KR102280104B1 - Method for preparing silver nanowire using m13 bacteriophage - Google Patents

Abstract

The present invention relates to a method for producing a silver nanowire based on M13 bacteriophage, and more specifically, it does not use an additional reducing agent because it uses the reducing power of the M13 bacteriophage itself, and uses the M13 bacteriophage as a template. It relates to a method for manufacturing silver nanowires based on M13 bacteriophage that can be formed long in one direction and can be manufactured in the shape of a single crystal by manufacturing the nanowires in an optimal process environment.

Description

Manufacturing method of silver nanowires based on M13 bacteriophage {METHOD FOR PREPARING SILVER NANOWIRE USING M13 BACTERIOPHAGE}

The present invention relates to a method for producing a silver nanowire based on M13 bacteriophage, and more specifically, it does not use an additional reducing agent because it uses the reducing power of the M13 bacteriophage itself, and uses the M13 bacteriophage as a template. It relates to a method for manufacturing silver nanowires based on M13 bacteriophage that can be formed long in one direction and can be manufactured in the shape of a single crystal by manufacturing the nanowires in an optimal process environment.

1D nanomaterials have played a crucial role in the development of numerous devices such as waveguides, biosensors, filters, photovoltaic cells and batteries. Despite the various advantages of these materials, it is still challenging to fabricate high-quality metal nanowires in an efficient and scalable manner. More specifically, long monocrystalline nanowires are more advantageous than short polycrystalline nanowires for optoelectronic applications. It is impossible to avoid the internal ohmic resistance of nanowires in nanodevice applications. In addition, crystallinity can affect not only the electronic properties, but also the optical properties of nanowires. Rising domain boundaries and surface roughness due to polycrystallinity can limit the surface plasmon propagation length as surface plasmons can be reduced. Moreover, the overall quality and related properties depend on the length of the nanowire. When fabricating optoelectronic devices with nanowire networks, individual nanowire lengths of 100 μm or more must be achieved to realize their value in practical applications. However, the reality is that it is very difficult to manufacture long nanowires from single crystals.

In order to solve this problem, as a method for synthesizing a metal nanowire having a long length, using a bacteriophage as a template may be one alternative. Phages are bionanowires, like filamentous tubes that encapsulate single-stranded DNA. In addition, it has a high density of chemical reactors and is used as an attractive material for synthetic molds. In another aspect, the virus direct self-assembly technique is completely processable in solution, simple and relatively inexpensive. Although phage direct growth has many characteristics, there are disadvantages that need to be addressed. First, the length of the phage limits the length of nanowires that can be grown. Second, viruses compete to aggregate in solution, forming nanowires of poor quality.

Therefore, in order to supplement the above-mentioned problems, the present inventors recognized that it is urgent to develop a method for manufacturing single-crystal metal nanowires that can be grown in one direction using bacteriophages, and completed the present invention.

Republic of Korea Patent Publication No. 10-2018-0044252

Materials Research Express, 2018, 5(2)

An object of the present invention is not to use an additional reducing agent using the reducing power of M13 bacteriophage itself, and the length of the silver nanowire in one direction from nanometers (nm) to micrometers (μm) using M13 bacteriophage as a template. It is to provide a method for manufacturing silver nanowires based on M13 bacteriophage that can be adjusted to produce short or long.

Another object of the present invention is to provide a method for producing silver nanowires based on M13 bacteriophage capable of producing single-crystal silver nanowires by establishing a process environment using an optimal solvent in consideration of the binding affinity between the solvent and silver ions. will do

Another object of the present invention is to provide a method for producing silver nanowires based on M13 bacteriophage, which can be easily applied to all silver based on molecular-level interactions and can produce nanowires as single crystals with a uniform surface. will provide

The problems of the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention provides a method for producing a silver nanowire based on bacteriophage.

Hereinafter, the present specification will be described in more detail.

The present invention provides a method for producing a silver nanowire comprising the following steps.

(S1) preparing a first solution by adding M13 bacteriophage to a solvent;

(S2) preparing a second solution by adding an Ag salt to a solvent; and

(S3) preparing a silver nanowire by adding the second solution to the first solution.

In the present invention, the solvent is pyridine, and the silver salt is silver nitrate (AgNO ₃ , Silver nitrate).

In the present invention, the silver nanowire is characterized in that it is a single crystal.

In the present invention, the first solution and the second solution are characterized in that 1: 65 to 95 mg / mL ratio is mixed.

In the present invention, the silver nanowire is characterized in that it is formed to a length of 900 nm to 600 μm.

The manufacturing method of the metal nanowire of the present invention does not use an additional reducing agent using the reducing power of the M13 bacteriophage itself, and the metal nanowire in one direction using the M13 bacteriophage as a template from nanometer (nm) units to micrometers (μm) ) can be made short or long by adjusting the length up to the unit.

In addition, the method for manufacturing a metal nanowire of the present invention can manufacture a single crystal metal nanowire by establishing a process environment using an optimal solvent in consideration of the binding affinity between the solvent and the metal ion.

In addition, the method for manufacturing metal nanowires of the present invention is easily applied to all metals based on molecular-level interactions, so that it is possible to manufacture nanowires as single crystals uniformly on the surface without being limited to metal types.

Effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a graph calculating the binding affinity between silver (Ag, silver) ions and M13 bacteriophage according to the solvent.
2 is a TEM image confirming the crystallization of silver ions around M13 bacteriophage using silver nanowires (Example 1) prepared using pyridine.
3 is a CV graph confirming the electrochemical properties of silver nanowires according to solvents (pyridine, ethanol and water).
4 is an SEM image of silver nanowires prepared using pyridine (Example 1), ethanol (Comparative Example 1), and water (Comparative Example 2) as solvents.
5 is an EDS mapping image confirming that silver is uniformly formed as a single crystal on the surface of the silver nanowire.
6 is an SEM image confirming the unidirectional growth of silver nanowires prepared with or without the addition of M13 bacteriophage.
7 is an SEM image of silver nanowires prepared according to a mixing concentration ratio of the first solution and the second solution.

The terms used in this specification have been selected as currently widely used general terms as possible while considering the functions in the present invention, which may vary depending on the intention or precedent of a person skilled in the art, the emergence of new technology, and the like. In addition, in a specific case, there is a term arbitrarily selected by the applicant, and in this case, the meaning will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term and the overall content of the present invention, rather than the name of a simple term.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Numerical ranges are inclusive of the values defined in that range. Every maximum numerical limitation given throughout this specification includes all lower numerical limitations as if the lower numerical limitation were expressly written. Every minimum numerical limitation given throughout this specification includes all higher numerical limitations as if the higher numerical limitation were expressly written. Any numerical limitation given throughout this specification shall include all numerical ranges within the broader numerical range, as if the narrower numerical limitation were expressly written.

Hereinafter, examples of the present invention will be described in detail, but it is obvious that the present invention is not limited by the following examples.

The present invention provides a method for producing a silver nanowire comprising the following steps.

(S1) preparing a first solution by adding M13 bacteriophage to a solvent;

(S2) preparing a second solution by adding an Ag salt to a solvent; and

(S3) preparing a silver nanowire by adding the second solution to the first solution.

More specifically, the step (S1) may be a step of preparing a first solution by adding M13 bacteriophage to a solvent.

The M13 bacteriophage is a filamentous bacteriophage and means a bacteriophage composed of a long cylindrical protein coat having a circular (single strand) DNA. More specifically, the M13 bacteriophage has a protein coat composed of five different types of proteins (P3, P6, P7, P8, P9), but most of them are P8 expressed in gene 8, which constitutes the coat protein of the phage. The structure of P8 is composed of α-helical particles and constitutes the long envelope of the phage in repetitive alignment. Five types of envelope proteins constituting M13 bacteriophage exist for structural stability of M13 bacteriophage particles. In particular, P3 plays an essential role in host cell recognition and infection, and consists of subdivision domains. .

The M13 bacteriophage applied to the present invention may be an M13 bacteriophage in which the EDG peptide (Glutamic acid (E) - Aspartic acid (D) - Glycine acid (G)) is present at the end of the pVIII peptide. More specifically, the EDG peptide has a structure in which Glutamic acid (E) and Aspartic acid (D) have one surplus electron at the ends, and due to this, 2 x 2700 surplus electrons exist on the surface of the M13 bacteriophage, resulting in a significant negative electrode. characteristics will be displayed. In addition, M13 bacteriophage having an EDG peptide at the end of the pVIII peptide may exhibit excellent hydrophilicity.

The M13 bacteriophage may be used as a template of the silver nanowire. When the M13 bacteriophage is used as a template of the silver nanowire, it has a unidirectional growth direction and is not in the form of a nanocylinder grown in multiple directions, but in a linear form of silver nanowires that are grown in one direction. It is possible.

The M13 bacteriophage may be added to the solvent and vortexed for 5 to 30 minutes to uniformly disperse. By performing the vortex, M13 bacteriophage can be uniformly dispersed in the solvent.

The solvent may be pyridine. When the pyridine is used as a solvent, the crystallization rate of the silver ions can be controlled by using the excellent binding affinity between the silver ions to be crystallized on the surface of the M13 bacteriophage, and this results in the crystallization of silver in a single crystal form on the surface of the M13 bacteriophage. It becomes possible to manufacture silver nanowires.

In the present invention, the step (S2) may be a step of preparing a second solution by adding a silver salt to a solvent.

The silver salt may be silver nitrate (AgNO ₃ , Silver nitrate). More specifically, in the case of silver sulfate (Ag ₂ SO ₄ ), 0.83 g/100 mL (at 25 °C), in the case of silver chloride (AgCl), 520 µg/100 mL (at 50 °C), ch/ While only 100 mL (based on 20°C), the silver nitrate is 256 g/100 mL (based on 25°C), and has a high solubility of 122 g/100 mL even in an environment of 0°C. As the solubility of the silver nitrate is excellent, the binding affinity between solvents can be increased, so that the silver salt is most preferably silver nitrate.

The solvent may be pyridine. More specifically, since the binding affinity between the silver ion and pyridine of the silver salt is excellent, the interaction energy between the silver and pyridine is the most stable. In other words, due to the strong binding (excellent binding affinity) between silver and pyridine, when silver ions are crystallized in the M13 bacteriophage, they can be slowly crystallized, which results in the formation of single-crystal silver nanowires on the surface of the M13 bacteriophage. can be formed.

The pyridine may be a solvent that limits the reduction kinetics between the silver ions. More specifically, the pyridine may have the most stable and excellent silver ion migration properties when silver ions are crystallized on the surface of M13 bacteriophage.

In the present invention, the step (S3) may be a step of preparing a silver nanowire by adding the second solution to the first solution.

When adding the second solution to the first solution, additional stirring may be performed for uniform mixing. The stirring may be carried out for 1 to 30 minutes, preferably for 10 to 20 minutes.

When the silver nanowire is prepared by adding the second solution to the first solution, maintaining the silver nanowire at 25 to 28° C. may be additionally included. The holding may be performed for 1 to 10 hours, preferably for 3 to 7 hours, and most preferably for 4 to 6 hours, the time at which the step of the silver nanowire is completed If so, it can be easily applied.

The first solution and the second solution may be mixed in a ratio of 1: 65 to 95 mg/mL. When the first solution and the second solution are mixed at a ratio of 1: 65 mg/mL or less, the amount of silver ions crystallized in the M13 bacteriophage is reduced, making it difficult to form silver nanowires with uniform spacing, When the first solution and the second solution are mixed in excess of 1: 95 mg/mL, the amount of silver ions crystallized in the M13 bacteriophage is excessive, causing aggregation of silver ions, which prevents the production of single-crystal silver nanowires it becomes impossible Accordingly, the first solution and the second solution are preferably mixed in a ratio of 1: 65 to 95 mg/mL.

The silver nanowire may be formed to a length of 900 nm to 600 μm. More specifically, the silver nanowire is generated on the surface of M13 bacteriophage, and since the length of the M13 bacteriophage is about 880 nm, the silver nanowire may be formed from a length of 900 nm, which is longer than the length of the M13 bacteriophage. have. The silver nanowire can be manufactured to a length of not only nanometers (nm) but also micrometers (μm), so that it can be used for electrodes requiring low junction density and resistance loss.

Advantages and features of the present invention, and methods of achieving them, will become apparent with reference to the embodiments described below in detail. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only the embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention pertains It is provided to fully inform those who have the scope of the invention, and the present invention is only defined by the scope of the claims.

The reagents and solvents mentioned below were purchased from Sigma-Aldrich Korea unless otherwise specified, and the Gaussian 09 program was used to calculate the quantum mechanics-based general density function (DFT), and to optimize the adsorption structure of GD peptide and silver ions. For this purpose, the B3LYP hybrid functional with LanL2DZ basis set was used for RH, and the charge distribution simulation was calculated using the Vienna ab-initio simulation package. In addition, cyclic voltammetry (CV) was measured with The K0264 Micro-Cell Kit / AMETEK Scientific instruments (program DY2000), and the M13 bacteriophage used in Examples and Comparative Examples has a length of about 880 nm, about 6.6 A diameter of nm, M13 bacteriophage containing about 2700 peptides on the surface was used.

Example 1. Silver nanowire 1 of the present invention

M13 bacteriophage containing the EDG peptide at the end of the pVIII peptide was added to pyridine and vortexed for 15 minutes to prepare a first solution of 0.01 mg/mL of M13 bacteriophage dispersed in pyridine. Then, silver nitrate (AgNO ₃ ) was added to pyridine to prepare a second solution of 5 mM. Next, the second solution was added to the first solution and stirred for 15 minutes to prepare silver nanowires, and the silver nanowires were dried at room temperature for 5 hours to finally prepare silver nanowires.

Comparative Example 1. Comparative silver nanowire 1 prepared in ethanol

M13 bacteriophage was added to ethanol, and the M13 bacteriophage was dispersed in pyridine by vortexing for 15 minutes to prepare a first solution of 0.01 mg/mL. Then, silver nitrate (AgNO ₃ ) was added to ethanol to prepare a second solution of 5 mM. Next, the second solution was added to the first solution and stirred for 15 minutes to prepare a silver nanowire, and the silver nanowire was dried at room temperature for 5 hours to finally prepare a comparative silver nanowire 1.

Comparative Example 2. Comparative silver nanowire 2 prepared in water

M13 bacteriophage was added to water, and the M13 bacteriophage was dispersed in pyridine by vortexing for 15 minutes to prepare a first solution of 0.01 mg/mL. Then, silver nitrate (AgNO ₃ ) was added to water to prepare a second solution of 5 mM. Next, the second solution was added to the first solution and stirred for 15 minutes to prepare a silver nanowire, and the silver nanowire was dried at room temperature for 5 hours to finally prepare a comparative silver nanowire 2.

Comparative Example 3. Comparative silver nanowire 3 without the addition of M13 bacteriophage

Silver nitrate (AgNO ₃ ) was added to pyridine to prepare silver nanowires, and the silver nanowires were dried at room temperature for 5 hours to finally prepare comparative silver nanowires 3 .

Comparative Example 4. Comparative silver nanowire 4 according to the concentration of M13 bacteriophage added

M13 bacteriophage was added to pyridine, and the M13 bacteriophage was dispersed in pyridine by vortexing for 15 minutes to prepare a first solution of 0.005 mg/mL. Then, silver nitrate (AgNO ₃ ) was added to ethanol to prepare a second solution of 5 mM. Next, the second solution was added to the first solution and stirred for 15 minutes to prepare a silver nanowire, and the silver nanowire was dried at room temperature for 5 hours to finally prepare a comparative silver nanowire 4.

Comparative Example 5. Comparative silver nanowire 5 according to the concentration of M13 bacteriophage added

M13 bacteriophage was added to pyridine, and the M13 bacteriophage was dispersed in pyridine by vortexing for 15 minutes to prepare a first solution of 0.1 mg/mL. Then, silver nitrate (AgNO ₃ ) was added to ethanol to prepare a second solution of 5 mM. Next, the second solution was added to the first solution and stirred for 15 minutes to prepare a silver nanowire, and the silver nanowire was dried at room temperature for 5 hours to finally prepare a comparative silver nanowire 5.

Experimental Example 1. Confirmation of binding affinity according to solvent

Silver ions and solvents through quantum mechanics-based universal density function (DFT) calculation method; And the adsorption energy (binding affinity) between the silver ion and the M13 bacteriophage was confirmed, and the results are shown in FIG. 1 .

Referring to FIG. 1 , it can be seen that the energy of pyridine is the largest in the adsorption energy between pyridine, acetone, ethanol, and water and silver ions, which indicates that it has the most stable bond. More specifically, it means that the larger the adsorption energy between the silver ions and the solvent, the slower the silver ions crystallize on the surface of the M13 bacteriophage.

Experimental Example 2. Confirmation of crystallization of silver ions

TEM was measured to confirm the crystallization of silver ions around M13 bacteriophage using silver nanowires (Example 1) prepared using pyridine, and the results are shown in FIG. 2 .

Referring to FIG. 2 , in the case of silver nanowires prepared using pyridine (Example 1), due to the high binding affinity between silver ions and pyridine, the crystallization rate at which silver ions are crystallized on the surface of M13 bacteriophage is sufficiently slow. Silver nanowires could be produced by natural drying without pretreatment. More specifically, FIGS. 2(a) to 2(c) show that silver ions gather on the surface of M13 bacteriophage over time in the manufacturing process of silver nanowires.

Experimental Example 3. Confirmation of electrochemical properties according to solvent

In order to confirm the electrochemical properties according to the solvent, the CV of the solvent (pyridine, ethanol and water), the solvent + M13 bacteriophage and the solvent + M13 bacteriophage + silver ions were measured. The CV was measured in a voltage range of -2 to 2 V, and silver chloride (AgCl) was used as a reference, and the results are shown in FIG. 3 .

Referring to Figure 3 (a), the electrochemical activity was not confirmed in the pure pyridine solvent, when M13 bacteriophage was added, a very faint oxidation-reduction reaction was confirmed. In addition, in the case of a silver nanowire containing pyridine + M13 bacteriophage + silver ions (Example 1), two distinct peaks, a reduction peak (i) and an oxidation peak (i'), are identified, which indicate that the single crystal silver nanowire means formed. Referring to Figure 3 (b), in the case of ethanol, it can be confirmed that the oxidation-reduction reaction from the original. In addition, in the case of silver nanowires containing ethanol + M13 bacteriophage + silver ions (1 in comparison), two redox pairs (ii-ii', iii-iii') are identified, which are polycrystalline silver nanowires. means that it is formed. Referring to FIG. 3(c) , it can be confirmed that the oxidation-reduction reaction is originally exhibited in the case of water as in ethanol. In addition, in the case of silver nanowires containing water + M13 bacteriophage + silver ions (Comparative Example 2), multiple oxidation-reduction pairs were confirmed, because crystalline silver nanowires were not properly formed. From the above results, it is proven that single crystal nanowires can be formed only from silver nanowires using pyridine.

Experimental Example 4. SEM image confirmation

SEM was measured to confirm that the silver nanowires prepared by the method of the present invention were formed into single crystals, and the results are shown in FIG. 4 .

Referring to FIG. 4(a), it can be seen that the silver nanowires (Example 1) prepared using pyridine are uniformly crystallized in the form of single crystals on the surface of M13 bacteriophage. This was the same as the result of the electrochemical properties confirmed in Experimental Example 2. On the other hand, referring to FIG. 4( b ), it can be seen that the silver nanowires prepared using ethanol (Comparative Example 1) were crystallized in the form of polycrystals. In addition, referring to FIG. 4( c ), in the case of silver nanowires prepared using water (Comparative Example 2), it can be confirmed that crystalline silver was not crystallized, so that the nanowires were not properly prepared. It can be seen that the above results also show the same results as the electrochemical experiments confirmed in Experimental Example 2.

From the above results, when ethanol is used as a solvent, silver nanowires are formed, but the surface is rough in the form of polycrystals rather than single crystals, which means that the reduction kinetics in migration is not sufficient for ethanol to control silver ions. suggest that it is not In addition, since water has a low binding affinity between silver ions, it can be expected that the bond with silver ions is rapidly decomposed, and it is rapidly combined with M13 bacteriophage to be prepared in an aggregated form. Therefore, it has been demonstrated that the optimal solvent for forming single-crystal silver nanowires is pyridine.

Experimental Example 5. Confirmation of crystallization uniformity of silver nanowires

EDS was measured to confirm that the silver nanowires prepared by the method of the present invention were uniformly formed as single crystals on the surface of M13 bacteriophage, and the results are shown in FIG. 5 .

Referring to FIG. 5 , it can be seen that the silver nanowire (Example 1) prepared using pyridine is formed by uniformly crystallizing silver ions into single crystals on the surface of M13 bacteriophage.

Experimental Example 6. Confirmation of unidirectional growth of silver nanowires

SEM was measured to confirm the unidirectional growth of silver nanowires prepared with or without the addition of M13 bacteriophage, and the results are shown in FIG. 6 .

Referring to Figure 6 (a), in the case of Comparative Example 3 to which the M13 bacteriophage is not added, it can be seen that the crystal growth is not made, so that the nanowire itself is not formed. On the other hand, in the case of the silver nanowire of the present invention prepared in Example 1, it can be confirmed that the crystal is unidirectional. From the above results, it can be confirmed that unidirectional silver nanowires are prepared due to the addition of M13 bacteriophage.

Through the above results, it can be confirmed that the growth direction during the crystallization process of silver ions on the surface of M13 bacteriophage greatly affects the final structure of the silver nanowire. If the M13 bacteriophage is not added, the directionality of the silver nanowires will be lost, so it will be formed in the form of silver nanocylinders instead of silver nanowires.

Experimental Example 7. Confirmation of the optimal ratio of silver nanowires

SEM was measured to confirm the optimal concentration ratio of M13 bacteriophage added in preparing silver nanowires, and the results are shown in FIG. 7 .

Referring to Figure 7 (a), the silver nanowires (Example 1) prepared by mixing the first solution and the second solution in a ratio of 1: 85 mg/mL was confirmed that the silver nanowires were prepared in an appropriate amount and thickness. can On the other hand, referring to FIG. 7(b), in the case of comparative silver nanowire 4 (Comparative Example 4) prepared by mixing the first solution and the second solution in a ratio of 1: 170 mg/mL, silver crystallized in M13 bacteriophage It can be seen that the amount of ions is reduced, so that the silver nanowires are not properly formed. In addition, referring to FIG. 7(c), in the case of comparative silver nanowire 5 (Comparative Example 5) prepared by mixing the first solution and the second solution in a ratio of 100:85 (20:17) mg/mL, M13 It can be confirmed that the amount of silver ions crystallized in the bacterial phage is excessive, causing aggregation of silver ions, which makes it impossible to manufacture single-crystal silver nanowires. From the above results, it was demonstrated that the optimal ratio in preparing silver nanowires is that the first solution and the second solution are mixed at a ratio of 1: 65 to 95 mg/mL.

From the above description, those skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without changing the technical spirit or essential characteristics thereof. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims (5)

(S1) preparing a first solution by adding M13 bacteriophage to pyridine;
(S2) adding silver nitrate (AgNO ₃ , Silver nitrate) to pyridine to prepare a second solution; and
(S3) adding the second solution to the first solution to prepare a single crystal silver nanowire;
The first solution and the second solution are mixed in a ratio of 1: 65 to 95 mg/mL,
The silver nanowire is a method of manufacturing a silver nanowire, characterized in that it is formed in a length of 900 nm to 600 μm. delete delete delete delete

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