A nanoscale glass tip and a method of making the same

Abstract

This application belongs to the field of detection instrument technology and discloses a nanoscale glass tip and its preparation method. The nanoscale glass tip includes: a glass body in the shape of a triangular prism, one of the apex of the glass body being the tip angle, the rounded corner diameter of the tip angle being less than 50 nm, and the three adjacent surfaces of the tip angle being covered with an inner metal film and an outer metal film from the inside to the outside. The adhesion of the inner metal film to the glass body and the adhesion of the outer metal film to the inner metal film are both greater than the adhesion of the outer metal film to the glass body; thereby improving detection accuracy and reducing the probability of metal film detachment.

Description

Technical Field

[0001] This application relates to the field of detection instrument technology, and more specifically, to a nanoscale glass tip and its preparation method. Background Technology

[0002] In near-field super-resolution single-molecule group photoelectric microscopy, the tip, as part of the metal-molecule-metal bond, needs to possess properties such as conductivity and light transmittance in order to simultaneously achieve near-field enhanced Raman detection and electrical detection.

[0003] In existing technologies, near-field super-resolution single-molecule group photomicroscopes mostly use tips made of pure metal. External illumination will generate strong far-field background noise and sample photobleaching, thus limiting the detection accuracy of super-resolution single-molecule group photomicroscopes.

[0004] To address this, some researchers have proposed depositing metal films of different materials at specific locations on a glass tip to modulate the photon spin coupling system and alter the Raman signal of molecular vibrations. However, ensuring the tip remains clean during fabrication is challenging, leading to the formation of large metal particles (diameter > 20 nm) during the deposition process. This affects the surface roughness of the metal layer at the tip, limiting the optical and electrical measurement accuracy of the microscope. Furthermore, when the tip diameter is reduced to below 50 nm, the metal film is prone to detachment. Summary of the Invention

[0005] The purpose of this application is to provide a nanoscale glass tip and its preparation method, which can improve detection accuracy and reduce the probability of metal film detachment.

[0006] In a first aspect, this application provides a nanoscale glass tip, comprising a quasi-triangular prism-shaped glass body, one of the apex angles of the glass body being a tip angle, the rounded corner diameter of the tip angle being less than 50 nm, and the three adjacent surfaces of the tip angle being sequentially covered with an inner metal film and an outer metal film from the inside to the outside, wherein the adhesion of the inner metal film to the glass body and the adhesion of the outer metal film to the inner metal film are both greater than the adhesion of the outer metal film to the glass body.

[0007] Since the main body of the nanoscale glass tip is glass, it can reduce far-field background noise and photobleaching compared with pure metal tips, thus improving the accuracy of microscope detection. Since the radius of the tip corner is less than 50nm, it can stably form metal-molecule-metal bonds during use. Since an inner metal film is set between the outer metal film and the glass body, the adhesion strength between the outer metal film and the glass body can be improved, thereby reducing the probability of metal film detachment.

[0008] Preferably, the material of the inner metal film is Al, Fe, Cu, Cr or Ti; and the material of the outer metal film is Au, Ag or Cu.

[0009] It can effectively improve the bonding strength between the outer metal film and the glass body, thereby reducing the probability of the metal film falling off.

[0010] Preferably, the thickness of the inner metal film is 1nm-5nm; and the thickness of the outer metal film is 15nm-35nm.

[0011] Preferably, the inner metal film is made of Cr, the outer metal film is made of Au, the thickness of the inner metal film is 2 nm, and the thickness of the outer metal film is 20 nm.

[0012] Secondly, this application provides a method for preparing nanoscale glass tips, which includes the steps described above:

[0013] A1. Clean the glass slide;

[0014] A2. Cut the cleaned glass sheet to obtain a glass body with pinpoint corners;

[0015] A3. Sequentially deposit inner and outer metal films on the three adjacent surfaces of the tip corner of the glass body to obtain a nanoscale glass tip;

[0016] A4. The morphology of the tip angle of the nanoscale glass tip is detected by scanning electron microscopy in order to screen out qualified nanoscale glass tips.

[0017] Preferably, step A1 includes:

[0018] A101. Wipe both sides of the glass slide with a lint-free cloth and anhydrous ethanol;

[0019] A102. Place the wiped glass slide into a detergent solution for ultrasonic cleaning and remove residual foam;

[0020] A103. The glass slide is placed in pure water for ultrasonic cleaning;

[0021] A104. The glass slide is cleaned sequentially with tetrahydrofuran and isopropanol;

[0022] A105. Dry the glass sheet.

[0023] The cleaning process described above ensures the cleanliness of the glass slide, thereby preventing the formation of large metal particles (diameter > 20 nm) during subsequent vapor deposition, which could affect the surface roughness of the metal layer at the tip and improve the optical and electrical measurement accuracy of the microscope.

[0024] Preferably, step A102 includes:

[0025] Place the glass slide into the cleaning rack, so that both surfaces of the glass slide are exposed outside the cleaning rack;

[0026] Place the cleaning rack into the cleaning container, and add dish soap and pure water into the cleaning container;

[0027] The cleaning container is placed in an ultrasonic cleaning device for cleaning;

[0028] Remove any remaining foam.

[0029] Preferably, step A2 includes:

[0030] Place the glass slide on a first glass slide;

[0031] Using one of the straight edges of a second glass slide as a cutting ruler, a first cutting line is drawn on the upper surface of the glass slide using a scribing tool along the cutting ruler; the first end of the first cutting line extends to the edge of the glass slide, and the second end is located inside the glass slide;

[0032] The glass sheet is broken along the first cutting line to obtain two half-glass sheets; both half-glass sheets have a first broken edge line formed by the natural extension of the second end of the first cutting line.

[0033] Use a scribing tool to draw a second cutting line along the cutting ruler on the half-glass slide; the first end of the second cutting line extends to the edge of the half-glass slide except for the first broken edge line, and the second end is located inside the half-glass slide;

[0034] The half-glass slide is broken along the second cutting line to obtain a broken piece containing a sharp corner; the sharp corner is formed by the first broken edge line and the second broken edge line formed by the natural extension of the second end of the second cutting line;

[0035] At a position on the broken piece that is a first distance from the vertex of the sharp angle, the half-glass sheet is broken to obtain a glass body containing the sharp angle;

[0036] Using an optical microscope, valid glass bodies are selected from the glass bodies based on the shape of the pointed corner, and the upper apex of the pointed corner of the valid glass body is taken as the pinpoint of the valid glass body.

[0037] Preferably, step A3 includes:

[0038] The glass body is attached to the vapor deposition table using high-temperature resistant tape; the vapor deposition table has a 45° inclined slope, one side of the glass body is in contact with the inclined slope and the pin tip is pointing downward and extending out of the inclined slope;

[0039] The vapor deposition stage is placed in the vapor deposition machine, and the inner metal film and the outer metal film are vapor deposited in sequence.

[0040] Preferably, after step A4, the method further includes the following step:

[0041] A5. Place the qualified nanoscale glass needle tips into a needle tip holder and store the needle tip holder in a vacuum desiccator.

[0042] Beneficial effects: The nanoscale glass tip and its preparation method provided in this application, since the main body of the nanoscale glass tip is glass, can reduce far-field background noise and photobleaching compared with pure metal tips, thus improving the accuracy of microscope detection; since the radius of the tip corner is less than 50nm, it can stably form metal-molecule-metal linkages during use; since an inner metal film is set between the outer metal film and the glass body, the adhesion strength between the outer metal film and the glass body can be improved, thereby reducing the probability of metal film detachment. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the structure of a nanoscale glass tip provided in an embodiment of this application.

[0044] Figure 2 A side view of a nanoscale glass needle tip provided in an embodiment of this application.

[0045] Figure 3 A flowchart illustrating the method for preparing nanoscale glass tips provided in this application embodiment.

[0046] Figure 4 This is a schematic diagram of the cleaning rack.

[0047] Figure 5 This is a schematic diagram for depicting the cutting line.

[0048] Figure 6 This is a schematic diagram illustrating the principle of cutting a glass sheet.

[0049] Figure 7 This is a schematic diagram illustrating the principle of cutting a glass sheet.

[0050] Figure 8 This is a schematic diagram of the vapor deposition station.

[0051] Figure 9 This is a diagram showing the connection structure between the glass body and the evaporation stage.

[0052] Figure 10 This is a schematic diagram of the needle tip holder.

[0053] Figure 11 This is a topographic image of a nanoscale glass needle tip.

[0054] Figure 12This is a morphology diagram of another nanoscale glass tip.

[0055] Labeling Explanation: 1. Glass Body; 101. Needle Tip Corner; 2. Inner Metal Film; 3. Outer Metal Film; 4. Cleaning Rack; 401. Loading Chassis; 402. First Connecting Rod; 403. Positioning Placement Slot; 404. Boss; 5. Evaporation Stage; 501. Inclined Surface; 502. Wedge-Shaped Stage; 503. Connecting Strip; 504. Second Connecting Rod; 6. Needle Tip Holding Rack; 601. Box Body; 602. Box Lid; 603. Loading Rack; 604. Positioning Slot. Detailed Implementation

[0056] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0057] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0058] Please refer to Figures 1-2 A nanoscale glass tip in some embodiments of this application includes a prism-like glass body 1 (which may be a prism with all straight edges or may contain at least one curved edge), one vertex of the glass body 1 being a tip angle 101 (the prism-like glass body 1 has a total of six vertices, and one of them is designated as the tip angle 101), the radius of the tip angle 101 being less than 50 nm, and the three adjacent surfaces of the tip angle 101 ( Figure 1 Surfaces a, b, and c are all covered from the inside out with an inner metal film 2 and an outer metal film 3 (e.g., ...). Figure 2 As shown, the adhesion of the inner metal film 2 to the glass body 1 and the adhesion of the outer metal film 3 to the inner metal film 2 are both greater than the adhesion of the outer metal film 3 to the glass body 1.

[0059] Since the main body of the nanoscale glass tip is glass, it can reduce far-field background noise and photobleaching compared with pure metal tips, thus improving the accuracy of microscope detection. Since the radius of the tip angle 101 is less than 50nm, it can stably form metal-molecule-metal bonds during use. Since an inner metal film 2 is set between the outer metal film 3 and the glass body 1, the bonding strength between the outer metal film 3 and the glass body 1 can be improved, thereby reducing the probability of metal film detachment.

[0060] The materials of the inner metal membrane 2 and the outer metal membrane 3 can be set according to actual needs.

[0061] For example, the material of the inner metal film 2 can be, but is not limited to, Al, Fe, Cu, Cr, or Ti; the material of the outer metal film 3 can be, but is not limited to, Au, Ag, or Cu. Using these materials can effectively improve the bonding strength between the outer metal film 3 and the glass substrate 1, thereby reducing the probability of the metal film detaching.

[0062] Preferably, the thickness of the inner metal film 2 is 1 nm-5 nm; the thickness of the outer metal film 3 is 15 nm-35 nm. This ensures sufficient inner metal layer adheres to the surface of the glass tip, thereby improving the adhesion strength between the outer metal film 3 and the glass substrate 1. Simultaneously, controlling the thickness of the inner metal film to within 5 nm prevents it from affecting the formation of monomolecular segments. Furthermore, controlling the thickness of the outer metal film 3 to 15 nm-35 nm ensures both the conductivity and light transmittance of the tip.

[0063] In one possible implementation, the inner metal film 2 is made of Cr, the outer metal film 3 is made of Au, the thickness of the inner metal film 2 is 2 nm, and the thickness of the outer metal film 3 is 20 nm.

[0064] refer to Figure 3 This application provides a method for preparing nanoscale glass tips, which includes the steps described above:

[0065] A1. Clean the glass slide;

[0066] A2. Cut the cleaned glass sheet to obtain a glass body 1 with a needle-like angle 101;

[0067] A3. The inner metal film 2 and the outer metal film 3 are deposited sequentially on the three adjacent surfaces of the needle tip 101 of the glass body 1 to obtain a nanoscale glass needle tip;

[0068] A4. The morphology of the tip angle 101 of the nanoscale glass tips was examined using a scanning electron microscope in order to screen out qualified nanoscale glass tips.

[0069] The glass slide can be a square cover glass with a side length of 20mm, but it is not limited to this.

[0070] In some preferred embodiments, step A1 includes:

[0071] A101. Wipe both sides of the glass slide with a lint-free cloth and anhydrous ethanol;

[0072] A102. After wiping, the glass slide is placed in a detergent solution for ultrasonic cleaning to remove residual foam;

[0073] A103. Place the glass slide in pure water for ultrasonic cleaning;

[0074] A104. Clean the glass slide sequentially with tetrahydrofuran and isopropanol;

[0075] A105. Dry glass slides.

[0076] The above cleaning process ensures the cleanliness of the glass slide, thereby preventing the formation of large metal particles (diameter > 20 nm) during subsequent vapor deposition, which would affect the surface roughness of the metal layer at the tip angle 101 and improve the optical and electrical measurement accuracy of the microscope.

[0077] In step A101, a lint-free cloth soaked in anhydrous ethanol is used to wipe both sides of the glass slide.

[0078] Step A102 includes:

[0079] B1. Place the glass slide into the cleaning rack 4, so that two surfaces of the glass slide (referring to the two surfaces perpendicular to the thickness direction) are exposed outside the cleaning rack 4;

[0080] B2. Place the cleaning rack 4 into the cleaning container, and add dish soap and pure water to the cleaning container;

[0081] B3. Place the cleaning container in an ultrasonic cleaning device for cleaning;

[0082] B4. Remove residual foam.

[0083] Specifically, see Figure 4The cleaning rack 4 includes a loading base 401 and a first connecting rod 402. The first connecting rod 402 is vertically connected to the top surface of the loading base 401. The loading base 401 has multiple positioning slots 403 extending through its upper and lower surfaces. The width of each positioning slot 403 is greater than the thickness of the glass sheet. Bosses 404 are provided at the bottom of both ends of each positioning slot 403, and both ends of the positioning slot 403 have semi-circular edges. The positioning slots 403 are used for inserting glass sheets. The two bosses 404 respectively support the two lower corners of the glass sheet inserted into the positioning slot 403. The two semi-circular edges of the positioning slot 403 clamp the edges of the glass sheet inserted into the positioning slot 403. The first connecting rod 402 is used for hand gripping to allow for the placement and removal of the cleaning rack 4. In use, the glass slide is inserted into the positioning groove 403. The two lower corners of the glass slide press against the two protrusions 404 to achieve vertical positioning. The edges on both sides of the glass slide are clamped by the semi-circular edges at both ends of the positioning groove 403 to achieve positioning in the thickness direction. Since the width of the positioning groove 403 is greater than the thickness of the glass slide, the detergent solution can contact both surfaces of the entire glass slide. This makes it convenient to pick up and put in multiple glass slides at the same time during cleaning, and there will be no dead corners left on the two surfaces. In addition, by inserting the glass slide into the positioning groove 403, it is possible to prevent the glass slide from adsorbing to the loading chassis 401 due to liquid tension, and to prevent the glass slides from adsorbing and sticking to each other due to liquid tension.

[0084] In step B2, a beaker can be used as a cleaning container (but is not limited to this). Add 2g of dish soap to the beaker, and then add pure water to the beaker until it covers the glass slide by about 5mm (i.e., the liquid level is about 5mm above the glass slide).

[0085] In step B3, the cleaning container can be placed in an ultrasonic cleaning device for 10 minutes and then the waste liquid can be poured out.

[0086] Depending on the cleaning effect, steps B1-B4 can be repeated one to three times.

[0087] Step A103 includes:

[0088] Place the cleaning rack 4 (with the glass slide still in the cleaning rack 4) into the cleaning container, and add pure water to the cleaning container until it covers the glass slide by about 5mm;

[0089] Place the cleaning container in an ultrasonic cleaning device for 10 minutes and then pour out the waste liquid.

[0090] Step A104 includes:

[0091] Place the cleaning rack 4 (with the glass slide still in the cleaning rack 4) into the cleaning container, and add tetrahydrofuran into the cleaning container until it covers the glass slide by about 5 mm;

[0092] Place the cleaning container in an ultrasonic cleaning device for 10 minutes and then pour out the waste liquid;

[0093] Place the cleaning rack 4 (with the glass slide still in the cleaning rack 4) into the cleaning container, and add isopropyl alcohol to the cleaning container until it covers the glass slide by about 5 mm.

[0094] Place the cleaning container in an ultrasonic cleaning device for 10 minutes and then pour out the waste liquid.

[0095] In step A105, the cleaning container (along with the cleaning rack 4 and the glass plate located in the cleaning rack 4) can be placed in a constant temperature drying oven and dried for 3 hours.

[0096] Specifically, refer to Figures 5-7 Step A2 includes:

[0097] A201. Place the glass slide on a first glass slide (e.g., ...). Figure 5 In the diagram, d represents the first glass slide, and e represents the glass plate.

[0098] A202. Using one of the straight edges of a second glass slide as a cutting ruler, use a scribing tool to draw the first cutting line along the cutting ruler on the upper surface of the glass slide (e.g., Figure 5 In the diagram, f represents the second glass slide, g represents the scribing tool, and h represents the first cutting line; the first end of the first cutting line extends to the edge of the glass slide, and the second end is located inside the glass slide.

[0099] A203. Break the glass sheet along the first cutting line to obtain two half-glass sheets; both half-glass sheets have a first breakage edge line formed by the natural extension of the second end of the first cutting line (e.g., ...). Figure 6 , Figure 7 In the diagram, the dashed line i represents the first break edge.

[0100] A204. Using a scribing tool, draw a second cutting line on the half-glass slide along the cutting ruler; the first end of the second cutting line extends to the edge of the half-glass slide except for the first broken edge line, and the second end is located inside the half-glass slide (e.g., Figure 6 , Figure 7 In the diagram, the solid line j represents the second tangent line.

[0101] A205. Break the half-glass along the second cutting line to obtain a broken piece containing a sharp angle; the sharp angle is enclosed by the first broken edge line and the second broken edge line naturally extended from the second end of the second cutting line (e.g., Figure 6 , Figure 7In the diagram, angles α and β are both sharp angles, the dashed line k is the second breakage edge line, and L is the broken piece.

[0102] A206. At a position on the broken piece that is a first distance from the vertex of the sharp angle, break the half glass piece to obtain a glass body 1 containing the sharp angle;

[0103] A207. Using an optical microscope, select effective glass bodies from the glass bodies 1 based on the shape of the apex angle, and use the upper apex angle of the apex angle of the effective glass body (i.e., the apex angle located on the upper surface of the glass sheet during cutting) as the needle tip angle 101 of the effective glass body.

[0104] In practice, if two intersecting cutting lines are directly drawn on a glass slide using a scribing tool, and then the glass slide is broken along these lines to obtain sharp angles (α and β), the scribing lines will not be smooth straight lines. They will contain burrs and cause micro-cracks on the glass surface near the cutting lines. These burrs and micro-cracks can easily lead to substandard sharpness at the apex of the sharp angle (i.e., the rounded corner diameter exceeds 50 nm), resulting in unsuccessful fabrication of nanoscale glass needle tips and a large number of defective products. Here, the sharp angle is formed by the naturally extending break-off edge line from the two cutting lines. This avoids the burrs and micro-cracks caused by the scribing tool affecting the sharpness at the apex of the sharp angle, thus improving the yield rate. It should be noted that when the glass plate is broken along the cutting lines, the cutting lines only affect the approximate extension direction of the naturally extending break-off edge line. The naturally extending break-off edge line is uncontrollable and may be a relatively straight line (e.g., ...). Figure 6 (As shown) could also be a curved line (such as) Figure 7 As shown in the figure, the main factor affecting the performance of nanoscale glass needle tips is the sharpness of the tip angle 101 (i.e., the radius of the rounded corner). As long as the radius of the tip angle 101 meets the requirements, whether the edge is straight or not does not affect the performance.

[0105] In this process, a first glass slide is used as a pad and one of the straight edges of a second glass slide is used as a cutting ruler. Since both the first and second glass slides are glass, their hardness is the same as that of glass sheets. Under normal operating conditions, the first and second glass slides are not likely to scratch the glass sheets.

[0106] Preferably, the apex angles (α and β) are acute angles, making it easier to obtain a glass body 1 with a needle-like angle 101 having a suitable sharpness.

[0107] The drawing tool may include, but is not limited to, a tungsten carbide alloy drawing pen with a sharp tip (such as...). Figure 5 (g) or diamond glass cutter.

[0108] In step A206, the break line can be drawn on the broken piece at a position with a first distance from the vertex of the sharp corner using a line drawing tool (e.g., Figure 6 , Figure 7 The solid line m in the diagram extends both ends of the break line to the edge of the broken piece, and then the broken piece is broken at the break line to obtain the glass body 1. Preferably, the first distance is 4mm-6mm.

[0109] In step A207, the morphology of the fracture surfaces (i.e., adjacent surfaces b and c) on both sides of the needle tip corner 101 is observed by an optical microscope. If the two fracture surfaces are smooth and burr-free, and the three edges formed at the needle tip corner 101 are clearly visible, and there is no obvious damage on the glass body 1, then the corresponding glass body 1 is determined to be a valid glass body.

[0110] By using a microscope to remove invalid glass substrates, the yield of nanoscale glass tips obtained after subsequent vapor deposition can be improved.

[0111] In some preferred embodiments, step A3 includes:

[0112] A301. Use high-temperature resistant tape to attach the glass body 1 to the vapor deposition table 5; the vapor deposition table 5 has a 45° inclined slope 501, one side of the glass body 1 is attached to the inclined slope 501 with the pin tip 101 pointing downwards and extending beyond the inclined slope 501 (e.g., Figure 9 (as shown)

[0113] A302. Place the vapor deposition table 5 in the vapor deposition machine and perform vapor deposition of the inner metal film 2 and the outer metal film 3 in sequence.

[0114] Among them, reference Figure 8 The vapor deposition stage 5 includes two symmetrically arranged wedge-shaped stages 502. The side of the two wedge-shaped stages 502 that is close to each other is a slope 501. The two wedge-shaped stages 502 are connected and fixed together by two connecting strips 503. A second connecting rod 504 is vertically connected to one of the connecting strips 503. The second connecting rod 504 is used for hand gripping to facilitate the placement and removal of the vapor deposition stage 5. In use, multiple glass bodies 1 can be attached to each slope 501 to improve the preparation efficiency.

[0115] By making one side of the glass body 1 ( Figure 1 The inner metal film 2 and outer metal film 3 on the three adjacent surfaces near the needle tip 101 are deposited by vapor deposition on the 45° inclined slope 501, which can make the thickness of the inner metal film 2 and outer metal film 3 more uniform.

[0116] In step A4, after the vapor deposition is completed, the morphology of the needle tip angle 101 is detected by scanning electron microscopy, which can effectively screen out unqualified nanoscale glass needle tips and ensure product quality.

[0117] For example Figure 11 and Figure 12 The image shows the morphology of the tip angle 101 of two qualified nanoscale glass tips after being magnified 100,000 times (the material of the inner metal film 2 is Cr and the thickness is 2nm, and the material of the outer metal film 3 is Au and the thickness is 20nm). It can be seen that the rounded corner diameter of the tip angle 101 is less than 50nm, and the surface metal layer is uniform and has low roughness.

[0118] Preferably, after step A4, the method further includes the following step:

[0119] A5. Place the qualified nanoscale glass needle tip into the needle tip holder 6, and store the needle tip holder 6 in a vacuum desiccator.

[0120] Among them, the structure of the needle tip holder 6 is as follows: Figure 10 As shown, it includes a box body 601, a box cover 602, and a loading rack 603 disposed inside the box body 601. The box body 601 is provided with a plurality of positioning slots 604 adapted to the nanoscale glass needle tip. The positioning slots 604 are used for the insertion of the nanoscale glass needle tip to achieve positioning of the nanoscale glass needle tip.

[0121] In summary, the nanoscale glass tip and its preparation method of this application have the following advantages:

[0122] 1. Compared with pure metal-based needle tips, the nanoscale glass needle tip of this application can reduce far-field background noise and photobleaching, and improve the accuracy of microscope detection.

[0123] 2. Compared with existing glass tip preparation processes, the success rate of glass tip preparation has been improved by optimizing the cleaning, cutting, storage and vapor deposition processes. The fillet diameter of the tip with angle 101 is smaller (<50nm), which can stably form metal-molecule-metal bonds during use.

[0124] 3. By designing a special cleaning rack 4, the adhesion phenomenon during the glass slide cleaning process is reduced, and the surface cleanliness of the nano-level glass needle tip is improved.

[0125] 4. By designing a special needle tip holder 6 to store nano-sized glass needle tips, the problem of bumps and knocks during storage and movement of nano-sized glass needle tips is avoided, making it convenient to store and retrieve nano-sized glass needle tips.

[0126] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0127] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing nanoscale glass needle tips, characterized in that, For the preparation of nanoscale glass tips, the nanoscale glass tips include a prism-shaped glass body (1), one of the apex angles of the glass body (1) is a tip angle (101), the rounded diameter of the tip angle (101) is less than 50 nm, and the three adjacent surfaces of the tip angle (101) are covered with an inner metal film (2) and an outer metal film (3) from the inside to the outside. The adhesion of the inner metal film (2) to the glass body (1) and the adhesion of the outer metal film (3) to the inner metal film (2) are both greater than the adhesion of the outer metal film (3) to the glass body (1). The method for preparing the nanoscale glass needle tip includes the following steps: A1. Clean the glass slide; A2. Cut the cleaned glass sheet to obtain a glass body (1) with a pinpoint angle (101). A3. The inner metal film (2) and the outer metal film (3) are deposited sequentially on the three adjacent surfaces of the needle tip (101) of the glass body (1) to obtain a nanoscale glass needle tip; A4. The morphology of the tip angle (101) of the nanoscale glass tip was detected by scanning electron microscopy to screen out qualified nanoscale glass tips; Step A2 includes: Place the glass slide on a first glass slide; Using one of the straight edges of a second glass slide as a cutting ruler, a first cutting line is drawn on the upper surface of the glass slide using a scribing tool along the cutting ruler; the first end of the first cutting line extends to the edge of the glass slide, and the second end is located inside the glass slide; The glass sheet is broken along the first cutting line to obtain two half-glass sheets; both half-glass sheets have a first broken edge line formed by the natural extension of the second end of the first cutting line. A second cutting line is drawn on the half-glass slide along the cutting ruler using a scribing tool; the first end of the second cutting line extends to the edge of the half-glass slide except for the first broken edge line, and the second end is located inside the half-glass slide. The half-glass slide is broken along the second cutting line to obtain a broken piece containing a sharp angle; the sharp angle is formed by the first broken edge line and the second broken edge line formed by the natural extension of the second end of the second cutting line; At a position on the broken piece that is a first distance from the vertex of the pointed corner, the half-glass piece is broken to obtain a glass body (1) containing the pointed corner. Using an optical microscope, valid glass bodies are selected from the glass bodies (1) based on the shape of the apex angle, and the upper apex angle of the apex angle of the valid glass body is taken as the pinpoint angle (101) of the valid glass body.

2. The method for preparing nanoscale glass tips according to claim 1, characterized in that, The material of the inner metal film (2) is Al, Fe, Cu, Cr or Ti; the material of the outer metal film (3) is Au, Ag or Cu.

3. The method for preparing nanoscale glass tips according to claim 2, characterized in that, The thickness of the inner metal film (2) is 1nm-5nm; the thickness of the outer metal film (3) is 15nm-35nm.

4. The method for preparing nanoscale glass tips according to claim 3, characterized in that, The inner metal film (2) is made of Cr, the outer metal film (3) is made of Au, the thickness of the inner metal film (2) is 2 nm, and the thickness of the outer metal film (3) is 20 nm.

5. The method for preparing nanoscale glass tips according to claim 1, characterized in that, Step A1 includes: A101. Wipe both sides of the glass slide with a lint-free cloth and anhydrous ethanol; A102. Place the wiped glass slide into a detergent solution for ultrasonic cleaning and remove residual foam; A103. The glass slide is placed in pure water for ultrasonic cleaning; A104. The glass slide is cleaned sequentially with tetrahydrofuran and isopropanol; A105. Dry the glass sheet.

6. The method for preparing nanoscale glass tips according to claim 5, characterized in that, Step A102 includes: Place the glass slide into the cleaning rack (4) so ​​that both surfaces of the glass slide are exposed outside the cleaning rack (4); Place the cleaning rack (4) into the cleaning container, and add dish soap and pure water into the cleaning container; The cleaning container is placed in an ultrasonic cleaning device for cleaning; Remove any remaining foam.

7. The method for preparing nanoscale glass tips according to claim 1, characterized in that, Step A3 includes: The glass body (1) is attached to the vapor deposition table (5) using high-temperature resistant tape; the vapor deposition table (5) has a 45° inclined slope (501), one side of the glass body (1) is attached to the inclined slope (501) and the pin tip (101) is facing down and extends out of the inclined slope (501); Place the vapor deposition stage (5) in the vapor deposition machine and perform vapor deposition of the inner metal film (2) and the outer metal film (3) in sequence.

8. The method for preparing nanoscale glass tips according to claim 1, characterized in that, Following step A4, the following steps are also included: A5. Place the qualified nanoscale glass needle tip into the needle tip holder (6) and store the needle tip holder (6) in a vacuum desiccator.

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