A leather-based flexible sensor based on in-situ generation of nano-silver from polyphenol compounds and a preparation method and application thereof

Abstract

The application discloses a kind of leather-based flexible sensor based on polyphenol compound in-situ generation nano-silver and its preparation method and application, belong to intelligent leather products and flexible wearable technology field.Lean as flexible substrate, utilize the oxidation-reduction process between polyphenol compound and silver ion evenly deposit nano-silver in collagen fiber, obtain leather-based flexible sensor with good conductivity, sensing and antibacterial performance.Polyphenol compound contains a large number of active phenolic hydroxyl group, as reducing agent and stabilizer, can realize in-situ synthesis and stable existence of nano-silver in leather.Meanwhile, polyphenol compound as crosslinking agent, by forming hydrogen bond and coordination between collagen fiber and nano-silver makes nano-silver fixed in leather, ensure its firm combination.In addition, polyphenol compound and nano-silver synergistic antibacterial, can avoid the particle aggregation and leakage of nano-silver, ensure that leather-based flexible sensor can have excellent conductivity, sensing and antibacterial performance.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent leather products and flexible wearable technologies, and specifically relates to a leather-based flexible sensor based on in-situ generation of nanosilver from polyphenol compounds, as well as a preparation method and application thereof. Background Art

[0002] Leather, a natural polymer material derived from animal hides, has long been used in the manufacture of wearable products. Its unique multi-level structure gives leather excellent mechanical strength and flexibility, making it ideally suited for the substrate material requirements of flexible sensors. In recent years, leather has been gradually incorporated into the design and development of flexible sensors. In addition to possessing sensing properties, other practical properties for leather-based flexible sensors should also be considered. For example, leather-based flexible sensors are typically attached directly to the surface of the skin. Oils and other organic pollutants secreted by the skin in daily life can easily contaminate the sensor, affecting not only its sensing performance but also the growth of bacteria, posing a threat to human health. Therefore, imparting good antibacterial properties to leather-based flexible sensors can fully protect them from bacterial interference.

[0003] As an inorganic antimicrobial agent, silver nanoparticles possess excellent antimicrobial properties, with minimum inhibitory concentrations reaching 10 μg / mL against bacteria such as Escherichia coli and Staphylococcus aureus. After binding to the cell wall or membrane of microorganisms, silver nanoparticles can directly enter the microorganisms and rapidly bind to the sulfhydryl groups of oxygen-metabolizing enzymes, inactivating the enzymes and suffocating the microorganisms by blocking respiratory metabolism. Consequently, they can kill most microorganisms that come into contact with them. Furthermore, silver nanoparticles' surface effects, quantum size effects, and quantum tunneling effects give them exceptional activity and permeability, further enhancing their antimicrobial properties. Furthermore, silver nanoparticles possess excellent electrical conductivity. Therefore, their high antimicrobial and electrical conductivity properties can be exploited to fabricate antimicrobial leather-based flexible sensors. However, due to their high surface energy, direct incorporation of silver nanoparticles into leather can cause particle aggregation and phase separation from the substrate, leading to silver nanoparticle leakage and instability. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a leather-based flexible sensor based on the in-situ generation of nanosilver from polyphenol compounds and a preparation method thereof, so as to improve the conductivity and sensing performance of the leather-based flexible sensor while ensuring that the leather-based flexible sensor has good antibacterial properties.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention discloses a method for preparing a leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds, comprising the following steps:

[0007] 1) dissolving a polyphenol compound in deionized water and adjusting the pH value of the system to 8.0-8.5 to obtain a polyphenol compound solution;

[0008] 2) placing the leather in the polyphenol compound solution obtained in step 1), shaking, and washing to obtain polyphenol compound-modified leather;

[0009] 3) placing the polyphenol compound modified leather obtained in step 2) in a silver source solution, shaking to remove residual silver ions, and vacuum drying to obtain a leather-based flexible sensor based on in-situ generation of nanosilver by polyphenol compounds.

[0010] Preferably, in step 1), the mass ratio of the polyphenol compound to deionized water is (3.5-10.8):(42.5-85.7).

[0011] Preferably, in step 1), the polyphenol compound is any one of tannic acid, polydopamine, luteolin, apigenin, quercetin, kaempferol, myricetin, hesperetin, naringenin, flavanone alcohols, catechin, epicatechin, anthocyanidin, proanthocyanidin and chalcone.

[0012] Preferably, in step 1), the pH value of the system is adjusted to about 8.0-8.5 using tris(hydroxymethyl)aminomethane buffer.

[0013] Preferably, in step 2), the mass of the polyphenol compound solution is 100% of the mass of the leather.

[0014] Preferably, in step 2), the oscillation time is 2 to 15 hours, and the oscillation speed is 100 to 300 r / min.

[0015] Preferably, in step 3), the silver source is any one of silver nitrate, silver acetate and silver fluoride, the concentration of the silver source solution is 0.01-0.75 mol / L, and the mass of the silver source solution is 100% of the mass of the leather.

[0016] Preferably, in step 3), the oscillation time is 3 to 20 hours, and the oscillation speed is 100 to 300 r / min.

[0017] Preferably, in step 3), the vacuum drying temperature is 35-60° C. and the time is 8-15 h.

[0018] In a second aspect, the present invention discloses a leather-based flexible sensor based on in-situ generation of nanosilver from polyphenol compounds, which is prepared by the above-mentioned preparation method. The conductivity of the leather-based flexible sensor is 14.31 to 18.90 S / m.

[0019] Preferably, the leather-based flexible sensor has a relative resistance change of 79.02% to 82.68% at a bending angle of 180°.

[0020] Preferably, the antibacterial rates of the leather-based flexible sensor against Staphylococcus aureus and Escherichia coli are 99.97% to 99.99% and 99.98% to 99.99%, respectively.

[0021] The third aspect of the present invention discloses the application of the above-mentioned leather-based flexible sensor based on in-situ generation of nanosilver from polyphenol compounds in the production of wearable products.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The present invention provides a method for preparing a leather-based flexible sensor based on in-situ generation of nanosilver from polyphenol compounds. The method uses leather as a flexible substrate and polyphenol compounds as a reducing agent to prepare the leather-based flexible sensor by in-situ generation of nanosilver inside collagen fibers.

[0024] (1) The preparation principle of the leather-based flexible sensor based on the in situ generation of silver nanoparticles by polyphenol compounds is as follows: First, the polyphenol compound and leather are mixed evenly under weak alkaline conditions. The polyphenol compound molecules are adsorbed on the surface of the collagen fibers due to the action of phenolic hydroxyl groups. The polyphenols on the outside are oxidized into quinone substances and self-polymerized to form a polyphenol compound coating layer. Subsequently, the leather modified with polyphenol compounds is immersed in a silver source solution. As the solution penetrates into the leather, silver ions are gradually adsorbed by the phenolic hydroxyl groups on the benzene rings of the polyphenol compounds and reduced to zero-valent elemental silver, which further aggregates and grows to form silver nanoparticles. At the same time, the phenolic hydroxyl groups on the polyphenol compounds are oxidized into quinones, and the lone pair electrons and π electrons in their structure can stabilize the silver nanoparticles. During the entire reaction process, the polyphenol compound acts as a reducing agent and stabilizer. The electrochemical potential difference between the polyphenol compound and the silver ions drives the reaction, thereby realizing the green preparation of silver nanoparticles and obtaining a leather-based flexible sensor based on the in situ generation of silver nanoparticles by polyphenol compounds.

[0025] (2) The performance enhancement principle of leather-based flexible sensors based on the in-situ generation of silver nanoparticles by polyphenol compounds is as follows: ① Conductive and sensing performance: Silver nanoparticles, as one of the metal materials with the highest electrical conductivity, are formed in situ inside the collagen fibers and contact each other, forming an electronic conductive path, which gives the leather-based flexible sensor good conductive properties. During the deformation process, the disordered migration of highly conductive silver nanoparticles causes the conductive network structure to change, thereby converting the input mechanical signal into an electrical signal output, so that the leather-based flexible sensor exhibits excellent perception of external force stimulation. ② Antibacterial performance: The cell membrane is the main site of action of polyphenol compounds for antibacterial effect; silver nanoparticles interact with bacterial proteins, deoxyribonucleic acid, lipids and enzymes; in addition, the stabilizing effect of polyphenol compounds on silver nanoparticles increases the contact area and action sites between silver nanoparticles and bacteria, thereby enhancing the killing effect of leather-based flexible sensors on bacteria.

[0026] The leather-based flexible sensor, fabricated using the aforementioned method and utilizing in situ silver nanoparticles generated from polyphenolic compounds, exhibits excellent electrical conductivity, sensing, and antibacterial properties, with a maximum conductivity of 18.90 S / m. When bent at a 180° angle, the relative resistance of the leather-based flexible sensor changes by 82.68%. Furthermore, the leather-based flexible sensor exhibits an antibacterial rate of 99.99% against both Staphylococcus aureus and Escherichia coli. This preparation method is not only simple to operate but also enables in situ formation of silver nanoparticles within the leather, resulting in a leather-based flexible sensor with stable overall performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The conductivity diagram of the leather-based flexible sensor prepared in Example 1; wherein a is the untreated original leather, and b is the leather-based flexible sensor based on the in-situ generation of nanosilver by tannic acid;

[0028] Figure 2 This is a graph showing the relative resistance change of the leather-based flexible sensor prepared in Example 1, wherein the bending angle is 180°;

[0029] Figure 3 This is a graph showing the antibacterial performance test results of the original leather and the prepared leather-based flexible sensor in Example 1. DETAILED DESCRIPTION

[0030] To facilitate understanding of the features and effects of the present invention by those skilled in the art, the following provides a general description and definition of the terms and expressions used in the specification and claims. Unless otherwise indicated, all technical and scientific terms used herein have the ordinary meanings as understood by those skilled in the art regarding the present invention. In the event of conflict, the definitions in this specification shall prevail.

[0031] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0032] Herein, all features such as values, amounts, amounts, and concentrations defined in numerical ranges or percentage ranges are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to include and specifically disclose all possible subranges and individual values ​​within the range (including integers and fractions).

[0033] In this document, unless otherwise specified, “include,” “including,” “contains,” “has” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0034] Herein, all possible combinations of the various technical features in the various embodiments or examples are not described in order to simplify the description. Thus, the various technical features in the various embodiments or examples can be combined with each other as long as there is no contradiction, and all possible combinations should be considered as falling within the scope of the present specification.

[0035] The application provides a preparation method of a leather-based flexible sensor based on in-situ generation of nano-silver from polyphenol compounds, and the specific steps are as follows:

[0036] (1) mixing polyphenol compounds and deionized water in a mass ratio of (3.5-10.8):(42.5-85.7), stirring until dissolved, adjusting the pH value of the system to about 8.0-8.5 with a tris buffer solution, and obtaining a polyphenol compound solution;

[0037] In the formula, the polyphenol compound is any one of tannic acid, polydopamine, luteolin, apigenin, quercetin, kaempferol, myricetin, hesperetin, naringenin, flavanone, catechin, epicatechin, anthocyanin, proanthocyanidin and chalcone.

[0038] (2) placing the leather in the polyphenol compound solution obtained in step (1) and oscillating at 100-300 r / min for 2-15 h, repeatedly washing with deionized water, and obtaining a polyphenol compound modified leather;

[0039] In the formula, the mass of the polyphenol compound solution is 100% of the mass of the leather.

[0040] (3) placing the polyphenol compound modified leather obtained in step (2) in a silver source solution with a concentration of 0.01-0.75 mol / L, oscillating at 100-300 r / min for 3-20 h, repeatedly washing with deionized water to remove residual silver ions, and vacuum drying at 35-60 DEG C for 8-15 h to obtain a leather-based flexible sensor based on in-situ generation of nano-silver from polyphenol compounds.

[0041] In the formula, the silver source is any one of silver nitrate, silver acetate and silver fluoride; and the mass of the silver source solution is 100% of the mass of the polyphenol compound modified leather.

[0042] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not used to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content of the present application, and these equivalent forms also fall within the scope of the appended claims.

[0043] The following examples were prepared using conventional instruments and equipment in the art. Experimental methods in the following examples, where specific conditions are not specified, were generally performed under conventional conditions or according to the conditions recommended by the manufacturer. The various raw materials used in the following examples, unless otherwise specified, were conventional commercially available products, with specifications conventional in the art. In the present specification and the following examples, unless otherwise specified, "%" indicates percentage by weight, "part" indicates parts by weight, and "ratio" indicates weight ratio.

[0044] Example 1

[0045] (1) 3.5 g of tannic acid was added to 58.9 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.1 with tris (hydroxymethyl)aminomethane buffer to obtain a tannic acid solution;

[0046] (2) Leather (cowhide) was placed in a tannic acid solution (the mass of the tannic acid solution was 100% of the mass of the leather), shaken at 100 rpm for 2 h, and repeatedly washed with deionized water to obtain tannic acid-modified leather;

[0047] (3) The tannic acid-modified leather was placed in a 0.48 mol / L silver nitrate solution (the mass of the silver nitrate solution was 100% of the mass of the leather) and shaken at 170 r / min for 8 h. It was repeatedly washed with deionized water to remove residual silver ions and dried in vacuo at 60°C for 11 h to obtain a leather-based flexible sensor with in situ nanosilver generated by tannic acid.

[0048] The performance of the obtained leather-based flexible sensor based on in situ generation of silver nanoparticles by tannic acid was tested.

[0049] The conductivity test results of the original leather (sample a) and the leather-based flexible sensor based on in situ generation of nanosilver by tannic acid (sample b) are shown in Figure 2. Figure 1 As shown, it can be seen that the original leather has no conductive ability, but after the in situ synthesis of nanosilver in it, the leather-based flexible sensor based on the in situ generation of nanosilver by tannic acid has better conductive properties, and its conductivity can reach 17.56S / m.

[0050] The relative resistance change curve of the leather-based flexible sensor based on in-situ generation of nanosilver by tannic acid at a bending angle of 180° is shown in the figure. Figure 2 As shown in the figure, it can be seen that under cyclic bending, the response electrical signal of the leather-based flexible sensor based on the in-situ generation of nanosilver by tannic acid regularly shows peaks, and its relative resistance change value is 81.15%, which shows that it has good sensing ability and adaptability.

[0051] The results of treating Staphylococcus aureus and Escherichia coli plate colonies with the prepared leather-based flexible sensor based on in situ generation of nanosilver by tannic acid are as follows: Figure 3As shown in the figure, compared with the blank control group without sample, the number of Staphylococcus aureus and Escherichia coli in the culture dish was significantly reduced after the addition of leather-based flexible sensor with in situ generated silver nanoparticles based on tannic acid, and the inhibition rate against both bacteria could reach 99.99%, which shows that the prepared leather-based flexible sensor has excellent antibacterial activity.

[0052] Example 2

[0053] (1) 8.7 g of polydopamine was added to 42.5 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.3 with tris (hydroxymethyl)aminomethane buffer to obtain a polydopamine solution;

[0054] (2) Leather (pigskin) was placed in a polydopamine solution (the mass of the polydopamine solution was 100% of the mass of the leather) and shaken at 300 rpm for 6 h, and repeatedly washed with deionized water to obtain polydopamine-modified leather;

[0055] (3) The polydopamine-modified leather was placed in a 0.01 mol / L silver fluoride solution (the mass of the silver fluoride solution was 100% of the mass of the leather) and oscillated at 210 r / min for 3 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 35°C for 13 h to obtain a leather-based flexible sensor with in situ generation of nanosilver based on polydopamine.

[0056] Example 3

[0057] (1) 5.6 g of catechin was added to 77.6 g of deionized water, stirred until dissolved, and the pH of the system was adjusted to about 8.0 with tris(hydroxymethyl)aminomethane buffer to obtain a catechin solution;

[0058] (2) Leather (cowhide) was placed in a catechin solution (the mass of the catechin solution was 100% of the mass of the leather) and shaken at 130 rpm for 10 h, and then repeatedly washed with deionized water to obtain catechin-modified leather;

[0059] (3) The catechin-modified leather was placed in a 0.75 mol / L silver nitrate solution (the mass of the silver nitrate solution was 100% of the mass of the leather) and oscillated at 100 r / min for 11 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 52°C for 8 h to obtain a leather-based flexible sensor with in situ generated silver nanoparticles based on catechin.

[0060] Example 4

[0061] (1) 10.8 g of anthocyanidin was added to 65.4 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.2 with tris (hydroxymethyl)aminomethane buffer to obtain an anthocyanidin solution;

[0062] (2) Leather (sheepskin) was placed in an anthocyanin solution (the mass of the anthocyanin solution was 100% of the mass of the leather) and shaken at 260 r / min for 15 h, and repeatedly washed with deionized water to obtain anthocyanin-modified leather;

[0063] (3) The anthocyanin-modified leather was placed in a 0.32 mol / L silver acetate solution (the mass of the silver acetate solution was 100% of the leather mass) and shaken at 140 r / min for 16 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 47°C for 12 h to obtain a leather-based flexible sensor with in situ generation of nanosilver based on anthocyanin.

[0064] Example 5

[0065] (1) adding 9.2 g of kaempferol to 50.6 g of deionized water, stirring until dissolved, and adjusting the pH of the system to about 8.5 with tris(hydroxymethyl)aminomethane buffer to obtain a kaempferol solution;

[0066] (2) placing leather (pigskin) in a kaempferol solution (the mass of the kaempferol solution is 100% of the mass of the leather) and shaking at 225 rpm for 4 h, and repeatedly washing with deionized water to obtain kaempferol-modified leather;

[0067] (3) The kaempferol-modified leather was placed in a 0.61 mol / L silver fluoride solution (the mass of the silver fluoride solution was 100% of the leather mass) and oscillated at 300 r / min for 5 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 60°C for 15 h to obtain a leather-based flexible sensor with in situ nanosilver generated by kaempferol.

[0068] Example 6

[0069] (1) Add 7.4 g of flavanone alcohol to 85.7 g of deionized water, stir until dissolved, and adjust the pH value of the system to about 8.4 with tris (hydroxymethyl)aminomethane buffer to obtain a flavanone alcohol solution;

[0070] (2) placing leather (cowhide) in a flavanone alcohol solution (the mass of the flavanone alcohol solution is 100% of the mass of the leather) and shaking at 185 rpm for 13 h, and repeatedly washing with deionized water to obtain flavanone alcohol-modified leather;

[0071] (3) The flavanone alcohol-modified leather was placed in a 0.12 mol / L silver acetate solution (the mass of the silver acetate solution was 100% of the leather mass) and shaken at 230 r / min for 20 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 59°C for 9 h to obtain a leather-based flexible sensor with in situ nanosilver generated by flavanone alcohol.

[0072] Example 7

[0073] (1) 5.0 g of luteolin was added to 60.0 g of deionized water, stirred to dissolve, and then the pH value of the system was adjusted to about 8.4 with a tris-hydroxymethyl aminomethane buffer to obtain a luteolin solution;

[0074] (2) The leather (sheepskin) was placed in the luteolin solution (the mass of luteolin was 100% of the mass of the leather) and oscillated at 200 r / min for 10 h, repeatedly washed with deionized water, and a luteolin-modified leather was obtained;

[0075] (3) The luteolin-modified leather was placed in a silver nitrate solution with a concentration of 0.20 mol / L (the mass of the silver nitrate solution was 100% of the mass of the leather), oscillated at 210 r / min for 15 h, repeatedly washed with deionized water to remove residual silver ions, and vacuum dried at 50°C for 9 h to obtain a leather-based flexible sensor based on in-situ generated silver nanoparticles.

[0076] Example 8

[0077] (1) 4.3 g of apigenin was added to 52.0 g of deionized water, stirred to dissolve, and then the pH value of the system was adjusted to about 8.4 with a tris-hydroxymethyl aminomethane buffer to obtain an apigenin solution;

[0078] (2) The leather (cowhide) was placed in the apigenin solution (the mass of apigenin was 100% of the mass of the leather) and oscillated at 220 r / min for 9 h, repeatedly washed with deionized water, and an apigenin-modified leather was obtained;

[0079] (3) The apigenin-modified leather was placed in a silver fluoride solution with a concentration of 0.40 mol / L (the mass of the silver fluoride solution was 100% of the mass of the leather), oscillated at 160 r / min for 12 h, repeatedly washed with deionized water to remove residual silver ions, and vacuum dried at 45°C for 10 h to obtain a leather-based flexible sensor based on in-situ generated silver nanoparticles.

[0080] Example 9

[0081] (1) 10.8 g of epicatechin was added to 85.7 g of deionized water, stirred to dissolve, and then the pH value of the system was adjusted to about 8.3 with a tris-hydroxymethyl aminomethane buffer to obtain an epicatechin solution;

[0082] (2) The leather (pigskin) was placed in the epicatechin solution (the mass of epicatechin was 100% of the mass of the leather) and oscillated at 280 r / min for 5 h, repeatedly washed with deionized water, and an epicatechin-modified leather was obtained;

[0083] (3) The epicatechin-modified leather was placed in a 0.60 mol / L silver nitrate solution (the mass of the silver nitrate solution was 100% of the mass of the leather) and oscillated at 200 r / min for 16 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum dried at 45°C for 8 h to obtain a leather-based flexible sensor with in situ nanosilver generated by epicatechin.

[0084] Example 10

[0085] (1) 5.0 g of quercetin was added to 45.0 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.2 with tris (hydroxymethyl)aminomethane buffer to obtain a quercetin solution;

[0086] (2) placing leather (sheepskin) in a quercetin solution (the mass of quercetin is 100% of the mass of the leather) and shaking at 270 r / min for 5 h, and repeatedly washing with deionized water to obtain quercetin-modified leather;

[0087] (3) The quercetin-modified leather was placed in a 0.50 mol / L silver acetate solution (the mass of the silver acetate solution was 100% of the leather mass) and oscillated at 210 r / min for 16 h. The leather was repeatedly washed with deionized water to remove residual silver ions and dried in vacuo at 45 °C for 8 h to obtain a leather-based flexible sensor based on in situ generation of silver nanoparticles by quercetin.

[0088] Example 11

[0089] (1) 4.6 g of proanthocyanidins were added to 52.5 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.3 with tris (hydroxymethyl)aminomethane buffer to obtain a proanthocyanidin solution;

[0090] (2) Leather (cowhide) was placed in a proanthocyanidin solution (the mass of proanthocyanidin was 100% of the mass of leather) and shaken at 180 r / min for 5 h, and repeatedly washed with deionized water to obtain proanthocyanidin-modified leather;

[0091] (3) The proanthocyanidin-modified leather was placed in a 0.32 mol / L silver fluoride solution (the mass of the silver fluoride solution was 100% of the leather mass) and oscillated at 200 r / min for 18 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum dried at 45°C for 10 h to obtain a leather-based flexible sensor with in situ generation of nanosilver based on proanthocyanidin.

[0092] Example 12

[0093] (1) Add 7.6 g of myricetin to 60.5 g of deionized water, stir until dissolved, and adjust the pH value of the system to about 8.3 with tris(hydroxymethyl)aminomethane buffer to obtain a myricetin solution;

[0094] (2) Leather (pigskin) was placed in a myricetin solution (the mass of myricetin was 100% of the mass of the leather) and shaken at 140 rpm for 10 h, and repeatedly washed with deionized water to obtain myricetin-modified leather;

[0095] (3) The myricetin-modified leather was placed in a 0.28 mol / L silver fluoride solution (the mass of the silver fluoride solution was 100% of the leather mass) and oscillated at 150 r / min for 16 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum dried at 45°C for 10 h to obtain a leather-based flexible sensor with in situ nanosilver generated by myricetin.

[0096] Example 13

[0097] (1) 6.9 g of hesperetin was added to 50.0 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.3 with tris (hydroxymethyl)aminomethane buffer to obtain a hesperetin solution;

[0098] (2) Leather (cowhide) was placed in a hesperetin solution (the mass of hesperetin was 100% of the mass of the leather) and shaken at 280 rpm for 6 h, and repeatedly washed with deionized water to obtain hesperetin-modified leather;

[0099] (3) The hesperetin-modified leather was placed in a 0.60 mol / L silver nitrate solution (the mass of the silver nitrate solution was 100% of the mass of the leather) and oscillated at 200 r / min for 16 h. The leather was repeatedly washed with deionized water to remove residual silver ions and vacuum-dried at 38°C for 8 h to obtain a leather-based flexible sensor with in situ nanosilver generated based on hesperetin.

[0100] Example 14

[0101] (1) 4.2 g of naringenin was added to 53.0 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to approximately 8.4 with tris(hydroxymethyl)aminomethane buffer to obtain a naringenin solution;

[0102] (2) Leather (pigskin) was placed in a naringenin solution (the mass of naringenin was 100% of the mass of the leather) and shaken at 200 rpm for 10 h, and then repeatedly washed with deionized water to obtain naringenin-modified leather;

[0103] (3) The naringenin-modified leather was placed in a 0.20 mol / L silver nitrate solution (the mass of the silver nitrate solution was 100% of the leather mass) and shaken at 210 r / min for 10 h. The leather was repeatedly washed with deionized water to remove residual silver ions and dried in vacuo at 52°C for 9 h to obtain a leather-based flexible sensor with in situ nanosilver generated based on naringenin.

[0104] Example 15

[0105] (1) 5.0 g of chalcone was added to 58.0 g of deionized water, stirred until dissolved, and the pH value of the system was adjusted to about 8.4 with tris (hydroxymethyl)aminomethane buffer to obtain a chalcone solution;

[0106] (2) placing the leather (sheepskin) in a chalcone solution (the mass of chalcone is 100% of the mass of the leather) and shaking it at 220 r / min for 8 h, and repeatedly washing it with deionized water to obtain chalcone-modified leather;

[0107] (3) The chalcone-modified leather was placed in a 0.50 mol / L silver acetate solution (the mass of the silver acetate solution was 100% of the leather mass) and shaken at 170 r / min for 15 h. The leather was repeatedly washed with deionized water to remove residual silver ions and dried in vacuo at 58°C for 10 h to obtain a leather-based flexible sensor with in situ nanosilver generated based on chalcone.

[0108] Table 1 shows the performance test results of the leather-based flexible sensors based on in-situ polyphenolic silver nanoparticle generation prepared in Examples 1 to 6. As can be seen from the table, the leather-based flexible sensors based on in-situ polyphenolic silver nanoparticle generation prepared using the above method exhibit excellent electrical conductivity, sensing, and antibacterial properties, with a maximum conductivity of 18.90 S / m. When bent at a 180° angle, the relative resistance change of the leather-based flexible sensors based on in-situ polyphenolic silver nanoparticle generation reached 82.68%. Furthermore, the antibacterial rates of the leather-based flexible sensors against Staphylococcus aureus and Escherichia coli reached 99.99%, demonstrating that the leather-based flexible sensors based on in-situ polyphenolic silver nanoparticle generation possess excellent electrical conductivity, sensing, and antibacterial properties.

[0109] Table 1 Performance of nanosilver / leather-based flexible sensors

[0110]

[0111] The above content is only for explaining the technical idea of ​​the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds, characterized in that: Here are the steps: 1) dissolving a polyphenol compound in deionized water and adjusting the pH value of the system to 8.0-8.5 to obtain a polyphenol compound solution; wherein the polyphenol compound is any one of tannic acid, polydopamine, luteolin, apigenin, quercetin, kaempferol, myricetin, hesperetin, naringenin, flavanol, catechin, epicatechin, anthocyanidin, proanthocyanidin, and chalcone; 2) placing the leather in the polyphenol compound solution obtained in step 1), shaking, and washing to obtain polyphenol compound-modified leather; The mass of the polyphenol compound solution is 100% of the mass of the leather; 3) placing the polyphenol compound-modified leather obtained in step 2) in a silver source solution, shaking to remove residual silver ions, and vacuum drying to obtain a leather-based flexible sensor based on in-situ generation of nanosilver by the polyphenol compound; The concentration of the silver source solution is 0.01~0.75 mol / L, and the mass of the silver source solution is 100% of the mass of the leather.

2. The method for preparing a leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to claim 1, characterized in that: In step 1), the mass ratio of the polyphenol compound to deionized water is (3.5-10.8): (42.5-85.7).

3. The method for preparing a leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to claim 1, characterized in that: In step 3), the silver source is any one of silver nitrate, silver acetate and silver fluoride.

4. The method for preparing a leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to claim 1, characterized in that: In step 3), the vacuum drying temperature is 35-60°C and the time is 8-15 h.

5. The leather-based flexible sensor based on in-situ generation of nanosilver from polyphenol compounds, prepared by the preparation method according to any one of claims 1 to 4, characterized in that: The electrical conductivity of the leather-based flexible sensor is 14.31-18.90 S / m.

6. The leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to claim 5, characterized in that: The leather-based flexible sensor has a relative resistance change of 79.02% to 82.68% at a bending angle of 180°.

7. The leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to claim 5, characterized in that: The antibacterial rates of the leather-based flexible sensor against Staphylococcus aureus and Escherichia coli are 99.97%-99.99% and 99.98%-99.99%, respectively.

8. Use of the leather-based flexible sensor based on in-situ generation of silver nanoparticles from polyphenol compounds according to any one of claims 5 to 7 in the manufacture of wearable products.

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