity (a potential space between the lung and the chest wall) contains a small amount of lubricating fluid, and its production and absorption are in dynamic balance. When this balance is disrupted due to diseases or pathological factors, resulting in excessive fluid production or slow absorption, pleural effusion will form. Clinically, tuberculous pleural effusion (TPE) and malignant pleural effusion (MPE) are more common.

[0003] Currently, the clinical detection methods for TPE include routine examination of pleural effusion, five biochemical tests, mycobacterium tuberculosis culture, bacterial smear (acid-fast staining), tuberculous infection T-cell detection, and pleural biopsy by thoracentesis. Although pleural biopsy is the gold standard for the diagnosis of tuberculous pleurisy and TPE, there is still a possibility that the tissue sample obtained by puncture is not infected with mycobacterium tuberculosis; the results of mycobacterium tuberculosis culture and bacterial smear of pleural effusion may both be negative; the remaining detection methods all have a certain false positive rate, which is a sufficient but unnecessary condition for the diagnosis of tuberculous pleurisy.

[0004] MPE, also known as cancerous pleural effusion, accounts for 38% - 53% of all pleural effusions. It is a disease caused by primary malignant tumors of the pleura or metastasis of malignant tumors from other parts to the pleura. Currently, the clinical detection methods for MPE include routine examination of pleural fluid by thoracentesis, five biochemical tests, imaging examination, medical thoracoscopy, bronchoscopy, and pathological biopsy of pleural tissue obtained by fine needle aspiration guided by ultrasound or CT. Although pleural biopsy is the gold standard for the diagnosis of MPE, there is still a possibility that the tissue sample obtained by puncture is non-lesional tissue; the biochemical and cytological tests of pleural effusion can both show negative results or false positives, which is a sufficient but unnecessary condition for the diagnosis of MPE.

[0005] In summary, the existing clinical detection and diagnosis methods for TPE or MPE in pleural effusion still rely on pathological examination. This method is usually time-consuming and has a certain false positive rate. Therefore, how to quickly and highly sensitively detect TPE or MPE is an urgent problem to be solved at present, which can promote timely treatment and ultimately improve patient care. Summary of the Invention

[0006] To solve the above problems, the present invention provides a memristor for detecting pleural effusion and a preparation method thereof. The memristor of the present invention is based on a multi-layer oxide functional layer. The Fe2O3 oxide layer and the SiO2 oxide layer form a Fe2O3 / SiO2 oxide composite layer. The Fe2O3 / SiO2 oxide composite layer forms an inorganic oxide composite functional layer with memristive effect. After contacting with malignant pleural effusion or tuberculous pleural effusion, the Fe2O3 / SiO2 oxide composite layer is polarized inside, resulting in the generation of a bioelectric effect, forming a detection sensitive layer. And through the good matching of the work function between the transparent glass electrode and the Fe2O3 / SiO2 oxide composite layer, it has excellent electrochemical performance and shows great potential for detecting TPE or MPE.

[0007] The present invention solves the above technical problems through the following technical solutions.

[0008] The first object of the present invention is to provide a memristor, which includes a transparent glass electrode, an inorganic oxide layer and a metal electrode sequentially arranged from bottom to top. The transparent glass electrode is an FTO electrode or an ITO electrode, and the inorganic oxide layer is a Fe2O3 oxide layer and a SiO2 oxide layer arranged from bottom to top.

[0009] Further, the thickness of the transparent glass electrode is 200 nm to 300 nm.

[0010] Further, the thickness of the inorganic oxide layer is 320 nm to 380 nm.

[0011] Further, the thickness ratio of the Fe2O3 oxide layer to the SiO2 oxide layer is 9:6 to 11.

[0012] Further, the metal electrode is an Ag electrode, and the thickness of the Ag electrode is 500 nm to 600 nm.

[0013] The second object of the present invention is to provide a preparation method of the above memristor, including the following steps: S1. By means of magnetron sputtering, a transparent glass electrode is sputtered and deposited on a glass substrate.

[0014] S2. By means of magnetron sputtering, a Fe2O3 oxide layer and a SiO2 oxide layer are sequentially deposited on the transparent glass electrode to obtain an inorganic oxide layer.

[0015] S3. A metal mask plate with openings is covered on the SiO2 oxide layer. By means of DC sputtering, a metal electrode is deposited in the openings of the metal mask plate, and the metal mask plate is removed to obtain a memristor.

[0016] Further, during the magnetron sputtering process, the target-substrate distance is 8 cm to 12 cm, and the vacuum degree is 3×10 -4 Pa to 4×10 -4 Pa, the working gas is argon, the sputtering gas pressure is 0.6 Pa to 0.8 Pa, the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 45 min to 55 min.

[0017] Further, during the DC sputtering process, the target-substrate distance is 8 cm to 12 cm, and the vacuum degree is 2×10 -4 Pa to 3×10 -4 Pa, the working gas is argon, the sputtering gas pressure is 0.5 Pa to 0.6 Pa, the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 12 min to 15 min.

[0018] The present invention has the following beneficial effects compared with the prior art: The memristor based on the multi-layer oxide functional layer provided by the present invention includes a transparent glass electrode, an inorganic oxide layer, and a metal electrode that are sequentially formed from bottom to top. The transparent glass electrode is an FTO electrode or an ITO electrode. The inorganic oxide layer is an Fe2O3 oxide layer and an SiO2 oxide layer that are arranged from bottom to top. The Fe2O3 oxide layer and the SiO2 oxide layer form an Fe2O3 / SiO2 oxide composite layer, and an inorganic oxide composite functional layer with a memristive effect is formed based on the Fe2O3 / SiO2 oxide composite layer. Based on oxygen vacancy migration and interface charge regulation, among them, Fe2O3 is an n-type semiconductor rich in oxygen vacancies. Under the action of an electric field, oxygen vacancies migrate and move towards the SiO2 interface to form a local conductive channel. SiO2 is used as an insulating layer to limit the vacancy migration path and prevent the overgrowth of filaments. When a reverse voltage is applied, the vacancies are drawn back to the Fe2O3 layer and the filaments break, and the resistance returns to the high-resistance state. Therefore, after the Fe2O3 / SiO2 oxide composite layer contacts malignant pleural effusion or tuberculous pleural effusion, polarization occurs inside, resulting in the generation of a bioelectric effect, forming a detection sensitive layer, and having a good match through the work function of the transparent glass electrode and the Fe2O3 / SiO2 oxide composite layer, having excellent electrochemical performance. According to the electrical signal differences of pleural effusion, cells can be effectively distinguished, with good sensitivity, obvious effects, and good repeatability, showing great potential for detecting TPE or MPE. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic structural diagram of the memristor of the present invention.

[0020] Among them, 1 is a transparent glass electrode, 2 is an inorganic oxide layer, and 3 is a metal electrode.

[0021] Figure 2 It is an analysis diagram of the memristive characteristics of the Ag / SiO2 / Fe2O3 / FTO memristive device prepared in Example 1 of the present invention before the dropwise addition of tuberculous pleural effusion. Among them Figure 2 in (a) is the typical I-V curve of the device before the addition of tuberculous pleural effusion, and (b) is the typical semi-logarithmic I-V curve of the device after the addition of tuberculous pleural effusion; (c) is the analysis of the retention characteristics of the device for 100 cycles.

[0022] Figure 3 It is the stability analysis of the Ag / SiO2 / Fe2O3 / FTO memristive device prepared in Example 1 of the present invention after the dropwise addition of tuberculous pleural effusion. Among them Figure 3 in (a) is the typical I-V curve of the device after the liquid drop is added; (b) is the typical semi-logarithmic I-V curve of the device after the addition of tuberculous pleural effusion; (c) is the analysis of the retention characteristics of the device for 100 cycles.

[0023] Figure 4 It is the memristive characteristic analysis of the Ag / SiO2 / Fe2O3 / ITO memristive device prepared in Example 2 of the present invention before the dropwise addition of malignant pleural effusion. Among them Figure 4 in a is the typical I-V curve of the device before and after the addition of malignant pleural effusion; b is the typical semi-logarithmic I-V curve of the device before and after the addition of malignant pleural effusion.

[0024] Figure 5 It is the stability analysis of the Ag / SiO2 / Fe2O3 / ITO memristive device prepared in Example 2 of the present invention before and after the dropwise addition of tuberculous pleural effusion. Among them Figure 5 in a is the typical I-V curve of the device before and after the addition of tuberculous pleural effusion; b is the typical semi-logarithmic I-V curve of the device before and after the addition of tuberculous pleural effusion. Detailed implementation manners

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0026] On the one hand, the present invention provides a memristor for detecting pleural effusion, such as Figure 1As shown in the figure, it includes a transparent glass electrode 1, an inorganic oxide layer 2, and a metal electrode 3 that are sequentially arranged from bottom to top. The transparent glass electrode 1 is an FTO electrode or an ITO electrode, and the inorganic oxide layer 2 is an Fe2O3 oxide layer and a / SiO2 oxide layer arranged from bottom to top.

[0027] The memristor based on a multi-layer oxide functional layer provided by the present invention includes a transparent glass electrode 1, an inorganic oxide layer 2, and a metal electrode 3 that are sequentially arranged from bottom to top. The transparent glass electrode 1 is an FTO electrode or an ITO electrode, and the inorganic oxide layer 2 is an Fe2O3 oxide layer and a SiO2 oxide layer arranged from bottom to top. The Fe2O3 oxide layer and the SiO2 oxide layer form an Fe2O3 / SiO2 oxide composite layer, and an inorganic oxide composite functional layer with a memristive effect is formed by the Fe2O3 / SiO2 oxide composite layer. Based on oxygen vacancy migration and interface charge regulation, among them, Fe2O3 is an n-type semiconductor rich in oxygen vacancies. Under the action of an electric field, oxygen vacancies migrate and move towards the SiO2 interface to form a local conductive channel. SiO2 is used as an insulating layer to limit the vacancy migration path and prevent the overgrowth of filaments. When a reverse voltage is applied, the vacancies migrate back to the Fe2O3 layer under the drive of the voltage, and the conductive filaments break, and the resistance returns to the high-resistance state. Therefore, after the Fe2O3 / SiO2 oxide composite layer contacts malignant pleural effusion or tuberculous pleural effusion, polarization occurs inside, resulting in the generation of a bioelectric effect, forming a detection sensitive layer, and having a good match through the work function of the transparent glass electrode and the Fe2O3 / SiO2 oxide composite layer, having excellent electrochemical performance. According to the electrical signal differences of pleural effusion, cells can be effectively distinguished, with good sensitivity, obvious effects, and good repeatability, showing great potential for detecting TPE or MPE.

[0028] In a specific embodiment, the thickness of the transparent glass electrode 1 is 200 nm to 300 nm.

[0029] In a specific embodiment, the thickness of the inorganic oxide layer 2 is 320 nm to 380 nm.

[0030] In a specific embodiment, the metal electrode 3 is an Ag electrode, and the thickness of the Ag electrode is 500 nm to 600 nm.

[0031] In the present invention, for the memristor based on a multi-layer oxide functional layer, the performance of the memristor also depends on the thickness of each layer. By precisely regulating the thickness matching and interface engineering, reversible changes in resistance can be achieved. Through biofunctionalization and its unique resistance change characteristics, polarization can occur inside after contact with malignant pleural effusion or tuberculous pleural effusion, thereby causing changes in the resistance of the memristor, and further being reflected as its memristive behavior. According to the electrical signal differences of pleural effusion, cells can be effectively distinguished, and the effects are obvious.

[0032] In a specific embodiment, the thickness ratio of the Fe2O3 oxide layer to the SiO2 oxide layer is 9:6 to 11. In the present invention, the thickness ratio of Fe2O3 (n-type semiconductor) to SiO2 (insulator) can ensure the optimization of carrier distribution through the interfacial polarization effect, reduce the baseline noise during the reading of microvolt-level bio-signals. In a preferred embodiment, the thickness ratio of the Fe2O3 oxide layer to the SiO2 oxide layer is 9:8, and this ratio can reduce the density of interfacial trap states by about 30%, reducing the background interference in the acquisition of bioelectric signals.

[0033] , Additionally, the present invention provides a method for preparing the above-mentioned memristor, comprising the following steps: S1. By means of magnetron sputtering, deposit a transparent glass electrode 1 on a glass substrate.

[0034] S2. By means of magnetron sputtering, sequentially deposit an Fe2O3 oxide layer and an SiO2 oxide layer on the transparent glass electrode 1 to obtain an inorganic oxide layer 2.

[0035] S3. Cover the SiO2 oxide layer with a metal mask template having openings, and by means of DC sputtering, deposit a metal electrode 3 within the openings of the metal mask template, and remove the metal mask template to obtain a memristor.

[0036] For the memristor device prepared by the present invention, the method of preparing the memristor by magnetron sputtering is only a conventional and preferred method, aiming to improve the bonding property between the transparent glass electrode 1, the inorganic oxide layer 2, and the metal electrode 3. The preparation process is simple and the cost is low. The raw materials for the prepared memristor device are abundant and inexpensive, and a double-layer oxide of Fe2O3 and SiO2 with higher stability is used as the functional layer, with obvious effects and good repeatability. In the present invention, the metal mask template is a conventional mask template, and the material of the mask template can be stainless steel, copper, nickel, titanium, etc. In a preferred embodiment, the material of the mask template is stainless steel. The openings on the metal mask template are round holes, evenly distributed on the metal mask template. The diameter of the round holes can be 0.8 mm to 1.5 mm, and the number of round holes is 100 to 150. The metal electrode 3 is deposited within the round holes.

[0037] In a specific embodiment, during the magnetron sputtering process, the target-substrate distance is 8 cm to 12 cm, the vacuum degree is 3×10 -4 Pa to 4×10 -4 Pa, the working gas is argon, the sputtering gas pressure is 0.6 Pa to 0.8 Pa, the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 45 min to 55 min.

[0038] In a specific embodiment, during the DC sputtering process, the target-substrate distance is 8 cm to 12 cm, the vacuum degree is 2×10 -4 Pa to 3×10 -4 Pa, the working gas is argon, the sputtering gas pressure is 0.5 Pa to 0.6 Pa, and the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 12 min to 15 min.

[0039] The present invention also provides the application of the above memristor in detecting tuberculous pleural effusion or malignant pleural effusion. Further, when the transparent glass electrode 1 is an FTO electrode, the memristor selectively detects tuberculous pleural effusion; when the transparent glass electrode 1 is an ITO electrode, the memristor selectively detects malignant pleural effusion.

[0040] The following is further illustrated by specific embodiments.

[0041] Example 1 A memristor includes an FTO electrode, an Fe2O3 oxide layer, an SiO2 oxide layer, and an Ag electrode that are sequentially formed from bottom to top; the thickness of the FTO electrode is 250 nm, the thickness of the Fe2O3 oxide layer is 180 nm, the thickness of the SiO2 oxide layer is 160 nm, and the thickness of the Ag electrode is 550 nm.

[0042] The preparation method of the above memristor includes the following steps: S1. Clean the substrate: Put the glass substrate into deionized water, alcohol, acetone, alcohol, and deionized water in sequence and ultrasonically clean for 30 min to completely clean the surface oil stain. After the glass substrate is dried with N2, it is used as the substrate and put into the magnetron sputtering chamber.

[0043] S2. Deposit the FTO electrode on the glass substrate by magnetron sputtering: Install the FTO target on the magnetron sputtering target gun, set the target-substrate distance to 10 cm, pump the background vacuum degree of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering gas pressure is 0.6 Pa, and the sputtering power is 60 W / cm 2 , and the sputtering time is 50 min. Under these parameters, it can ensure that the deposition uniformity of FTO reaches the best, and an FTO electrode with a thickness of 250 nm can be obtained.

[0044] S3. Deposit the Fe2O3 oxide thin film on the FTO electrode by magnetron sputtering: Install the Fe2O3 compound target on the magnetron sputtering target gun, the atomic ratio of Fe to O is 2:3, set the target-substrate distance to 8 cm, and pump the background vacuum degree of the sputtering chamber to 3×10 -4Ar with a purity of 99.999% was introduced as the working gas, the sputtering pressure was 0.6 Pa, and the sputtering power was 65 W / cm 2 , the sputtering time was 55 min, and an Fe2O3 oxide layer of about 180 nm was obtained.

[0045] S4. A SiO2 oxide layer thin film was deposited on the Fe2O3 oxide layer by magnetron sputtering: A SiO2 compound target was installed on the magnetron sputtering target gun, the Si:O atomic ratio was 1:2, the target-substrate distance was set to 8 cm, and the background vacuum degree of the sputtering chamber was pumped to 3×10 -4 Pa, Ar with a purity of 99.999% was introduced as the working gas, the sputtering pressure was 0.6 Pa, and the sputtering power was 65 W / cm 2 , the sputtering time was 45 min, and a SiO2 oxide layer of about 160 nm was obtained.

[0046] S5. The upper electrode Ag was prepared on the SiO2 oxide layer by magnetron sputtering: A metal mask plate with round holes with a pore diameter of 1 mm was covered on the surface of the SiO2 oxide layer, the number of round holes was 120, and a circular top electrode was deposited by DC sputtering. An Ag metal target was installed on the magnetron sputtering DC target, the target-substrate distance was set to 10 cm, and the background vacuum degree of the sputtering chamber was pumped to 2×10 -4 Pa, Ar with a purity of 99.999% was introduced as the working gas, the sputtering pressure was 0.5 Pa, and the sputtering power was 65 W / cm 2 , the sputtering time was 15 min, the thickness of the electrode Ag was 550 nm, and a memristor, Ag / SiO2 / Fe2O3 / FTO memristor, was obtained.

[0047] Example 2 A memristor includes an FTO electrode, an Fe2O3 oxide layer, a SiO2 oxide layer, and an Ag electrode that are sequentially formed from bottom to top; the thickness of the FTO electrode is 200 nm, the thickness of the Fe2O3 oxide layer is 180 nm, the thickness of the SiO2 oxide layer is 160 nm, and the thickness of the Ag electrode is 600 nm.

[0048] The preparation method of the above-mentioned memristor includes the following steps: S1. Cleaning the substrate: The glass substrate was sequentially placed in deionized water, alcohol, acetone, alcohol, and deionized water and ultrasonically treated for 30 min to completely clean the surface oil stain. After being dried with N2, the glass substrate was used as the substrate and placed in the magnetron sputtering chamber.

[0049] S2. Deposit the FTO electrode on the glass substrate by magnetron sputtering: Install the FTO target on the magnetron sputtering gun, set the target-substrate distance to 10 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.8 Pa, and the sputtering power is 65 W / cm 2 . Under this parameter, the uniformity of FTO deposition can be guaranteed to be the best, and an FTO electrode with a thickness of 200 nm can be obtained.

[0050] S3. Deposit the Fe2O3 oxide film on the FTO electrode by magnetron sputtering: Install the Fe2O3 compound target on the magnetron sputtering gun, with the atomic ratio of Fe to O being 2:3, set the target-substrate distance to 8 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, and the sputtering power is 65 W / cm 2 . The sputtering time is 50 min to obtain an Fe2O3 oxide layer of about 180 nm.

[0051] S4. Deposit the SiO2 oxide layer film on the Fe2O3 oxide layer by magnetron sputtering: Install the SiO2 compound target on the magnetron sputtering gun, with the atomic ratio of Si to O being 1:2, set the target-substrate distance to 8 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, and the sputtering power is 65 W / cm 2 . The sputtering time is 45 min to obtain an SiO2 oxide layer of about 160 nm.

[0052] S5. Prepare the upper electrode Ag on the SiO2 oxide layer by magnetron sputtering: Cover the surface of the SiO2 oxide layer with a metal mask plate having circular holes with a diameter of 1.5 mm, and the number of circular holes is 120. Deposit the circular top electrode by DC sputtering. Install the Ag metal target on the magnetron sputtering DC target, set the target-substrate distance to 10 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.5 Pa, and the sputtering power is 65 W / cm 2 . The sputtering time is 15 min to obtain an Ag electrode with a thickness of 600 nm, and a memristor, the Ag / SiO2 / Fe2O3 / FTO memristor, is obtained.

[0053] Example 3 A memristor includes an ITO electrode, an Fe2O3 oxide layer, an SiO2 oxide layer, and an Ag electrode, which are sequentially formed from bottom to top; the thickness of the ITO electrode is 250 nm, the thickness of the Fe2O3 oxide layer is 180 nm, the thickness of the SiO2 oxide layer is 160 nm, and the thickness of the Ag electrode is 500 nm.

[0054] The preparation method of the above-mentioned memristor includes the following steps: S1. Clean the substrate. Put the glass substrate into deionized water, alcohol, acetone, alcohol, and deionized water in sequence and ultrasonicate for 25 min to completely clean the surface oil stain. After the glass substrate is dried with N2, it is used as the substrate and put into the magnetron sputtering chamber.

[0055] S2. Deposit the ITO electrode on the glass substrate by magnetron sputtering: Install the ITO target on the magnetron sputtering gun, set the target-substrate distance to 10 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, the sputtering power is 60 W / cm 2 The sputtering time is 50 min. Under these parameters, the ITO deposition uniformity can reach the best, and an ITO thin film with a thickness of 250 nm can be obtained.

[0056] S3. Deposit the Fe2O3 thin film on the ITO electrode by magnetron sputtering: Install the Fe2O3 compound target on the magnetron sputtering gun, with the Fe:O atomic ratio of 2:3, set the target-substrate distance to 8 cm, evacuate the background vacuum of the sputtering chamber to 3×10 - 4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, the sputtering power is 65 W / cm 2 , and the sputtering time is 55 min to obtain an Fe2O3 oxide layer of about 180 nm.

[0057] S4. Deposit the SiO2 oxide layer thin film on the Fe2O3 oxide layer by magnetron sputtering: Install the SiO2 compound target on the magnetron sputtering gun, with the Si:O atomic ratio of 1:2, set the target-substrate distance to 8 cm, evacuate the background vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, the sputtering power is 65 W / cm 2 , and the sputtering time is 45 min to obtain an SiO2 oxide layer of about 160 nm.

[0058] S5. Prepare the top electrode Ag on the SiO2 oxide layer by magnetron sputtering: Cover the surface of the SiO2 oxide layer with a metal mask plate having circular holes with a pore diameter of 1 mm. The number of circular holes is 120. Deposit the circular top electrode by DC sputtering. Install an Ag metal target on the magnetron sputtering DC target. Set the target-substrate distance to 10 cm. Pump the base vacuum of the sputtering chamber to 2×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.5 Pa, and the sputtering power is 65 W / cm 2 . The sputtering time is 15 min, and the thickness of the electrode Ag obtained is 500 nm, obtaining a memristor named Ag / SiO2 / Fe2O3 / ITO memristor.

[0059] Example 4 A memristor includes an ITO electrode, an Fe2O3 oxide layer, an SiO2 oxide layer, and an Ag electrode that are sequentially formed from bottom to top; the thickness of the ITO electrode is 300 nm, the thickness of the Fe2O3 oxide layer is 180 nm, the thickness of the SiO2 oxide layer is 160 nm, and the thickness of the Ag electrode is 500 nm.

[0060] The preparation method of the above memristor includes the following steps: S1. Clean the substrate. Put the glass substrate into deionized water, alcohol, acetone, alcohol, and deionized water in sequence and ultrasonically clean for 25 min to completely clean the surface oil stain. After the glass substrate is dried with N2, it is used as the substrate and put into the magnetron sputtering chamber.

[0061] S2. Sputter and deposit the ITO electrode on the glass substrate by magnetron sputtering: Install an ITO target on the magnetron sputtering target gun. Set the target-substrate distance to 8 cm. Pump the base vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.8 Pa, and the sputtering power is 65 W / cm 2 . The sputtering time is 55 min. Under this parameter, the ITO deposition uniformity can be guaranteed to reach the best, and an ITO thin film with a thickness of 300 nm can be obtained.

[0062] S3. Deposit the Fe2O3 thin film on the ITO electrode by magnetron sputtering: Install an Fe2O3 compound target on the magnetron sputtering target gun, and the atomic ratio of Fe to O is 2:3. Set the target-substrate distance to 10 cm. Pump the base vacuum of the sputtering chamber to 3×10 -4 Pa, introduce argon with a purity of 99.999% as the working gas, the sputtering pressure is 0.6 Pa, and the sputtering power is 65 W / cm 2, the sputtering time was 55 min, and an Fe2O3 oxide layer of about 180 nm was obtained.

[0063] S4. A SiO2 oxide layer thin film was deposited on the Fe2O3 oxide layer by magnetron sputtering: A SiO2 compound target was installed on the magnetron sputtering target gun, the Si:O atomic ratio was 1:2, the target-substrate distance was set to 10 cm, and the base vacuum of the sputtering chamber was pumped to 3×10 -4 Pa, argon with a purity of 99.999% was introduced as the working gas, the sputtering pressure was 0.6 Pa, and the sputtering power was 65 W / cm 2 , the sputtering time was 45 min, and a SiO2 oxide layer of about 160 nm was obtained.

[0064] S5. The upper electrode Ag was prepared on the SiO2 oxide layer by magnetron sputtering: A metal mask plate with round holes having a pore diameter of 1.2 mm was covered on the surface of the SiO2 oxide layer, and the number of round holes was 100. The circular top electrode was deposited by DC sputtering. An Ag metal target was installed on the magnetron sputtering DC target, the target-substrate distance was set to 10 cm, and the base vacuum of the sputtering chamber was pumped to 3×10 -4 Pa, argon with a purity of 99.999% was introduced as the working gas, the sputtering pressure was 0.6 Pa, and the sputtering power was 65 W / cm 2 , the sputtering time was 12 min, the thickness of the electrode Ag was 500 nm, and a memristor was obtained, named Ag / SiO2 / Fe2O3 / ITO memristor.

[0065] Since the memristors prepared in Example 1 and Example 2 and Example 3 and Example 4 have similar structures and basically the same performance, Example 1 and Example 3 were used as objects for detecting the application in tuberculous pleural effusion or malignant pleural effusion.

[0066] Among them, the Ag / SiO2 / Fe2O3 / FTO memristor prepared in Example 1 was used to detect tuberculous pleural effusion, including the following steps: The memristor was operated in a no-load state. At a voltage of -1.5V to 1.5V, the typical current-voltage (I-V) curve of the memristor was tested. The current of the memristor was stable at 10 mA to 15 mA at 2.8V, and its (I-V) curve was continuously monitored. When the I-V curve of the memristor was stable in the no-load state, the obtained tuberculous pleural effusion was dropped onto the silver electrode of the memristor, and the I-V curves of the memristor before and after the liquid drop were detected.

[0067] Figure 2 is the analysis diagram of the memristive characteristics of the Ag / SiO2 / Fe2O3 / FTO memristive device prepared in Example 1 of the present invention before the tuberculous pleural effusion was dropped. Among themFigure 2 Among them, (a) is the typical I-V curve of the device before dropping tuberculous pleural effusion, and (b) is the typical semi-logarithmic I-V curve of the device after dropping tuberculous pleural effusion; (c) is the retention characteristic analysis of the device for 100 cycles. As Figure 2 shown, it can be clearly seen that the device has very stable memristive characteristics and retention characteristics before dropping the liquid.

[0068] Figure 3 This is the stability analysis of the Ag / SiO2 / Fe2O3 / FTO memristive device prepared in Example 1 of the present invention after dropping tuberculous pleural effusion. Among them Figure 3 among them, (a) is the typical I-V curve of the device after dropping the liquid; (b) is the typical semi-logarithmic I-V curve of the device after dropping tuberculous pleural effusion; (b) is the retention characteristic analysis of the device for 100 cycles. As Figure 3 shown, it can be clearly seen that the device has obvious discrimination ability for tuberculous pleural effusion.

[0069] Among them, the Ag / SiO2 / Fe2O3 / ITO memristor prepared in Example 3 of the present invention for detecting tuberculous pleural effusion includes the following steps: The memristor operates in a no-load state. At a voltage of -1.5V to 1.5V, the typical current-voltage (I-V) curve of the memristor is tested. When the current of the memristor is stable at 10 mA to 15 mA at 2.8V, and its (I-V) curve is continuously monitored. After the I-V curve of the memristor is stable in the no-load state, the obtained malignant pleural effusion is dropped onto the silver electrode of the memristor, and the I-V curves of the memristor before and after dropping the liquid are detected.

[0070] Figure 4 This is the memristive characteristic analysis of the Ag / SiO2 / Fe2O3 / ITO memristive device prepared in Example 3 of the present invention before dropping malignant pleural effusion. Among them Figure 4 among them, a is the typical I-V curve of the device before and after dropping malignant pleural effusion; b is the typical semi-logarithmic I-V curve of the device before and after dropping malignant pleural effusion. As Figure 4 shown, it can be clearly seen that the device has obvious ability to distinguish malignant pleural effusion.

[0071] Figure 5 This is the stability analysis of the Ag / SiO2 / Fe2O3 / ITO memristive device prepared in Example 3 of the present invention before and after dropping tuberculous pleural effusion. Among them Figure 5 among them, a is the typical I-V curve of the device before and after dropping tuberculous pleural effusion; b is the typical semi-logarithmic I-V curve of the device before and after dropping tuberculous pleural effusion. As Figure 5 shown, it can be clearly seen that the device has no obvious discrimination ability for tuberculous pleural effusion.

[0072] It should be noted that when the present invention involves numerical ranges, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the adopted step methods are the same as those in the embodiments, in order to avoid redundancy, the present invention describes the preferred embodiments. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0073] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A memristor for detecting pleural effusion, characterized in that, It includes a transparent glass electrode (1), an inorganic oxide layer (2), and a metal electrode (3) that are sequentially formed from bottom to top. The transparent glass electrode (1) is an FTO electrode or an ITO electrode, and the inorganic oxide layer (2) is an Fe2O3 oxide layer and an SiO2 oxide layer that are arranged from bottom to top.

2. The memristor for detecting pleural effusion according to claim 1, wherein The thickness of the transparent glass electrode (1) is 200 nm to 300 nm.

3. The memristor for detecting pleural effusion according to claim 1, characterized in that, The thickness of the inorganic oxide layer (2) is 320 nm to 380 nm.

4. A memristor for detecting pleural effusion according to claim 1, characterized in that, The thickness ratio of the Fe2O3 oxide layer to the SiO2 oxide layer is 9:6 to 11.

5. A memristor for detecting pleural effusion according to claim 1, characterized in that The metal electrode (3) is an Ag electrode, and the thickness of the Ag electrode is 500 nm to 600 nm.

6. A method for preparing a memristor for detecting pleural effusion according to any one of claims 1 to 5, characterized in that, It includes the following steps: By means of magnetron sputtering, the transparent glass electrode (1) is sputter-deposited on a glass substrate; By means of magnetron sputtering, an Fe2O3 oxide layer and an SiO2 oxide layer are sequentially deposited on the transparent glass electrode (1) to obtain the inorganic oxide layer (2); A metal mask template with openings is covered on the SiO2 oxide layer. By means of DC sputtering, the metal electrode (3) is deposited in the openings of the metal mask template, and the metal mask template is removed to obtain a memristor.

7. The preparation method of the memristor for detecting pleural effusion according to claim 6, characterized in that, During the magnetron sputtering process, the target-substrate distance is 8 cm to 12 cm, the vacuum degree is 3×10 -4 Pa to 4×10 -4 Pa, the working gas is argon, the sputtering gas pressure is 0.6 Pa to 0.8 Pa, the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 45 min to 55 min.

8. The preparation method of the memristor for detecting pleural effusion according to claim 6, characterized in that, During the DC sputtering process, the target-substrate distance is 8 cm to 12 cm, and the vacuum degree is 2×10 -4 Pa to 3×10 -4 Pa. The working gas is argon, the sputtering gas pressure is 0.5 Pa to 0.6 Pa, the sputtering power is 60 W / cm 2 to 65 W / cm 2 , and the sputtering time is 12 min to 15 min.

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