A hexagonal boron nitride-graphene planar heterojunction and its application in the targeted delivery of biomacromolecules

Abstract

The present invention discloses a hexagonal boron nitride-graphene planar heterojunction and its application in the directional delivery of biomacromolecules. The present invention is a nanoscale planar heterojunction composed of a specific pattern of hexagonal boron nitride and peripheral graphene. Nanoscale water droplets adsorbed on the planar heterojunction can move spontaneously from one end to the other. Water droplets can carry biomacromolecules with different functions, such as nucleic acids and polypeptides, thereby achieving directional transport of functional biomacromolecules. Different from other forms of molecular directional transport methods, the present invention can rely on the wettability gradient of the graphene-hexagonal boron nitride planar heterojunction to achieve transport. It has a simple structure and does not require an external force field or additional energy supply. The speed and distance of transport can be controlled by adjusting the pattern shape of the hexagonal boron nitride. The biomacromolecules always maintain their structural stability and biological activity during the transport process. The present invention has great application potential in the fields of nano-drug delivery, biosensor design, etc.

Description

Technical Field

[0001] The present invention belongs to the field of nanomaterial design and relates to the application of nanomaterials with a wettability gradient in the directional transport of biomacromolecules, and specifically to a hexagonal boron nitride-graphene planar heterojunction and its application in the directional delivery of biomacromolecules. Background Art

[0002] The self-propelled motion of water droplets on nanomaterial surfaces has attracted considerable attention due to its advantage of requiring no external actuating devices. Over the past few decades, inspired by the widespread presence of surface-structured materials in natural systems, researchers have successfully designed and utilized surface-structured materials to simulate the self-propelled transport of water droplets. Among these, wettability gradient materials have been demonstrated theoretically, experimentally, and simulated to possess the potential for directional transport of water droplets at the nanoscale and microscale. For example, chemically modified artificial surface materials can achieve rapid water droplet transport without external energy input. Furthermore, utilizing directional transport of water droplets to achieve rapid and stable delivery of biomacromolecules has important applications in biosensing, drug delivery, and bio-nanomedical device design. However, given the inherent physicochemical properties of biomacromolecules (e.g., hydrophilicity or hydrophobicity) and their potential interactions with material surfaces, the design of self-propelled biomacromolecule systems still faces various challenges. Summary of the Invention

[0003] Addressing the current technological gap in self-propelled transport of biomacromolecules, the present invention designs a hexagonal boron nitride-graphene planar heterojunction and its application in the targeted delivery of biomacromolecules. The hexagonal boron nitride-graphene planar heterojunction is a track system for the targeted transport of biomacromolecules using a wettability gradient. This nanoscale planar heterojunction, composed of a specifically patterned hexagonal boron nitride and a surrounding graphene structure, allows nanoscale water droplets adsorbed on this planar heterojunction to spontaneously migrate from one end to the other.

[0004] The technical solution adopted in the present invention is as follows:

[0005] A hexagonal boron nitride-graphene planar heterojunction is first fabricated by etching edges into the hexagonal boron nitride (hBN) layer, creating a triangular pattern throughout the hBN. Graphene crystals then grow along the edges of the triangular pattern, ultimately forming a strip-shaped planar heterojunction (G-hBN) with the hBN in the middle covalently bonded to the graphene on either side. This heterojunction serves as a transport track for self-propelled nanodroplets. These nanodroplets, containing dissolved biomacromolecules, are adsorbed by the G-hBN and spontaneously migrate toward the base of the hBN triangle.

[0006] Furthermore, the hBN triangular pattern is etched using a nanofabrication process. The triangular pattern can be, but is not limited to, a triangle, a trumpet, a semi-spindle, a trapezoid, or the like. The length of the triangular pattern can range from tens to hundreds of nanometers.

[0007] Furthermore, the graphene at the edge of the hBN approximately triangular pattern is achieved by graphene covalent growth technology.

[0008] Furthermore, a nanodroplet carrying a biomacromolecule is adsorbed onto the heterojunction material, such that the contact surface between the nanodroplet and the material is centered on hBN and flanked by graphene. (If the hBN pattern is an isosceles triangle, the vertex of the triangle is selected as the nanodroplet's area; if the hBN pattern is other irregular shapes, the contact surface is ensured to be centered on hBN and flanked by graphene.) Without the need for an external drive device, the nanodroplet instantly accelerates toward the base of the hBN triangle until it completely enters the hBN region, completing medium- and long-distance transport in microseconds. The biomacromolecules transported by the nanodroplet are various nucleic acids or polypeptides.

[0009] Furthermore, the angle of the hBN approximate triangular pattern (the vertex angle if the hBN pattern is an isosceles triangle; the smaller angle if the hBN pattern is another irregular shape) can be altered through nanofabrication etching, enabling regulation of transport speed and distance. The speed of directional transport can be varied by adjusting the angle of the boron nitride approximate triangular pattern, with the speed varying between 0.01 m / s and 0.1 m / s. The angle of the approximate triangular pattern ranges from 0 degrees to 60 degrees. The distance of directional transport can be varied by adjusting the angle of the boron nitride approximate triangular pattern, with the distance varying between tens of nanometers and hundreds of nanometers. When the angle of the approximate triangular pattern is 9.4 degrees, both transport speed and distance can be achieved, reaching a transport speed of 0.05 m / s and a transport distance of 78 nanometers (a distance approximately 50 times the size of the biomacromolecule being transported).

[0010] Furthermore, in the planar heterojunction, the outer graphene is covalently bonded to the central hexagonal boron nitride, forming a complete strip-like track. The overall two-dimensional planar track can be rectangular, square, elliptical, or other shapes, but is not limited to these two-dimensional planar structures. The width of the two-dimensional planar track ranges from a few nanometers to tens of nanometers, and the length ranges from tens of nanometers to hundreds of nanometers. This planar heterojunction achieves directional transport without the need for additional energy sources or external force fields. The speed of directional transport is stable and is not affected by changes in the concentration of biomacromolecules in the nanodroplet.

[0011] Furthermore, the transport speed and stability of biomacromolecules by nano-water droplets are characterized by molecular dynamics (MD) simulations, which utilize all-atom molecular dynamics to simulate the transport of target molecules across a planar heterojunction with a specific patterned frame. The MD simulations, using all-atom molecular dynamics simulations, demonstrate stable, directional, and spontaneous movement of water droplets ranging from a few nanometers to tens of nanometers in size along the track.

[0012] The inventive principle of the present invention is:

[0013] Graphene, a widely studied and applied planar hydrophobic material, can be integrated with the relatively hydrophilic planar material hexagonal boron nitride (hBN) to form a heterojunction (G-hBN). Currently, G-hBN integration technology enables precise spatial control of material patterns, and G-hBN exhibits significant advantages in mechanical and chemical stability. This paper selects graphene and hBN as the base materials for the planar heterojunction. Using G-hBN integration technology, a specific pattern is designed to impart a wettability gradient to the G-hBN, enabling self-driven directional transport of nanodroplets carrying biomacromolecules. All-atom molecular dynamics simulations are used to evaluate the performance of G-hBN in biomacromolecule transport.

[0014] The beneficial effects of the present invention are as follows:

[0015] The hBN triangular pattern track designed in this invention exhibits a stable wettability gradient, enabling instantaneous acceleration of water nanodroplets carrying various biomacromolecules (DNA, RNA, or peptides) and stable, self-driven microsecond-scale transport of biomacromolecules over medium and long distances (distances ranging from several to hundreds of times the biomacromolecule's size). Because the angles of the hBN triangular pattern can be varied, the wettability gradient of the designed track can be adjusted. By switching materials with different hBN patterns, the transport speed and distance of the biomacromolecules can be controlled. Leveraging the unique properties of hBN, the material ensures that biomacromolecules in water droplets are adsorbed to the hBN region during transport, while maintaining their structure and maximizing their activity. This invention has applications in the design of biosensors and drug delivery systems, providing technical support for the efficient and stable targeted transport of biomacromolecules. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings;

[0017] Figure 1 FIG2 is an orbital system diagram of hexagonal boron nitride (hBN) and graphene in an embodiment of the present invention. The boron atoms of hBN are shown in light orange, the nitrogen atoms of hBN are shown in blue, and the carbon atoms of graphene are shown in cyan.

[0018] Figure 2 This is the theoretical simulation result of the spontaneous movement of a nano-water droplet carrying a double-stranded DNA molecule on a track in an embodiment of the present invention. The main chain of the DNA in the droplet is shown in yellow.

[0019] Figure 3 These are theoretical simulation results of the transport of double-stranded DNA molecules on graphene-hexagonal boron nitride heterojunction materials (G-hBN) with different hBN patterns in an embodiment of the present invention.

[0020] Figure 4 The theoretical transport speed of double-stranded DNA molecules on different G-hBN in the examples of the present invention.

[0021] Figure 5 This is the theoretical longest transport distance of double-stranded DNA molecules on different G-hBNs in the examples of the present invention.

[0022] Figure 6 Schematic diagram of an approximately triangular pattern and its angles. DETAILED DESCRIPTION

[0023] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0024] Take the double-stranded DNA molecule with a length of 11 bp (5'-CTCGAATCTAC-3' and 5'-GTAGATTCGAG-3') as an example. Figure 1 The figure shows a hexagonal boron nitride-graphene planar heterojunction (G-hBN) provided by the present invention. The center of the hexagonal boron nitride (hBN) is an isosceles triangle pattern, flanked by graphene. The specific process for achieving directional transport of double-stranded DNA molecules using the planar heterojunction as a transport track is as follows:

[0025] The double-stranded DNA molecules are dissolved in nano-water droplets with a diameter of about 8 nanometers (the specific size of the nano-water droplets can be determined based on preliminary experiments).

[0026] A nano-water droplet carrying a double-stranded DNA molecule was adsorbed onto one side of the vertex of the hBN triangular pattern of the G-hBN track. Using a simulation method based on the basic principles of Newtonian mechanics (molecular dynamics simulation: simulation temperature: 300K, simulation step size: 2fs), it was observed that the water droplet and the double-stranded DNA molecule contained therein moved toward the bottom edge of the triangular pattern by self-propelled motion until the water droplet completely entered the hBN area ( Figure 2 ). This demonstrates the feasibility of this system for transporting biomacromolecules.

[0027] Depend on Figure 3-5 It can be seen that the vertex angle of the hBN triangle pattern can affect the transport speed and distance of double-stranded DNA molecules. Molecular dynamics simulation methods can be used to simulate the process of G-hBN tracks transporting such double-stranded DNA molecules in hBN triangle patterns with different vertex angles. Each angle was simulated three times to ensure reproducibility ( Figure 3 ), and calculate the corresponding theoretical transport speed ( Figure 4 According to the different vertex angles of the hBN triangle of G-hBN and the hemispherical diameter of the water droplet when adsorbed on hBN, the theoretical longest transport distance of different G-hBN can be estimated ( Figure 5 ).

[0028] like Figure 6 As shown, the triangular pattern can also be a trumpet, a half-spindle, or a trapezoid. Since the hBN pattern is of other irregular shapes, when transporting biomacromolecules, it is necessary to ensure that the contact surface between the water droplet and the material is hBN in the middle and graphene on both sides (i.e., on the left side of the figure). The nano-water droplet can instantly accelerate toward the base of the hBN triangle (i.e., on the right side).

[0029] The above description is merely a preferred embodiment of one or more embodiments of this specification and is not intended to limit one or more embodiments of this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of one or more embodiments of this specification shall be included in the scope of protection of one or more embodiments of this specification.

Claims

1. A hexagonal boron nitride-graphene planar heterojunction, characterized in that: The planar heterojunction includes a hexagonal boron nitride (hBN) layer with a near-triangular pattern in the middle and graphene located on the periphery of the hBN. The angle of the near-triangular pattern ranges from 2.5 degrees to 60 degrees, and the near-triangle shape is specifically a triangle, a trumpet shape, a half-spindle shape, or a trapezoid. The preparation method of the planar heterojunction is as follows: first, the edge of the hexagonal boron nitride (hBN) layer is etched to make the entire hBN present a near-triangular pattern; then, the graphene crystallizes and grows along the edges of the near-triangular pattern, ultimately forming a strip-shaped planar heterojunction G-hBN in which the middle hBN is covalently connected to the graphene on both sides.

2. The hexagonal boron nitride-graphene planar heterojunction according to claim 1, characterized in that: In the planar heterojunction, the length of the approximately triangle ranges from tens of nanometers to hundreds of nanometers.

3. The hexagonal boron nitride-graphene planar heterojunction according to claim 1, characterized in that: The strip-shaped planar heterojunction G-hBN has a shape of rectangle, square or ellipse.

4. The hexagonal boron nitride-graphene planar heterojunction according to claim 1, characterized in that: The strip-shaped planar heterojunction G-hBN has a width of several nanometers to several tens of nanometers, and a length of several tens of nanometers to several hundred nanometers.

5. The use of a hexagonal boron nitride-graphene planar heterojunction according to claim 1, characterized in that: As a transport track for self-propelled nano-water droplets; first dissolve the biomacromolecules in the nano-water droplets, and then adsorb the entire nano-water droplet on the G-hBN track, so that the middle of the contact surface between the nano-water droplet and the material is hBN and both sides are graphene, then the nano-water droplet will spontaneously move from one side of the hBN approximate triangle to the other side.

6. The use of a hexagonal boron nitride-graphene planar heterojunction according to claim 5, characterized in that: The speed of the planar heterojunction's directional transport of nano-water droplets is changed by adjusting the vertex angle of the approximate triangle, and the variable speed range is 0.01 m / s ~ 0.1 m / s.

7. The use of a hexagonal boron nitride-graphene planar heterojunction according to claim 5, characterized in that: The distance of nano-water droplets transported in a planar heterojunction is changed by adjusting the vertex angle of the approximate triangle, and the variable range of the distance is from tens of nanometers to hundreds of nanometers.

8. The use of a hexagonal boron nitride-graphene planar heterojunction according to claim 5, characterized in that: The biological macromolecules transported by nano-water droplets are various nucleic acids or polypeptide molecules.

Images