Conductive hydrogel electrode, preparation method thereof, and conductive hydrogel battery

Abstract

The present invention belongs to the field of new energy technology, and specifically relates to a conductive hydrogel electrode, a preparation method thereof, and a conductive hydrogel battery. The preparation method of the conductive hydrogel electrode comprises the following steps: 1) uniformly mixing bovine serum albumin and a polypyrrole dispersion, stirring at room temperature, and uniformly dispersing; 2) uniformly dispersing an iron metal organic framework material into the solution obtained in step 1), and uniformly dispersing; 3) dispersing a crosslinking agent and the like into the above solution, and fully stirring and dissolving; 4) taking out the solution and pouring it into a mold, and heating it in a water bath to prepare a composite material of bovine serum albumin, polypyrrole hydrogel, and an iron metal organic framework, and obtaining a conductive hydrogel electrode. The present invention uses protein as the main structure of the hydrogel electrode, and by adding conductive materials and catalytic materials to form the positive and negative poles of the battery, it can use simulated biological body fluids for energy supply, which can solve the problems of requiring external power supply for charging and poor biocompatibility of the material.

Description

Technical Field

[0001] The present invention belongs to the field of new energy technology, and in particular relates to a conductive hydrogel electrode, a preparation method thereof, and a conductive hydrogel battery. Background Art

[0002] At present, the batteries commonly used in our daily lives include dry batteries, lead-acid batteries, lithium batteries, etc., which are made of hard materials and are relatively large in size. They are not suitable for small wearable devices. In addition, these batteries need to be charged or replaced regularly and cannot be used for a long time. Currently, research has found that self-powered battery technologies such as piezoelectricity and triboelectricity can make batteries miniaturized, but the electricity generated by these technologies has disadvantages such as instability and unsustainability. Compared with the above methods, enzyme biofuel cells can use biological enzymes as efficient electrocatalysts to convert substances such as glucose, ascorbic acid, lactic acid, electrolytes, etc. in the body into stable and continuous current. This type of battery can be miniaturized, improve portability during use, and has low production costs. It also has the advantages of being green and biocompatible.

[0003] Human skin is composed of soft, water-rich tissue. Using batteries constructed with hard, dry electronic components significantly increases the resistance between the tissue and the electrodes, affecting electrochemical performance. Hydrogels, as lightweight patches suitable for skin, do not hinder movement, making them more suitable than traditional batteries for use in wearable, miniaturized devices. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention provides a conductive hydrogel electrode, a method for preparing the same, and a conductive hydrogel battery. This invention utilizes protein as the main structure of the hydrogel electrode, adding conductive and catalytic materials to form the battery's cathode and anode. This battery utilizes biomimetic body fluids for energy, addressing the need for external power supply and poor biocompatibility.

[0005] The technical solutions provided by the present invention are as follows:

[0006] A method for preparing a conductive hydrogel electrode comprises the following steps:

[0007] 1) uniformly mixing bovine serum albumin and polypyrrole dispersion, stirring at room temperature, and uniformly dispersing;

[0008] 2) evenly dispersing the iron metal organic framework material into the solution obtained in step 1);

[0009] 3) Dispersing 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide into the above solution and stirring thoroughly to dissolve;

[0010] 4) The solution is taken out and poured into a mold, and heated in a water bath to prepare a composite material of bovine serum albumin, polypyrrole hydrogel and iron metal organic framework, thereby obtaining a conductive hydrogel electrode.

[0011] In the above technical solution, bovine serum albumin (BSA) serves as the main hydrogel material, polypyrrole serves as the conductive material, and an iron metal organic framework (FeMOF) serves as the catalytic conductive material. The resulting material can be used as a positive electrode or sensor material. Under the action of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide, the BSA self-polymerizes and cross-links to form the main hydrogel framework structure. This is further physically cross-linked and cured in a water bath.

[0012] Specifically, in the solution obtained in step 1), the content of bovine serum albumin is 30-60 wt%; the content of polypyrrole is 3.68×10 -2 ~7.35×10 -2 wt%.

[0013] Specifically, in the solution obtained in step 2), the content of the iron metal organic framework material is 0.5-1 wt%.

[0014] Specifically, in the solution obtained in step 3), the content of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.10-1.84 wt %; and the content of N-hydroxysuccinimide is 1.02-1.93 wt %.

[0015] Specifically, the solution obtained in step 4) is heated in a water bath at a temperature of 45 to 55° C. for 25 to 35 minutes.

[0016] Furthermore, glucose oxidase is added in step 2), and the content of glucose oxidase in the resulting solution is 0.5-1.5 wt %, preferably 10-20 mM.

[0017] Based on the above technical solution, by further adding glucose oxidase, glucose can be oxidized to release hydrogen peroxide, which is further catalyzed by the iron metal organic framework material to obtain hydroxyl radicals, which can be used as the battery negative electrode to carry out battery reactions.

[0018] The present invention also provides a conductive hydrogel electrode prepared by the above preparation method.

[0019] The present invention also provides a conductive hydrogel battery, comprising:

[0020] Sealed shell;

[0021] The conductive hydrogel positive electrode provided by the above technical solution is fixed on one side of the sealed shell;

[0022] The conductive hydrogel negative electrode sheet provided by the above technical solution is fixed on the other side of the sealed shell;

[0023] and a biological fluid-mimicking electrolyte filled in the sealed shell.

[0024] Based on the above technical solution, the conductive hydrogel battery, as an enzyme biofuel cell, can imitate biological fluids or biological fluids to provide energy for electrolytes.

[0025] Specifically, the bio-mimicking electrolyte is an aqueous solution containing at least glucose. The glucose content can be any concentration below the saturation concentration. The bio-mimicking electrolyte contains dissolved oxygen.

[0026] The present invention also provides an application of a conductive hydrogel electrode for preparing a wearable sensor or an implantable sensor. The electrode is prepared using the above method without adding an iron metal organic framework material or glucose oxidase.

[0027] Based on the above technical solution, due to its good biocompatibility, it can be used as an implantable sensor or wearable sensor, can output stable signals for a long time, has high conductivity, can be used as a human motion signal sensor, has good mechanical properties, and has good comfort, can be miniaturized, and has a simple structure.

[0028] Because it can adapt to human skin, can be implanted in the body, and has stable output electrochemical properties, it can be used as a sensor for signal sensing such as electrocardiogram, electromyography, movement and sound output. Furthermore, this hydrogel battery can be used to monitor body fluid concentration.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention uses bovine serum albumin as the main framework material of the hydrogel, making this protein hydrogel electrode have better biocompatibility than other hydrogel electrodes;

[0031] 2. The present invention uses polypyrrole materials and metal-organic framework materials as conductive materials, providing hydrogel batteries with dual conductivity of electronic and ionic conductivity, and has better sensing performance than other hydrogels made of single conductive materials;

[0032] 3. The hydrogel battery of the present invention has good mechanical and adhesion properties and is more comfortable than commercial rubber, plastic, and metal-based electrodes;

[0033] 4. The hydrogel battery of the present invention does not require external power supply for charging and can be directly powered by the electrolyte;

[0034] 5. The hydrogel electrode of the present invention can be used as an electrode to monitor multiple physiological indicators, such as electrocardiogram, electromyography, and sound output, and can further monitor body fluid concentration when used as an implantable battery;

[0035] 6. The hydrogel battery of the present invention has multiple functions and can be further functionalized while performing monitoring and sensing. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a physical picture of the hydrogel electrode.

[0037] Figure 2 This is a cell growth diagram of the hydrogel electrode and cells co-incubated in the embodiment.

[0038] Figure 3 This is a motion signal sensing diagram of the hydrogel electrode attached to the human body in the embodiment.

[0039] Figure 4 Graph showing the output voltage of the hydrogel battery in the embodiment.

[0040] Figure 5 Schematic diagram of the structure of the conductive hydrogel battery in the embodiment.

[0041] Figure 6 Schematic diagram of the conductive hydrogel battery in the embodiment.

[0042] Attachment Figure 5 The structures represented by each number are listed as follows:

[0043] 1. Sealed shell, 2. Positive electrode, 3. Negative electrode. DETAILED DESCRIPTION

[0044] The principles and features of the present invention are described below. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0045] Unless otherwise specified, the test methods used in the examples of the present invention are conventional methods; the materials and reagents used are commercially available reagents and materials unless otherwise specified.

[0046] Preparation of iron metal organic framework material: Add 2-methylimidazole with a configured mass fraction of 8.5wt% to ultrapure water, and after fully dissolving under magnetic stirring at 1000r / min, add zinc nitrate with a configured mass fraction of 1.4wt% and ferrous sulfate with a configured mass fraction of 0.08wt% to the above solution, then heat in a water bath at 15°C and magnetically stir at 1000r / min for 20 minutes. Collect the resulting solid material, wash with ultrapure water, and centrifuge at 12000rpm at 4°C using a low-temperature high-speed centrifuge. After repeating the washing and centrifugation 5 times, collect the precipitate, freeze it in a -80°C refrigerator for 24 hours, and then use a freeze dryer to vacuum dry it at -60°C for 24 hours to obtain the iron metal organic framework material.

[0047] The synthesis method of the metal organic framework material loaded with glucose oxidase is similar to that of the above-mentioned iron metal organic framework material, except that glucose oxidase with a mass fraction of 1 wt% after configuration is added during the synthesis process.

[0048] In one embodiment, when preparing a bovine serum albumin / polypyrrole hydrogel electrode, bovine serum albumin with a mass fraction of 30 to 60 wt% after configuration and bovine serum albumin with a mass fraction of 3.68×10 -2 ~7.35×10 -2 wt% polypyrrole dispersion is evenly mixed, stirred at room temperature for 1 hour, and evenly dispersed; then the iron metal organic framework material with a mass fraction of 0.5 to 1wt% after configuration is evenly dispersed into the above solution, and fully and evenly dispersed for 1 hour; further, 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride with a mass fraction of 1.10 to 1.84wt% after configuration and N-hydroxysuccinimide with a mass fraction of 1.02 to 1.93wt% after configuration are dispersed into the above solution, fully stirred for 10 minutes, and dissolved; the solution is taken out and poured into a mold, and heated in a water bath at 50°C for 30 minutes to complete the preparation of the cathode electrode, which is used as the positive electrode of the battery.

[0049] The iron metal organic framework material was replaced with a metal organic framework material loaded with glucose oxidase, and the anode electrode was prepared according to the same steps as above and used as the negative electrode of the battery.

[0050] Example 1

[0051] Step 1: Prepare bovine serum albumin gel by dispersing bovine serum albumin with a mass fraction of 30 wt% in ultrapure water and stirring at room temperature for 1 hour to disperse uniformly;

[0052] Step 2: Disperse 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (having a mass fraction of 1.10 wt%) and N-hydroxysuccinimide (having a mass fraction of 1.02 wt%) into the above solution, stir thoroughly for 10 minutes, and dissolve;

[0053] Step 3: Pour the solution into a mold and heat it in a 50°C water bath for 30 minutes to complete the preparation of the bovine serum albumin gel.

[0054] Test its biocompatibility.

[0055] Example 2

[0056] Step 1: Prepare bovine serum albumin / polypyrrole hydrogel electrode, and mix bovine serum albumin with a mass fraction of 30 wt% and a -2 wt% polypyrrole dispersion was uniformly mixed and stirred at room temperature for 1 h to disperse uniformly;

[0057] Step 2: Disperse 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (having a mass fraction of 1.10 wt%) and N-hydroxysuccinimide (having a mass fraction of 1.02 wt%) into the above solution, stir thoroughly for 10 minutes, and dissolve;

[0058] Step 3: Pour the solution into a mold and heat it in a 50°C water bath for 30 minutes to complete the preparation of the bovine serum albumin / polypyrrole hydrogel electrode.

[0059] Test its human motion sensing performance and biocompatibility.

[0060] Example 3

[0061] Step 1: Prepare bovine serum albumin / polypyrrole hydrogel / iron metal organic framework material electrode, and mix bovine serum albumin with a mass fraction of 30 wt% and a -2 wt% polypyrrole dispersion was uniformly mixed and stirred at room temperature for 1 h to disperse uniformly;

[0062] Step 2: Evenly disperse the iron metal organic framework material with a mass fraction of 0.50 wt% after configuration into the above solution and fully disperse it for 1 hour;

[0063] Step 3: Disperse 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (having a mass fraction of 1.10 wt%) and N-hydroxysuccinimide (having a mass fraction of 1.02 wt%) into the above solution, stir thoroughly for 10 minutes, and dissolve;

[0064] Step 4: Take out the solution and pour it into the mold. Heat it in a 50°C water bath for 30 minutes to complete the preparation of the bovine serum albumin / polypyrrole hydrogel / iron metal organic framework material cathode electrode.

[0065] Test the electrochemical performance and biocompatibility.

[0066] Example 4

[0067] The difference from Example 3 is that the iron metal organic framework material loaded with glucose oxidase is added in step 2. The hydrogel electrode prepared in this example is a bovine serum albumin / polypyrrole hydrogel / glucose oxidase iron metal organic framework material anode.

[0068] Test the electrochemical performance and biocompatibility.

[0069] Test results:

[0070] 1. Test the biocompatibility of the hydrogel electrode, such as Figure 1 This is a photo of the hydrogel electrode. Weigh 1g of each hydrogel from Examples 1, 2, 3, and 4, and soak them in 3mL of DMEM medium for 24h. Take out the leachate from each hydrogel and add 10% fetal bovine serum to each. Next, press 2×10 4 NIH 3T3 cells were seeded into 12-well plates at a density of 10 cells / well. After the NIH 3T3 cells adhered to the plate, the culture medium extracts of different groups of hydrogel electrodes were added and cultured in a 37°C incubator for 24 hours and 48 hours. After completion, the toxicity of each group of hydrogels on cells was detected using the CCK-8 kit. The results are shown in Figure 2. Figure 2 Figure 2 shows cell growth patterns of cells co-incubated with hydrogel electrodes in the examples. NIH 3T3 cells cultured in each group of hydrogel culture medium extracts grew normally, as did the blank control group of NIH 3T3 cells without hydrogel extracts. This demonstrates that the hydrogels prepared in the above examples have excellent biocompatibility and do not affect normal cell growth.

[0071] 2. Test the human motion signal sensing performance. The bovine serum albumin / polypyrrole hydrogel electrode prepared in Example 2 was attached to the finger joint and connected to the Keithley 2450 via a wire. The electrode was adjusted to the resistance detection mode. The finger was bent to 30°, 60°, 90°, and 0° respectively. The resistance change of the hydrogel electrode was detected. The resistance change rate of the hydrogel was further calculated to observe the sensing ability of the hydrogel electrode. Figure 3 Figure 2 shows the motion signal sensing of a hydrogel electrode attached to a human body. This hydrogel electrode exhibits excellent motion signal sensing capabilities, demonstrating a fast and sensitive response and excellent continuous sensing signal stability, demonstrating its suitability for use as a wearable sensor device.

[0072] 3. Test the electrochemical signal. The bovine serum albumin / polypyrrole hydrogel / iron metal organic framework cathode electrode of Example 3 and the bovine serum albumin / polypyrrole hydrogel / glucose oxidase iron metal organic framework anode of Example 4 were placed in a 15 mM glucose solution after connecting the positive and negative hydrogel electrodes to the wires. They were then connected to the Shanghai Chenhua CHI660E electrochemical workstation and their open circuit voltages were tested. Figure 4 The output voltage of the hydrogel battery in this embodiment is shown in Figure 2. A stable output voltage can be observed over a long period of time, demonstrating that this conductive hydrogel battery is an enzyme biofuel cell that can be directly powered by glucose, a biological fluid, without requiring external power supply.

[0073] Example 5

[0074] like Figure 5 As shown, the conductive hydrogel battery comprises: a sealed housing 1; a positive electrode 2 fixed to one side of the sealed housing 1; and a negative electrode 3 fixed to the other side of the sealed housing 1. The sealed housing is filled with a biomimetic electrolyte. The sealed housing may be provided with a liquid injection port. The positive and negative electrodes may be the electrodes of Example 4. Figure 6 The figure shows the principle diagram of the conductive hydrogel battery. Current is generated during the anode and cathode reactions. The anode serves as the negative electrode of the battery and the cathode serves as the positive electrode of the battery.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a conductive hydrogel electrode, characterized in that: The following steps are involved: 1) uniformly mixing bovine serum albumin and polypyrrole dispersion, stirring at room temperature, and uniformly dispersing; 2) evenly dispersing the iron metal organic framework material into the solution obtained in step 1); 3) Dispersing 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide into the above solution and stirring thoroughly to dissolve; 4) The solution is taken out and poured into a mold, and heated in a water bath to prepare a composite material of bovine serum albumin, polypyrrole hydrogel and iron metal organic framework, thereby obtaining a conductive hydrogel electrode.

2. The method for preparing a conductive hydrogel electrode according to claim 1, wherein: In the solution obtained in step 1), the content of bovine serum albumin is 30-60 wt%; the content of polypyrrole is 3.68×10 -2 ~7.35×10 -2 wt%.

3. The method for preparing a conductive hydrogel electrode according to claim 1, wherein: In the solution obtained in step 2), the content of the iron metal organic framework material is 0.5-1 wt%.

4. The method for preparing a conductive hydrogel electrode according to claim 1, wherein: In the solution obtained in step 3), the content of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 1.10-1.84 wt %; and the content of N-hydroxysuccinimide is 1.02-1.93 wt %.

5. The method for preparing a conductive hydrogel electrode according to claim 1, wherein: In step 4), the solution obtained is heated in a water bath at a temperature of 45 to 55° C. for 25 to 35 minutes.

6. The method for preparing a conductive hydrogel electrode according to any one of claims 1 to 5, characterized in that: Glucose oxidase is also added in step 2), and the content of glucose oxidase in the obtained solution is 0.5-1.5 wt%.

7. A conductive hydrogel electrode prepared according to the preparation method according to any one of claims 1 to 6.

8. A conductive hydrogel battery, characterized in that: include: Sealed shell; A conductive hydrogel electrode according to any one of claims 1 to 5 fixed to one side of the sealed housing as a positive electrode; The conductive hydrogel electrode according to claim 6 fixed on the other side of the sealed shell serves as a negative electrode; and a biological fluid-mimicking electrolyte filled in the sealed shell.

9. The conductive hydrogel battery according to claim 8, characterized in that: The bio-mimicking electrolyte is an aqueous solution containing at least glucose.

10. A conductive hydrogel electrode according to claim 7, characterized in that: Used to prepare wearable sensors or implantable sensors.

Images