CN-122013206-A - Self-assembled monolayer anchored hybrid lipid-copolymer mask and forming method and application thereof

CN122013206ACN 122013206 ACN122013206 ACN 122013206ACN-122013206-A

Abstract

A self-assembled monolayer anchored hybrid lipid-copolymer mask and a forming method and application thereof belong to the field of electrochemical processing. The mask comprises a metal-hydroxyl anchoring monolayer and a hybridization bilayer, wherein the metal-hydroxyl anchoring monolayer is combined on the surface of a workpiece anode through covalent bonds, the hybridization bilayer is fixed through the anchoring monolayer, the hybridization bilayer is formed by cooperative self-assembly of a lipid amphiphilic monomer and a block copolymer amphiphilic monomer, and the length of a hydrophobic block of the block copolymer is matched with the length of a lipid hydrophobic tail and the thickness of a transmembrane hydrophobic region of a target ion channel protein. The forming method comprises the steps of constructing an anchoring monolayer by surface chemical modification, preparing self-assembly solution, carrying out cooperative self-assembly at an oil-water interface, and the like. The invention improves the breakdown voltage of the mask and the bonding strength of the substrate, and is suitable for atomic scale electrochemical processing of high potential materials such as copper, gold, platinum, semiconductors and the like.

Inventors

XU ZHENGYANG
XIAO YOUPING

Assignees

南京航空航天大学

Dates

Publication Date: 20260512
Application Date: 20260113

Claims (8)

1. The self-assembled monolayer anchored hybrid lipid-copolymer mask is characterized in that the mask is formed on the surface of a workpiece anode and comprises a metal-hydroxyl anchored monolayer which is combined on the surface of the workpiece anode through a covalent bond, and a hybrid bilayer which is fixed through the anchored monolayer and is formed by cooperative self-assembly of a lipid amphiphilic monomer and a block copolymer amphiphilic monomer, wherein the length of a hydrophobic block of the block copolymer amphiphilic monomer is matched with the length of a hydrophobic tail of the lipid amphiphilic monomer and the thickness of a transmembrane hydrophobic region of a target ion channel protein.
2. The self-assembled monolayer anchored hybrid lipid-copolymer mask of claim 1, wherein the metal-hydroxyl anchored monolayer is formed by a surface chemical modification process comprising inert and reducing plasma treatment and subsequent water vapor dissociation.
3. The self-assembled monolayer anchored hybrid lipid-copolymer mask of claim 1, wherein the copolymer amphiphilic monomer is a block copolymer lipid comprising a hydrophobic block and a hydrophilic block.
4. A method for forming a self-assembled monolayer anchored hybrid lipid-copolymer mask according to any one of claims 1 to 3, comprising the steps of S1, chemically modifying the surface of a workpiece anode to construct a layer of covalently bonded metal-hydroxyl anchored monolayer thereon in situ, S2, dissolving a lipid amphiphilic monomer and a block copolymer amphiphilic monomer in an oily organic solvent to obtain a self-assembled solution, wherein the hydrophobic block length of the block copolymer amphiphilic monomer is matched with the hydrophobic tail length of the lipid amphiphilic monomer and the transmembrane hydrophobic region thickness of a target ion channel protein, and S3, introducing the self-assembled solution to the interface of the workpiece anode surface treated in step S1 and an aqueous solution, so that the hydrophilic head groups of the lipid amphiphilic monomer and the block copolymer amphiphilic monomer are combined with the monolayer, and the hydrophobic parts thereof are synergistically self-assembled in the oily organic solvent to form the anchored hybrid lipid-copolymer mask.
5. The method according to claim 4, wherein in step S1, the chemical modification comprises treating the anode of the workpiece in a plasma atmosphere of a mixture of inert and reducing gases to remove surface oxides and expose metal active sites, and subsequently introducing steam to the surface of the anode of the workpiece to dissociate water molecules and form the metal-hydroxyl anchored monolayer.
6. The method of forming as claimed in claim 4, wherein in step S2, the oily organic solvent is a nonpolar solvent having a low surface tension, a high boiling point and being chemically inert, for stabilizing the structure of the hybrid mask during self-assembly and subsequent processing.
7. The method of forming a hybrid mask according to claim 4, further comprising the step S4 of introducing the target ion channel protein into the hybrid mask after the hybrid mask is formed in step S3, and then applying a DC pre-bias voltage to adjust the conformation and orientation of the ion channel protein in the mask.
8. Use of a self-assembled monolayer anchored hybrid lipid-copolymer mask according to any of claims 1 to 3 for atomic scale electrochemical processing of a surface of a metal or semiconductor material having a standard electrode potential higher than 0.5V.

Description

Self-assembled monolayer anchored hybrid lipid-copolymer mask and forming method and application thereof Technical Field The invention relates to the field of electrochemical processing, in particular to a self-assembled monolayer anchored hybrid lipid-copolymer mask, a forming method and application thereof. Technical Field Electrolytic machining (ECM) is a special machining technique for removing material by the anodic dissolution principle, and the basic unit for removing the material is metal ions, so that the electrochemical machining method has the potential of realizing atomic-level precision machining in principle. The key to achieving this potential is whether the electrochemical reaction can be confined stably and precisely to the atomic scale space. Conventional phospholipid bilayer formed by self-assembly of natural or single synthetic phospholipids typically have breakdown voltages below 400 mV. For Fe, ni, ti, al and its alloys, this voltage window is typically sufficient to drive the anodic dissolution. However, for Cu, au, pt and most semiconductor materials, the minimum required electrolytic voltage may exceed this range, resulting in the metal not yet starting to dissolve effectively and the mask being broken down, thereby disabling the insulation shielding in the non-processed areas and preventing processing. In order to improve the stability of the bionic membrane, many researches have been carried out in the related field. For example, in the field of nanopore gene sequencing, chinese inventions CN113416344B, CN114106329B and CN113402768a disclose methods of introducing polymerizable phospholipids, in situ polymerization using photocrosslinking or click chemistry, or hybrid polymerization with hydrophobic monomers with double bonds, etc., in order to improve the mechanical strength and stability of the supported lipid bilayer membrane. Although the methods can obviously improve the breakdown voltage and the service life of the membrane, the application scene is a gene sequencing pool with solution environments on both sides, and the self-assembly and the stabilization of the membrane are relatively easy. In the electrolytic machining scene, one side of the bionic mask is a solid metal electrode, and the other side of the bionic mask is electrolyte, so that the interface environment is more complex and harsh. To build a strong biomimetic membrane on a metal surface, an additional surface hydration step is typically required to introduce hydroxyl groups (-OH) as anchor points. However, the hydroxyl groups introduced by conventional plasma or ultraviolet treatment have low coverage rate and are mostly physically adsorbed, and the bonding force is weak （Tang H, Shen Z, Shen Y, et al. Reinforcing self-assembly of hole transport molecules for stable inverted perovskite solar cells[J]. Science, 2024, 383(6688): 1236-1240.）,, so that the hydroxyl groups are easy to fall off under the electrochemical and fluid disturbance in the processing process, and the mask is invalid. Furthermore, oxygen or water vapor is needed for introducing hydroxyl into the plasma as a gas source, so that unnecessary oxidation of metal is caused, and a higher breakdown voltage is needed for the surface oxide layer to dissolve the metal in an electrochemical environment, so that the requirements on the mechanical strength and stability of the bionic membrane are high. On the other hand, in addition to bio-phospholipids, block copolymers with amphiphilic properties are also capable of self-assembling in solution to form lipid bilayer structures （Zhang X, Fu W, Palivan C G, et al. Natural channel protein inserts and functions in a completely artificial, solid-supported bilayer membrane[J]. Scientific Reports, 2013, 3(1): 2196.）, and generally have higher mechanical and chemical stability. However, when the copolymer is used for electrolytic processing of masks, a key matching problem must be solved, namely, the length of the hydrophobic region of the block copolymer must be precisely matched with the dimension of the transmembrane hydrophobic region of the target ion channel protein (for example, the polymerization degree m and n of the PBD-PEO copolymer which is usually used in gene sequencing must be carefully selected), and too long hydrophobic chains can lead to the ion channel protein not being properly inserted or dysfunctional, so that electrolyte ions cannot reach the metal surface through the pore channels of the ion channel. In addition, the traditional strategy of enhancing the stability of the membrane by adding components such as cholesterol or polyethylene glycol (PEG) has the limitation that the cholesterol is easy to oxidize in an electrochemical environment and possibly damages the structure of ion channel proteins and causes membrane phase separation, and the high-purity functional PEG has high cost and is unfavorable for large-scale application. Disclosure of Invention The invention provides a self-asse