Preparation method and application of micro-pit with polycarbonate as base material

Abstract

The invention belongs to the technical field of material preparation, and particularly relates to a preparation method and application of a micro-pit with polycarbonate as a base material. The method provided by the invention mainly comprises the following steps: accelerating heavy ions by using an accelerator, bombarding a base material by using the accelerated heavy ions, and after the heavy ions damage polycarbonate, etching the polycarbonate by using an etching agent added with a corrosion inhibitor to obtain micro-pits with specific diameters and depths, and cleaning and drying the etched sample. The preparation of the micro-pit is realized by accelerating impact of the polycarbonate with heavy ions, the method breaks through the limitation of the traditional photoetching technology, the pattern of the micro-pit is directly defined through heavy ion bombardment, a mask is not needed, the material cost is reduced, production interruption and extra cost caused by damage of the mask are also avoided, and the production efficiency is improved. And the processing process is relatively simple, multiple complex photoetching and etching steps are not needed, the production efficiency is greatly improved, the production period is shortened, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of material preparation, and particularly relates to a micro-pit preparation method taking polycarbonate as a base material and application thereof. BACKGROUND

[0002] With the continuous progress of science and technology, at present, a variety of new detection technologies with high sensitivity, strong specificity and rapid diagnosis are developing rapidly and are increasingly applied to the detection of animal diseases. Among them, single molecule detection technology can study the structure and function of biological molecules at the single molecule level, and can be used for the detection of low-abundance biomarkers in complex samples. It has great application potential in single molecule imaging and tracking of low-concentration proteins, nucleic acids and other biological related molecules, ultra-sensitive quantitative analysis and precision medicine, and has been widely used in early diagnosis of diseases, exploration of potential diseases, live cell single virus tracing and DNA sequencing and other fields.

[0003] Digital ELISA, as a new single molecule detection technology, disperses single molecules into high-throughput micro-pits for independent reaction, and realizes single molecule level detection through detection and statistics of the signal of each micro-reactor. For example, in 2010, David Walt and David Duffy team developed the "Digital ELISA" technology, which uses labeled galactosidase to catalyze the substrate to generate a fluorescent signal instead of the PCR signal amplification process in digital PCR, disperses single molecule proteins labeled with beta galactosidase into high-throughput micro-reactors for independent reaction, thereby achieving extremely high detection sensitivity. However, digital ELISA technology still faces many challenges in practical application. The micro-pit digital ELISA has problems such as high difficulty and cost of chip processing, and low production efficiency. At present, the preparation method of micro-pit detection chip mainly adopts photolithography technology. Photolithography technology needs high-precision mask, complex photolithography equipment and complicated experimental operation. These factors not only increase the preparation cost of the chip, but also reduce the preparation efficiency of the chip. There are great difficulties in the technical level and commercialization level.

[0004] Therefore, it is very important to develop a preparation method of single molecule detection micro-pit with more stable performance and a new type of single molecule detection chip, improve the chip preparation efficiency, reduce the chip preparation cost, and improve the commercial value. SUMMARY

[0005] In view of the above problems, the application provides a micro-pit preparation method taking polycarbonate as a base material and application thereof. By accelerating heavy ions to bombard polycarbonate through a high-energy accelerator, the limitations of traditional photolithography technology are broken, the micro-pit preparation cost is greatly reduced, and the problems and defects existing in the prior art are effectively solved.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for preparing micropits using polycarbonate as a substrate includes the following steps: S1. Irradiation: Heavy ions are accelerated using an accelerator to obtain a heavy ion beam, and then the heavy ion beam is used to bombard the polycarbonate substrate to generate nuclear tracks, thereby obtaining a damaged polycarbonate substrate. S2, Etching: The damaged polycarbonate substrate obtained in step S1 is etched with an etchant to obtain a polycarbonate substrate containing micropits. S3. Cleaning and drying: Clean the micro-pitted polycarbonate substrate obtained in step S2 with cleaning solution, and dry it in a vacuum drying oven to obtain the final product.

[0007] Preferably, in step S1, the heavy ions are accelerated to an energy of 50-1000 MeV using an accelerator, and the heavy ions are Ar ions.

[0008] Preferably, the polycarbonate substrate in step S1 is a polycarbonate film; the thickness of the polycarbonate film is 0.002~5mm.

[0009] Preferably, the heavy ion beam described in step S1 is scanned into a rectangular plane using a beam scanner.

[0010] Preferably, in step S1, during the bombardment of the polycarbonate substrate with accelerated heavy ions, the polycarbonate substrate is bombarded with heavy ions in the atmosphere, and a titanium film is used for vacuum isolation. After bombarding the polycarbonate substrate, the density of the nuclear track is 1 × 10⁻⁶ per square centimeter. 4 ~1×10 9 ions.

[0011] In the actual preparation process, since the thickness of the polycarbonate film is between 0.002 and 5 mm, the energy of the accelerated heavy ions is controlled to be between 50 and 1000 MeV. After breakdown by the accelerated Ar ions, the density of the nuclear track of the resulting polycarbonate substrate is 1 × 10⁻⁶. 4 ~1×10 9 ions / cm 2 The length of the nuclear track ranges from 0.1 to 50 micrometers.

[0012] Preferably, the etchant in step S2 is one of sodium hydroxide solution or potassium hydroxide solution.

[0013] Preferably, the etchant in step S2 further includes a corrosion inhibitor, which is selected from one or more of molybdates and tungstates.

[0014] Preferably, the etching temperature in step S2 is 50~80℃ and the etching time is 1~120min; the diameter of the micropits on the polycarbonate substrate obtained in step S2 is 0.3~45μm and the depth of the micropits is 0.2~30μm.

[0015] In order to obtain micropits with adjustable diameter and depth, the present invention requires precise selection of etching conditions in the actual micropit preparation process: after multiple experimental screenings, NaOH or KOH solution was finally selected as the etchant, with a concentration of 0.1~15mol / L, and chemical etching was performed on the irradiated polycarbonate film at a temperature of 50~80℃ for a time of 1~120min.

[0016] However, due to the surface damage, structural changes, and enhanced chemical activity of the substrate after heavy ion bombardment, the damaged substrate is more susceptible to corrosion. If etching time and other conditions are not strictly controlled, over-corrosion can easily occur, affecting the substrate quality. Therefore, to reduce the difficulty of process control, the etchant in step S2 of this invention also includes a corrosion inhibitor, which is selected from one or more of methionine, histidine, molybdate, and tungstate.

[0017] This invention incorporates a corrosion inhibitor during the etching of polycarbonate films to prevent excessive erosion caused by untimely monitoring or process control errors. Furthermore, by controlling the etching rate, the etching process can be monitored in real time, allowing for timely adjustments to bombardment angles and heavy ion energy. This enables the fabrication of micropits in various shapes, including cylindrical, conical, symmetrical biconical, and asymmetrical biconical shapes. The corrosion inhibitor prevents excessive corrosion caused by high-speed etching, thus avoiding damage to the designed shape. In particular, the biconical micropits, through their unique geometry, perfectly combine optics, fluid dynamics, and surface chemistry, achieving the goal of long-term, high signal-to-noise ratio, real-time observation of single-molecule behavior, thereby driving the birth and development of disruptive technologies such as single-molecule sequencing.

[0018] In the process of researching corrosion inhibitors, this invention discovered that when molybdate or tungstate is selected as the core corrosion inhibitor component, it exhibits excellent corrosion resistance. This corrosion inhibitor component can rapidly form a dense and stable passivation protective film on the polycarbonate film surface, effectively blocking direct contact between the polycarbonate film and corrosive media such as moisture and ions, while simultaneously inhibiting the occurrence and aggravation of electrochemical corrosion reactions on the polycarbonate substrate surface. Ultimately, it not only reliably protects the integrity of the polycarbonate film surface structure but also significantly prevents excessive corrosion, rust peeling, and other problems associated with polycarbonate.

[0019] The present invention also provides a polycarbonate substrate containing micropits prepared by the aforementioned preparation method.

[0020] The present invention also provides an application of the polycarbonate substrate containing the micropits in the preparation of a single-molecule detection chip.

[0021] Compared with existing technologies, this invention achieves the fabrication of micropits by accelerating the bombardment of polycarbonate substrates with heavy ions. This method overcomes the limitations of traditional photolithography and has significant advantages and beneficial effects: (1) Traditional photolithography requires the use of high-precision photomasks to define the pattern of micro-pits. The production cost of photomasks is very high and they are easily damaged. However, the present invention defines the pattern of micro-pits by heavy ion bombardment, which eliminates the need for photomasks. This not only reduces material costs but also avoids production interruptions and additional costs caused by photomask damage. (2) The present invention uses heavy ion bombardment to not only control the size of the micro-pit, but also to achieve more complex shape control. By adjusting the energy and bombardment angle of the heavy ions, micro-pits with different shapes can be prepared, such as circular, square, elliptical, etc., and even micro-pits with special structures, such as conical micro-pits, stepped micro-pits, etc., providing more possibilities for the application of micro-pits. (3) The processing of the present invention is relatively simple, without the need for multiple complex photolithography and etching steps. The micro-pits can be prepared in one heavy ion bombardment and etching process. This greatly improves production efficiency, shortens the production cycle, and reduces production costs. Attached Figure Description

[0022] Figure 1 Schematic diagrams of different shapes of micropits prepared from polycarbonate substrate in Example 5; Figure 2 This is a schematic diagram of the micro-pits in the polycarbonate (PC) film in Example 1. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are only for better explanation of the present invention and do not limit the technical solutions of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The reagents and equipment used in this invention are all conventional reagents and equipment in the art.

[0024] Example 1: A method for preparing micropits using polycarbonate as a substrate The specific process of the micro-pit preparation method is as follows: S1. Irradiation: Ar ions are accelerated to an energy of 70 MeV using an accelerator to obtain a quasi-monoenergetic Ar ion beam, which is then used to irradiate a polycarbonate film with a thickness of 0.01 mm to generate nuclear tracks on the polycarbonate film, thus obtaining a damaged polycarbonate film. S2. Etching: Using a 1 mol / L NaOH solution, the irradiated polycarbonate film was chemically etched at 50°C for 5 minutes to obtain a polycarbonate film containing micropits. S3. Cleaning and drying: The polycarbonate film containing micropits obtained in step S2 is washed repeatedly with clean water and deionized water. After cleaning, it is dried in a vacuum drying oven to obtain a polycarbonate film with micropits. Figure 2 By cutting polycarbonate films with micropits, single-molecule detection chips can be fabricated.

[0025] Example 2: A method for preparing micropits using polycarbonate as a substrate The specific process of the micro-pit preparation method is as follows: S1. Irradiation: Ar ions are accelerated to an energy of 210 MeV using an accelerator to obtain a quasi-monoenergetic Ar ion beam, which is then used to irradiate a 0.1 mm thick polycarbonate film to generate nuclear tracks on the polycarbonate film and obtain a damaged polycarbonate film. S2. Etching: Using a 5 mol / L NaOH solution, the irradiated polycarbonate film was chemically etched at 50°C for 20 min to obtain a polycarbonate film containing micropits. S3. Cleaning and Drying: The polycarbonate film containing micropits obtained in step S2 is washed repeatedly with clean water and deionized water. After cleaning, it is dried in a vacuum drying oven to obtain a polycarbonate film with micropits. The polycarbonate film with micropits can be cut to make a chip for single-molecule detection.

[0026] Example 3: A method for preparing micropits using polycarbonate as a substrate The specific process of the micro-pit preparation method is as follows: S1. Irradiation: Ar ions are accelerated to an energy of 630 MeV using an accelerator to obtain a quasi-monoenergetic Ar ion beam, which is then used to irradiate a 2 mm thick polycarbonate film to generate nuclear tracks on the polycarbonate film, thus obtaining a damaged polycarbonate film. S2. Etching: Using a 10 mol / L NaOH solution, the irradiated polycarbonate film was chemically etched at 70°C for 60 min to obtain a polycarbonate film containing micropits. S3. Cleaning and Drying: The polycarbonate film containing micropits obtained in step S2 is washed repeatedly with clean water and deionized water. After cleaning, it is dried in a vacuum drying oven to obtain a polycarbonate film with micropits. The polycarbonate film with micropits can be cut to make a chip for single-molecule detection.

[0027] Example 4: A method for preparing micropits using polycarbonate as a substrate The specific process of the micro-pit preparation method is as follows: S1. Irradiation: Ar ions are accelerated to an energy of 980 MeV using an accelerator to obtain a quasi-monoenergetic Ar ion beam, which is then used to irradiate a 5 mm thick polycarbonate film to generate nuclear tracks on the polycarbonate film, thus obtaining a damaged polycarbonate film. S2. Etching: Using a 15 mol / L NaOH solution, the irradiated polycarbonate film was chemically etched at 50°C for 100 min to obtain a polycarbonate film containing micropits. S3. Cleaning and Drying: The polycarbonate film containing micropits obtained in step S2 is washed repeatedly with clean water and deionized water. After cleaning, it is dried in a vacuum drying oven to obtain a polycarbonate film with micropits. The polycarbonate film with micropits can be cut to make a chip for single-molecule detection.

[0028] Example 5: A method for preparing micropits using polycarbonate as a substrate The specific process of the micro-pit preparation method is as follows: S1. Irradiation: Ar ions are accelerated to an energy of 980 MeV using an accelerator to obtain a quasi-monoenergetic Ar ion beam, which is then used to irradiate a 5 mm thick polycarbonate film to generate nuclear tracks on the polycarbonate film, thus obtaining a damaged polycarbonate film. S2. Etching: Using a 15 mol / L NaOH solution, a certain weight of sodium molybdate is added to the solution until the final concentration of sodium molybdate is 0.9 g / L. The irradiated polycarbonate film is chemically etched at a temperature of 50°C for 120 min to obtain a polycarbonate film containing micropits. S3. Cleaning and Drying: The polycarbonate film containing micropits obtained in step S2 is washed repeatedly with clean water and deionized water. After cleaning, it is dried in a vacuum drying oven to obtain a polycarbonate film with micropits. The polycarbonate film with micropits can be cut to make a chip for single-molecule detection.

[0029] Comparative Example 1: A method for preparing micropits The method for preparing the micro-pits is similar to that in Example 5; The difference from Example 5 is that in Comparative Example 1, sodium molybdate was replaced with an equal amount of sodium silicate during etching, and the final concentration of sodium silicate was 0.6 g / L.

[0030] Comparative Example 2: A method for preparing micropits The method for preparing the micro-pits is similar to that in Example 5; The difference from Example 5 is that Comparative Example 2 uses bismuth ions as heavy ions.

[0031] Comparison of Micropit Parameters in Experiment Example 1 1. Experimental sample: The micro-pitted polycarbonate film prepared in Examples 1-5.

[0032] 2. Experimental method: During the experiment, the density and length of the nuclear track generated on the polycarbonate film during irradiation were recorded in real time, and the opening diameter and depth of individual micropits were measured after cleaning and drying.

[0033] 3. Experimental results: The specific experimental results are shown in Table 1.

[0034] Table 1. Parameters related to micropits on polycarbonate film substrate.

[0035]

[0036] As shown in Table 1 above, this invention obtains nuclear tracks of different densities and lengths by adjusting the heavy ion beam energy and irradiation time. The change in heavy ion beam energy has a significant impact on the density of the nuclear tracks, ranging from 10... 4 ~10 9 Furthermore, during the etching process, etching temperature and time directly affect the size and depth of the micropores. As temperature and time increase, the diameter and depth of the micropores gradually increase. However, the addition of an etching inhibitor alters the diameter and depth of the micropores to varying degrees. This demonstrates that by changing the etching temperature and time, micropores of different sizes can be prepared, effectively improving the preparation efficiency and laying the foundation for their application in single-molecule detection.

[0037] Experiment Example 2: Comparison of Micro-pit Shapes 1. Experimental samples: Micropits prepared in Example 5 and micropits prepared in Comparative Examples 1-2; 2. Experimental method: The sample surface was scanned with a focused electron beam to observe the shape of different micro-pits; 3. Experimental Results: Taking Example 5 as an example, the possible effects of controlling heavy ion energy and angle are as follows: By adjusting the bombardment angle, heavy ion energy, etc., a cylindrical hole can be obtained ( Figure 1 a) Conical hole ( Figure 1 (b) Symmetrical double conical hole ( Figure 1 c) Asymmetric double conical hole ( Figure 1Micropits of shapes such as d) can also be obtained, including hemispherical, ellipsoidal, or teardrop-shaped micropits. These micropits can be further used for single-molecule detection. In contrast, in Comparative Example 1, due to the change in the type of corrosion inhibitor, the etching rate control effect decreased during etching, making it impossible to obtain the aforementioned micropit shapes. Furthermore, over-etching easily occurred, leading to penetration. In Comparative Example 2, bismuth ion beam irradiation of the polycarbonate film resulted in poor etching selectivity. Since bismuth is a highly inert metal element, it hardly participates in chemical reactions during ion beam processing, and material removal relies almost entirely on physical sputtering. Therefore, the etching selectivity is very poor, making precise stop control difficult and the shape of the micropits uncontrollable.

Claims

1. A method for preparing micropits using polycarbonate as a substrate, characterized in that, Includes the following steps: S1. Irradiation: Heavy ions are accelerated using an accelerator to obtain a heavy ion beam, and then the heavy ion beam is used to bombard the polycarbonate substrate to generate nuclear tracks, thereby obtaining a damaged polycarbonate substrate. S2, Etching: The damaged polycarbonate substrate obtained in step S1 is etched with an etchant to obtain a polycarbonate substrate containing micropits. S3. Cleaning and drying: Clean the polycarbonate substrate containing micro-pits obtained in step S2 with cleaning solution, and dry it in a vacuum drying oven to obtain the final product.

2. The micro-pit fabrication method according to claim 1, characterized in that, Step S1 describes accelerating heavy ions to an energy of 50-1000 MeV using an accelerator, wherein the heavy ions are Ar ions.

3. The method for preparing micropits as described in claim 1, characterized in that, The polycarbonate substrate in step S1 is a polycarbonate film; the thickness of the polycarbonate film is 0.002~5mm.

4. The method for preparing micropits as described in claim 1, characterized in that, The heavy ion beam described in step S1 is scanned into a rectangular plane using a beam scanner.

5. The method for preparing micropits as described in claim 1, characterized in that, In step S1, during the bombardment of the polycarbonate substrate with accelerated heavy ions, the polycarbonate substrate is bombarded with heavy ions in the atmosphere, and a titanium film is used for vacuum isolation. After bombardment, the density of the nuclear track is 1 × 10⁻⁶ per square centimeter. 4 ~1×10 9 ions.

6. The method for preparing micropits as described in claim 1, characterized in that, The etchant mentioned in step S2 is one of sodium hydroxide solution or potassium hydroxide solution.

7. The method for preparing micropits as described in claim 6, characterized in that, The etchant in step S2 also includes a corrosion inhibitor, which is selected from one or more of molybdates and tungstates.

8. The method for preparing micropits as described in claim 1, characterized in that, In step S2, the etching temperature is 50~80℃ and the etching time is 1~120min; the diameter of the micropits on the polycarbonate substrate obtained in step S2 is 0.3~45μm and the depth of the micropits is 0.2~30μm.

9. A polycarbonate substrate containing micropits prepared by the preparation method according to any one of claims 1 to 8.

10. An application of the polycarbonate substrate containing micropits as described in claim 9 in the fabrication of a single-molecule detection chip.

Images