A flexible high polymer material with glucose response, its preparation method and application in preparing biosensors

Abstract

The application relates to the technical field of high polymer material preparation, and particularly discloses a flexible high polymer material with glucose response, a preparation method thereof and application of the flexible high polymer material in preparation of a biosensor. The preparation method of the flexible high polymer material with glucose response comprises the following steps: S1. reacting a prepolymer with a polyhydric alcohol to obtain a copolymer; S2. dissolving the copolymer with an organic solvent, then adding hydroxylated carbon nanotubes, poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate, uniformly stirring, and then performing ultrasonic treatment; after the ultrasonic treatment is completed, the reaction product is poured into a mold, and the flexible high polymer material with glucose response is obtained after solidification. The flexible high polymer material with glucose response has good glucose, pH and temperature multi-response performance, and also has good mechanical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material preparation, in particular to a flexible high polymer material with glucose response, a preparation method thereof and application thereof in preparing a biosensor. BACKGROUND

[0002] Diabetes is a serious health problem caused by its hyperglycemic metabolic properties, affecting millions of people worldwide. In addition, diabetes is often associated with serious complications such as chronic diabetic wounds, and the stimulation of persistent hyperglycemia can disrupt the regeneration of the skin, making the wound tissue unable to heal in a normal physiological way, and hyperglycemia can also increase the risk of bacterial infection of the wound, leading to chronic wounds and even increasing the risk of death. Therefore, the monitoring of blood glucose is crucial for diabetic patients, and the development of non-invasive continuous blood glucose monitoring biosensors makes diabetic wound management easier. Recently, various corresponding glucose oxidase (GOx)-based electrochemical biosensors with high selectivity and rapid glucose response have been developed. Unfortunately, GOx-based biosensors have the problems of insufficient stability and low sensitivity, which seriously limit the popularization and application of electrochemical enzymatic glucose biosensors.

[0003] Therefore, it is urgent to develop a new type of electrochemical non-enzymatic glucose biosensor with high efficiency, fast response and excellent stability. Zhang et al. developed an electrochemical non-enzymatic glucose hydrogel sensor based on phenylboronic acid (PBA) (Guo et. al, 2021). Since phenylboronic acid has high specificity for glucose, the sensor shows perfect response sensitivity and stability in a wide temperature range (25-55℃) and concentration range (20-200mM). Similarly, the Dautta group manufactured a PBA-based sensor for continuous monitoring of glucose (Dautta et. al, 2020). The sensor showed excellent response stability and high sensitivity in the glucose concentration range of 2.5-22mM, and there was no signal drift or lag phenomenon after continuous monitoring of low-high glucose concentration for 45 days. Because of the strong intermolecular force between boronic acid and glucose molecules due to the strong chemical bond, this force does not weaken or disappear over time. It has been proven that, unlike GOx and glucose, PBA and glucose can reversibly form stable boronic acid bonds when combined with 1,2 or 1,3 cis diols, and by regulating the substrate stereochemistry and electronic affinity, the binding strength and specificity of PBA and glucose can be easily controlled, thus developing a glucose biosensor with high stability, excellent response performance and strong adaptability. Therefore, the phenylboronic acid polymer-based biosensor is a potential alternative to enzyme sensors and has great application potential in the field of diabetes management in the future. However, the existing phenylboronic acid-based biosensors have the problem of mutual exclusion of mechanical strength and conductivity, and it is necessary to develop a flexible glucose biosensor that can exhibit high elongation under large deformation and good conductivity. SUMMARY

[0004] In order to overcome at least one of the technical problems existing in the prior art, the present application first provides a preparation method of a flexible polymer material with glucose response.

[0005] The technical solution of the present application is as follows:

[0006] The present application first provides a preparation method of a flexible polymer material with glucose response, which comprises the following steps:

[0007] S1. Reacting the prepolymer with the polyol to obtain a copolymer;

[0008] S2. Dissolving the copolymer with an organic solvent, then adding hydroxylated carbon nanotubes, poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate, stirring uniformly, and then performing ultrasonic treatment; after the ultrasonic treatment is completed, the reaction product is poured into a mold, and after solidification, the flexible polymer material with glucose response is obtained.

[0009] Preferably, the mass ratio of the prepolymer to the polyol in step S1 is 75-95:25-5.

[0010] Preferably, the reaction in step S1 refers to a reaction at 65-75°C for 1-3 hours.

[0011] Most preferably, the reaction in step S1 refers to a reaction at 70°C for 2 hours.

[0012] Preferably, the prepolymer in step S1 is prepared from caprolactone and 1,4,8-trithiaspiro-[4,6]-9-undecanone.

[0013] Preferably, the specific preparation method of the prepolymer in step S1 is: taking caprolactone and 1,4,8-trithiaspiro-[4,6]-9-undecanone as raw materials, and reacting under the action of a catalyst to obtain a prepolymer.

[0014] Preferably, the mass ratio of caprolactone to 1,4,8-trithiaspiro-[4,6]-9-undecanone is 3-5:1.

[0015] Most preferably, the mass ratio of caprolactone to 1,4,8-trithiaspiro-[4,6]-9-undecanone is 4:1.

[0016] Preferably, the catalyst is Sn(Oct)2.

[0017] Preferably, the mass amount of the catalyst is 1-5% of the total amount of the raw materials caprolactone and 1,4,8-trithiaspiro-[4,6]-9-undecanone.

[0018] Most preferably, the mass amount of the catalyst in step (1) is 3% of the total amount of the raw materials caprolactone and 1,4,8-trithiaspiro-[4,6]-9-undecanone.

[0019] Preferably, the reaction refers to a reaction at 55-65°C for 1-3 hours, and then a reaction at 100-120°C for 16-30 hours under a vacuum of 0.001 Pa.

[0020] Most preferably, the reaction refers to a reaction at 60°C for 2 hours, and then a reaction at 115°C for 24 hours under a vacuum of 0.001 Pa.

[0021] Preferably, the polyol in step S1 is prepared from epoxidized vegetable oil and (3-aminophenyl)boronic acid.

[0022] Preferably, the specific preparation method of the polyol in step S1 is: taking epoxidized vegetable oil and (3-aminophenyl)boronic acid, and then performing a heating reaction; after the reaction is completed, the product is taken to obtain the polyol.

[0023] Preferably, the molar ratio of the epoxy vegetable oil and (3-aminophenyl)boronic acid is 1:1-1.5.

[0024] Most preferably, the molar ratio of the epoxy vegetable oil and (3-aminophenyl)boronic acid is 1:1.2.

[0025] Preferably, the reaction refers to stirring at 90-110℃ for 40-80 minutes.

[0026] Most preferably, the reaction refers to stirring at 100℃ for 60 minutes.

[0027] Preferably, the epoxy vegetable oil is selected from one or more than one combination of epoxy soybean oil, epoxy corn oil, epoxy rapeseed oil, epoxy olive oil and epoxy linseed oil.

[0028] Preferably, in step S2, the amount of the hydroxylated carbon nanotube added is 1-3% of the mass of the copolymer.

[0029] Preferably, the amount of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate added is 1-3% of the mass of the copolymer.

[0030] Preferably, the stirring time in step S2 is 50-80 minutes; and the ultrasonic time is 1-3 hours.

[0031] Most preferably, the stirring time in step S2 is 60 minutes; and the ultrasonic time is 2 hours.

[0032] The application also provides a flexible high polymer material with glucose response prepared by the above preparation method.

[0033] The application also provides an application of the flexible high polymer material with glucose response in preparing a biosensor.

[0034] Preferably, the preparation method of the sensor is: cutting the flexible high polymer material with glucose response of claim 8 into a strip, then coating conductive silver paste on both ends of the strip, and assembling with a wire to obtain the biosensor.

[0035] Beneficial effects:

[0036] (1) The copolymer prepared by the prepolymer and the polyol raw material of the application has excellent biocompatibility, mechanical properties and self-repairing properties; and the phenylboronic acid in the copolymer of the application can specifically bind with glucose, which provides a material basis for glucose response.

[0037] (2) Hydroxylated carbon nanotubes have high aspect ratio, usually as excellent conductive fillers to enhance mechanical strength and form effective percolation networks, thus forming stable and continuous electron transport paths;

[0038] (3) Poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate have excellent ion and electron transport properties, stable doping environment, lower redox potential and the advantage of easy functionalization. In particular, the construction of a dual-conductive network of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate and hydroxylated carbon nanotubes not only reduces the loading amount of hydroxylated carbon nanotubes, but also forms a uniform and dense percolation network through π-π interaction, thereby improving the conductivity and linear range of the glucose sensor.

[0039] (3) In addition, in the process of preparing a flexible polymer material based on the copolymer prepared from the prepolymer and polyol raw materials of the present application, poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate are added; it can react with the copolymer prepared from the prepolymer and polyol raw materials of the present application, and can greatly improve the sensitivity to glucose under pH environmental conditions. The conductive composite material prepared by using it has excellent biocompatibility, mechanical properties and self-repairing properties, wherein the strain of the conductive composite material exceeds 1000%, and the self-healing efficiency can reach 90% at 45°C for 30 min. The biosensor exhibits excellent linear response to glucose concentration in the range of 0 μM-4 mM, with a sensitivity coefficient of 1.12 A / mM and a regression coefficient of 0.964. In addition, the biosensor has linear response to glucose with different pH values and temperature responses. At the same time, the biosensor has good cell compatibility, blood compatibility, and antibacterial effect on Escherichia coli and Staphylococcus aureus, and the biosensor has good application potential in the management of diabetic wounds. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 Mechanical properties of the flexible polymer material with glucose response of the present application.

[0041] Figure 2 Electromechanical response properties of the flexible polymer material with glucose response of the present application.

[0042] Figure 3 Glucose response linear relationship of the biosensor of the present application.

[0043] Figure 4 pH linear response relationship of the biosensor of the present application.

[0044] Figure 5 Temperature response behavior of the biosensor of the present application.

[0045] Figure 6 Biocompatibility of the biosensor material of the present application. DETAILED DESCRIPTION

[0046] The present application is further explained with reference to the specific examples below, which examples do not limit the application in any form.

[0047] Example 1: Preparation of flexible polymeric material with glucose response

[0048] (1) The prepolymer and polyol with a mass ratio of 90:10 were dissolved in tetrahydrofuran (THF) and reacted at 70°C for 2 hours; a copolymer was obtained.

[0049] (2) The copolymer was dissolved in tetrahydrofuran at 70°C to form a uniform solution; then hydroxylated carbon nanotubes (added in an amount of 2 wt.% of the copolymer) and poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate (PEDOT:PSS) (added in an amount of 1 wt.% of the copolymer) were added to the solution and stirred for 60 minutes; after 2 hours of continuous ultrasonic treatment, the mixture was transferred to a polytetrafluoroethylene mold, and after removing the solvent at 60°C, a flexible polymeric material with glucose response was obtained;

[0050] The prepolymer in step (1) was prepared by the following method: caprolactone and 1,4,8-trioxaspiro-[4,6]-9-undecanone were mixed in a round-bottom flask under N2 atmosphere to obtain a mixture, and then Sn(Oct)2 dissolved in anhydrous toluene was added to the mixture; the reaction was first carried out at 60°C for 2 hours, and then the temperature was raised to 115°C under a vacuum of 0.001 Pa for continuous reaction for 24 hours; the reaction mixture was cooled to room temperature and extracted with dichloromethane (DCM); then, the residue was removed by centrifugation to obtain the prepolymer;

[0051] The polyol in step (1) was prepared by the following method: the polyol was prepared by the following method: epoxy soybean oil and (3-aminophenyl)boronic acid (ABa) were added to a round-bottom flask in a molar ratio of 1:1.2, and stirred at 100°C for 60 minutes; the reaction was cooled to room temperature, extracted with ethyl acetate and washed with saturated NaCl solution; finally, the ethyl acetate was removed by rotary evaporation to obtain the polyol.

[0052] Example 2: Preparation of flexible polymeric material with glucose response

[0053] Only the mass fraction of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate (PEDOT:PSS) (2 wt.%) in step (2) of Example 1 was changed, and the rest of the parameters and steps refer to Example 1.

[0054] Example 3: Preparation of flexible high polymer material with glucose response

[0055] Only the mass fraction of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate (PEDOT:PSS) in step (2) of Example 1 was changed (3 wt.%), and the rest of the parameters and steps refer to Example 1.

[0056] Comparative Example 1: Preparation of flexible high polymer material with glucose response

[0057] The difference from Example 1 is that no poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate (PEDOT:PSS) is added in step (2); only hydroxylated carbon nanotubes (HCNT) (2 wt.%) is added; and the rest of the parameters and steps refer to Example 1.

[0058] Table 1: Mechanical and electrical properties of flexible high polymer material with glucose response

[0059] Examples Tensile stress (MPa) Elongation at break (%) GF Example 1 11.05±0.12 916.1±63.60 2.06 Example 2 10.27±0.45 1170.3±64.05 9.01 Example 3 10.14±0.09 1072±53.58 7.01 Comparative Example 1 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 18.32±1.79 1151.3±44.22 1.26

[0060] The specific steps of the experiment of the relative resistance change of the sensor under different strains are as follows:

[0061] The electromechanical properties of the strain sensor were measured using a digital multimeter (Keithley 2401) and a CHI760E workstation (CH Instruments, Austin, TX, USA). When a certain stress is applied to the flexible sensor, the resistance value of the sensor will change accordingly.

[0062] The gauge factor (GF) is considered an important parameter for quantitatively evaluating the sensitivity of the sensor, representing the typical strain relative resistance response law. GF can be expressed as the following equation

[0063]

[0064] Where ΔR is the resistance change, and Δε is the tensile strain.

[0065] As can be seen from the test results in Table 1, the flexible high polymer material with glucose response prepared based on the copolymer prepared from the prepolymer and the polyol raw materials of the present application has excellent mechanical properties.

[0066] In addition, it can be seen from the test results in Table 1 that the GF of the flexible polymer material with glucose response prepared in Example 1 is significantly higher than that of the flexible polymer material with glucose response prepared in Comparative Example 1; in particular, the GF of the flexible polymer material with glucose response prepared in Examples 2 and 3 is much higher than that of the flexible polymer material with glucose response prepared in Comparative Example 1; this shows that, in the process of preparing the flexible polymer material based on the copolymer prepared from the prepolymer and the polyol raw material of the present application, the addition of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate can react with the copolymer prepared from the prepolymer and the polyol raw material of the present application, and can significantly or greatly improve the response sensitivity of the flexible polymer material with glucose response.

[0067] Preparation of a biosensor

[0068] The flexible polymer material with glucose response described in Example 1, 2 or 3 is cut into a rectangular strip (30 mm x 10 mm x 0.4 mm), silver conductive paste is applied to both ends of the strip, and copper wires are assembled to obtain a biosensor sensor.

[0069] The specific steps of the response experiment of the biosensor to different glucose concentrations and temperatures are as follows:

[0070] The glucose response is characterized by exposing the sensor to different concentrations of glucose solution (0-4 mM in PBS solution). The pH value of the glucose solution (400 μM) is adjusted to 6-8, and the pH dependence of the glucose sensor is characterized by testing the electromechanical response at different pH values. The glucose solution (400 μM), the mixed solution of glucose (400 uM) and uric acid (400 uM), and the mixed solution of glucose (400 uM) and ascorbic acid (400 uM) are prepared respectively, and the selectivity of the glucose sensor is characterized by monitoring the current signal of the sensor in different solutions. The response stability of the glucose sensor is studied by continuously and alternately exposing the sensor to low concentration (PBS solution without glucose) and high concentration (PBS solution containing 400 uM glucose) solutions.

[0071] The temperature sensitivity measurement of the sensor is to immerse the assembled sensor in water and measure the resistance value of the sensor at different water temperatures (34.0-42.0℃). The response stability of the temperature sensor is characterized by repeating the test 10 times at 38.0℃.

[0072] The above examples are the preferred embodiments of the present application, but the embodiments of the present application are not limited by the examples, and any changes, modifications, substitutions, combinations, simplifications made without departing from the spirit and principles of the present application shall be equivalent replacement methods and shall be within the scope of protection of the present application.

Claims

1. A method for preparing a flexible polymeric material having a glucose response, characterized by, The preparation method comprises the following steps: S1. reacting a prepolymer with a polyol to obtain a copolymer; S2. dissolving the copolymer with an organic solvent, then adding hydroxylated carbon nanotubes, poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate, stirring uniformly, then performing ultrasonic treatment; after the ultrasonic treatment is completed, the reaction product is poured into a mold, and the flexible polymer material with glucose response is obtained after solidification; The prepolymer in step S1 is prepared from caprolactone and 1, 4, 8-trithiepan-4, 6-9-undecanone; The polyol in step S1 is prepared from epoxidized vegetable oil and (3-aminophenyl)boronic acid; The mass ratio of caprolactone to 1, 4, 8-trithiepan-4, 6-9-undecanone is 3-5:1; The molar ratio of epoxidized vegetable oil to (3-aminophenyl)boronic acid is 1:1-1.

5.

2. The method for preparing a glucose-responsive flexible polymer material according to claim 1, characterized in that, In step S2, the amount of hydroxylated carbon nanotubes added is 1-3% of the mass of the copolymer.

3. The method for preparing a glucose-responsive flexible polymer material according to claim 1, characterized in that, The amount of poly(3,4-ethylenedioxythiophene) and polystyrene sulfonate added is 1-3% of the mass of the copolymer.

4. The method for preparing a glucose-responsive flexible polymer material according to claim 1, characterized in that, The stirring time in step (2) is 50-80 minutes; and the ultrasonic treatment time is 1-3 hours.

5. The method for preparing a glucose-responsive flexible polymer material according to claim 4, characterized in that, The stirring time in step (2) is 60 minutes; and the ultrasonic treatment time is 2 hours.

6. The flexible polymer material with glucose response prepared by the preparation method of any one of claims 1-5.

7. The use of the flexible polymer material with glucose response of claim 6 in the preparation of a biosensor.

8. Use according to claim 7, characterized in that, The preparation method of the biosensor is as follows: the flexible polymer material with glucose response is cut into a strip, then conductive silver paste is applied to both ends of the strip, and the biosensor is assembled with wires. The preparation method of the biosensor is as follows: the flexible polymer material with glucose response is cut into a strip, then conductive silver paste is applied to both ends of the strip, and the biosensor is assembled with wires.

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