Preparation process of ZIF-8 / Hb mixed LB film

Abstract

The invention relates to the technical field of composite films, in particular to a preparation process of a ZIF-8 / Hb mixed LB film, which comprises the following steps: adding a hemoglobin solution into an aqueous solution of zinc nitrate hexahydrate, and stirring for reaction to obtain a first reaction solution; adding an aqueous solution of 2-methylimidazole into the first reaction solution, carrying out a stirring reaction, carrying out centrifugal washing, and drying to obtain ZIF-8 / Hb nanoparticles; adding the ZIF-8 / Hb nanoparticles into an isooctane solution of sodium dioctyl sulfosuccinate, and carrying out ultrasonic dispersion to obtain a second reaction solution; drawing a pi-A curve of ZIF-8 / Hb, and preparing a ZIF-8 / Hb film through a multifunctional LB film drawing machine and setting film drawing parameters; according to the invention, a reverse micelle synergistic stable interface is realized, a nano-particle film forming bottleneck is broken through, the biological activity is accurately reserved, an electrochemical sensing interface and technological parameters are intelligently regulated and controlled, and the effect of customizable film performance is realized.

Description

Technical Field

[0001] This invention relates to the field of composite thin film technology, and specifically to a preparation process for a ZIF-8 / Hb hybrid LB thin film. Background Technology

[0002] Metal-organic frameworks (MOFs) are a new class of porous crystalline materials. With their designable porous structures, high specific surface area, and unique chemical tunability, they have shown great application potential in gas separation, catalytic conversion, and biosensing. In recent years, with the continuous and in-depth research on the novel metal-organic framework material ZIF-8, innovative combinations of ZIF-8 and hemoglobin (Hb) have been achieved. ZIF-8 is a nanoscale particle composed of zinc ions from zinc nitrate hexahydrate and 2-methylimidazole. ZIF-8 [2-4] possesses many advantages, such as high porosity, large specific surface area, tunable surface properties, and pH-induced biodegradability. These advantages make ZIF-8 rich in multiple functions, enabling its wide application in various fields, such as gas adsorption and separation, pharmaceuticals, catalysis, and transport [5-]. Hemoglobin (Hb) is a key protein found in red blood cells, whose main function is to transport oxygen and carbon dioxide in the body, while also participating in acid-base balance regulation. Its natural quaternary structure endows it with molecular recognition and peroxidase-like catalytic activity, as well as unique electron transfer capabilities, providing natural molecular recognition sites and chemical coupling platforms for constructing multifunctional biological interfaces. Combining the porous adsorption properties of ZIF-8 with the biological functions of hemoglobin holds promise for constructing a composite system integrating molecular recognition, biocatalysis, and interface response; however, its nanoscale controllable assembly and functional synergistic mechanisms still require further exploration. Langmuir-Blodgett (LB)B, as a classic interface engineering method, precisely controls the molecular arrangement behavior at the gas-liquid interface, thereby transferring ordered molecular layers to a solid substrate to prepare two-dimensional films with highly controllable layer number, orientation, and packing density.

[0003] In existing technologies, ZIF-8 / Hb nanoparticles tend to aggregate and settle in aqueous phases, making it difficult to form a uniform monolayer at the gas-liquid interface. LB films constructed using traditional physical mixing methods suffer from pore collapse and Hb leakage. Pure Hb lacks amphiphilicity and cannot form films independently. While ZIF-8 can stabilize the interface through surface modification, its collapse pressure is low and its molecular arrangement is loose, making it difficult to support multiple film-stretching operations. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation process for ZIF-8 / Hb hybrid LB films, which achieves a synergistic stable interface of reverse micelles, breaks through the bottleneck of nanoparticle film formation, accurately retains bioactivity, empowers the intelligent control of electrochemical sensing interfaces and process parameters, and achieves the effect of customizable film performance.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A process for preparing a ZIF-8 / Hb hybrid LB film includes the following steps:

[0007] S1. Preparation of ZIF-8 / Hb nanoparticles:

[0008] Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence;

[0009] The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution.

[0010] Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles;

[0011] S2. Preparation of ZIF-8 / Hb membrane:

[0012] ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution.

[0013] The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membranes were prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

[0014] As a further aspect of the present invention: Preparation of isooctane solution of sodium dioctyl succinate sulfonate: Weigh 0.2314 g of sodium dioctyl succinate sulfonate and dissolve it in 100 mL of isooctane solution.

[0015] As a further aspect of the present invention: Preparation of an aqueous solution of zinc nitrate hexahydrate: Weigh 100 mg of zinc nitrate hexahydrate and dissolve it in 50 mL of deionized water.

[0016] As a further aspect of the present invention: Preparation of an aqueous solution of 2-methylimidazole: Dissolve 200 mg of 2-methylimidazole in 50 mL of water.

[0017] As a further aspect of the present invention: in S1, the stirring reaction time corresponding to the first reaction solution is 5 min.

[0018] As a further aspect of the present invention: in S1, the stirring reaction time corresponding to the second reaction solution is 24 hours and the stirring temperature is 25°C.

[0019] As a further aspect of the present invention: the process of drying after centrifugal washing is as follows:

[0020] Centrifuge at 12,000 rpm, discard the supernatant, wash the resulting green solid three times with ethanol, spread it into a petri dish, and dry it in an oven at 60°C.

[0021] As a further aspect of the present invention: the addition of ZIF-8 / Hb nanoparticles to an isooctane solution of sodium dioctyl succinate sulfonate is specifically as follows:

[0022] Weigh 0.03 g of ZIF-8 / Hb nanoparticles and mix them with 3 mL of isooctane solution of sodium dioctyl succinate sulfonate.

[0023] As a further aspect of the present invention: in S2, the initial membrane pressure, the final membrane pressure, and the number of film formations in the Setting interface are adjusted according to the π-A curve.

[0024] As a further aspect of the present invention: in S2, the film-forming time interval, constant film pressure, number of film-forming cycles, and film-forming direction in the Setting interface are adjusted according to the film-forming condition.

[0025] The beneficial effects of this invention are:

[0026] This invention overcomes the challenges of interfacial aggregation and activity decay of ZIF-8 / Hb hybrid LB films; it retains the bioelectrochemical activity of Hb, providing a highly sensitive interface for biosensors; and the intelligent film stretching parameter system guided by the π-A curve enables controllable preparation and performance customization of nanocomposite films. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is the π-A curve isotherm diagram of ZIF-8 in this invention;

[0029] Figure 2 This is the π-A curve isotherm diagram of ZIF-8 / Hb in this invention;

[0030] Figure 3This is a metallographic microscope image of the ZIF-8 / HbLB film in this invention;

[0031] Figure 4 This is the infrared spectrum of the ZIF-8 / HbLB film sample in this invention;

[0032] Figure 5 This is a CV curve of different scan rates for ZIF-8 / Hb LB membranes (concentrations a: 15 mg / mL, b: 20 mg / mL, c: 30 mg / mL, d: 40 mg / mL) in PBS buffer according to the present invention.

[0033] Figure 6 This is a CV curve of conductive glass in PBS buffer solution at different scan rates in this invention. Detailed Implementation

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] Example 1

[0036] The present invention provides a process for preparing a ZIF-8 / Hb hybrid LB film, which specifically includes the following steps:

[0037] S1. Preparation of ZIF-8 / Hb nanoparticles:

[0038] Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence;

[0039] The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution.

[0040] Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles;

[0041] More specifically, 0.2314 g of sodium dioctyl succinate sulfonate was weighed using an analytical balance and dissolved in 100 mL of isooctane solution. To ensure complete dissolution, the solution was then stirred using an ultrasonic oscillator for 30 min. This effectively and uniformly dispersed sodium dioctyl succinate sulfonate in the isooctane solution.

[0042] Weigh 100 mg of zinc nitrate hexahydrate using an analytical balance and dissolve it in 50 mL of deionized water. Prepare a 15 mg / mL hemoglobin solution and add 1 mL of the solution to the above solution. Stir for five minutes to allow the reaction to complete.

[0043] Subsequently, 200 mg of 2-methylimidazole was dissolved in 50 mL of water at 25 °C and poured into the above solution, then transferred to an electric stirrer and stirred for 24 h.

[0044] After stirring, the mixture was transferred to a centrifuge and centrifuged at 12,000 rpm. The supernatant was poured off, and the resulting green solid was washed three times with ethanol. The solid was then diffused into a petri dish, placed in an oven, and dried at 60°C to obtain green powder, namely ZIF-8 / Hb nanoparticles.

[0045] S2. Preparation of ZIF-8 / Hb membrane:

[0046] ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution.

[0047] The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membrane was prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

[0048] More specifically, weigh 0.03g of ZIF-8 / Hb nanoparticles using an analytical balance, measure 3mL of isooctane solution of sodium dioctyl succinate sulfonate in a 10mL centrifuge tube, add the measured ZIF-8 / Hb to this solution, and transfer to a CNC ultrasonic machine for ultrasonic vibration until completely dispersed. Draw the solution using a 5mL medical syringe and slowly drop it onto the water surface until an oil-droplet-like insoluble oil film appears. Click "Plot Curve" to plot the π-A curve of ZIF-8 / Hb. After the curve is measured, adjust the initial membrane pressure, final membrane pressure, and number of film-forming cycles in the Settings interface according to the π-A curve (the device provides uniform film-forming motion and sinusoidal motion film-forming). Click "Film Formation" on the main page, and the barrier will reciprocate according to the settings. It will automatically stop after film formation is complete. Adjust the abrasion time interval, constant membrane pressure, number of film-forming cycles, and film-forming direction in the Settings interface according to the film formation situation. Once the film stretching process is complete, the ZIF-8 / Hb film stretching is finished.

[0049] Example 2

[0050] The present invention provides a process for preparing a ZIF-8 / Hb hybrid LB film, which specifically includes the following steps:

[0051] S1. Preparation of ZIF-8 / Hb nanoparticles:

[0052] Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence;

[0053] The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution.

[0054] Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles;

[0055] More specifically, 0.2314 g of sodium dioctyl succinate sulfonate was weighed using an analytical balance and dissolved in 100 mL of isooctane solution. To ensure complete dissolution, the solution was then stirred using an ultrasonic oscillator for 30 min. This effectively and uniformly dispersed sodium dioctyl succinate sulfonate in the isooctane solution.

[0056] Weigh 100 mg of zinc nitrate hexahydrate using an analytical balance and dissolve it in 50 mL of deionized water. Prepare a 20 mg / mL hemoglobin solution and add 1 mL of the solution to the above solution. Stir for five minutes to allow the reaction to complete.

[0057] Subsequently, 200 mg of 2-methylimidazole was dissolved in 50 mL of water at 25 °C and poured into the above solution, then transferred to an electric stirrer and stirred for 24 h.

[0058] After stirring, the mixture was transferred to a centrifuge and centrifuged at 12,000 rpm. The supernatant was poured off, and the resulting green solid was washed three times with ethanol. The solid was then diffused into a petri dish, placed in an oven, and dried at 60°C to obtain green powder, namely ZIF-8 / Hb nanoparticles.

[0059] S2. Preparation of ZIF-8 / Hb membrane:

[0060] ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution.

[0061] The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membrane was prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

[0062] More specifically, weigh 0.03g of ZIF-8 / Hb nanoparticles using an analytical balance, measure 3mL of isooctane solution of sodium dioctyl succinate sulfonate in a 10mL centrifuge tube, add the measured ZIF-8 / Hb to this solution, and transfer to a CNC ultrasonic machine for ultrasonic vibration until completely dispersed. Draw the solution using a 5mL medical syringe and slowly drop it onto the water surface until an oil-droplet-like insoluble oil film appears. Click "Plot Curve" to plot the π-A curve of ZIF-8 / Hb. After the curve is measured, adjust the initial membrane pressure, final membrane pressure, and number of film-forming cycles in the Settings interface according to the π-A curve (the device provides uniform film-forming motion and sinusoidal motion film-forming). Click "Film Formation" on the main page, and the barrier will reciprocate according to the settings. It will automatically stop after film formation is complete. Adjust the abrasion time interval, constant membrane pressure, number of film-forming cycles, and film-forming direction in the Settings interface according to the film formation situation. Once the film stretching process is complete, the ZIF-8 / Hb film stretching is finished.

[0063] Example 3

[0064] The present invention provides a process for preparing a ZIF-8 / Hb hybrid LB film, which specifically includes the following steps:

[0065] S1. Preparation of ZIF-8 / Hb nanoparticles:

[0066] Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence;

[0067] The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution.

[0068] Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles;

[0069] More specifically, 0.2314 g of sodium dioctyl succinate sulfonate was weighed using an analytical balance and dissolved in 100 mL of isooctane solution. To ensure complete dissolution, the solution was then stirred using an ultrasonic oscillator for 30 min. This effectively and uniformly dispersed sodium dioctyl succinate sulfonate in the isooctane solution.

[0070] Weigh 100 mg of zinc nitrate hexahydrate using an analytical balance and dissolve it in 50 mL of deionized water. Prepare a 30 mg / mL hemoglobin solution and add 1 mL of the solution to the above solution. Stir for five minutes to allow the reaction to complete.

[0071] Subsequently, 200 mg of 2-methylimidazole was dissolved in 50 mL of water at 25 °C and poured into the above solution, then transferred to an electric stirrer and stirred for 24 h.

[0072] After stirring, the mixture was transferred to a centrifuge and centrifuged at 12,000 rpm. The supernatant was poured off, and the resulting green solid was washed three times with ethanol. The solid was then diffused into a petri dish, placed in an oven, and dried at 60°C to obtain green powder, namely ZIF-8 / Hb nanoparticles.

[0073] S2. Preparation of ZIF-8 / Hb membrane:

[0074] ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution.

[0075] The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membrane was prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

[0076] More specifically, weigh 0.03g of ZIF-8 / Hb nanoparticles using an analytical balance, measure 3mL of isooctane solution of sodium dioctyl succinate sulfonate in a 10mL centrifuge tube, add the measured ZIF-8 / Hb to this solution, and transfer to a CNC ultrasonic machine for ultrasonic vibration until completely dispersed. Draw the solution using a 5mL medical syringe and slowly drop it onto the water surface until an oil-droplet-like insoluble oil film appears. Click "Plot Curve" to plot the π-A curve of ZIF-8 / Hb. After the curve is measured, adjust the initial membrane pressure, final membrane pressure, and number of film-forming cycles in the Settings interface according to the π-A curve (the device provides uniform film-forming motion and sinusoidal motion film-forming). Click "Film Formation" on the main page, and the barrier will reciprocate according to the settings. It will automatically stop after film formation is complete. Adjust the abrasion time interval, constant membrane pressure, number of film-forming cycles, and film-forming direction in the Settings interface according to the film formation situation. Once the film stretching process is complete, the ZIF-8 / Hb film stretching is finished.

[0077] Example 4

[0078] The present invention provides a process for preparing a ZIF-8 / Hb hybrid LB film, which specifically includes the following steps:

[0079] S1. Preparation of ZIF-8 / Hb nanoparticles:

[0080] Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence;

[0081] The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution.

[0082] Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles;

[0083] More specifically, 0.2314 g of sodium dioctyl succinate sulfonate was weighed using an analytical balance and dissolved in 100 mL of isooctane solution. To ensure complete dissolution, the solution was then stirred using an ultrasonic oscillator for 30 min. This effectively and uniformly dispersed sodium dioctyl succinate sulfonate in the isooctane solution.

[0084] Weigh 100 mg of zinc nitrate hexahydrate using an analytical balance and dissolve it in 50 mL of deionized water. Prepare a 40 mg / mL hemoglobin solution and add 1 mL of the solution to the above solution. Stir for five minutes to allow the reaction to complete.

[0085] Subsequently, 200 mg of 2-methylimidazole was dissolved in 50 mL of water at 25 °C and poured into the above solution, then transferred to an electric stirrer and stirred for 24 h.

[0086] After stirring, the mixture was transferred to a centrifuge and centrifuged at 12,000 rpm. The supernatant was poured off, and the resulting green solid was washed three times with ethanol. The solid was then diffused into a petri dish, placed in an oven, and dried at 60°C to obtain green powder, namely ZIF-8 / Hb nanoparticles.

[0087] S2. Preparation of ZIF-8 / Hb membrane:

[0088] ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution.

[0089] The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membrane was prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

[0090] More specifically, weigh 0.03g of ZIF-8 / Hb nanoparticles using an analytical balance, measure 3mL of isooctane solution of sodium dioctyl succinate sulfonate in a 10mL centrifuge tube, add the measured ZIF-8 / Hb to this solution, and transfer to a CNC ultrasonic machine for ultrasonic vibration until completely dispersed. Draw the solution using a 5mL medical syringe and slowly drop it onto the water surface until an oil-droplet-like insoluble oil film appears. Click "Plot Curve" to plot the π-A curve of ZIF-8 / Hb. After the curve is measured, adjust the initial membrane pressure, final membrane pressure, and number of film-forming cycles in the Settings interface according to the π-A curve (the device provides uniform film-forming motion and sinusoidal motion film-forming). Click "Film Formation" on the main page, and the barrier will reciprocate according to the settings. It will automatically stop after film formation is complete. Adjust the abrasion time interval, constant membrane pressure, number of film-forming cycles, and film-forming direction in the Settings interface according to the film formation situation. Once the film stretching process is complete, the ZIF-8 / Hb film stretching is finished.

[0091] Performance Analysis

[0092] like Figure 1 and Figure 2 As shown, the surface pressure increases as the tank area decreases. Combining the two graphs, using the ZIF-8 curve as a reference for the π-A isotherm, we can see that the ZIF / Hb curve is shifted to the left compared to the ZIF-8 curve. This indicates that the area occupied by this mixed system is smaller than that of pure ZIF-8. However, the termination points of the two curves are very close, suggesting that adding Hb to ZIF-8 affects the structural stability of the membrane. The slope of the curve reflects the density of molecular arrangement and phase rigidity. A steep upward segment indicates ordered molecular arrangement. Both π-A curves represent that their respective systems can be orderedly arranged on the water surface.

[0093] like Figure 3 As shown, this image is an image of the ZIF-8 / HbLB film under a metallographic microscope. Figure a shows the shape of the ZIF-8 / HbLB film on a silicon wafer under a 5x lens; Figure b shows the shape of the ZIF-8 / HbLB film on a silicon wafer under a 10x lens; Figure c shows the shape of the ZIF-8 / HbLB film on a silicon wafer under a 40x lens.

[0094] like Figure 4As shown in the left figure, the ZIF-LB membrane exhibits the most commonly used and distinctive peaks of ZIF-8 in the ranges of ~1580 cm⁻¹ (C=N), ~1425 cm⁻¹ (Zn-N), ~995 cm⁻¹, and ~760 cm⁻¹. Characteristic peaks of hemoglobin powder are also visible: amide I band (1650-1660 cm⁻¹) and band II band (1560-1570 cm⁻¹); multiple peaks in the ranges of 1520-1530 cm⁻¹ (C=O / CO) and 1170-1350 cm⁻¹. The prepared ZIF-8 / HbLB membrane shows most of the characteristic peaks of both ZIF-8 and Hb. For example, in the right figure, the peak at 1580 cm⁻¹ in the ZIF-8 / HbLB membrane shows a characteristic peak of ZIF-8, while the characteristic peaks of hemoglobin show a red shift in the ZIF-8 / HbLB membrane, indicating that ZIF-8 restriction leads to changes in the protein's secondary structure.

[0095] like Figure 5 As shown in Figure a, the CV curve in Figure a presents a crescent shape opening downwards. This crescent-shaped CV curve is likely closely related to the reversibility of the redox reaction, reaction kinetics, and initial concentration distribution. The crescent shape is particularly noticeable when only Ox is initially present, and Red gradually forms and reaches a steady state during the reaction. Figure b shows a rectangular shape. A rectangular CV curve indicates that the electrochemical process of the electrochemical device is relatively stable during charge and discharge, meaning that the electrochemical active centers of the material exhibit high chemical stability throughout the process. Figure c shows an irregular rectangular shape. Irregular rectangular CV curves are usually associated with high electrochemically active surface area, indicating that the material surface has many active sites available for electrochemical reactions. Figure d presents a normal reversible cycle curve. The effect of different scan rates on the electrochemistry of the LB membrane in PBS buffer solution is shown in the figure. Figure 6 The effect of different scan rates (5, 10, 15, 20, 50, 100, 150, and 200 mV / s from low to high) on the redox reaction of the ZIF-8 / HbLB film in a three-electrode system was investigated. For the ZIF-8 / HbLB film, the higher the scan rate, the larger the peak value. It is relatively stable at a scan rate of 50 mV / s, with a potential range of -0.8 to 0.8 V.

[0096] This invention investigates the behavior of ZIF-8 / Hb reverse micelle monolayers at the gas-liquid interface using isothermal curves of surface pressure and area of ​​the monolayer. The element-A curve shows that the collapse pressure of the ZIF-8 / Hb monolayer is very close to that of ZIF-8, indicating that the addition of hemoglobin (Hb) does not affect the stability of the membrane. Hemoglobin was composited using a metal-organic framework (MOF) method, and ZIF-8 / Hb nanoparticles were transferred to a glass slide using LB film technology for infrared spectroscopy. Peak values ​​were then observed at various locations. Electrochemical characterization of ZIF-8 / Hb nanoparticles transferred to conductive glass using LB film technology revealed a pair of good quasi-reversible redox peaks, indicating that the electrochemical activity of hemoglobin remains excellent. These results demonstrate a favorable formation process for the ZIF-8 / Hb electrode.

[0097] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A process for preparing a ZIF-8 / Hb hybrid LB film, characterized in that, Includes the following steps: S1. Preparation of ZIF-8 / Hb nanoparticles: Prepare an aqueous solution of zinc nitrate hexahydrate and a hemoglobin solution in sequence; The hemoglobin solution was added to the aqueous solution of zinc nitrate hexahydrate, and the mixture was stirred to obtain the first reaction solution. Prepare an aqueous solution of 2-methylimidazole, add the aqueous solution of 2-methylimidazole to the first reaction solution, stir the reaction, centrifuge, wash and dry to obtain ZIF-8 / Hb nanoparticles; S2. Preparation of ZIF-8 / Hb membrane: ZIF-8 / Hb nanoparticles were added to an isooctane solution of sodium dioctyl succinate sulfonate and ultrasonically dispersed until an oil droplet-shaped insoluble oil film appeared on the water surface, thus obtaining the second reaction solution. The π-A curve of ZIF-8 / Hb was plotted, and ZIF-8 / Hb membranes were prepared by using a multifunctional LB membrane stretching machine and setting the stretching parameters.

2. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, Preparation of isooctane solution of sodium dioctyl succinate sulfonate: Weigh 0.2314 g of sodium dioctyl succinate sulfonate and dissolve it in 100 mL of isooctane solution.

3. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, Preparation of an aqueous solution of zinc nitrate hexahydrate: Weigh 100 mg of zinc nitrate hexahydrate and dissolve it in 50 mL of deionized water.

4. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, Preparation of aqueous solution of 2-methylimidazole: Dissolve 200 mg of 2-methylimidazole in 50 mL of water.

5. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, In S1, the stirring reaction time corresponding to the first reaction solution is 5 minutes.

6. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, In S1, the stirring reaction time for the second reaction solution is 24 hours, and the stirring temperature is 25°C.

7. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, The process of drying after centrifugal washing is as follows: Centrifuge at 12,000 rpm, discard the supernatant, wash the resulting green solid three times with ethanol, spread it into a petri dish, and dry it in an oven at 60°C.

8. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, The specific steps for adding ZIF-8 / Hb nanoparticles to an isooctane solution of sodium dioctyl succinate sulfonate are as follows: Weigh 0.03 g of ZIF-8 / Hb nanoparticles and mix them with 3 mL of isooctane solution of sodium dioctyl succinate sulfonate.

9. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, In S2, adjust the starting membrane pressure, ending membrane pressure, and number of film formation cycles in the Setting interface according to the π-A curve.

10. The preparation process of a ZIF-8 / Hb hybrid LB film according to claim 1, characterized in that, In S2, adjust the film-forming time interval, constant film pressure, number of film-forming cycles, and film-forming direction in the Setting interface according to the film formation.

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