Sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer type and manufacturing method and detection method thereof

Abstract

The invention relates to a sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types and a manufacturing method and a detection method thereof. The sensor is a terahertz biomedical sensor composed of a substrate and an electromagnetic resonance unit array arranged on one side of the substrate. The electromagnetic resonance unit array adopts a periodic non-contact double-gap split resonator design, and can effectively adjust the transmission characteristics of terahertz waves. Different types of cells have respective unique dielectric constants, and the dielectric constants are associated with harmonic peak offset of a terahertz wave transmission spectrum and can be used as a basis for detecting and distinguishing tumor types. By means of the method, changes of physical characteristics of colorectal cancer cells of different types are quantified, and intelligent judgment of tumor types is achieved. The terahertz biomedical sensor has the advantages of rapidness and high sensitivity, can significantly improve the early diagnosis and precise classification capabilities of colorectal cancer, and provides an efficient detection tool for clinical application.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical detection and relates to terahertz technology, and specifically relates to a sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types, and a manufacturing method and a detection method thereof. Background Art

[0002] At present, the main methods used in the biomedical field to diagnose colorectal cancer include colonoscopy, fecal occult blood test, fecal DNA testing, imaging examinations such as CT and MRI, as well as high-sensitivity detection methods such as accurate quantification of relevant biomarkers based on PCR amplification (such as patent CN118441054A) and WGS sequencing of plasma samples based on colony differences (such as patent CN109852714A). However, since the symptoms of early intestinal cancer are not obvious, many methods have low sensitivity in early detection, which can easily lead to missed diagnosis. The specificity of existing detection methods in distinguishing benign polyps from malignant tumors also needs to be improved. In addition, invasive methods such as colonoscopy may cause discomfort and psychological stress to patients, affecting their compliance. Furthermore, some high-precision detection methods such as fecal DNA testing and advanced imaging examinations are expensive, which limits their widespread application.

[0003] Terahertz waves (0.1-10 THz) lie between microwaves and infrared rays, have good penetrability, and have low photon energy, thus avoiding ionization damage to biological tissues. The energy in this waveband matches the vibrational energy levels of biological macromolecules, the rotational energy levels of dipoles, and the energy levels of vibrational transitions, giving it great application potential in fields such as biomedical research. In addition, terahertz waves are highly sensitive to differences in moisture and tissue, enabling high-contrast imaging and facilitating early identification of cancerous tissues. Terahertz metasurfaces achieve precise control of the phase and amplitude of electromagnetic waves through the design and manipulation of nanostructures, making them suitable for high-sensitivity, high-resolution imaging and sensing.

[0004] Patent CN110632291B provides a terahertz biosensor and its preparation and detection methods. Its main principle is to determine the type of cancer by identifying tumor markers of different cancers. The manufacturing method of this terahertz biosensor is relatively complex and involves multiple biochemical reagents. The operation is complicated and difficult to use.

[0005] Therefore, there is an urgent need for a method for determining colorectal cancer that is easy to manufacture and operate, has high sensitivity, good specificity, and low cost. Summary of the Invention

[0006] The purpose of the present invention is to solve the problems of low sensitivity, poor specificity, easy patient stress and high cost in existing colorectal cancer diagnosis methods. Aiming at the current application needs of terahertz technology in the biomedical field, a sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types, as well as its manufacturing method and detection method are provided.

[0007] This application provides a novel detection method based on a subwavelength periodic artificial microstructure array. By adding cell samples to the subwavelength periodic artificial microstructure resonant unit, the local dielectric environment is altered, causing a shift in the resonant peak of the terahertz transmission spectrum. This shift is correlated with the dielectric constant of different cells and can therefore be used as a basis for detecting and distinguishing tumor types.

[0008] According to the above objectives and technical principles, the present invention provides the following technical solutions:

[0009] One of the technical solutions of the present invention is to provide a sensor for seamless detection of colorectal adenocarcinoma and colorectal cancer types; the sensor is a terahertz biomedical sensor, comprising the following structure:

[0010] substrate,

[0011] An electromagnetic resonance unit array located on one side of the substrate, wherein the electromagnetic resonance unit array is composed of periodically adjacently arranged electromagnetic resonance units, and the electromagnetic resonance units are non-contact double-gap split resonator electromagnetic resonance units;

[0012] The electromagnetic resonance unit includes a square ring-shaped outer arm, an inner arm, and two connecting arms connected between the inner and outer arms; the two connecting arms are located on opposite sides of the inner arm; a gap is provided on the opposite side of the inner arm that is not connected to the connecting arm; the inner arm, outer arm, and connecting arm are all made of a gold layer.

[0013] Furthermore, the substrate is made of polyimide, has a thickness of 75 μm, and a size of 1 cm×1 cm.

[0014] Furthermore, the electromagnetic resonance unit is a rectangular area of ​​96 μm × 96 μm, which includes a square ring-shaped outer arm with an outer side length of 84 μm and a width of 6 μm, and a blank area with a width of 6 μm outside the outer arm; the inner arm is arranged inside the outer arm, the outer side of the inner arm is 60 μm long and 6 μm wide, and the distance between the outer side of the inner arm and the inner side of the outer arm is 6 μm; the width of the connecting arm is 6 μm; the width of the gap is 3 μm;

[0015] Furthermore, the thickness of the inner arm, outer arm, and connecting arm is 200 nm; the connecting arm is located in the middle of the upper and lower sides of the inner arm; the gap on the left side of the inner arm is located in the middle of the left side of the inner arm, and the gap on the right side of the inner arm is 20.5 μm away from the center of the right side;

[0016] Furthermore, the substrate and the electromagnetic resonance unit are bonded via a metal Cr layer with a thickness of 20 nm.

[0017] A second technical solution of the present invention is to provide a method for manufacturing the above-mentioned sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types, comprising the following steps:

[0018] Step 1: Spin-coat a sacrificial layer of polymethyl methacrylate (PMMA) onto a cleaned silicon (Si) wafer to obtain a PMMA / Si wafer;

[0019] Step 2: Attach a clean polyimide film to the PMMA layer of the PMMA / Si wafer to obtain a polyimide / PMMA / Si wafer, clean it with isopropyl alcohol and water, and dehydrate it for 2 minutes;

[0020] Step 3: Use a spin coater to spin-coat photoresist on the Polyimide layer, then use a photolithography machine to expose the desired structural pattern, and finally use a developer to develop and remove excess photoresist. The remaining structural pattern is the electromagnetic resonance unit array pattern;

[0021] Step 4: Continuously deposit 20nm of chromium (Cr) and 200nm of gold (Au) thin films on the polyimide to obtain a deposited Polyimide / PMMA / Si wafer;

[0022] Step 5: Use acetone to remove the unexposed PMMA and the residual metal Cr layer in the deposited Polyimide / PMMA / Si wafer. The product finally peeled off from the silicon wafer is the sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types.

[0023] Furthermore, in the first step, the silicon (Si) wafer is used as a carrier, and the size is preferably 3 inches; the polymethyl methacrylate is used as a sacrificial layer; and the spin coating refers to spin coating the polymethyl methacrylate onto the cleaned silicon wafer through a coating machine at a speed of 3000 rad / min within 30 seconds.

[0024] Furthermore, in the second step, the finished polyimide film is used as a substrate of the sensor, with a size of 60 mm×60 mm and a thickness of 75 μm; the dehydration temperature is 120° C. and is carried out in an oven.

[0025] Furthermore, in the third step, the photoresist is spin-coated at a speed of 2500 rad / min and for a duration of 30 seconds; the structural pattern is the above-mentioned inner and outer arms, connecting arms, and gap structure.

[0026] Furthermore, in the fourth step, the method of depositing the metal film is selected from electron beam deposition, thermal evaporation deposition and chemical vapor deposition, preferably electron beam deposition; specifically, when electron beam deposition is used, a 20 nm thick chromium (Cr) layer is first deposited as an adhesion layer at a deposition rate of Then 200nm thick gold is deposited at a deposition rate of This makes it easier for gold to adhere to the substrate.

[0027] Furthermore, in the fifth step, acetone was used to remove the unexposed PMMA and the residual metal Cr layer, and the deposited Polyimide / PMMA / Si wafer was immersed in an acetone solution for more than 2 hours until the PMMA sacrificial layer was dissolved and peeled off to obtain a sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types.

[0028] The third technical solution of the present invention is to provide a detection method for the above-mentioned sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types.

[0029] The detection method comprises the following steps:

[0030] S1, place the test cell / standard cell on the side of the sensor with the gold layer and fix it;

[0031] S2. Place the cell-fixed sensor in a terahertz time-domain spectroscopy system, measure the terahertz transmission spectrum, and obtain a terahertz peak position versus frequency displacement curve. Based on the difference in the spectrum between the cell to be tested and the standard cell, determine the type of the cell to be tested.

[0032] Furthermore, the terahertz time-domain spectroscopy system has a frequency band of 0.1THz to 1.5THz, and a resolution higher than 10GHz.

[0033] Furthermore, the cells to be tested can affect the dielectric environment of the terahertz sensor, causing its terahertz transmission peak to shift. Different types of cancer cells have different transmission peak shifts, and the type of cells to be tested can be detected and judged by the shift.

[0034] Compared with the prior art, the present invention has the following advantages and outstanding effects:

[0035] (1) The present invention relates to a terahertz biomedical sensor. By adding cell samples to a subwavelength-sized periodic artificial microstructure resonant unit, the local dielectric environment can be changed, thereby causing the resonant peak of the terahertz transmission spectrum to shift. The shift is associated with the dielectric constant of different cells and can therefore serve as a basis for detecting and distinguishing tumor types.

[0036] (2) The terahertz biomedical sensor of the present invention has the function of precisely controlling the phase and amplitude of electromagnetic waves, thereby achieving high-resolution imaging. The sensor can detect tiny sample changes, so the required sample volume is small, the operation is simple, and the application is wide. The sensor only needs to control the concentration of cells by counting to achieve the purpose of controlling variables, which simplifies the experimental steps. The results are generated quickly, significantly reducing waiting time and improving diagnostic efficiency. The sensor is very sensitive to differences in moisture and molecular structure in biological tissues, and can accurately detect tiny differences between cancerous tissues and normal tissues, thereby improving the sensitivity and specificity of early cancer detection.

[0037] (3) The terahertz biomedical sensor of the present invention has a simple preparation process, low cost, and good practicality. These characteristics make it show significant potential in the early diagnosis and monitoring of colorectal cancer and can serve as an effective auxiliary diagnostic tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a top view of the non-contact double-gap split resonator electromagnetic resonance structure of a structural unit located on the front of the structure in the terahertz biomedical sensor of the present invention, wherein the left side is the overall view and the right side is a partial enlarged view, ① represents the polyimide layer, and ② represents the gold layer;

[0039] Figure 2 Schematic diagram of a cross section of the terahertz biomedical sensor of the present invention, wherein ① represents a polyimide layer, ② represents a gold layer, ③ represents a metal Cr bonding layer, and ④ a dotted box represents a periodic non-contact double-gap split resonator electromagnetic resonance unit array;

[0040] Figure 3 This is a transmission spectrum diagram of the terahertz biomedical sensor of the present invention; (b) in the figure is the result of (a) after amplification in the 0.8-1.0 THz band. DETAILED DESCRIPTION

[0041] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail, clearly and completely below with reference to specific embodiments. It should be noted that the following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0042] All raw materials of the present invention are not particularly limited in their sources and can be purchased from the market or prepared according to conventional methods well known to those skilled in the art.

[0043] Example 1 Fabrication of a Biosensor

[0044] A terahertz biomedical sensor for seamlessly detecting colorectal adenocarcinoma and colorectal cancer types, the manufacturing method of which is as follows:

[0045] Step 1: Clean a 3-inch silicon (Si) wafer and use it as a carrier. Use polymethyl methacrylate (PMMA) as a sacrificial layer and spin coat it onto the cleaned Si wafer using a Laurell spinner 650M at a speed of 3000 rad / min within 30 seconds.

[0046] Step 2: Cut a 75μm thick polyimide film of approximately 60mm×60mm and attach it to the PMMA layer. The polyimide will serve as the substrate of the metasurface. The prepared polyimide / PMMA / Si wafer is then cleaned with isopropyl alcohol and water and dehydrated at 120°C for 2 minutes in an oven.

[0047] Step 3: Use a spin coater to spin-coat photoresist (AZ 1512HS) onto the polyimide film of the wafer obtained above at a speed of 2500 rad / min for 30 seconds; use a photolithography machine (MLA150 maskless aligner, Heidelberg Instruments) for exposure; and use a developer (726MIF) for development to remove excess photoresist and retain the desired structural pattern.

[0048] Step 4: Electron beam deposition (PVD75, KURT J.Lesker) is used to deposit a metal film. First, a 20 nm thick layer of chromium (Cr) is deposited as an adhesion layer at a deposition rate of Then 200nm of gold is deposited at a deposition rate of This makes it easier for gold to adhere to the substrate.

[0049] Step 5: Use acetone to remove the unexposed resist and residual metal layer. Soak the deposited polyimide / PMMA / Si wafer in acetone solution for more than 2 hours until the PMMA sacrificial layer dissolves and peels off to obtain the desired metasurface sample.

[0050] According to the above steps, a terahertz biomedical sensor for detecting colorectal adenocarcinoma and colorectal cancer types is obtained, and its structure is as follows: Figures 1-2 As shown. The terahertz biomedical sensor consists of a polyimide substrate and an electromagnetic resonance unit array on one side of it. The polyimide substrate is 75μm thick and 1cm×1cm in size. The electromagnetic resonance unit array is a periodic non-contact double-gap split resonator electromagnetic resonance unit array with a period of 96μm. The periodic non-contact double-gap split resonator electromagnetic resonance unit array is composed of a 200nm thick gold layer. The substrate area covered by the electromagnetic resonance unit array includes multiple adjacent 96μm×96μm rectangular areas, each of which has a non-contact double-gap split resonator electromagnetic resonance unit formed on it.

[0051] The non-contact dual-gap split resonator electromagnetic resonance unit is formed on a 96μm×96μm rectangular area and is divided into a square ring outer arm and a square ring inner arm. The outer arm has a lateral length of 84μm and a width of 6μm, and is 6μm away from the 96μm×96μm rectangular area on all sides. The inner arm is located inside the outer arm, has a lateral length of 60μm and a width of 6μm, and is 6μm away from the outer arm on all sides. It is connected to the outer arm by a connecting arm at the middle position of the upper and lower sides, and the connecting arm is 6μm wide. There is a 3μm wide gap on each side, the left gap is located in the middle of the left side of the inner arm, and the right gap is 20.5μm away from the center of the right side. Adjacent meta-atoms are in non-contact interaction.

[0052] Example 2 Characterization and Application of Biological Sensors

[0053] The properties of the product prepared in Example 1 of the present invention were characterized by using a terahertz time-domain spectroscopy system (TERA K15 Menlosystem GmbH) from the Key Laboratory of Optoelectronic Materials and Devices of Shanghai Normal University. Figure 3 As shown, the following steps are included:

[0054] (1) First, different cell types were separated from the culture dish using 10 mmol / L pH 7.4 PBS at 4°C, and the cell concentration was controlled at 6 × 10 5 ml -1The cells were then dropped onto the ultra-surface and centrifuged at 350 g for 5 minutes. Afterwards, the cells were washed twice with PBS and fixed with 2% paraformaldehyde at 4°C for 15 minutes. After fixation, the cells were washed twice with PBS, and the excess PBS was completely removed after the second wash.

[0055] (2) Different cells have different effects on the dielectric environment of the metamaterial. When the dielectric environment around the metamaterial changes, the terahertz transmission peak will shift. The terahertz transmission spectrum is tested by the terahertz time-domain spectroscopy system, and the displacement curve of the terahertz peak position with frequency is obtained.

[0056] (3) By comparing the terahertz transmission spectra of different cells with the standard transmission spectra ( Figure 3 (a)) Comparative analysis was performed to distinguish different colorectal adenocarcinomas from colorectal cancer cells.

[0057] In addition, to ensure the accuracy and universality of the data, the above operations need to be repeated 3-5 times. The specific performance parameters of the system are capable of achieving 10GHz resolution transmission spectrum scanning in the frequency band of 0.2THz to 2.0THz.

[0058] Figure 3 The performance of a filter for detecting the characteristic terahertz spectral lines of nitrogen ions using the aforementioned resonant unit was demonstrated. Transmission characteristics were measured over a test frequency range of 0.45 THz to 1.05 THz. The tests primarily used normal colorectal cells and five different types of colorectal cancer cells, which were uniformly suspended and coated onto the metasurface of the biomedical sensor described in this application, completely covering the entire metasurface. Detailed information on each cell type is shown in Table 1.

[0059] Table 1 Different types of colorectal cells selected*

[0060]

[0061] *The above cells are all at 6×10 5 ml -1 Measured against concentration background.

[0062] Figure 3The data (data are normalized transmittance) show that the resonance peak frequencies of the transmission spectra of the metasurfaces attached to different types of cells are all between 0.6THZ and 0.7THz in the low-frequency band. Compared with normal cells, the resonance peak of adenocarcinoma cells in the low-frequency band is reduced by 0.001 to 0.041THz, and the resonance peak of colon cancer cells in the low-frequency band is reduced by 0.050 to 0.077THz compared with normal cells; the resonance peak frequencies in the high-frequency band are all between 0.85THz and 0.95THz. Compared with normal cells, the resonance peak of adenocarcinoma cells in the low-frequency band is reduced by 0.023 to 0.044THz, and the resonance peak of colon cancer cells in the low-frequency band is reduced by 0.062 to 0.097THz. Figure 3 The Fano linear fit shown by the dotted line in (b) reveals that various cell indicators affect the linear evolution of the spectral line profile of the entire spectrum, and each tumor cell has a different offset to the bound state effect in the continuous domain.

[0063] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A sensor for non-trace detection of colorectal adenocarcinoma and colorectal cancer types, characterized in that: The sensor is a terahertz biomedical sensor, comprising the following structure: Substrate, An electromagnetic resonance unit array located on one side of the substrate, the electromagnetic resonance unit array is composed of electromagnetic resonance units arranged adjacent to each other periodically, and the electromagnetic resonance unit is a non-contact type double-gap split resonator electromagnetic resonance unit; The electromagnetic resonance unit includes a square ring-shaped outer arm, an inner arm, and two connecting arms connected between the inner arm and the outer arm; the two connecting arms are located on opposite sides of the inner arm; a gap is provided on the opposite side of the inner arm that is not connected to the connecting arm; the inner arm, the outer arm, and the connecting arm are all made of a gold layer.

2. A sensor for seamless detection of colorectal adenocarcinoma and colorectal cancer types according to claim 1, characterized in that: The substrate is made of polyimide with a thickness of 75 μm; The electromagnetic resonance unit is a rectangular area of ​​96 μm×96 μm, which includes a square ring outer arm with an outer side length of 84 μm and a width of 6 μm, and a blank area with a width of 6 μm outside the outer arm. The inner arm is arranged inside the outer arm, the outer side of the inner arm is 60 μm long and 6 μm wide, and the distance between the outer side of the inner arm and the inner side of the outer arm is 6 μm; The width of the connecting arm is 6 μm; The width of the gap is 3 μm; The thickness of the inner arm, outer arm and connecting arm is 200 nm; The connecting arm is arranged in the middle of the upper and lower sides of the inner arm; The gap on the left side of the inner arm is in the middle of the left side of the inner arm, and the gap on the right side of the inner arm is 20.5 μm away from the center of the right side; The substrate and the electromagnetic resonance unit are bonded together via a metal Cr layer with a thickness of 20 nm.

3. A method for manufacturing a sensor for seamless detection of colorectal adenocarcinoma and colorectal cancer types according to any one of claims 1 to 3, characterized in that: The steps include: Step 1: Spin-coat PMMA on a silicon wafer to obtain a PMMA / Si wafer; Step 2: attach a clean Polyimide film to the PMMA layer of the PMMA / Si wafer to obtain the Polyimide / PMMA / Si wafer, then clean and dry it; Step 3: Use a coating machine to spin-coat the photoresist on the Polyimide layer, then use a photolithography machine to expose the required structural pattern, and finally use a developer to develop and remove excess photoresist. The remaining structural pattern is the electromagnetic resonance unit array pattern; Step 4: Continuously deposit 20nm of chromium and 200nm of gold thin film layers on the Polyimide to obtain a deposited Polyimide / PMMA / Si wafer; Step 5: Use acetone to remove the unexposed PMMA and the residual metal Cr layer in the deposited Polyimide / PMMA / Si wafer. The product finally peeled off from the silicon wafer is the sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types.

4. The manufacturing method according to claim 3, characterized in that: In the first step, the PMMA is used as a sacrificial layer; the silicon wafer is used as a carrier; the spin coating refers to spin coating the PMMA onto the cleaned silicon wafer at a speed of 3000 rad / min within 30 seconds through a coating machine.

5. The manufacturing method according to claim 3, characterized in that: In the second step, the finished Polyimide film is used as the substrate for the sensor.

6. The manufacturing method according to claim 3, characterized in that: In the third step, the photoresist is spin-coated at a speed of 2500 rad / min and lasts for 30 seconds.

7. The manufacturing method according to claim 3, characterized in that: In the fourth step, the method of depositing the metal film is selected from any one of electron deposition, thermal evaporation deposition or chemical vapor deposition; firstly, a 20 nm thick Cr layer is deposited as an adhesive layer at a deposition rate of Then 200nm thick gold is deposited at a deposition rate of 8. The manufacturing method according to claim 3, characterized in that: In the fifth step, acetone is used to remove the unexposed PMMA and the residual metal Cr layer. The deposited Polyimide / PMMA / Si wafer is immersed in an acetone solution for more than 2 hours until the PMMA sacrificial layer is dissolved and peeled off to obtain a sensor for traceless detection of colorectal adenocarcinoma and colorectal cancer types.

9. A detection method for a sensor for seamless detection of colorectal adenocarcinoma and colorectal cancer types as claimed in claim 1, characterized in that: The following steps are involved: S1, place the cell to be tested / standard cell on the side of the sensor with the gold layer and fix it; S2, placing the above-mentioned sensor with fixed cells in a terahertz time-domain spectroscopy system, testing the terahertz transmission spectrum, obtaining a displacement curve of the terahertz peak position with frequency, and judging the type of the cell to be tested based on the difference in the spectrum between the cell to be tested and the standard cell.

10. The detection method according to claim 9, characterized in that: The terahertz time-domain spectroscopy system has a frequency band of 0.1THz to 1.5THz and a resolution higher than 10GHz; the cells to be tested can affect the dielectric environment of the terahertz sensor, causing its terahertz transmission peak to shift. Different types of cancer cells have different transmission peak shifts, and the type of cells to be tested can be detected and judged by the shift.

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