A protein conductive ink, a protein device and a preparation method

Abstract

The present invention relates to the field of material technology, and particularly relates to a protein conductive ink, a protein device and a preparation method. The protein conductive ink provided by the present invention comprises a silk fibroin solution and a conductive ink; the conductive ink comprises a graphene oxide dispersion or a reduced graphene oxide dispersion; the number of silk fibroin molecules in the silk fibroin solution is greater than the number of oxygen-containing groups in the conductive ink. By controlling the number of functional groups contained in the two, the formed ink has more stable thermal properties, and a denser conductive film can be formed on the protein film subsequently.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and particularly relates to a protein conductive ink, a protein device and a preparation method thereof. Background Art

[0002] Silk fibroin film is an ideal biomaterial for medical device manufacturing, which has excellent and adjustable mechanical properties, controllable degradation properties and excellent biosecurity. In some application scenarios, it is necessary to form a conductive circuit on the protein film.

[0003] However, when the existing conductive ink is sprayed onto the protein film, there are problems of low adhesion and poor stability. Therefore, it is necessary to provide a new conductive ink with high adhesion and good stability. Summary of the Invention

[0004] To solve the above technical problems, on the one hand, the present application discloses a protein conductive ink, which comprises a silk fibroin solution and a conductive ink;

[0005] The conductive ink comprises a graphene oxide dispersion or a reduced graphene oxide dispersion;

[0006] The number of silk fibroin molecules in the silk fibroin solution is greater than the number of oxygen-containing groups in the conductive ink.

[0007] In an exemplary embodiment, the ratio range of the number of silk fibroin molecules in the silk fibroin solution to the number of oxygen-containing groups in the conductive ink is 1.2:1 to 2:1.

[0008] In an exemplary embodiment, the mass fraction of the solute in the protein conductive ink is less than 1%.

[0009] In an exemplary embodiment, the mass fraction range of the solute in the silk fibroin solution is 5% to 10%.

[0010] In an exemplary embodiment, the silk fibroin molecules in the silk fibroin solution can bind to the oxygen-containing groups in the conductive ink.

[0011] On the other hand, the present application also provides a protein device, which comprises a protein film and a protein conductive film;

[0012] The protein conductive film is disposed on the protein film, and the protein conductive film is formed by spraying the above protein conductive ink onto the protein film.

[0013] On the other hand, the present application also provides a preparation method of a protein device, which comprises:

[0014] Laying the protein film flat on a heating platform and performing low-temperature heating;

[0015] Spray the above-mentioned protein conductive ink onto a preset area of the protein film to obtain an initial protein device;

[0016] In a vacuum environment, perform steam crosslinking treatment and drying on the initial protein device to obtain a protein device.

[0017] In an exemplary embodiment, the temperature range of the low-temperature heating is 20-45 °C.

[0018] In an exemplary embodiment, the preset area is the area of the protein film exposed by placing a mask on the protein film.

[0019] In an exemplary embodiment, during the spraying process, the deformation amount of the protein film is less than or equal to a preset deformation amount.

[0020] Adopting the above technical solution, the protein conductive ink provided by this application has the following beneficial effects:

[0021] The protein conductive ink provided by this application includes a silk fibroin solution and a conductive ink; the conductive ink includes a graphene oxide dispersion or a reduced graphene oxide dispersion; the number of silk fibroin molecules in the silk fibroin solution is greater than the number of oxygen-containing groups in the conductive ink. By controlling the number of functional groups contained in the two, when they are subsequently sprayed onto the protein film, the conductive components can be fully combined with the protein molecules and form a conductive film that adheres sufficiently to the substrate protein film. Description of the Drawings

[0022] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic diagram of the preparation process of a protein device provided by an embodiment of this application;

[0024] Figure 2 It is a schematic diagram of the structure of a protein device provided by an embodiment of this application;

[0025] Figure 3 It is a schematic diagram of a protein device after being cut provided by an embodiment of this application;

[0026] Figure 4 It is a schematic diagram of the structure of a protein device in its initial state provided by an embodiment of this application;

[0027] Figure 5It is a schematic structural diagram of a protein device in a torsional state provided by an embodiment of the present application;

[0028] Figure 6 It is a schematic structural diagram of a protein device in a stretched state provided by an embodiment of the present application. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope protected by the present application.

[0030] As used herein, the term "one embodiment" or "embodiment" refers to a specific feature, structure, or characteristic that may be included in at least one implementation manner of the present application. In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be construed as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that such data may be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0031] For the purposes of the following detailed description, it should be understood that the present invention may take various alternative variations and step sequences, unless explicitly specified to the contrary. In addition, except in any operating instance, or otherwise indicated, all numbers representing the amounts of ingredients used in the specification and claims should be understood to be modified in all instances by the term "about". Thus, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0032] Although the numerical ranges and parameters setting forth the broad scope of the present invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in its respective testing measurements.

[0033] When a numerical range is disclosed herein, the above range is considered continuous and includes the minimum and maximum values of the range, as well as every value therebetween. Further, when the range refers to integers, every integer between the minimum and maximum values of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all sub-ranges subsumed therein. For example, the specified range from "1 to 10" should be considered to include any and all sub-ranges between the minimum value 1 and the maximum value 10. Exemplary sub-ranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0034] Example 1:

[0035] The protein conductive ink provided by this application includes a silk fibroin solution and a conductive ink; the conductive ink includes a graphene oxide dispersion or a reduced graphene oxide dispersion; the number of silk fibroin molecules in the silk fibroin solution is greater than the number of oxygen-containing groups in the conductive ink.

[0036] Based on the conductive film printed by the above protein conductive ink, during subsequent crosslinking, the conductive components, the silk fibroin molecules of the conductive film, and the silk fibroin film of the substrate can be fully crosslinked with each other, thereby greatly improving the adhesion between the conductive film and the protein film.

[0037] Optionally, the protein solution includes components such as silk fibroin and sericin. There are groups in the silk fibroin that can crosslink and combine with each other to form conformations such as α-helix and β-sheet.

[0038] Optionally, the molecular weight of the hydrolyzed protein (i.e., the molecular weight of the solute in the above protein solution) is about 1000 - 5000. Depending on the different preparation processes, the molecular weight of the hydrolyzed protein is also different.

[0039] Optionally, the oxygen-containing groups of the conductive ink may include hydroxyl groups, carboxyl groups, etc., which can bind to silk fibroin molecules.

[0040] In an exemplary embodiment, the ratio range of the number of silk fibroin molecules in the silk fibroin solution to the number of oxygen-containing groups in the conductive ink is 1.2:1 to 2:1, such as 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1. The number of silk fibroin molecules is slightly greater than the number of oxygen-containing groups, so that a sufficient number of graphene oxide / reduced graphene oxide molecules can be cross-linked and attached to the surface of the protein film. However, the number of silk fibroin molecules should not be too large, which may lead to poor conductivity.

[0041] In an exemplary embodiment, the mass fraction of the solute in the protein conductive ink is less than 1%. Subsequently, the protein conductive ink is convenient for spraying.

[0042] In an exemplary embodiment, the mass fraction range of the solute in the silk fibroin solution is 5% to 10%, such as 5%, 6%, 7%, 8%, 9%, 10%. Specifically, the mass fraction range of the solute in the silk fibroin solution is still determined by the number of silk fibroin molecules in the protein solution and the number of chemical bonds in the conductive ink, that is, the number of silk fibroin molecules in the silk fibroin solution and the number of oxygen-containing groups in the conductive ink are in a preset ratio.

[0043] Subsequently, the protein conductive ink can be sprayed onto the protein film, so that a protein conductive film can be formed on the protein film to obtain a protein device. Specifically, in practical applications, a single-layer conductive structure can be applied, that is, the protein conductive ink is sprayed onto a single-layer protein film; it can also be applied to a protein film with a multi-layer conductive structure. First, the protein conductive ink is sprayed onto a single-layer protein film, and then combined with other protein films with conductive structures through a protein bonding process to obtain a protein film with a multi-layer conductive structure. When printing the protein conductive ink in this application, a conductive film with good adhesion and patterning is printed without changing the original properties of the protein film, so that a device based on silk fibroin with a complex multi-layer conductive structure can be prepared. By using the oxygen-containing groups of graphene oxide / reduced graphene oxide to combine with the silk fibroin molecules of the conductive film and the substrate silk fibroin film through the way of water vapor cross-linking, the adhesion of the conductive ink is enhanced.

[0044] Example 2:

[0045] On the other hand, please refer to Figure 1 , this application also provides a preparation method of a protein device, which includes:

[0046] S101: Place the protein film flat on a heating platform and perform low-temperature heating.

[0047] In this embodiment, the temperature range of the low-temperature heating is 20 to 45 °C, such as 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C.

[0048] In this embodiment, in step S101, specifically, the protein film can be fixed in a flat state by a fixture and placed on a heating platform. The fixture can pre-stretch and then dry the protein film, thereby adjusting the deformation properties of the protein film after encountering water. For example, it can make the protein film shrink, and can also make the surface of the protein film flat, so that it can be fully adhered to the mask, thereby improving the accuracy of the sprayed pattern.

[0049] It should be noted that the purpose of the above low-temperature heating is to keep the protein film in a dry state at all times, to avoid local rapid wetting of the protein film resulting in deformation and printing deformation, and the fixture is to maintain the properties and printing shape obtained by the original treatment during subsequent crosslinking.

[0050] S103: Sprinkle the protein conductive ink as described above on the preset area of the protein film to obtain an initial protein device.

[0051] In this embodiment, the preset area is the area of the protein film exposed when the mask is placed on the protein film.

[0052] In this embodiment, during the spraying process, the deformation amount of the protein film is less than or equal to the preset deformation amount, and the preset deformation amount is within ±1%. That is to say, the spraying speed should be appropriate, generally low, to ensure that the protein film remains in a relatively dry state during the printing process, thereby avoiding accidental deformation of the film.

[0053] S105: In a vacuum environment, perform steam crosslinking treatment and drying on the initial protein device to obtain a protein device.

[0054] In this embodiment, in the free state in a humid environment, silk protein molecules will spontaneously combine, so that the sprayed silk protein molecules crosslink with the protein film.

[0055] In this embodiment, after the above step S105, a dry conductive film will be formed on the surface of the original protein film. By placing the film prepared by drying the protein solution in a steam environment, a suitable humidity can make the molecules have a certain activity while being close enough, thereby improving the crosslinking efficiency. Optionally, the steam crosslinking time can be about 24h, such as 22h, 23h, 24h, 25h, etc., and a basically fully crosslinked protein film can be obtained.

[0056] It should be noted that the effect of the local rapid wetting in step S103 is different from the uniform and slow wetting in step S105 when placed in a steam environment. Here, low-temperature heating and slow spraying are both to keep the film in a sufficiently dry state to avoid local rapid wetting of the film resulting in deformation and printing deformation.

[0057] Example 3

[0058] Another method for preparing protein devices is provided below. The specific process includes the following steps:

[0059] First, prepare a protein solution with a mass fraction of about 7% and a conductive ink, which can be a graphene oxide dispersion or a reduced graphene oxide dispersion. At this time, the ratio range of the number of silk fibroin molecules in the silk fibroin solution to the number of oxygen-containing groups in the conductive ink is 1:1 to 2:1, that is, the number of silk fibroin molecules in the silk fibroin solution is greater than the number of oxygen-containing groups in the conductive ink, so that a sufficient number of graphene oxide / reduced graphene oxide molecules can be cross-linked and attached to the surface of the protein film, and at the same time, it has a good conductivity.

[0060] Then mix the two and dilute the mixed solution, specifically including the protein solution and the conductive ink, so that the solute mass fraction of the mixed solution is about 1% or less; then mix the diluted protein solution and the conductive ink in proportion.

[0061] Take a dry protein film fixed on a fixture, place it on a hot plate not higher than 45 °C and heat it continuously at a low temperature; place the patterned mask on the surface of the protein film; use tools such as a spray gun to break up the solution prepared in the dilution into fine droplets, and slowly spray it on the protein film through the mask; control the spraying rate to ensure that the protein film remains in a relatively dry state during the printing process, so as to avoid accidental deformation of the film.

[0062] After printing, place the protein film in a vacuum kettle with water at the bottom, evacuate to make it moist inside for steam cross-linking for about 24 hours, so that the protein solution printed on the surface is cross-linked and adhered to the protein film, thereby improving the adhesion.

[0063] Please refer to Figure 2 , which shows a schematic diagram of a prepared protein device. The conductive film on the surface of the protein device prepared based on the above method provided in this application is uniform. By cutting it, the cut protein device diagram as shown in Figure 3 can be obtained. It can be seen that the cut at the cut is flat and there is no situation of the conductive film peeling up, indicating that the adhesion between the conductive film and the underlying protein film is good. Further, by cutting the protein device into strip test strips, Figure 4 shows a schematic diagram of a test strip. By respectively performing the torsion as shown in Figure 5 and Figure 6After stretching as shown, it can be seen that the conductive film still adheres well to the protein film. Subsequently, the conductivity of a test strip with a width of about 1 cm was tested. Specifically, the test strip was completely wetted with PBS solution, and the residual solution was wiped off. A multimeter was used for measurement. Specifically, the positive and negative probes of the multimeter were respectively placed at positions about 2 cm apart on the surface of the protein film. The corresponding measured resistance was about 100 kΩ, indicating that a conductive film in an ionic liquid infiltration state (such as in vivo implantation) can be prepared on the surface of the protein film by this method. The conductive film has excellent adhesion to the protein film substrate and can deform with the deformation of the wet protein film.

[0064] It should be noted that the above is the process of preparing a conductive structure on a single-layer protein film. However, when a multi-layer conductive structure needs to be prepared, the process of preparing a conductive structure on a single-layer protein film can be repeated, and then combined with other protein films with conductive structures through a protein bonding process to obtain a protein film with a multi-layer conductive structure.

[0065] Silk fibroin film is an ideal biomaterial for medical device manufacturing, which has excellent and adjustable mechanical properties, controllable degradation properties, and excellent biosecurity. However, it may cause protein denaturation when heated or in contact with organic solvents, and it will deform when exposed to water. Therefore, a conductive ink that does not affect the properties of the protein film itself and can deform with the protein film and its printing method are needed. The protein conductive ink provided in this application can be cross-linked twice, that is, including a primary cross-linking of the protein film as a printing substrate to make it insoluble in water, and another cross-linking of the conductive film and the substrate protein film together after inkjet printing to make them fully adhere, improving its adhesion to the protein film; at the same time, when continuously heating the protein film at a low temperature, tiny droplets are sprayed on its surface for printing to avoid protein denaturation.

[0066] The above are only optional embodiments of this application and are not intended to limit this application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of this application shall be included in the protection scope of this application.

Claims

1. A protein conductive ink, characterized in that: Including silk protein solution and conductive ink; The conductive ink includes a graphene oxide dispersion or a reduced graphene oxide dispersion; The number of silk protein molecules in the silk protein solution is greater than the number of oxygen-containing groups in the conductive ink; The ratio of the number of silk protein molecules in the silk protein solution to the number of oxygen-containing groups in the conductive ink is in the range of 1.2:1 to 2:

1.

2. The protein conductive ink according to claim 1, characterized in that: The mass fraction of the solute in the protein conductive ink is less than 1%.

3. The protein conductive ink according to claim 1, characterized in that: The mass fraction of the solute in the silk protein solution ranges from 5% to 10%.

4. The protein conductive ink according to claim 1, characterized in that: The silk protein molecules in the silk protein solution can be combined with the oxygen-containing groups in the conductive ink.

5. A protein device, characterized in that Including protein film and protein conductive film; The protein conductive film is provided on the protein film, and the protein conductive film is formed by spraying the protein conductive ink according to any one of claims 1 to 4 onto the protein film.

6. A method for preparing a protein device, characterized in that: include: Place the protein film flat on the heating platform and heat it at low temperature; Spraying the protein conductive ink according to any one of claims 1 to 4 onto a predetermined area of the protein film to obtain an initial protein device; The initial protein device is subjected to water vapor cross-linking treatment and dried in a vacuum environment to obtain a protein device.

7. The preparation method according to claim 6, characterized in that The temperature range of the low-temperature heating is 20-45°C.

8. The preparation method according to claim 6, characterized in that The preset area is the area of the protein film exposed when the mask is placed on the protein film.

9. The preparation method according to claim 6, characterized in that During the spraying process, the deformation of the protein film is less than or equal to the preset deformation.

Images