CN-122016440-A - Preparation method of biological sample for diamond near-surface quantum sensing

CN122016440ACN 122016440 ACN122016440 ACN 122016440ACN-122016440-A

Abstract

The application provides a preparation method of a biological sample for diamond near-surface quantum sensing, and belongs to the field of quantum sensing detection. The method comprises the steps of preparing a single-layer DNA paper folding structure, carrying out planarization pretreatment on the surface of diamond by utilizing plasma etching, injecting nitrogen ions to form NV color centers to obtain diamond containing the NV color centers, and sequentially adding a solution containing the single-layer DNA paper folding structure and a biological sample solution to be detected onto the diamond in a buffer solution environment containing cations for incubation to obtain the biological sample for near-surface quantum sensing of the diamond. The sample preparation method provides a reliable and efficient sample preparation foundation for detecting the single-molecule/single-particle biological sample with higher sensitivity and specificity based on the near-surface quantum sensing of the diamond.

Inventors

Chen sanyou
LI SHIJIE
SHI FAZHAN
SUN ZITING
LI WANHE
DU JIANGFENG

Assignees

中国科学技术大学苏州高等研究院
中国科学技术大学

Dates

Publication Date: 20260512
Application Date: 20260416

Claims (10)

1. A method for preparing a biological sample for near-surface quantum sensing of diamond, comprising: Preparing a single-layer DNA origami structure having a pre-designed biological sample binding site coupled to a biological sample by an interactive molecule pair; Flattening the surface of the diamond by plasma etching, and then injecting nitrogen ions to form an NV color center to obtain the diamond containing the NV color center; And in an environment containing a cation buffer solution, sequentially adding a solution containing the single-layer DNA paper folding structure and a biological sample solution to be detected to the diamond containing the NV color center for incubation so as to fix the biological sample on a biological sample binding site, thereby obtaining the biological sample for near-surface quantum sensing of the diamond.
2. The method of claim 1, wherein the step of determining the position of the substrate comprises, The interactive molecule pairs are coupled by biotin-streptavidin or base complementary pairing.
3. The method of claim 1, wherein the step of determining the position of the substrate comprises, The distance between the biological sample binding sites is 10-60 nm.
4. The method of claim 1, wherein the step of determining the position of the substrate comprises, The cation buffer comprises a first cation solution and a second cation solution; The first cation solution is 10-15 mM magnesium ion solution; The second cation solution comprises at least one of 0.5-5mM nickel ion, 5-250 mM magnesium ion, 100-400 mM sodium ion, 100-400 mM potassium ion and 2-10 mM calcium ion.
5. The method of claim 1, wherein the step of determining the position of the substrate comprises, The single-layer DNA paper folding structure is a rectangular structure or a triangular structure.
6. The method as recited in claim 1, further comprising: And cleaning the diamond containing the NV color center by using a strong oxidizing solution, wherein the strong oxidizing solution is a piranha solution or a mixed solution of three acids, and the mixed solution of three acids comprises 95-98% by mass of concentrated sulfuric acid, 70-72% by mass of perchloric acid and 65-68% by mass of concentrated nitric acid.
7. The method as recited in claim 6, further comprising: and (3) carboxylating or amination is carried out on the cleaned diamond containing the NV color center.
8. The method of claim 1, wherein the step of determining the position of the substrate comprises, The single-layer DNA paper folding structure further comprises a staple DNA chain containing a fluorescent label, and the staple DNA chain containing the fluorescent label is used for marking the single-layer DNA paper folding structure.
9. The method as recited in claim 1, further comprising: And carrying out magnetic resonance marking on the biological sample to be detected.
10. The method of claim 9, wherein the method of magnetic resonance labeling comprises any one of: (1) Introducing an electronic spin label to the biological sample to be detected through site-directed modification under the condition that the biological sample to be detected comprises proteins and/or nucleic acids; (2) In case the biological sample to be tested comprises proteins and/or nucleic acids, an isotopic nuclear spin tag is introduced during the expression of the proteins and/or the synthesis of the nucleic acids.

Description

Preparation method of biological sample for diamond near-surface quantum sensing Technical Field The application relates to the field of quantum sensing detection, in particular to a preparation method of a biological sample for diamond near-surface quantum sensing. Background The quantum sensing technology based on the diamond Nitrogen Vacancy (NV) color center has the characteristics of single molecule/single spin sensitivity, nanoscale spatial resolution, low background noise, strong substance resolving power, good biocompatibility and the like in the room temperature and atmospheric environment, and is particularly suitable for high-sensitivity, high-resolution and high-specificity detection and research of biomedical systems. The technology realizes detection of multiple physical quantities such as magnetism, temperature, charge and the like on the scale of single molecule, single cell and tissue, and has great application potential. As an emerging magnetic resonance means, NV color center technology advances the detection object from billions of molecules to single molecular scale, and improves the imaging resolution to nano level, and combines the inherent specificity of magnetic signals, so that the NV color center technology becomes an ideal tool for developing single molecular and nano scale researches, and opens up a new way for researching the structure and functions of biomacromolecules and biomagnetic materials. However, when single-molecule magnetic resonance detection is realized, the existing sample preparation method generally depends on randomly spreading molecules to be detected or randomly fixing the molecules to be detected on the surface of diamond through chemical crosslinking, and only can indirectly control the distance through regulating the total number of molecules, so that obvious randomness exists. The mode is poor in sample preparation controllability and low in single-molecule detection efficiency, and further popularization and application of the technology are restricted. Therefore, the development of a controllable and efficient single-molecule preparation strategy is of great significance. Disclosure of Invention In view of the above, in order to at least partially solve at least one of the above-mentioned technical problems, the present application provides a method for preparing a biological sample for diamond near-surface quantum sensing, which comprises the following steps S1 to S3. Step S1, preparing a single-layer DNA paper folding structure, wherein the single-layer DNA paper folding structure is provided with a biological sample binding site which is designed in advance, and the biological sample binding site is coupled with a biological sample through an interaction molecule pair. And S2, carrying out planarization pretreatment on the diamond surface by utilizing plasma etching, and then injecting nitrogen ions to form an NV color center, so as to obtain the diamond containing the NV color center. And step S3, sequentially adding a solution containing a single-layer DNA paper folding structure and a biological sample solution to be detected onto the diamond in the buffer solution environment containing cations for incubation so as to fix the biological sample on a biological sample binding site and obtain the biological sample for near-surface quantum sensing of the diamond. According to the embodiment of the application, the single-layer DNA paper folding structure with the pre-designed biological sample binding site is adopted, the plasma etching planarization pretreatment is combined on the diamond surface, and the incubation fixation is carried out in the buffer solution environment containing cations, so that the DNA paper folding structure is more complete and has higher density when the diamond surface is combined, the biological sample is controllably, orderly and highly densely fixed on the diamond near surface with nanometer precision, and a reliable and efficient sample preparation basis is provided for the single-molecule/single-particle detection with higher sensitivity and specificity based on the quantum sensing of the diamond near surface. Drawings FIG. 1 is a schematic flow chart of a preparation method of a biological sample for diamond near-surface quantum sensing. FIG. 2A is a schematic illustration of a triangle structured biotin-streptavidin interaction monolayer DNA paper folding structure of the present application. FIG. 2B is a schematic diagram of a rectangular structure of biotin-streptavidin interaction monolayer DNA paper folding structure of the application. FIG. 3A is a schematic diagram of a triangle structure of a single-layer DNA folded paper. FIG. 3B is a schematic diagram of a rectangular structure of a single-layer DNA folded paper of the DNA complementary strand of the present application. FIG. 4 is an atomic force microscope (AMF) characterization of a single-layer DNA paper folding of biotin-streptavidin interactions prepa